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Aspergillosis is an infectious mycotic disease which mainly affects chicks at 1 to 3 weeks of age. This report describes an outbreak of aspergillosis in 13-day-old broiler chicks reared in an open-sided poultry house on deep litter system. The total number of birds kept in the affected house was 4000 with the mortality rate of 5%. The farmer noticed signs of weakness since the arrival of day-old chicks, and eventually, 200 chicks died within 13 days. Clinical signs observed were stunted growth, dyspnoea, torticollis, incoordination, swollen hock joint, and crooked toes. Postmortem findings revealed yellow to white caseous nodular lesion at the air sacs and lung with granular appearance upon cross section. The feed and organs samples were collected for microbiological and histopathological evaluation. Aspergillus spp. were isolated on Sabouraud dextrose agar (SDA) with whitish to grey-green appearance and stained using lactophenol cotton blue. Periodic acid-Schiff (PAS) staining in the brain tissue revealed the presence of fungal hyphae and vesicle. Histopathological findings revealed alveolar emphysema, atelectasis, thrombosis, and pneumonic lung with granulomatous tissue and granulomatous encephalitis. Culling of the affected birds and removal of the contaminated bedding and feed in the house are essential measures to control and prevent the disease occurrence. Treatment using fungicide such as copper sulphate is recommended to prevent further spread of the disease in the flock.

The avian respiratory system is well adapted to the manifold physiological requirements. The lungs are relatively small, though extremely functional. The main bronchus runs through the lungs to open in the air sacs. The ventrobronchi branches cranially from the main bronchus. More caudally, the dorsobronchi branches from the main bronchus. Then, the dorso-bronchi split to form the para-bronchi. The air sac walls in the pigeon (Columba livia) appear to consist of two perpendicularly arranged thin layers of connective tissue, covered with flat epithelium. Trauma, vitamin A deficiency and, hormonal unbalances are known to cause lesions in the respiratory system. On rare occasions, pathology of the trachea can be found. Aspirated particles of seeds or peanuts may lead to accumulations of fat in the main bronchus. More chronic irritation may lead the production of "Bronchiolar Associated Lymphoid Tissue". A variety of pathologies resulting in respiratory dysfunctions are described.

Swim bladders in sciaenid fishes function in hearing in some and sound production in almost all species. Sciaenid swim bladders vary from simple carrot-shaped to two-chambered to possessing various diverticula. Diverticula that terminate close to the ears improve hearing. Other unusual diverticula heading in a caudal direction have not been studied. The fresh-water Asian species Boesemania microlepis has an unusual swim bladder with a slightly restricted anterior region and 6 long-slender caudally-directed diverticula bilaterally. We hypothesized that these diverticula modify sound spectra. Evening advertisement calls consist of a series of multicycle tonal pulses, but the fundamental frequency and first several harmonics are missing or attenuated, and peak frequencies are high, varying between

Slight changes in lung volume have previously been reported in ducks. We studied the functional structure of the lung of the domestic duck using classical anatomical techniques as well as ultrasound monitoring to unravel the causes of such changes. Later dorsal and medioventral secondary bronchi were superficially positioned and covered with a thin transparent and collapsible membrane, internally lined with a cuboidal to squamous epithelium. The lung parenchyma was rigid, with atria well supported by septa containing smooth muscles, interparabronchial septa reinforced by collagen fibres, and blood capillaries supported by epithelial plates. On ultrasound monitoring, an outward and inward movement of the lung surface during inspiration and expiration, respectively, was evident at the region where the airways were covered by the thin membranes. The movements plausibly facilitated air movement in the lung just like the air sacs. We conclude that volume changes in the duck lung occur due to a slight morphological adaptation rather than a change in the archetypical design of the avian lung parenchyma.

This study investigates the sounds and the anatomy of the sound-producing organ in the male and female sand-dwelling cusk-eel Parophidion vassali. Although both sexes have similar external phenotype, they can be distinguished by their sonic apparatus and sounds. As in many Ophioidei, Parophidion vassali presents a panel of highly derived characters. Fish possess three pairs of sonic muscles, and males have mineralized swimbladder caps on which inserts the ventral sonic muscle, a neural arch that pivots, a stretchable swimbladder fenestra, an osseous swimbladder plate and a rounded pressure-release membrane in the caudal swimbladder. Females, however, do not possess anterior swimbladder caps, a swimbladder fenestra and the caudal rounded membrane. Males possess the unusual ability to produce sounds starting with a set of low amplitude pulses followed by a second set with higher amplitudes clearly dividing each sound unit into two parts. Females do not vary their sound amplitude in this way: they produce shorter sounds and pulse periods but with a higher peak frequency. Morphology and sound features support the sound-producing mechanism is based on a rebound system (i.e. quick backward snap of the anterior swimbladder). Based on features of the sounds from tank recordings, we have putatively identified the sound of male Parophidion vassali at sea. As these species are ecologically cryptic, we hope this work will allow assessment and clarify the distribution of their populations.

Necropsy of two free-ranging common blackbirds (Turdus merula) found dead in central Italy revealed the presence of a high number of cyclocoelid flukes in the coelomatic cavity. Cyclocoelid flukes primarily infect avian respiratory system. Histologically, air sac walls were covered with a fibrinous exudate containing degenerate heterophils, many trematodes and some colonies of Gram-positive cocci. The superficial bronchi and parabronchi were markedly distended, and the adjacent pulmonary parenchyma was congested and collapsed. Trematodes, surrounded by a mild suppurative to pyogranulomatous inflammatory reaction, were also observed on the pericardial, intestinal, kidney and hepatic serosal surfaces. The death of the two examined birds was likely due to the high parasite load and associated severe lesions. At parasitological examination, flukes showed a tongue-shaped elongate body, tapered anteriorly and rounded posteriorly, of 2,088–2,314 μm in width and 8,268–11,830 μm in length. The mouth was slightly oval and sub-terminal, with a small oral sucker. The oval pharynx measured 250–309 μm, and the two caeca joined posteriorly. Two large (550–702 μm × 450–520 μm) globular testes were situated obliquely to each other, whereas an oval (250 × 300 μm in mean) or round (about 334 μm in diameter) intertesticular ovary was placed in a longitudinal straight line with the testes. The ootype was about 110 μm in diameter, while the brown-yellow eggs measured 131.5 × 73.9 μm in mean. The genital pore was post-pharyngeal, while the symmetrically arranged vitelline glands were not confluent posteriorly. Morphoflogical diagnosis led to the identification of Morishitium polonicum, a cyclocoelid fluke species that typically inhabits the air sacs of blackbirds. The morphological diagnosis was corroborated by molecular phylogenetic analysis of the mitochondrial (CO1, ND1) DNA loci. The present study provides the first report of pathological lesions and death caused by M. polonicum in birds. Keywords: Air sac trematodes, Cyclocoelidae, Death, Histopathological lesions, Morishitium polonicum, Turdus merula

The avian bronchial tree has a unique and elaborate architecture for the maintenance of unidirectional airflow. Gross descriptions of this bronchial arrangement have traditionally relied upon dissection and casts of the negative (air-filled) spaces. In this study, the bronchial trees of five deceased African grey parrots (Psittacus erithacus) were segmented from micro-computed tomography (μCT) scans into three-dimensional (3D) surface models, and then compared. Select metrics of the primary bronchi and major secondary branches in the μCT scans of 11 specimens were taken to assess left-right asymmetry and quantify gross lung structure. Analysis of the 3D surface models demonstrates variation in the number and distribution of secondary bronchi with consistent direct connections to specific respiratory air sacs. A single model of the parabronchi further reveals indirect connections to all but two of the nine total air sacs. Statistical analysis of the metrics show significant left-right asymmetry between the primary bronchi and the origins of the first four secondary bronchi (the ventrobronchi), consistently greater mean values for all right primary bronchus length metrics, and relatively high coefficients of variation for cross-sectional area metrics of the primary bronchi and secondary bronchi ostia. These findings suggest that the lengths of the primary bronchi distal to the ventrobronchi do not preserve lung symmetry, and that aerodynamic valving can functionally accommodate a wide range of bronchial proportions.

The avian lung is highly specialized and is both functionally and morphologically distinct 30 from that of their closest extant relatives, the crocodilians. It is highly partitioned, with a 31 unidirectionally ventilated and immobilized gas-exchanging lung, and functionally decoupled, 32 compliant, poorly vascularized ventilatory air-sacs. To understand the evolutionary history of 33 the archosaurian respiratory system, it is essential to determine which anatomical 34 characteristics are shared between birds and crocodilians and the role these shared traits play 35 in their respective respiratory biology. To begin to address this larger question, we examined 36 the anatomy of the lung and bronchial tree of ten American alligators (Alligator 37 mississippiensis) and eleven ostriches (Struthio camelus) across an ontogenetic series using 38 traditional and micro-computed tomography (µCT), three-dimensional (3D) digital models, and 39 morphometry. Intraspecific variation and left to right asymmetry were present in certain 40 aspects of the bronchial tree of both taxa but was particularly evident in the cardiac (medial) 41 region of the lungs of alligators and the caudal aspect of the bronchial tree in both species. The 42 cross-sectional area of the primary bronchus at the level of the major secondary airways and 43 cross-sectional area of ostia scaled either isometrically or negatively allometrically in alligators 44 and isometrically or positively allometrically in ostriches with respect to body mass. Of fifteen 45 lung metrics, five were significantly different between the alligator and ostrich, suggesting that 46 these aspects of the lung are more interspecifically plastic in archosaurs. One metric, the 47 distances between the carina and each of the major secondary airways, had minimal 48 intraspecific or ontogenetic variation in both alligators and ostriches, and thus may be a 49 conserved trait in both taxa. In contrast to previous descriptions, the 3D digital models and CT 50 scan data demonstrate that the pulmonary diverticula pneumatize the axial skeleton of the 51 ostrich directly from the gas-exchanging pulmonary tissues instead of the air sacs. Global and 52 specific comparisons between the bronchial topography of the alligator and ostrich reveal 53 multiple possible homologies, suggesting that certain structural aspects of the bronchial tree 54 are likely conserved across Archosauria, and may have been present in the ancestral 55 archosaurian lung.

Nothronychus was a large, derived therizinosaur from the Upper Cretaceous of Utah and New Mexico. The genus is known from elements that have been referred to single individuals. Therizinosaurs were unusual maniraptoran theropods close to the origin of birds. The axial skeleton is extensively pneumatized, but CT scans reveal an apneumatic synsacrum. Inferred air sacs invade the basicranium, the presacral vertebrae, and the proximal caudal vertebrae, but bypassed the sacrum resulting in a caudosacral hiatus similar to some sauropods and reflecting the development of multiple diverticula from the abdominal air sac. The vertebral pneumatic chambers are described here and compared with those observed in the theropod Allosaurus and the recent avian Dinornis. The vertebrae of Nothronychus are intermediate between those two theropods. It is inferred to have possessed avian-like abdominal air sacs. This theropod would have had unidirectional lungs, as in birds, but this character cannot be related to endothermy.

Made available in DSpace on 2021-06-25T10:45:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-08-01. Added 1 bitstream(s) on 2021-07-15T14:35:02Z : No. of bitstreams: 1 S0100-736X2020000800637.pdf: 3853348 bytes, checksum: be6ed02f27c3e202fd5b384f842f87c6 (MD5) Polanco J.B.A., Mamprim M.J., Silva J.P., Inamassu L.R. & Schimming B.C. 2020. Computed tomographic and radiologic anatomy of the lower respiratory tract in the red-food tortoise (Chelonoids carbonaria). Pesquisa Veterinária Brasileira 40(8):637-646. Departamento de Anatomia, Instituto de Biociências, Universidade Estadual Paulista “Júlio de Mesquita Filho”, Rua Prof. Dr. Antônio Celso Wagner Zanin 250, Distrito de Rubião Junior, Botucatu, SP 18618-689, Brazil. E-mail: bruno.schimming@unesp.br The diagnosis of several diseases in chelonians is a challenge in the veterinary clinic, because a detailed physical examination with auscultation and palpation is difficult due the presence of carapace and plastron. Imaging analysis such as radiography and computed tomography (CT) have been shown to be beneficial for diagnosis, prognosis and treatment in numerous animal species. Thus, this study aimed to identify and describe the structures of the lower respiratory tract in red-foot tortoises, by computed tomography, radiography and gross anatomy in twelve red-foot tortoises (Chelonoidis carbonaria), adults and of both sexes. The lower respiratory tract in these animals comprised the larynx, trachea, bronchi and the lungs. The presence of epiglottic cartilage was not observed in the animals studied. CT allowed the observation of the intrapulmonary part of the bronchi, which was accompanied by large intrapulmonary blood vessels. The lungs presented a reticulated parenchyma, without lobulations. Each lung had a small chamber located near the cranial and caudal poles. These structures were identified in CT and 3D CT reconstructions and these could suggest that these chambers could be non-respiratory structures, and could be comparable to the air sacs of birds. This study establishes normal CT anatomy of the lower respiratory tract of the red-foot tortoise; and may be used as a reference in the assessment of respiratory disorders in this tortoise. Graduate Program in Wild Animals Faculdade de Medicina Veterinária e Zootecnia (FMVZ) Universidade Estadual Paulista “Júlio de Mesquita Filho” (Unesp) Campus de Botucatu, Rua Prof. Doutor Walter Mauricio Correa s/n, Distrito de Rubião Junior DepartamentodeReproduçãoAnimaleRadiologiaVeterinária Faculdade de Medicina Veterinária e Zootecnia (FMVZ) Universidade Estadual Paulista “Júlio de Mesquita Filho” (Unesp) Campus de Botucatu, Rua Prof. Doutor Walter Mauricio Correa s/n, Distrito de Rubião Junior Departmento de Anatomia Instituto de Biociências Universidade Estadual Paulista “Júlio de Mesquita Filho” (Unesp), Rua Prof. Dr. Antônio Celso Wagner Zanin 250, Distrito de Rubião Junior Graduate Program in Wild Animals Faculdade de Medicina Veterinária e Zootecnia (FMVZ) Universidade Estadual Paulista “Júlio de Mesquita Filho” (Unesp) Campus de Botucatu, Rua Prof. Doutor Walter Mauricio Correa s/n, Distrito de Rubião Junior DepartamentodeReproduçãoAnimaleRadiologiaVeterinária Faculdade de Medicina Veterinária e Zootecnia (FMVZ) Universidade Estadual Paulista “Júlio de Mesquita Filho” (Unesp) Campus de Botucatu, Rua Prof. Doutor Walter Mauricio Correa s/n, Distrito de Rubião Junior Departmento de Anatomia Instituto de Biociências Universidade Estadual Paulista “Júlio de Mesquita Filho” (Unesp), Rua Prof. Dr. Antônio Celso Wagner Zanin 250, Distrito de Rubião Junior

Made available in DSpace on 2020-12-12T02:01:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-07-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) This study aimed to evaluate normal features of the heart and lower respiratory tract in toco toucans by means of radiography and helical computed tomography (CT) scanner. Fifteen healthy adult toco toucans (Ramphastos toco), 10 females and 5 males, average body mass of 650 g were studied. CT examination as well as right lateral and ventrodorsal radiographic examinations of the coelomic cavity were performed under chemical restraint. Heart, lungs, air sacs, trachea and syrinx were analysed. The mean values of heart length, heart width and thoracic cavity in radiographs were, respectively, 23.76 mm, 25.94 mm and 48.87 mm. In both X-rays and CT scans, the lung parenchyma had honeycomb-like pattern. The topographic areas of the anterior and posterior air sacs were visualized as dark and air-filled spaces in X-rays. On CT evaluation, the air sacs occupied a larger area in the coelomic cavity compared to X-ray. In the lateral radiographic view, the cervical part of the trachea was positioned more ventrally in the transition from cervical to thoracic regions showing a V-shaped appearance. In all CT planes was visible division of the trachea into the right and left main bronchi at the level of 3rd thoracic vertebra. The syrinx was difficult to visualize in X-rays, but on CT it was easily identified in axial slice. In conclusion, the normal features of toco toucan's heart and lower respiratory tract that were determined on X-rays and CT scans are useful to compare with sick toco toucans, as well as other bird species. Department of Animal Reproduction and Veterinary Radiology School of Veterinary Medicine and Animal Science São Paulo State University (Unesp) Department of Veterinary Surgery and Anesthesiology School of Veterinary Medicine and Animal Science São Paulo State University (Unesp) Animal Welfare and Research Department Denver Zoo Department of Animal Reproduction and Veterinary Radiology School of Veterinary Medicine and Animal Science São Paulo State University (Unesp) Department of Veterinary Surgery and Anesthesiology School of Veterinary Medicine and Animal Science São Paulo State University (Unesp)

How modification of gene expression generates novel traits is key to understanding the evolutionary process. We investigated the genetic basis for the origin of the piscine gas bladder from lungs of ancestral bony vertebrates. Distinguishing these homologous organs is the direction of budding from the foregut during development; lungs bud ventrally and the gas bladder buds dorsally. We investigated whether this morphological inversion is associated with molecular inversion of conserved genes regulating lung and gasbladder development. Using laser-capture microdissection and RNA-seq, we assayed transcript abundance and compared expression patterns between dorsal and ventral foregut tissues at three developmental stages spanning gasbladder development. Our focal taxon, bowfin (Amia calva), representing the sistergroup to teleosts, is an early diverging ray-finned fish with a gas bladder. We discovered a number of genes with unknown function during lung development that are differentially expressed during gas bladder development and annotated to functions relevant for organ budding. We also identified several known lung-regulatory genes exhibiting inverted dorsoventral expression during gasbladder relative to lung development. Specifically, we found Tbx5 is strongly expressed in the dorsal mesoderm surrounding the gas bladder during bowfin development, and several interacting genes are co-expressed dorsally with Tbx5. In contrast, in mouse and bichir (Polypterus senegalus), the only ray-finned fish that have lungs, Tbx5 is expressed in the ventral lung mesoderm during development. Our data demonstrating dorsoventral inversion of conserved genes suggests that these genes may have contributed to the evolutionary transition between ventral lungs and a dorsal gas bladder in ray-finned fishes.

Emphysema is a chronic respiratory disease characterized by interalveolar septa destruction and enlarged air sacs. How the inhalation dosimetry in the pulmonary acini varies in the time course of emphysema is still unclear. The aim of this study is to numerically evaluate the impact of septal destructions on particle deposition in a pyramid-shape subacinar model that is composed of 496 alveoli. Four emphysematous models were generated by progressively removing the inter-alveolar septa from the normal geometry. Spatial distribution and temporal evolution of particle deposition were quantified in expanding/contracting subacinar models on both total and regional basis using a well-validated discrete-phase Lagrangian model. Airflow fields in the subacinar cavities are sensitive to the septal raptures, with regular, radial streamlines in the proximal alveoli in the normal geometry in contrast to unsymmetrical and recirculating flows in the emphysematous subacini. Intensified collateral ventilation and significantly increased doses in the outer wall and base are observed in disease than heath. The deposition rate of small particles (1-1.5 μm) is more sensitive to the level of septal rapture than large particles (2.5-3 μm). Unexpectedly, more particles per unit area deposit on the outer wall and at the base of the subacinus than on the inner septal walls. The subacinus-averaged doses increase with progressing septal destructions, suggesting an escalating risk factor to the acinar health at the late stages of emphysema.

Sexual displays are some of the most dramatic and varied behaviors that have been documented. The elaboration of such behaviors often relies on the modification of existing morphology. To understand how display elaboration arises, we analyzed the laryngeal anatomy of three species of mice that vary in the presence and complexity of their vocal displays. Mice and rats have a specialized larynx that enables them to produce both low-frequency "audible" sounds, perhaps using vocal fold vibration, as well as distinct mechanisms that are thought to enable higher frequency sounds, such as vocal membrane vibration and intralaryngeal whistles. These mechanisms rely on different structures within the larynx. Using histology, we characterized laryngeal anatomy in Alston's singing mouse (Scotinomys teguina), the northern pygmy mouse (Baiomys taylori), and the laboratory mouse (Mus musculus), which produce different types of vocalizations. We found evidence of a vocal membrane in all species, as well as species differences in vocal fold and ventral pouch size. Presence of a vocal membrane in these three species, which are not known to use vocal membrane vibration, suggests that this structure may be widespread among muroid rodents. An expanded ventral pouch in singing and pygmy mice suggests that these mice may use an intralaryngeal whistle to produce their advertisement songs, and that an expanded ventral pouch may enable lower frequencies than laboratory mouse whistle-produced sounds. Variation in the laryngeal anatomy of rodents fits into a larger pattern across terrestrial vertebrates, where the development and modification of vocal membranes and pouches, or air sacs, are common mechanisms by which vocalizations diversify. Understanding variation in the functional anatomy of relevant organs is the first step in understanding how morphological changes enable novel displays.

Respirationis one of the functions that has vital importance for the continuity ofmetabolism. The level of metabolic activity of a living organism is dependenton the respiratory system which mediates the transport of oxygen to tissues andthe accumulation of accumulated carbon dioxide. Naris, cavitas nasalis, larynx,trachea, syrinx, primer bronchi (mesobronchi), secondary bronchi, inferiorbronchi (parabronchi), air capillaries, pulmo, air sacs and pneumatic bonesform respiratory tract of a bird. Half of the air taken in inspiration goes tothe caudal air sacs, and other half goes to thecranial air sacs over the lungs (leaving oxygen and loading carbon dioxide). Inthe expiration while the air in the caudal sacs passes through the lungs(leaving oxygen and loading carbon dioxide) to the trachea, the air in thecranial sacs passes to the trachea., Solunum,metabolizmanın devamlılığı için hayati öneme sahip olan fonksiyonlardanbirisidir. Bir canlının metabolik faaliyet düzeyi dokularına oksijentaşınmasına ve birikmiş karbondioksitin toplanmasına aracılık eden solunumsistemine bağlıdır. Bir kuşta solunum yolunu naris, cavitas nasalis, larynx,trachea, syrinx, primer bronchi (mesobronchi), sekonder bronchi, tersiyerbronchi (parabronchi), air capillaries, pulmo, air sacs ve pneumatik kemikleroluşturur. İnspiration’da alınan havanın yarısı caudal hava keselerine, diğeryarısı ise akciğer üzerinden (oksijeni bırakıp karbondioksit yüklenerek) cranialhava keselerine gider. Ekspiration’da caudal keselerdeki hava akciğer üzerinden(oksijeni bırakıp karbondioksit yüklenerek)trachea’ya geçerken,cranial keselerdeki hava da trachea’ya geçer.

This paper summarizes the main morphological tracts exhibited by lungs and gas bladders in fishes. The origin and organ location, the presence of a glottal region, the inner architecture, the characteristics of the exchange barrier and the presence of pulmonary arteries have been reviewed in the two types of air-breathing organs. With the exception of the dorsal (bladders) or ventral (lungs) origin from the posterior pharynx, none of the morphological traits analyzed can be considered specific for either lungs or gas bladders. This is exemplified by analysis of the morphology of the lung of the Dipnoii and Polypteriformes and of the bladder of the Lepisosteiformes. All of them are obligate air-breathers and show a lung-like (pulmonoid) air-breathing organ. However, while the lungfish lung and the bladder of the Lepisosteiformes occupy a dorsal position and are highly trabeculated, the polypterid lung occupies a ventral position and shows a smooth inner surface. Structural and ultrastructural differences are also highlighted. Noticeably, a large part of the inner surface area of the lung of the Australian lungfish is covered by a ciliated epithelium. A restricted respiratory surface area may help to explain the incapability of this species to aestivate. The respiratory bladder of basal teleosts displays a more complex morphology than that observed in more primitive species. The bladder of basal teleosts may appear divided into respiratory and non-respiratory portions, exhibit intricate shapes, invade adjacent structures and gain additional functions. The increase in morphological and functional complexity appears to prelude the loss of the respiratory functions.

A juvenile, wild-caught prairie falcon ( Falco mexicanus) kept for falconry was presented to a veterinary hospital for intermittent opisthotonos and torticollis. Clinical examination, complete blood count, serum biochemistry panel, and fecal analysis were unremarkable. Clinical signs did not resolve, and the bird was euthanized 6 mo after the appearance of clinical signs. Autopsy revealed a mild, unilateral hydrocephalus and nematodes within the thoracic air sac. Histopathology demonstrated mild, unilateral hydrocephalus; scattered glial nodules; meningeal nematode sections; and meningeal and intraventricular embryonated eggs. Morphology and molecular characterization were consistent with the air sac nematode Serratospiculum or Serratospiculoides spp. Air sac nematode infection can be associated with air sacculitis or pneumonia in falcons. Aberrant migration of air sac filariid nematodes Serratospiculum or Serratospiculoides spp. into the nervous system resulting in clinical disease is rare, but should be included in the differential diagnosis of neurologic diseases in falcons.

In an organized farm, desi chicken and turkeys were reported with the clinical signs of congestion of conjunctival mucous membrane, dullness, unilateral and bilateral head swelling and nasal discharge. Flock strength was 545 desi chickens and 296 turkeys of 75 and 50 days old respectively. Morbidity was 3.67 and 6.75% and mortality was 0.91 and 0.67% in chickens and turkeys respectively. On investigation, clinical signs started 12 days after the introduction of desi chicken from another organized farm. In total, 10 chickens and 20 turkeys showed clinical signs, of which 5 desi chicken and 2 turkeys died. On necropsy, the birds showed congestion of conjunctival mucous membrane, unilateral and bilateral infraorbital sinus swelling and caseous material with mucous exudates in the infraorbital sinus. Lungs were congested and edematous. Thoracic and abdominal air sacs were cloudy with beaded appearance, thickened with yellowish caseous material. Infraorbital sinus and ocular swab were collected from live birds. Infraorbital sinus swab, lung and air sacs were collected from dead birds. Mycoplasma gallisepticum was isolated from infraorbital sinus and air sac samples and was also confirmed by polymerase chain reaction. Histopathologically, mucopurulent sinusitis and airsacculitis were noticed. The Mycoplasma gallisepticum outbreak was effectively controlled by using effective treatment with 1% Tylosin and following strict bio-security measures.

Postcranial skeletal pneumaticity (PSP) characterizes extant birds. This feature is related to a series of air sacs connected to the lungs and prolonged in diverticula that invade bones internally. Previous works revealed that PSP was present along the line to birds, being distinctive of pterosaurs and saurischian dinosaurs. PSP is profuse in the vertebral column of sauropods and theropods and was very studied in sauropods, although scarcely in non-avian theropods. Here we analyze the vertebral pneumaticity of the unenlagiine theropod Unenlagia comahuensis, including the observation through CT scans. Unenlagiinae is a clade of southern dromaeosaurid theropods that is closely related to birds. The vertebral centra have lateral pneumatic foramina (lpf) within fossae (commonly termed ‘pleurocoels’) in middle and posterior dorsals, an unusual feature among extant birds and many non-avian theropods. Another possibly pneumatic fossa stands out at both sides of the neural spine base, which is not present in dorsals of other non-avian theropods, except the unenlagiine Unenlagia paynemili. CT scans revealed camellate tissue in the centra, consisting of small chambers separated by thin trabeculae. Camellae are also observed in the unenlagiines U. paynemili and Austroraptor cabazai, other dromaeosaurids, other coelurosaurs, and some non-coelurosaurian tetanurans. Instead, more primitive groups generally have camerae (larger chambers separated by scarce thick septa). Thus, a possible trend of the vertebral inner pneumaticity types is observed throughout non-avian theropod evolution, as indicated by previous authors. This study provides valuable information that helps to clarify this trend, not only in dromaeosaurids but also throughout theropod evolution.

The plainfin midshipman fish, Porichthys notatus, is a nocturnal marine teleost that uses social acoustic signals for communication during the breeding season. Nesting type I males produce multiharmonic advertisement calls by contracting their swim bladder sonic muscles to attract females for courtship and spawning while subsequently attracting cuckholding type II males. Here, we report intra- and intersexual dimorphisms of the swim bladder in a vocal teleost fish and detail the swim bladder dimorphisms in the three sexual phenotypes (females, type I and II males) of plainfin midshipman fish. Micro-computerized tomography revealed that females and type II males have prominent, horn-like rostral swim bladder extensions that project toward the inner ear end organs (saccule, lagena, and utricle). The rostral swim bladder extensions were longer, and the distance between these swim bladder extensions and each inner-ear end organ type was significantly shorter in both females and type II males compared to that in type I males. Our results revealed that the normalized swim bladder length of females and type II males was longer than that in type I males while there was no difference in normalized swim bladder width among the three sexual phenotypes. We predict that these intrasexual and intersexual differences in swim bladder morphology among midshipman sexual phenotypes will afford greater sound pressure sensitivity and higher frequency detection in females and type II males and facilitate the detection and localization of conspecifics in shallow water environments, like those in which midshipman breed and nest.

Great apes and siamangs—but not humans—possess laryngeal air sacs, suggesting that they were lost over hominin evolution. The absence of air sacs in humans may hold clues to speech evolution, but little is known about their functions in extant apes. We investigated whether gorillas use their air sacs to produce the staccato ‘growling’ of the silverback chest beat display. This hypothesis was formulated after viewing a nature documentary showing a display by a silverback western gorilla (Kingo). As Kingo growls, the video shows distinctive vibrations in his chest and throat under which the air sacs extend. We also investigated whether other similarly staccato vocalizations—the whinny, sex whinny, and copulation grunt—might also involve the air sacs. To examine these hypotheses, we collected an opportunistic sample of video and audio evidence from research records and another documentary of Kingo’s group, and from videos of other gorillas found on YouTube. Analysis shows that the four vocalizations are each emitted in rapid pulses of a similar frequency (8–16 pulses per second), and limited visual evidence indicates that they may all occur with upper torso vibrations. Future research should determine how consistently the vibrations co-occur with the vocalizations, whether they are synchronized, and their precise location and timing. Our findings fit with the hypothesis that apes—especially, but not exclusively males—use their air sacs for vocalizations and displays related to size exaggeration for sex and territory. Thus changes in social structure, mating, and sexual dimorphism might have led to the obsolescence of the air sacs and their loss in hominin evolution.

Some marine birds and mammals can perform dives of extraordinary duration and depth. Such dive performance is dependent on many factors, including total body oxygen (O2) stores. For diving penguins, the respiratory system (air sacs and lungs) constitutes 30-50% of the total body O2 store. To better understand the role and mechanism of parabronchial ventilation and O2 utilization in penguins both on the surface and during the dive, we examined air sac partial pressures of O2 (PO2) in emperor penguins (Aptenodytes forsteri) equipped with backpack PO2 recorders. Cervical air sac PO2s at rest were lower than in other birds, while the cervical air sac to posterior thoracic air sac PO2 difference was larger. Pre-dive cervical air sac PO2s were often greater than those at rest, but had a wide range and were not significantly different from those at rest. The maximum respiratory O2 store and total body O2 stores calculated with representative anterior and posterior air sac PO2 data did not differ from prior estimates. The mean calculated anterior air sac O2 depletion rate for dives up to 11 min was approximately one-tenth that of the posterior air sacs. Low cervical air sac PO2s at rest may be secondary to a low ratio of parabronchial ventilation to parabronchial blood O2 extraction. During dives, overlap of simultaneously recorded cervical and posterior thoracic air sac PO2 profiles supported the concept of maintenance of parabronchial ventilation during a dive by air movement through the lungs.

Birds and pterosaurs have pneumatic bones, a feature likely related to their flight capabilities but whose evolution and origin is still poorly understood. Pneumatic foramina are present on the external surface of the bone and are reliable indicators of post-cranial skeletal pneumatization present in Pterosauria, Eusauropoda, and Neotheropoda. Here, we carried out a qualitative analysis of the position, size and number of pneumatic foramina of the cervical and thoracic/dorsal vertebrae of pterosaurs and birds, as they have the potential to challenge hypotheses about the emergence and evolution of the respiratory trait in these groups. We also discussed differences between pneumatic and vascular foramina for identification purposes. Besides phylogenetic representativeness, the pterosaur taxonomic sampling considered the preservation of specimens and, for birds, their life habit, as this relates to the level of pneumatization. Pneumatic foramina on the lateral faces of the centrum of the mid-cervical vertebrae of pterosaurs and birds differ in position and size, and those adjacent to the neural canal additionally differ in number. The avian posterior cervical vertebrae show a higher number of pneumatic foramina in comparison to their mid-cervicals, while the opposite is true for pterosaurs, suggesting differences in the cervical air sac of these clades. Pneumatic foramina were found at the base of the transverse processes of the notarial vertebrae of birds, while they were absent from some of the pterosaurs analyzed here, revealing the presence of a pneumatic hiatus in the vertebral column that might be explained due to the distance of this structure to the cervical air sac. These findings indicate that, although the overall skeletal pneumatization of pterosaurs and birds present deep homologies, some pneumatic features occurred convergently because variation in the number of pneumatic foramina along the vertebral column is related to the position of the air sacs in pterosaurs and birds and/or the habit of each species. There is an evident reduction of the pneumatic foramina in birds that have aquatic foraging and an increase in the ones which perform static soaring. Although we did not find any external anatomical difference between pneumatic and vascular foramina, we observed that vascular foramina occur at specific sites and thus identification on the basis of location is reliable.

The gestation period of the Northern brown bandicoot, Isoodonnmacrourus is 12.5 days and the scope of this thesis embraces thenperiod of organogenesis during the terminal 5.5 days of gestation.Using wild caught and captive bred I. macrourus, fifty fournembryos of known age were obtained by a combination of vaginal caecansampling and bilateral hysterectomy. The stages represented weren7.5, 8.5, 9.5 10.5 and 11.5 days of gestation and birth, and werencollected between November 1978 and January 1984. This material plusnseveral unaged specimens was measured, photographed and seriallynsectioned for light microscopy.Pouch young from birth to 55 days were obtained by breeding I.nmacrourus in large outdoor enclosures between November 1978 and Mayn1984. This material was variously.treated for light and electronnmicroscopy.The development of a peramelid marsupial from the primitivenstreak stage to birth is described from known aged material for thenfirst time. The primitive streak appeared at 7 days, the firstnsomites at 8 days, and the pharangeal arches, optic and otic placodesnand forelimb buds at 8.5 days of gestation. The allantois becamenevident at 9 days of gestation and fused with the chorion to form andiscoidal chorio-allantoic placenta at 10.5 days. The hindlimbsnappeared at 9.5 days and the forelimbs acquired digits at 10.5 daysnof gestation. Hindlimb digits first appeared at birth. At birth thenepitrichium covered most of the eyes, plugged the external earncanals, sealed the lips around the teat and formed deciduous claws onnthe forelimb digits.A feature of the newborn I. macrourus which it shares with allnother newborn marsupials was the advanced nature of the cranial endncompared with the caudal end. This feature persisted well into pouchnlife. The advanced nature of the cranial end was reflectedninternally at birth where the tongue and neck muscles had the mostnadvanced secondary muscle fibers, the cranial nerves and theirnganglia were well formed and the cervical and thoracic spinal nervesnwere large and had prominent fiber tracts. These structures are thenindicators of the functional requirements for nipple search, sucking,nswallowing and possibly smell and touch.As in other marsupials the newborn of I. macrourus was dependentnon structures innervated by nerves arising from cranial and spinalnganglia and consequently from tissues of neural crest origin. Thenlack of cerebral differentation indicated that movements andncoordination of newborn I. macrourus were spinally generated at thisnstage.At birth the stomach of I. macrourus acted primarily as anreceptacle for milk and most nutrient absorption was achieved in thenduodenum. The eye and the ear were insufficiently developed at birthnto be functional and the lung was precociously developed to allow fornrespiration via superficially vascularised septa of non-alveolarnterminal air sacs. The lung at birth lacked goblet cells and mucousnglands and this could reflect the moist and protective nature of thenpouch. The late appearance of dust cells in the lung 9 days afternbirth may also be a result of protection by the pouch. The processnof alveolization is described for a marsupial for the first time. InnI. macrourus alveolization is incomplete at the end of pouch life, 55 days after birth. Neuroepithelial bodies are described for the firstntime in a marsupial lung.n n n n n n

This study aims to understand the relationships among morphological characteristics, their functional roles, and breeder preferences in Japanese native fowls. We analyzed and compared the shapes and sizes of the skeletal forelimb, pectoral girdle, and sternum among six breeds: Chabo, Oh-Shamo, Onagadori, Shokoku, Tosajidori, and Totenko. Because skeletal forelimb, pectoral girdle, and sternum are one of the bases for composing body appearance and for movement of birds such as flapping, we treated those skeletons. All measurements of size were smaller in Chabo than those in other breeds except Tosajidori. The largest measurement values of all parameters were observed in Oh-Shamo. The largest measurement values were observed in all measurements of Oh-Shamo. Short and wide forelimb bones and a short coracoid were observed in Chabo. Oh-Shamo was equipped with a wide sternum and a widely articulated coracoid. Shokoku and Totenko possessed longer bones that constitute the thoracic cavity. We suggest that the small bone size in ornamental fowls contributes toward a cute appearance and that the large bone size of fighting fowls is correlated with their masculinity and aggressiveness. The short forelimb bones, wide articulation, and corpus of forelimb bones in Chabo create a round and soft body silhouette. The observed short coracoid prevents Chabo from dragging its body on the ground while walking. The wide sternum and articulation of the coracoid observed in Oh-Shamo are considered to contribute to the ability to pounce on an opponent by flapping during a fight. The wide sternum of Oh-Shamo is considered to affect its body outline, producing a strong, masculine physical appearance. We also suggest that the characteristics observed in Shokoku and Totenko create a space for the vocal organs, such as clavicle air sacs. We suggest that the observed morphological characteristics underlie the function and breeder preferences of each breed.

Among the extant air-breathing vertebrates, the avian respiratory system is structurally the most complex and functionally the most efficient gas exchanger. Having been investigated for over four centuries, some aspects of its biology have been extremely challenging and highly contentious and others still remain unresolved. Here, while assessing the most recent findings, four notable aspects of the structure and function of the avian respiratory system are examined critically to highlight the questions, speculations, controversies and debates that have arisen from past research. The innovative techniques and experiments that were performed to answer particular research questions are emphasised. The features that are outlined here concern the arrangement of the airways, the path followed by the inspired air, structural features of the lung and the air and blood capillaries, and the level of cellular defence in the avian respiratory system. Hitherto, based on association with the proven efficiency of naturally evolved and human-made counter-current exchange systems rather than on definite experimental evidence, a counter-current gas exchange system was suggested to exist in the avian respiratory system and was used to explain its exceptional efficiency. However, by means of an elegant experiment in which the direction of the air-flow in the lung was reversed, a cross-current system was shown to be in operation instead. Studies of the arrangement of the airways and the blood vessels corroborated the existence of a cross-current system in the avian lung. While the avian respiratory system is ventilated tidally, like most other invaginated gas exchangers, the lung, specifically the paleopulmonic parabronchi, is ventilated unidirectionally and continuously in a caudocranial (back-to-front) direction by synchronized actions of the air sacs. The path followed by the inspired air in the lung-air sac system is now known to be controlled by a mechanism of aerodynamic valving and not by anatomical valves or sphincters, as was previously supposed. The structural strength of the air and blood capillaries is derived from: the interdependence between the air and blood capillaries; a tethering effect between the closely entwined respiratory units; the presence of epithelial-epithelial cell connections (retinacula or cross-bridges) that join the blood capillaries while separating the air capillaries; the abundance and intricate arrangement of the connective tissue elements, i.e. collagen, elastin, and smooth muscle fibres; the presence of type-IV collagen, especially in the basement membranes of the blood-gas barrier and the epithelial-epithelial cell connections; and a putative tensegrity state in the lung. Notwithstanding the paucity of free surface pulmonary macrophages, the respiratory surface of the avian lung is well protected from pathogens and particulates by an assortment of highly efficient phagocytic cells. In commercial poultry production, instead of weak pulmonary cellular defence, stressful husbandry practices such as overcrowding, force-feeding, and intense genetic manipulation for rapid weight gain and egg production may account for the reported susceptibility of birds to aerosol-transmitted diseases.

In a process called silvering, European eels prepare for their long-distance migration from European freshwater systems to the Sargasso Sea for reproduction. During this journey, eels perform extended diel vertical migrations, and the concomitant changes in hydrostatic pressure significantly affect the swimbladder, functioning as a buoyancy organ. As the swimbladder is primarily filled with oxygen, the tissue has to cope with extreme hyperoxic conditions, which typically are accompanied by the generation of reactive oxygen species (ROS) and oxidative stress. In addition, since the introduction of the parasitic nematode Anguillicola crassus in the early 1980s, swimbladder function of most of the European eels is impaired by the infection with this parasite. However, the exact pathways to detoxify ROS and how these pathways are affected by silvering or the infection are still unknown. In swimbladder and muscle tissue from uninfected and infected yellow, and from uninfected and infected silver eels, we measured the level of lipid peroxidation, which increases with ROS stress. To assess the capacity of the ROS defense systems, we analyzed the activities of superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx) and glutathione reductase (GR), and determined the concentration of the antioxidant glutathione (GSH + GSSG). In swimbladder tissue, we found increased concentrations of GSH + GSSG as well as higher activities of SOD, GPx and GR, suggesting that SOD and the glutathione cycle are important for ROS detoxification. Comparing swimbladder tissue of uninfected yellow with uninfected silver eels, the concentration of GSH + GSSG and the activity of SOD were higher after silvering, corresponding with lower levels of lipid peroxidation. Whereas in yellow eels the infection with A. crassus had no effect, in silver eels the capacity to cope with ROS was significantly impaired. In muscle tissue, silvering or the infection only affected the activity of SOD but in exactly the same way as in swimbladder tissue. Electronic supplementary material The online version of this article (doi:10.1007/s00360-016-0994-0) contains supplementary material, which is available to authorized users.

Computed tomography (CT) was used to compare the tissue structures involved in sound production and reception in a fetus and its maternal body of a female finless porpoise (Neophocaena asiaorientalis sunameri) found stranded at Huian, Fujian Province, China, in April 2014. Qualitative assessment of the CT images revealed the physical development of main acoustic tissues including melon, blubber, mandibular fat, muscle, and connective tissue in a 10-month old fetus. Compared to the maternal body, the cranium of the fetus was not enclosed, air sacs and nasal meatus were both absent, and the maxilla was much thinner. Furthermore, Hounsfield unit (HU) measurements from CT scanning were used to quantify the difference between the fetus and its maternal body for melon, blubber, mandibular fat, muscle, and connective tissue. Statistical analyses revealed significant differences in HU between all 5 structures melon, blubber, mandibular fat, muscle, and connective tissue (P < 0.001) both in the fetus and maternal body. The median HU values of melon, blubber, mandibular fat, and muscle in the fetus (−61.0, −74.0, −24.0, and 25.0, respectively) were higher than those recorded in the maternal body (−85.0, −85.0, −69.0, and 12.0, respectively). However, the median HU value of connective tissue (50.0) in the fetus was lower than that recorded in the maternal body (60.0). The results show that the acoustic tissue structures were not fully developed in the fetus and depending on the actual age of the fetus the structures may not be fully formed by the time of birth. Further studies are needed to determine at what age finless porpoise calves have fully developed the tissue structures needed to produce and use ultrasound beams for echolocation.

The respiratory tract is a key organ for many avian pathogens as well as a major route for vaccination in the poultry industry. To improve immune responses after vaccination of chickens through increased uptake of vaccines and targeting to antigen presenting cells, a better understanding of the avian respiratory immune system is required. Transgenic MacReporter birds were used expressing a reporter gene (eGFP or mApple) under the control of the CSF1R promoter and enhancer in cells of the mononuclear phagocyte (MNP) lineage to visualize the ontogeny of the lymphoid tissue, macrophages and dendritic cells, in the trachea, lung and air sac of birds from embryonic day 18–63 weeks of age. Small aggregates of CSF1R-transgene+ cells start to form at the openings of the secondary bronchi at 1 week of age, indicative of the early development of the organised bronchus-associated lymphoid tissue. Immunohistochemical staining revealed subpopulations of MNPs in the lung, based on expression of CSF1R-transgene, CD11, TIM4, LAMP1, and MHC II. Specialised epithelial cells or M cells covering the bronchus-associated lymphoid tissue expressed CSF1R-transgene and type II pneumocytes expressed LAMP1 suggesting that these epithelial cells are phagocytic and transcytose antigen. Highly organised lymphoid tissue was seen in trachea from 4 weeks onwards. Throughout the air sacs at all ages, CSF1R-transgene+ cells were scattered and at later stages, CSF1R-transgene+ cells lined capillaries. These results will serve as a base for further functional characterization of macrophages and dendritic cells and their role in respiratory diseases and vaccine responses. Electronic supplementary material The online version of this article (10.1186/s13567-018-0598-7) contains supplementary material, which is available to authorized users.

The five gill pairs of Mictyris longicarpus have the lowest weight specific area reported for any crab. The cuticle of the gill lamellae is lined with epithelial cells which have structural features characteristic of iontransporting cells. Pillar cells are regularly distributed in the epithelium and serve to maintain separation of the two faces of the lamellae. The central hemolymph space is divided into two sheets by a fenestrated septum of connective tissue cells. The dorsal portion of the marginal canal of each lamella receives hemolymph from the afferent branchial vessel and distributes it to the lamella while the ventral portion of the canal collects hemolymph and returns it to the efferent branchial vessel. The lung is formed from the inner lining of the branchiostegite and an outgrowth of this, the epibranchial membrane. Surface area is increased by invagination of the lining which forms branching, blind-ending pores, giving the lung a spongy appearance. The cuticle lining the lung is thin and the underlyng epithelial cells are extremely attenuated, giving a total hemolymph/gas distance of 90–475 nm. Venous hemolymph is directed close to the gas exchange surface by specialised connective tissue cells and by thin strands of connective tissue which run parallel to the cuticle. Air sacs are anchored in position by paired pillar cells filled with microtubules. Afferent hemolymph is supplied from the eye sinus, dorsal sinus, and ventral sinus. Afferent vessels interdigitate closely with efferent vessels just beneath the respiratory membrane. The two systems are connected by a “perpendicular system” which ramifies between the airways and emerges to form a sinus beneath the carapace and then flows back between the air sacs to the efferent vessels. The afferent side of the perpendicular system is the major site of gas exchange. Efferent vessels return via large pulmonary veins to the pericardial cavity. PaO2 levels were high (95.5 Torr), indicating highly efficient gas exchange.

The ontogeny of the digestive tract was studied histologically in burbot, Lota lota L., from hatching to 42 days post-hatch (dph). At hatching, the digestive tract consisted of a straight tube with discernible digestive accessory glands (the liver and the pancreas) dorsally attached to the yolk sac. Most of the yolk sac reserves were consumed during the first 12 days and were completely depleted by 17 dph. The first PAS-positive goblet cells appeared at 6 dph, dispersed within the epithelium of the oesophagus and increasing substantially in number and distribution as development progressed. At 12 dph, the first vacuoles (neutral lipids) appeared in the intestine, indicating the functional absorption of nutrients from food. Differentiation of gastric glands was first noticed at 17 dph and was extensive by 27 dph. L. lota larvae have a morphologically complete digestive tract by 32 dph. These findings on the development of the digestive system in L. lota may contribute to a better understanding of its ontogeny and can be useful for improvement of the larval rearing techniques of this promising species for freshwater aquaculture diversification.

From 2 exhibits in a zoological collection, 2 juvenile fairy bluebirds ( Irena puella ) and 1 adult blue-grey tanager (Thraupis episcopus) died within 3 months of one another. The cause of death was attributed to air sac trematodes, which were identified as Szidatitrema species based on morphology of adult trematodes and miracidia isolated from a snail intermediate host. To determine the extent of trematodiasis in the collection, individual exhibits within the same building as the original presenting cases were assessed, with birds representing 27 avian species from 9 orders. Sampling consisted of individual (n = 244) and pooled same-species group (n = 193) fecal examinations, and for some individuals, and tracheal swab (n = 106), resulting in a total of 543 samples. In addition, tracheal swabs were performed on 14 birds for comparative cytology, but no parasites were found. Flukes were positively identified in 4 tracheal swab samples (4%), 37 individual fecal samples (15%), and 52 of the group fecal samples (27%). When results of the swab method were compared with those of fecal examination, fecal testing was significantly associated (P < .001) with positive results. Based on these results, a screening process was instituted of 3- or 4-day combined fecal samples evaluated by both sedimentation and flotation techniques 2 weeks before outgoing shipments or intrazoo transfers of birds housed in exhibits known to have snail populations. Snail control methods also were initiated in all exhibits. Treatment with praziquantel was carried out on a case-by-case basis, and included oral, parenteral, and nebulized administration. Although control measures were expected to manage the infection and reduce distribution of the parasite to other collections, complete eradication of trematodes in the population is unlikely.

Respiratory diseases are a leading cause of morbidity and mortality in captivity reared, endangered whooping cranes (Grus americana). Objectives of this retrospective, case series, cross-sectional study were to describe computed tomography (CT) respiratory anatomy in a juvenile whooping crane without respiratory disease, compare CT characteristics with gross pathologic characteristics in a group of juvenile whooping cranes with respiratory aspergillosis, and test associations between the number of CT tracheal bends and bird sex and age. A total of 10 juvenile whooping cranes (one control, nine affected) were included. Seven affected cranes had CT characteristics of unilateral extrapulmonary bronchial occlusion or wall thickening, and seven cranes had luminal occlusion of the intrapulmonary primary or secondary bronchi. Air sac membrane thickening was observed in three cranes in the cranial and caudal thoracic air sacs, and air sac diverticulum opacification was observed in four cranes. Necropsy lesions consisted of severe, subacute to chronic, focally extensive granulomatous pathology of the trachea, primary bronchi, lungs, or air sacs. No false positive CT scan results were documented. Seven instances of false negative CT scan results occurred; six of these consisted of subtle, mild air sacculitis including membrane opacification or thickening, or the presence of small plaques found at necropsy. The number of CT tracheal bends was associated with bird age but not sex. Findings supported the use of CT as a diagnostic test for avian species with respiratory disease and tracheal coiling or elongated tracheae where endoscopic evaluation is impractical.

Beaked whales are medium-sized toothed whales that inhabit depths beyond the continental shelf; thus beaked whale strandings are relatively infrequent compared to those of other cetaceans. Beaked whales have been catapulted into the spotlight by their tendency to strand in association with naval sonar deployment. Studies have shown the presence of gas and fat emboli within the tissues and analysis of gas emboli is suggestive of nitrogen as the primary component. These findings are consistent with human decompression sickness (DCS) previously not thought possible in cetaceans. Because, tissue loading with nitrogen gas is paramount for the manifestation of DCS and nitrogen loading depends largely on the vascular perfusion of the tissues, we examined the anatomy of the extracranial arterial system using stranded carcasses of 16 beaked whales from five different species. Anatomic regions containing lipid and/or air spaces were prioritized as potential locations of nitrogen gas absorption due to the known solubility of nitrogen in adipose tissue and the nitrogen content of air, respectively. Attention was focused on the acoustic fat bodies and accessory sinus system on the ventral head. We found much of the arterial system of the head to contain arteries homologous to those found in domestic mammals. Robust arterial associations with lipid depots and air spaces occurred within the acoustic fat bodies of the lower jaw and pterygoid air sacs of the ventral head, respectively. Both regions contained extensive trabecular geometry with small arteries investing the trabeculae. Our findings suggest the presence of considerable surface area between the arterial system, and the intramandibular fat bodies and pterygoid air sacs. Our observations may provide support for the hypothesis that these structures play an important role in the exchange of nitrogen gas during diving.

The avian respiratory apparatus is separated into a gas exchanger (the lung) and ventilators (the air sacs). Synchronized bellows-like movements of the cranial and caudal air sacs ventilate the lung continuously and unidirectionally in a caudocranial direction. With the lungs practically rigid, after their insertion into the ribs and the vertebrae and on attaching to the membranous horizontal septum, surface tension is not a constraining factor to the intensity that the gas exchange tissue can subdivide. Delicate, transparent, capacious and avascular, the air sacs are not directly involved in gas exchange. The airway system comprises of a three-tiered system of passageways, namely a primary bronchus, the secondary bronchi and the tertiary bronchi (parabronchi). The crosscurrent system is formed by the perpendicular arrangement between the mass (convective) air flow in the parabronchial lumen and the centripetal (inward) flow of the venous blood in the exchange tissue; the countercurrent system consists of the centrifugal (outward) flow of air from the parabronchial lumen into the air capillaries and the centripetal (inward) flow of blood in the blood capillaries, and; the multicapillary serial arterialization system is formed by the blood capillaries and the air capillaries where venous blood is oxygenated in succession at the infinite number of points where the respiratory units contact exchange tissue. Together with the aforementioned systems, features like large capillary blood volume, extensive respiratory surface area and thin blood-gas barrier accord high pulmonary diffusing capacity of O2 that supports the high metabolic capacities and energetic lifestyles of birds.

Biological aspects and global demand for aquarium promote seahorses as new species with high potential for commercial purposes; however, the low newborn survival rate represents the main bottleneck of seahorses farming. In this study, the organogenesis of the Hippocampus reidi was analysed from release until the 30th day after birth, using histological and histochemical approaches. To study the stages of their early life, 360 individuals were killed, sectioned, and stained with haematoxylin and eosin, periodic acid-Schiff, and Sudan Black B techniques. At birth, mouth and anus were open, the swim bladder inflated, and the visual system highly developed. Among the results, it was emphasized the presence of the yolk sac until the 2nd day after birth, the loops of the intestine to accommodate its elongation, and the ability of the larvae to absorb lipids in the anterior and posterior tract of the intestine. A short time (7/8 days) between reabsorption of yolk sac and formation of gonads was registered, with primordial follicles visible from the 10th day after birth. For the first time, organogenesis in H. reidi was described in detail; seahorses underwent a marked metamorphosis, and the indirect development observed in this species lead up to reconsider the term "juvenile" used for H. reidi during this period.

Motivated by the work of palaeo-art “Double Death (2011),” a biomechanical analysis using three-dimensional digital models was conducted to assess the potential of a pair of the large, Late Cretaceous theropod dinosaur Carcharodontosaurus saharicus to successfully lift a medium-sized sauropod and not lose balance. Limaysaurus tessonei from the Late Cretaceous of South America was chosen as the sauropod as it is more completely known, but closely related to the rebbachisaurid sauropods found in the same deposits with C. saharicus. The body models incorporate the details of the low-density regions associated with lungs, systems of air sacs, and pneumatized axial skeletal regions. These details, along with the surface meshes of the models, were used to estimate the body masses and centers of mass of the two animals. It was found that a 6 t C. saharicus could successfully lift a mass of 2.5 t and not lose balance as the combined center of mass of the body and the load in the jaws would still be over the feet. However, the neck muscles were found to only be capable of producing enough force to hold up the head with an added mass of 424 kg held at the midpoint of the maxillary tooth row. The jaw adductor muscles were more powerful, and could have held a load of 512 kg. The more limiting neck constraint leads to the conclusion that two, adult C. saharicus could successfully lift a L. tessonei with a maximum body mass of 850 kg and a body length of 8.3 m. Anat Rec, 298:1367–1375, 2015. © 2015 Wiley Periodicals, Inc.

The macroscopic morphology of structures involved in sound generation in the Indian Ocean humpback dolphin (Sousa plumbea) were described for the first time using computed tomography imaging and standard gross dissection techniques. The Indian Ocean humpback dolphin may represent a useful comparative model to the bottlenose dolphin (Tursiops sp.) to provide insights into the functional anatomy of the sound production in dolphins, since these coastal dolphins exhibit similar body size and share similarities on acoustic behavior. The general arrangement of sound generating structures, that is, air sacs and muscles, was similar in both the bottlenose dolphin and the Indian Ocean humpback dolphin. The main difference between the two species existed in a small left posterior branch of the melon in the Indian Ocean humpback dolphin, which was not found in the bottlenose dolphin and might reflect an adaptation of directionality for high frequency communication sounds as seen in some other delphinids (e.g., Lagenorhynchus sp., Grampus griseus). Thus, this may be the main reason for the asymmetry of the sound production structures in dolphins. Additionally, the longer rostrum in Indian Ocean humpback dolphins might suggest a more directional echolocation beam compared to the Lahille's bottlenose dolphin. Anat Rec, 302:849-860, 2019. © 2018 Wiley Periodicals, Inc.

Although the basic schema of the body plan is similar among different species of amniotes (mammals, birds, and reptiles), the lung is an exception. Here, anatomy and physiology are considerably different, particularly between mammals and birds. In mammals, inhaled and exhaled airs mix in the airways, whereas in birds the inspired air flows unidirectionally without mixing with the expired air. This bird-specific respiration system is enabled by the complex tubular structures called parabronchi where gas exchange takes place, and also by the bellow-like air sacs appended to the main part of the lung. That the lung is predominantly governed by the parasympathetic nervous system has been shown mostly by physiological studies in mammals. However, how the parasympathetic nervous system in the lung is established during late development has largely been unexplored both in mammals and birds. In this study, by combining immunocytochemistry, the tissue-clearing CUBIC method, and ink-injection to airways, we have visualized the 3-D distribution patterns of parasympathetic nerves and ganglia in the lung at late developmental stages of mice and chickens. These patterns were further compared between these species, and three prominent similarities emerged: (1) parasympathetic postganglionic fibers and ganglia are widely distributed in the lung covering the proximal and distal portions, (2) the gas exchange units, alveoli in mice and parabronchi in chickens, are devoid of parasympathetic nerves, (3) parasympathetic nerves are in close association with smooth muscle cells, particularly at the base of the gas exchange units. These observations suggest that despite gross differences in anatomy, the basic mechanisms underlying parasympathetic control of smooth muscles and gas exchange might be conserved between mammals and birds.

Underwater sound production occurs in aquatic mammals, including cetaceans (whales, including dolphins and porpoises). While most aquatic mammals use the vocal folds of the larynx for generating sounds (including the infrasonic vocalizations of baleen whales), ultrasonic vocalization (USV) occurs only in odontocetes (toothed whales). It is unclear whether odontocetes can generate any sound with the larynx. However, there is ample experimental proof that the odontocete nasal region produces USVs. These sounds are made by airflow vibrating complex tissues surrounding the nasal aperture (blowhole). The involved structures consist of phonic lips (vibration source), air sacs (air capture and recycling) or a connective tissue theca (reflector), and melon (focuser, transducer). These nasal region tissues appear to be evolutionarily derived from homologous facial structures (e.g., lips, nasal cartilages, facial muscles) of other mammals. Sound production mechanisms of aquatic mammals will be discussed, with an emphasis on the USVs of odontocetes.

After the discovery of the flight-motor driven unidirectional gas exchange with rising PO2 in the blowfly, X-ray computer tomography (CT) was used to visualize the organization of the tracheal system in the anterior body with emphasis on the arrangement of the pathways for the airflows. The fly's head is preferentially supplied by cephalic tracheae originating from the ventral orifice of the mesothoracic spiracle (Sp1). The respiratory airflow during flight is a by-product of cyclic deformations of the thoracic box by the flight muscles. The air sacs below the tergal integument (scutum and scutellum) facilitate the respiratory airflow: The shortening of the thorax turns the scutellum and the wings downward and the scutum upward with a volume increase in the scutal air sacs. The resulting negative pressure sucks air from Sp1 through special tracheae towards the scutal air sacs. The airflow is directed by two valves that open alternately: (1) The hinged filter flaps of the metathoracic spiracles (Sp2) are passively pushed open during the upstroke by the increased tracheal pressure, thereby enabling expiration. (2) A newly described tracheal valve-like septum behind the regular spiracular valve lids of Sp1 opens passively and air is sucked in through Sp1 during the downstroke and prevents expiration by closing during the upstroke. This stabilizes the unidirectional airflow. The tracheal volume of the head, thorax and abdomen and their mass were determined. Despite the different anatomy in birds and flies the unidirectional airflow reveals a comparable efficiency of the temporal throughput in flies and hummingbirds.

Air sacs are an important component of the avian respiratory system, and corresponding structures also were crucial for the evolution of sauropod dinosaur gigantism. Inferring the presence of air sacs in fossils so far is restricted to bones preserving internal pneumatic cavities and foramina as osteological correlates. We here present bone histological correlates for air sacs as a new potential identification tool for these elements of the respiratory system. The analysis of several avian and non-avian dinosaur samples revealed delicate fibres in secondary trabecular and secondary endosteal bone that in the former case (birds) is known or in the latter (non-avian dinosaurs) assumed to have been in contact with air sacs, respectively. The bone histology of this ‘pneumosteal tissue’ is markedly different from those regions where muscles attached presenting classical Sharpey's fibres. The pneumatized bones of several non-dinosaurian taxa do not exhibit the characteristics of this ‘pneumosteum’. Our new histology-based approach thus can be instrumental in reconstructing the origin of air sacs among dinosaurs and hence for our understanding of this remarkable evolutionary novelty of the respiratory system.

Background There are few reports comparing type 1 alveolar epithelial cell development with histopathological image analysis. We investigated these as indicators of maturity in fetal lambs' lungs in a congenital diaphragmatic hernia (CDH) model. Methods We created left CDH in 4 fetal lambs at 75 or 76 days’ gestation (Group A). Controls were 5 sham-operated lambs (Group B); both groups delivered at term. The right lower lung lobe (RLL) and left lower lobe (LLL) were sampled. Using histopathological image analysis, alveoli/air sacs count (AC), alveoli/air sacs area percentage (AP), average area (AA), total area (TA), and perimeter (PM) were determined. We also evaluated total lung volumes, radial alveolar count (RAC), and Type 1 alveolar epithelial cells ratio (AT1 ratio), which we previously reported. Regression analysis was performed, with p Results RLL and LLL AT1 ratio and LLL RAC in Group A were lower than in Group B. There are no significant differences demonstrated by histopathological image analysis. In Group A, the AT1 ratio in the LLL was lower than in the RLL. There were no differences between LLL and RLL in Group B. Conclusion AT1 ratio was superior to the other indicators evaluating lung maturity.

Despite the diversity in fish auditory structures, it remains elusive how otolith morphology and swim bladder-inner ear (= otophysic) connections affect otolith motion and inner ear stimulation. A recent study visualized sound-induced otolith motion; but tank acoustics revealed a complex mixture of sound pressure and particle motion. To separate sound pressure and sound-induced particle motion, we constructed a transparent standing wave tubelike tank equipped with an inertial shaker at each end while using X-ray phase contrast imaging. Driving the shakers in phase resulted in maximised sound pressure at the tank centre, whereas particle motion was maximised when shakers were driven out of phase (180 degrees). We studied the effects of two types of otophysic connections-i.e. the Weberian apparatus (Carassius auratus) and anterior swim bladder extensions contacting the inner ears (Etroplus canarensis)-on otolith motion when fish were subjected to a 200 Hz stimulus. Saccular otolith motion was more pronounced when the swim bladder walls oscillated under the maximised sound pressure condition. The otolith motion patterns mainly matched the orientation patterns of ciliary bundles on the sensory epithelia. Our setup enabled the characterization of the interplay between the auditory structures and provided first experimental evidence of how different types of otophysic connections affect otolith motion.

Sporadic and geographically widespread reports of parasites affecting the Belted Kingfisher (Megaceryle alcyon) have been published but few have described details of the pathology. A female, adult kingfisher was found dead in a heavily wooded area of a zoo in Maryland, USA. At necropsy, numerous sexually dimorphic, 4.4-40.5-cm adult Monopetalonema alcedinis nematodes were found tightly wound within the coelomic cavity between organs and completely filling the caudal thoracic and abdominal air sacs. Abundant, 30-60-µm diameter, larvated, thick-walled ova were found in the bronchi and parabronchi, within the mesentery, and in the serosa of multiple coelomic organs. Monopetalonema alcedinis is a characteristic member of the superfamily Diplotriaenoidea, a group of nematodes occurring in birds and reptiles. Infective larvae within an invertebrate intermediate host are ingested and penetrate the intestine, traveling to the lungs and then into the air sacs, where the adult females release eggs. The ova are coughed up by the avian host and passed in feces. Specimens of M. alcedinis have been found in the Belted Kingfisher, although typically intensity of infection is low and infections remain asymptomatic. In contrast, we report the second documented case of high numbers of M. alcedinis resulting in pathologic changes in which parasitism contributed to host mortality.