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Cucullanus pinnai has been divided in two subspecies (C. pinnai pinnai and C. pinnai pterodorasi) based on the morphology of oesophastome. While C. pinnai pinnai apparently shows low host specificity and broad geographic occurrence, with certain morphological variations, C. pinnai pterodorasi was reported once, parasitizing Pterodoras granulosus. We used an integrative taxonomic approach to evaluate whether or not populations of C. pinnai pinnai from Trychomycterus spegazzinii (Escoipe River, Argentina) and Pimelodus fur (Miranda River, Brazil), and of C. pinnai pterodorasi from Pterodoras granulosus (Miranda River, Brazil) are conspecific. Parasites were observed using light microscopy and genetically characterized based on partial sequences of the 18S and 28S rDNA, ITS1-5.8S-ITS2, and COI mtDNA. Phylogenies were reconstructed and the Generalized Mixed Yule Coalescent (GMYC), Poisson Tree Process (bPTP), and Automatic Barcode Gap Discovery (ABGD) were used for species delimitation purposes. The present samples formed well-supported monophyletic assemblages, corroborating in part the results of morphological analyses; however, they grouped according to geographic origin. Species delimitation suggested conspecificity of C. pinnai pinnai with C. pinnai pterodorasi from Brazil; consequently, the morphology of oesophastome may be an intraspecific variation. Results also indicated that C. pinnai may represent a species complex as samples from Argentina were suggestive of an independent specific entity. However, definitive affirmations are premature, since there is no autapomorphy for separating C. pinnai from Brazil and Argentina and sampling was limited to three host species from two river basins. The phylogenetic reconstructions also confirmed the artificiality of some genera within Cucullanidae. [ABSTRACT FROM AUTHOR]

Purpose: To report a new species: Sprentascaris pampayensis, a Raphidascarididae parasite from the Neotropical region. Methods: During a parasitological survey, specimens were collected of a new species of Sprentascaris from Hypostomus commersoni Valenciennes from urban lakes in Santa Fe City, Santa Fe Province, in the Pampean region of Argentina. Morphological and morphometric descriptions, and molecular analyses were performed. Results: The new species, S. pampayensis n. sp., is characterized by having slightly extended lateral wings in both sexes, oral structure with three well-developed lips with double papillae, ventrolateral lips with an amphidial pore. Triangular buccal opening with three well-developed lips with flattened extensions at their bases, which end in a pointed manner towards the back. Males have 17 pairs of preanal papillae, 1 pair of adanal papillae, 3 pairs of postanal papillae and 1odd median postanal papilla located between the first and second pairs, unusual shape of caudal papillae with the central tubular part conspicuously elevated. Females have pre-equatorial vulva, smooth-shelled eggs, and mature embryonated eggs. Discussion: Sprentascaris pampayensis n. sp. differs morphologically and genetically from S. manherti Petter and Cassone, 1984, S. lanfrediae Melo, Santos, Giese, Santos and Santos, 2011 and S. andersoni Malta, Paiva, Elisei, Tavares and Pereira, 2018. Morphological and morphometric comparison also distinguishes it from S. pimelodi Petter and Cassone, 1984, S. hypostomi Petter and Cassone, 1984, S. marano Ramallo, 2009, and S. saltaensis Ailán-Choke, Ramallo and Davies, 2017. Sprentascaris pampayensis n. sp. is a new parasitic nematode of Hypostomus commersoni. [ABSTRACT FROM AUTHOR]

The objective of this work was to describe the dynamics of development and survival of the free-living stages of cattle gastrointestinal nematodes (GIN) in fecal matter (FM) and pasture during the dry season in the Lerma Valley, Salta province, northwestern Argentina (NWA) to contribute to GIN management. The climate in the region is characterized by a rainy summer followed by a dry season from middle autumn to early spring. Fecal matter from calves naturally infected with GIN was deposited on three experimental field plots in April, July and October 2019, corresponding to the beginning, middle and end of the dry season, respectively. Each experimental unit consisted of 7 stools of about 800 g and had four repetitions. To determine the development from egg to infective larvae (L3), the first sampling (5 g fecal matter) was performed from the 10th day post-contamination and continued every 3 days until L3 were found. Subsequently, a monthly sampling was made until two consecutive negative results were obtained. Sampling of pasture began three days after the L3 recovery from FM, and continued monthly until two negative results were obtained. The following parameters were evaluated: development time and development rate from egg to L3; permanence time of L3 in feces; time of appearance on pasture; migration rate; and permanence time of L3 on pasture. The main genera of parasites present were Cooperia and Haemonchus. Significant differences were observed in the development time among contamination months (p < 0.001); development time was highest in the July contamination (28 days), with October and April contamination averaging 9 and 10 days, respectively. Development time also showed significant differences (p < 0.01) among contamination months, being highest in October (31.48%). The highest permanence time in fecal matter values were recorded in the July contamination (183 days) and migration rate was highest in the October contamination (42.49%). The highest time of appearance on pasture value was recorded in the July contamination (117 days). Finally, the highest permanence time of L3 in feces values were detected in the October contamination (148 days). The results of this work show that fecal contamination in the NWA region in the dry season would play an epidemiological role in the GIN cycle as a source of infection for the next productive cycle in the rainy season., (Copyright © 2024 Elsevier B.V. All rights reserved.)

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Copyright of Revista Veterinaria is the property of Universidad Nacional del Nordeste and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

During a parasitological survey, specimens belonging to the genus Hedruris (Nematoda: Hedruridae) were found in the stomach of Synbranchus marmoratus Bloch from the Paraná Guazú River, Paraná River basin (Argentina). Comparative morphological studies with its congeners showed that these nematodes belonged to a new species, herein described as Hedruris anguila sp. nov. The new species can be distinguished from remaining Hedruris species by the pseudolabia size, the morphology and size of spicules, the length of female caudal hook, the shape and size of eggs and the particular morphology of the male tail. Hedruris anguila sp. nov. closely resembles Hedruris bifida Rossin & Timi, 2016 and H. suttonae Brugni & Viozzi, 2010, both also described from fish hosts, in the arrangement of caudal papillae and morphology of eggs, but differ in the size of female hook and spicules, and the number of caudal papillae in males. The main morphological features, host range and geographical distribution of all species in the genus Hedruris species are analyzed and discussed. This is the first report of a representative of the family Hedruridae parasitizing a species of Synbranchidae and the eleventh report of the genus Hedruris for a fish host. The number of valid species of Hedruris described was increased to 26, including the new species; 11 for the Neotropical Region and represent the third species found in fish host from Argentina. Based on morphological analysis, the speciation process probably occurred first in Gondwana and the non-mammillated eggs could be an ancestral morphological character. The diet of Synbranchus marmoratus and values of prevalence and mean intensity could indicate that this host species is a true definitive host for this nematode.

The Mermithidae is a family of nematodes parasitic in many kinds of insects, spiders, leeches, crustaceans and other invertebrates throughout the world. While conducting an assay with entomopathogenic nematodes, we found Armadillidium vulgare (Crustacea: Isopoda) individuals to be infected with Agamermis sp., marking the fourth known discovery of a mermithid infection in the order Isopoda. In this work, we contribute with an 18S rDNA sequence of the isolated nematode and the morphological and morphometrical characterization of the juveniles.

Longidorus juvenilis and L. laevicapitatus are described for the first time in Argentina. Longidorus juvenilis was found in the soil around the roots of Prunus persica at the Rio Negro province and L. laevicapitatus at the bottom of Canal del Este River at Buenos Aires province. Measurements and some photomicrographic images of these species are given. [ABSTRACT FROM AUTHOR]

Prochilodus lineatus has been considered an ecosystem engineer in the Neotropics given its influence on important ecosystem processes, and it is therefore relevant to understand their inter-specific relationships. The association of P. lineatus with parasitic helminths was studied in two isolated shallow lakes of the alluvial plain of the Middle Paraná River. Only two species of gastrointestinal nematodes were found: Spinitectus asperus (Cystidicolidae) and Klossinemella iheringi (Atractidae), with S. asperus having higher prevalence and mean intensity values. This is the first record of K. iheringi in the Middle Paraná River, Argentina, as well as the southernmost citation of S. asperus.

Here, we describe a new kathlaniid nematode, Falcaustra sanjuanensis sp. nov., from the large intestine of Odontophrynus cf. barrioi (Anura: Cycloramphidae), from San Juan Province, Argentina. The new species belongs to the Falcaustra group that possesses a pseudosucker. It resembles F. andrias in the distribution pattern of caudal papillae (six precloacal, four adcloacal, 12 postcloacal, one unpaired median anterior to the cloaca) but differs from F. andrias in the following characters: the longer size of males and females (11.17-13.45 mm and 10.1-15.5 mm, respectively); the longer size and form of the gubernaculum (0.17-0.23 mm, triangular form); the arrangement of postcloacal papillae (three pairs on the ventral side, two pairs on the lateral side, one pair on the subventral side) and unpaired papilla anterior to the cloaca located on the protuberance. The species description is based on light microscopy and scanning electron microscopy (SEM). Falcaustra sanjuanensis sp. nov. represents the 12th Neotropical species assigned to the genus. Also, we added a key to Neotropical species of Falcaustra. [ABSTRACT FROM AUTHOR]

A new species of the genus Protrellus, P. blatta sp. nov. parasitizing a field cockroach Blatella vaga Hebard, 1919, from El Tala river, Catamarca, Argentina, is described and illustrated. It is characterized by having the mouth opening circular, the buccal capsule with eight very small teeth, the nerve ring around oesophageal corpus, the excretory pore anterior to vulva, the vulva anterior to base of oesophagus, didelphic, the posterior ovary reflexed anterior to rectum, about one third of a body length from posterior end, the egg ellipsoidal, colourless, bearing a lateral cuticular crest, tail conical, with long filiform projection, the male with testis single, outstretched, one spicule, very small, short and straight, gubernaculums absent, the genital papillae arranged in three pairs of ventrolateral papillae, of which the first pair are close together and preanal position, two pairs postanal, tail conical and short, less than one twentieth of total body. A taxonomic key of Protrellus species is given. [ABSTRACT FROM AUTHOR]

Pelecitus tercostatus (Molin, 1860) (Onchocercidae, Dirofilariinae) was found in the leg of a Vinaceous-breasted Parrot Amazona vinacea (Aves, Psittaciformes) from Misiones, Argentina. The present report enlarges the host distribution of the species and represents the first record of any nematode in A. vinacea. The macroscopic lesions produced in the bird are also described. [ABSTRACT FROM AUTHOR]

The article analyzes the helminth community of O. bonariensis in two lagoons from Buenos Aires Province, Argentina. The fish sites were sampled in 2 sites namely the Salada Grande lagoon (SGL), General Lavalle and the Lacombe lagoon, Lezama in Buenos Aires, Argentina. Five species found in both lagoons include C. macdonaghi, Wolffhugelia matercula and Contracaecum sp. while species found exclusively in SGL include Thometrema bonariensis, Saccocoeliodes sp. and Ascocotyele sp. It cites the occurrence of cumulative infection processes which explain the increasing number of helminths throughout the life cycle of silversides.

The article reports on the first recorded cosmocercid nematode (Cosmocercella minor) in Argentina in the orange-legged Leaf Frog (Phyllomedusa hypochondrialis). Morphological details include subventral adanal alae and the lack of postanal caudal alae, the fine structure of the vesiculated rosettes, and the structure of the proximal end of spicules in males, and a confirmation of the amphidelphic condition in females. The four type host specimens were captured in Corrientes.

The acuarioid nematode Echinuria skrjabiniensis Efimov in Skryabin, Sobolev et Ivashkin, 1965 was found in Calidris bairdii and C. fuscicollis (Aves, Scolopacidae) examined from several locations from Patagonia, Argentina. These constitute new host records as well as the first record of this parasite species in South America. Using both light and scanning electron microscopies, new morphological details are provided, including the description of the left spicule and the number and the arrangement of male caudal papillae. The taxonomic history of the species is summarized, corroborating its correct spelling and valid name. [ABSTRACT FROM AUTHOR]

A new species of parasitic nematode, Hysterothylacium spirale sp. nov. (Ascaridoidea, Anisakidae), is described based on specimens collected from the intestine and pyloric caeca of the silvery john dory Zenopsis conchifer (Lowe) (Zeiformes, Zeidae), from the Argentinean Shelf (35°05′-40°46′S, 53°03′-58°07′W). Among the 66 valid species described so far in the genus, the new species most closely resembles H. zenis (Baylis, 1929). Both species, apparently specific for fishes of the family Zeidae, share the shape of the dorsal lip, the long expanded lateral alae originating from subventral interlabia and the ornamentation of the tail tip, as well as general morphometry. The combination of these shared features distinguishes both species from all congeners so far known. However, the new species is distinguishable from H. zenis by having shorter interlabia, and consequently the lateral alae originating more posteriorly, shorter spicules, a smaller number of postcloacal papillae and the presence of two pairs of double postcloacal papillae. [ABSTRACT FROM AUTHOR]

The article reports on the recovery of species of cosmocercid nematodes infecting the large intestines of hylid frogs, Hypsiboas raniceps, Dendropsophus nanus and Denropsophus sanborni, collected from the city of Corrientes in Argentina. Most nematode parasites of amphibians in Argentina are identified from leptodactylid and bufonid hosts, but the nematode fauna of hylid hosts is not commonly known. The hosts were parasitized by a few nematode species with low prevalence and intensity of infection.

The article presents a study that examined seventeen parasite species, including cestode, digeneans, and nematodes, that were recovered from fishes of genus Odontesthes smitti and Odontesthes nigricans in Argentina. Parasites such as Microsporidia, Cestoda, and Digenea, were found. Of the seventeen parasites collected, 14 were helminths, 2 were trematodes and there was a fungus. Component communities share most of the parasitic species.

The article presents a study which described Helminths of the Magellanic Penguin, Spheniscus magellanicus during the breeding season in Patagonian Coast, Chubut, Argentina. Parasite species including Tetrabothrius lutzi, Cardiocephaloides physalis, Contracaecum pelagicum, Cosmocephalus obvelatus and Corynosoma, were found on Magellanic penguins. Composition of helminth community of S. magellanicus is reported in Argentina for the first time which increased the host range of registered species.

The article offers information regarding the common lesser escuerzo Odontophrynus americanus from Corrientes in Argentina which is found to hold 3 species of Nematodes. It notes that the Cosmocerca podicipinus was the most dominant nematode species while the Cosmocerca parva had the highest mean intensity of infection. It cites that the 3 species of nematodes are reported for the first time from Odontophrynus americanus and members of the Cycloramphidae.

The article describes the characteristics and nature of a species called Hexamermis paranaense, a parasite of larvae of Diloboderus abderus Sturm. This species is characterized by three rows of genital papillae, pocket-shaped amphidial opening, and the anterior portion of the vagina muscularized. Larvae of D. abderus were collected in the fields of horticulture in Argentina in October 2002. Using a camera lucida microscope and a light microscope, drawings and measurements were made from live and fixed specimens.

Abstract: A total of 138 nematodes were found in the small intestine of Ctenomys talarum (Octodontidae) from Mar de Cobo, Argentina. A new nematode species, Pudica ctenomydis n. sp., is described. The new species more closely resembles P. pujoli Durette-Desset, 1990, parasite of Microcavia niata Thomas, from Bolivia. It can be distinguished from P. pujoli by the number of ridges and characteristics of the synlophe, the spicular morphology, differences in length between rays 9 and 10, and by the presence of a symmetrical caudal bursa and a cuticular expansion surrounding the body between vulva and anus in females. [Copyright &y& Elsevier]

The aims were to study the epidemiology and the effect of gastrointestinal nematodes (GINs) on yearling cattle in a semiarid region in Argentina and to evaluate the mineral serum levels. Ten- to twelve-month-old calves were monitored between November and April 2019. Animals were divided into three groups: untreated control (CONG; n = 20); group treated with moxidectin (MXD, 200 µg/kg) every 30-40 days (MXDG; n = 20); group equally MXD treated and mineral supplementation administered in November and January (MMG; n = 20). Individual GIN egg counts (epg) and fecal cultures were made every 30-40 days. Animal live weight gain was determined. On 7-11-18, 25-1-19, and 3-4-19, serum levels of Se, Cu, Zn, Mg, and Ca were determined by atom absorption spectrophotometry. At the start of the trial, epg values were low (x̄ = 5.5), which increased only in CONG towards the end of the assay (x̄ = 229). In both GMXD and MMG, epg remained very low (x̄ = 4.1). Cooperia spp. (81%) prevailed over Haemonchus spp. (9%) and Oesophagostomum spp. (9%). Deficiency of Se ranged between marginal and important, except for MMG, although mean values were always below normal. Cu was marginally deficient in CONG and MXDG on the first two sampling dates, whereas MMG had normal values after treatment. Mg had low values in the three groups (x̄ = 1.5 mg/dl), whereas Ca and Zn exhibited normal values. Live weight gain (LWG) was higher in MMG than in MXDG, with significant differences (p < 0.05) by mid-January and then, when epg increased, dewormed groups showed higher LWG (p < 0.034) than CONG. A negative effect of GINs on LWG was observed, as well as low to marginal levels of Se, Cu, and Mg., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

Filaria lorenzo n. sp. is described in the Lesser Grison, Galictis cuja from northern Patagonia, Argentina. The new species can be differentiated from the eight species of Filaria from the Old World by the shape of the sclerotized preesophageal ring. The four remaining species of the genus parasitize American Mephitidae and/or Mustelidae. Filaria carvalhoi from Brazil and F. texensis from USA lack a preesophageal ring, whereas F. taxideae from USA and F. conepati from Argentina share with our specimens a preesophageal ring mostly mushroom shaped. Our specimens differ from F. taxideae by lacking lateral alae, by a different ornamentation of the female tail and by the male lacking adcloacal papillae. The new species also differs from F. conepati by the shape of the preesophageal ring and by the shape of the eggs. The indirect examination of the types of F. conepati and F. carvalhoi, corroborated the existence of differences between these two species, allowing us to refute their synonymy, as proposed by some authors. Our results extend the taxonomy of Filaria to 13 species and comprise the first report of a filarioid nematode for an Argentinean mustelid, and the first report for Patagonia.

Skrjabinodon castillensis n. sp. is described and illustrated here, based on specimens found in the large intestines of Homonota horrida (province San Juan) and Homonota darwinii (province Neuquén) (Squamata: Phyllodactylidae) from Argentina. The new species is assigned to Skrjabinodon based lateral alae present in males, absent in females. Lateral alae beginning midway between lips and nerve ring and ending just posterior to first pair of caudal papillae. Females with vulva near esophageal bulb. In males, caudal alae absent, paired caudal papillae present. Skrjabinodon castillensis n. sp. represents the 9th species from the Neotropical realm. The new species differs from all other species assigned to Skrjabinodon by morphology of tail filament and number of tail filament spines. Skrjabinodon castillensis n. sp. is the only species of this genus known from Argentina. A key to the species of Skrjabinodon in the Neotropical realm is provided.

Two new species of free-living marine nematodes of the subfamily Enoplolaiminae are described from Ro Negro and Chubut Provinces, Argentina. Enoplolaimus variispiculum sp. n. is characterized by having asymmetric spicules, different in size and distal tips. It is the only species with this characteristic in the whole genus. Mesacanthoides flagellatum sp. n. is characterized by mandibles texture, weakly cuticularized and mottled and mandibular plates with pronounced v shaped incision posterior to the anterior bar. Cephalic capsule wider than long with setae on posterior end, males with long spicules, complex gubernaculum and flagellate tail.

In rivers and other watercourses from San Juan Province specimens of Hatcheria macraei (Girard, 1855), Psalidodon eigenmanniorum (=Astyanax eigenmanniorum (Cope, 1894), Jenynsia lineata (Jenyns, 1842) and Trichomycterus corduvensis Weyenbergh 1877 were captured. Of these, H. macraei and P. eigenmanniorum were parasitized with the nematodes Rhabdochona acuminata and Contracaecum sp., respectively. The morphometric analysis of the identified nematodes is included. They are the first records of parasitic nematodes of fish from San Juan Province. In this way, the geographical distribution of both nematodes was extended and H. macraei and P. eigenmanniorum were registered as new hosts.

Helminthological examination of viscera of six freshwater fish species, collected from Misión la Paz, Pilcomayo River, Province of Salta, Argentina, revealed the presence of five species of parasitic nematodes belonging to the Camallanidae, Cystidicolidae, Cucullanidae and Anisakidae  The material also contained one unknown species, Procamallanus (Spirocamallanus) tomsici sp. nov. collected from Pimelodus albicans, Pygocentrus nattereri and Hoplias misionera. This species is distinguished from its congeners all over de world by possessing six pores distinctly surrounding the mouth aperture, a buccal capsule with 3-4 spiral thickenings complete, females possessing a lateral cuticular ornamentation along the body, and two pairs of preanal and three pairs of postanal papillae in males. The findings represent new hosts and geographical records.

This study describes the morphology of Rhabdias elegans Gutierrez, 1945, isolated from the lungs of the toad Rhinella arenarum (Hensel, 1867) from Lomas de Tafi Tucumán, Argentina. This is the first record of R. elegans in R. arenarum from northwestern Argentina as previously described Rhabdias truncata is a species inquirendae. The distribution of R. elegans is extended since it was previously recorded in Buenos Aires, Chaco and Corrientes Provinces, Argentina. Our light microscopical study of morphological details of R. elegans revealed a few previously unreported structures in the apical region including position of the excretory pore and lateral sessile papillae in the tail. In addition, morphometric variability was observed on comparing present specimens and those described in previous studies. Our study made it possible to validate the occurrence of three Rhabdias species occurring in Argentina: R. elegans, R. füelleborni and R. cf. sphaerocephala. The information presented in this study represents an important contribution to the parasitological knowledge of R. arenarum from northwestern Argentina.

A summary of the parasitic nematodes of reptiles from Argentina is presented. It is a compilation of 29 parasitological papers published between 1992 and May 2020. This review includes information about 40 species of reptiles (4 snakes, 3 turtles, 1 anfisbaenian and 32 lizards). Twenty-six nematodes species have been reported from reptiles. The present review provides data on hosts, geographical distribution and site of infection. A host/parasite list is also provided.

Three new species of free-living marine nematodes of the genus Metoncholaimus are described from San Matías gulf (Río Negro, Argentina). Metoncholaimus sanmatiensis sp. n. is characterized by large body size, long spicules, small gubernaculum, presence of long setose pre- and postcloacal genital sensilla and presence of precloacal pores. Metoncholaimus perdisus sp. n. is characterized by small-sized body, short spicules, small gubernaculum, presence of long setose pre- and postcloacal genital sensilla and presence of pre- and postcloacal pores. Metoncholaimus paracavatus sp. n. is closely related to Oncholaimus cavatus but can be considered as a new Metoncholaimus species based on the presence of gubernaculum and the morphology of the demanian system. A compendium of all valid species, including new species, is given.

We describe Hedruris dratini n. sp. (Nematoda, Hedruridae) from Hydromedusa tectifera and Phrynops hilarii in Argentina based on morphological and molecular characters. Also, we provide information about its life cycle. The new species differs from other species of the genus by possessing the excretory pore, nerve ring and deirids at equal distance from the anterior end. Additionally, H. dratini n. sp. has mammilated eggs and males possess nine pairs of caudal papillae. The subadults and adults of H. dratini n. sp and H. orestiae were characterized by sequencing the small subunit ribosomal DNA (18S). We present for the first time a life cycle of a species of Hedruris that includes an amphipod as intermediate host and a reptile as definitive host. Furthermore, we analysed the host and geographic distribution of all Hedruris species. Although the genus has a cosmopolitan distribution and parasitizes a great host diversity, the majority of species have a Gondwanian distribution, with amphibians being the preferred hosts.

The nematode parasites can cause mechanical injuries such as irritation or atrophy of tissue and occlusions of the digestive tract, blood vessels or other ducts in their hosts. Some species belonging to the family Camallanidae have been the focus of histopathological studies because they lacerate the host´s intestinal wall with their buccal capsule. In this study, we describe the histopathological effects produced by Procamallanus (Spirocamallanus) pintoi in the small fish Corydoras micracanthus from Lesser River, in the northwest of Argentina, South America. The samples were processed with routine histology techniques. At light microscopy, specimens of P. (S.) pintoi were observed occupying the lumen of the gut. The histopathological sections revealed damage to the host intestine with the total destruction of the mucosa and submucosa, observed mainly in the region which is surrounding the buccal capsule of parasites. Moreover, an inflammatory reaction was observed with lymphatic accumulations in the affected tissue. This kind of degenerative and necrotic changes in the mucosa could affect negatively the absorption function of the host intestine, which may have adverse effects of the health status of fish. The present study provides the firs data about the histopathological effects of P. (S.) pintoi in C. micracanthus.

The aim of this work was to study the epidemiology and the harmful effect of gastrointestinal nematodes (GINs) on beef cattle in the piedmont forest and grassland region of northwestern Argentina, between March 2015 and March 2016. Sixty weaned female calves were divided into three groups: STG-calves treated systematically with 200 mcg/kg moxidectin every 40-50 days; LTG-calves treated as usually locally implemented, with 200 mcg/kg ivermectin on May 4 and August 5; and UTG-calves not receiving treatment. Moreover, a group of 20 untreated first-calving cows was monitored. Eggs per gram of faeces (epg) and faeces cultures were performed. Live weight gain (LWG) was recorded. Differences among groups were compared using analysis of variance and Tukey test. At the start of the experiment, mean epg was from moderate to high (595 ± 480); therefore, this group was treated in May. Mean UTG epg peaked (907 ± 754) in mid-winter, decreasing toward spring. LTG epg only decreased partially after treatment, showing 54.2% of ivermectin efficacy. Epg values of STG were always negligible values (95.8% of moxidectin efficacy). The dominant nematode genus was Cooperia (81.9%), followed by Haemonchus (15.5%). The effect of treatments was evident from middle autumn, with STG showing a significantly (p < 0.002) higher LWG than the other groups. Toward the end of the trial, LWG of STG and LTG increased by 27.2 and 8.2%, respectively, to those of UTG. This preliminary study showed a winter epg peak and a negative effect of GINs on LWG, even in moderately infected calves.

Background: Biological control of gastrointestinal nematodes of ruminants by use of nematophagous fungi would become part of any livestock parasite integral control system. Identifying autochthonous species that could then be selected for mass production is an important phase in the practical use of biological control., Aims: To search for nematophagous fungi with potential use as biological control agents against gastrointestinal nematodes in Argentina., Methods: Decomposing cattle faeces sampled in different locations were incubated in water agar 2% with Panagrellus sp. The developed nematophagous fungi were transferred to new water agar 2% plates and then to corn meal agar plates in order to carry out their identification. Fungal diversity and richness were also assessed., Results: Seventeen species from nine genera of nematophagous fungi were found. Twelve species were nematode-trapping fungi and three species plus two fungi identified to genus level corresponded to endoparasitic fungi. Arthrobotrys conoides, Arthrobotrys oligospora, Duddingtonia flagrans, Monacrosporium doedycoides, Arthrobotrys robusta and Drechmeria coniospora were the most frequently isolated species overall in the whole study (6.6%, 5.7%, 5.7%, 5.7%, 4.7% and 4.7%, respectively) although other species were more frequently recorded at local levels such as Arthrobotrys pyriformis (18.8%). Only A. conoides has been previously isolated from ruminant faecal samples in Argentina. Five nematode-trapping fungal species are mentioned for the first time in the Americas, Conclusions: D. flagrans and A. conoides, both identified in the present study, are among the most promising ones as biological control agents against gastrointestinal nematodes of ruminants., (Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.)

We explored the effects of a textile industry effluent on water quality, habitat quality and structural and functional responses of benthic communities in a lowland stream. Two sampling sites were selected: site 1 was located 300 m upstream of the outflow from the textile factory and site 2 was 500 m downstream from the discharge point. Samples of water, microbenthos, invertebrates and aquatic plants were taken seasonally. The effluent from the textile industry modified the structure of the microbenthic assemblages downstream, increased the density of organisms and the biomass of primary producers, but diminished the species richness. The oxygen consumption of the microbenthic community was 3 x higher downstream of the effluent and abnormal frustules of diatoms were noticed. The richness and abundance of invertebrate taxa were lower at the impacted site. The invertebrate modes of existence and the functional feeding groups were also significantly affected. This study is an important baseline for assessment of lowland streams with high water residence time and a notable development of hydrophytes. It will also provide a baseline for the monitoring and restoration, or remediation, programs using the metrics of biotic integrity, particularly in South American countries where such metrics are rarely employed.

The seasonality of immatures, imagoes and pathogens of Culex dolosus Lynch Arribálzaga, Culex intrincatus Brethes and Culex maxi Dyar from Punta Lara (Buenos Aires province, Argentina) was monitored weekly (larvae and pupae) or fortnightly (adults), from 1989 to 1991. Culex dolosus was present during all months. The larvae were parasitized by Geotrichum candidum Link ex Person, Smittium morbosum var. rioplatensis López Lastra, Coelomomyces sp., Achlya sp, Amblyospora dolosi García & Becnel and Strelkovimermis spiculatus Poinar & Camino. Conidia of Hyphomycetes, filarial worms of Onchocercidae and S. spiculatus were detected in adults. Cx. intrincatus was present from January to May; the immatures were parasitized by G. candidum, S. morbosum, Achlya sp. and Amblyospora sp. Larvae of Cx. maxi were collected from January to April, and adults in all months except for June and July. S. morbosum was the only parasite found in this mosquito.