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The manatee, Trichechus manatus manatus (Linnaeus, 1758), is one of the most endangered aquatic mammals in Brazil. The species is herbivore and occurs in shallow waters where plenty vegetation and fresh water sources are available. Even though marine mammals usually exhibit high mobility and dispersion capacity as if there would be no geographical barriers in the ocean, some species such as the manatee have restricted distribution, reflecting ecological requirements and their centers of geographical origin. It occurs in the east coast of Ceará State between the towns of Beberibe and Icapuí. Moreover, the latter considered an important area of manatee occurrence, as it combines ecological attributes essential to the maintenance of the species in the region. The aim of this study was to determinate the frequency of use of the Picos Beach, Icapuí (04°39'24"S / 37°26'59"W; 04°39'37"S / 37°25'58"W), by individuals of manatee, describing spatial and temporal use patterns. In order to record the distribution of the animals, an area of 1 km2 was selected and divided into four quartiles of equal size (Zones 1, 2, 3 and 4). A geoenvironmental analysis of the observation area and the geoecological attributes of each zone was accomplished. The monitoring of manatees was carried out from a fixed point installed on top of a cliff on Picos Beach between February and December 2012, three times a week, with a daily effort of six hours (7-10h; 13-16h). The observations were made by naked eye and with the aid of binoculars. The recordings were made by sighting continuous ad libitum, observing all the animals that appeared during each monitoring period (morning and afternoon). The individuals of manatee occurred during all the year in Picos Beach with a frequency varying between 80 to 100% among the monitored months. The time of residence represented 43.5% of the total sighting effort. The mean residence time of individuals was 48.1 minutes, suggesting that the Picos Beach is an important area for the species, which may use it as a foraging, feeding, reproduction and rest habitat. There was seasonal preference for the Zones 1 and 3, which have higher depth and tide level, and a greater proportion of muddy substrate and grass stands, in comparison to the other zones. This study revealed information about the manatee's habitat, which is relevant for understanding the use of resources and ecology of these animals, and essential for designing conservation and management strategies. [ABSTRACT FROM AUTHOR]

The population sizes of manatees in many regions remain largely unknown, primarily due to the challenging nature of conducting visual counts in turbid and inaccessible aquatic environments. Passive acoustic monitoring has shown promise for monitoring manatees in the wild. In this study, we present an innovative approach that leverages a convolutional neural network (CNN) for the detection, isolation and classification of manatee vocalizations from longterm audio recordings. To improve the effectiveness of manatee call detection and classification, the CNN works in two phases. First, a long-term audio recording is divided into smaller windows of 0.5 seconds and a binary decision is made as to whether or not it contains a manatee call. Subsequently, these vocalizations are classified into distinct vocal classes (4 categories), allowing for the separation and analysis of signature calls (squeaks). Signature calls are further subjected to clustering techniques to distinguish the recorded individuals and estimate the population size. The CNN was trained and validated using audio recordings from three different zoological facilities with varying numbers of manatees. Three different clustering methods (community detection with two different classifiers and HDBSCAN) were tested for their suitability. The results demonstrate the ability of the CNN to accurately detect manatee vocalizations and effectively classify the different call categories. In addition, our study demonstrates the feasibility of reliable population size estimation using HDBSCAN as clustering method. The integration of CNN and clustering methods offers a promising way to assess manatee populations in visually challenging and inaccessible regions using autonomous acoustic recording devices. In addition, the ability to differentiate between call categories will allow for ongoing monitoring of important information such as stress, arousal, and calf presence, which will aid in the conservation and management of manatees in critical habitats. [ABSTRACT FROM AUTHOR]

Evolving to become bigger and/or longer lived should increase cancer susceptibility, but this predicted increase is not observed, a contradiction named Peto's paradox. A solution is that cancer suppression evolves to minimize cancer susceptibility, and the discovery of 19 retrogene (RTG) copies of the tumor suppressor gene TP53 in the African elephant (Loxodonta africana) is increasingly cited as a classic example of such adaptive suppression. However, classic examples need rigorous evaluation and an alternative hypothesis is that the RTGs spread by genetic drift. This study shows that before its duplication, the ancestral elephant RTG was already truncated from 390 amino acids to 157 by a frameshift mutation, and that 14 of the 19 copies are now truncated to ≤88 amino acids. There was no compelling evidence of either positive or negative selection acting on these 88 codons, and the pattern of RTG accumulation fits a neutral model with a duplication rate of ~10-6 per generation. It is concluded that there is no evidence supporting the hypothesis that the 19 elephant RTGs spread to fixation by selection; instead, the evidence indicates that these RTGs accumulated primarily by segmental duplication and drift. It is shown that the evolutionary multistage model of carcinogenesis (EMMC) predicts the recruitment of 1-2 independently acting tumor suppressor genes to suppress the increased cancer risk in elephants, so it is possible that one or a few RTGs may have been favored by selection resulting in the known enhanced sensitivity of elephant cells to DNA damage. However, the analysis does not provide any support for either a direct (via conserved TP53 activity) or indirect (via supporting canonical TP53 function) role of the RTGs sequences, so that the presence of multiple copies of TP53 retrogenes in elephants needs to be further justified before being used as a classic example of tumor suppression in large-bodied animals.

The population sizes of manatees in many regions remain largely unknown, primarily due to the challenging nature of conducting visual counts in turbid and inaccessible aquatic environments. Passive acoustic monitoring has shown promise for monitoring manatees in the wild. In this study, we present an innovative approach that leverages a convolutional neural network (CNN) for the detection, isolation and classification of manatee vocalizations from long-term audio recordings. To improve the effectiveness of manatee call detection and classification, the CNN works in two phases. First, a long-term audio recording is divided into smaller windows of 0.5 seconds and a binary decision is made as to whether or not it contains a manatee call. Subsequently, these vocalizations are classified into distinct vocal classes (4 categories), allowing for the separation and analysis of signature calls (squeaks). Signature calls are further subjected to clustering techniques to distinguish the recorded individuals and estimate the population size. The CNN was trained and validated using audio recordings from three different zoological facilities with varying numbers of manatees. Three different clustering methods (community detection with two different classifiers and HDBSCAN) were tested for their suitability. The results demonstrate the ability of the CNN to accurately detect manatee vocalizations and effectively classify the different call categories. In addition, our study demonstrates the feasibility of reliable population size estimation using HDBSCAN as clustering method. The integration of CNN and clustering methods offers a promising way to assess manatee populations in visually challenging and inaccessible regions using autonomous acoustic recording devices. In addition, the ability to differentiate between call categories will allow for ongoing monitoring of important information such as stress, arousal, and calf presence, which will aid in the conservation and management of manatees in critical habitats.

Simple Summary: Fewer than 200 manatees are hosted permanently by zoological parks worldwide. Their living conditions differ considerably from zoo to zoo. Recent research on ecology, acoustics, cognition and behaviour has changed the perception humans have on manatees with implications for their welfare. Using the five-model approach, this study examines our current knowledge on manatees' behaviour and cognition, and suggests ways to improve their welfare in zoological parks. The order Sirenia comprises several species of manatees and one species of dugong. These popular marine mammals are relatively recent acquisitions to zoological parks throughout the world. As far as we know, there are less than 200 manatees, mostly American, a few African, and ever less Amazonian, currently in zoological parks. American manatees are predominantly found in zoos in Europe, North America, and in some Asian countries, while African ones are present exclusively in Asian zoos. The living conditions of captive manatees differ considerably from zoo to zoo (i.e., numbers, sex ratio, outdoor vs. indoor habitats, complex vs. simple habitats). Most research on manatee behaviour has been relatively recent, and studies on cognition, sociality, and ecology have a significant impact on our perception of manatee needs and management, with wider implications for their welfare. In the wild, manatees demonstrated various cognitive capacities; spatial memory and learning abilities play an important role in their daily life in a complex and dynamic environment. Furthermore, there is evidence that these mammals are more social animals than expected. Individuals show various personality traits on the boldness–shyness continuum and their sociality varies. All those parameters are important in terms of animal welfare. Several behavioural studies showed that standardized enrichment programs benefit and ensure the welfare of captive zoo animals. However, obtaining accurate information on the presence of manatees in zoos, living conditions, management, and consequently welfare remains challenging. This study examines the current knowledge on manatee behaviour and cognition and then discusses different approaches to improving the welfare of this charismatic marine mammal in zoological parks. [ABSTRACT FROM AUTHOR]

Hematology and blood chemistry tests constitute an easy-to-apply veterinary tool that evaluates an organism's systemic functioning and disease process by comparing the level of specific analytes against species norms. Such analyses help monitor marine mammals' health and nutritional status. Although reference values have been published for a few manatee populations, there are none for Antillean manatees (Trichechus manatus manatus) in Colombia. We aim to establish the reference values for hematology and serum chemistries for these manatees and determine if there are variations between individuals of different age groups and sex. Thus, we obtained whole blood and serum samples from 45 rehabilitated manatees from Colombia between 1992 and 2021. Complete Blood Count and Comprehensive Metabolic Panel values were calculated, and differences between age groups and sex were determined. Results were compared with published reference intervals of other Antillean manatee populations, Florida manatees (Trichechus manatus latirostris), and Amazonian manatees (Trichechus inunguis) from Brazil. We determined the reference intervals of hematology and serum chemistry for manatees in Colombia for different age and sex categories. No relevant clinical variations were found in hematological parameters due to sex. Marked differences were found between age groups, mainly among young animals with an expected faster metabolism. There were significant variations between hematological and blood chemistry values when the Colombian manatees were compared to manatees from Puerto Rico and Amazonian manatees from Brazil. Such variations are likely influenced by evolutionary history and environmental factors associated with differences in habitat salinity and diet. We recommend that future studies correlate these blood tests with specific panels. We further recommend conducting wild manatee health assessments as this information will yield essential data for species management schemes needed due to the multiple anthropogenic and environmental threats that manatees face today which put the Colombian manatee's health and ultimate survival at risk. [ABSTRACT FROM AUTHOR]

Abstract Evolving to become bigger and/or longer lived should increase cancer susceptibility, but this predicted increase is not observed, a contradiction named Peto's paradox. A solution is that cancer suppression evolves to minimize cancer susceptibility, and the discovery of 19 retrogene (RTG) copies of the tumor suppressor gene TP53 in the African elephant (Loxodonta africana) is increasingly cited as a classic example of such adaptive suppression. However, classic examples need rigorous evaluation and an alternative hypothesis is that the RTGs spread by genetic drift. This study shows that before its duplication, the ancestral elephant RTG was already truncated from 390 amino acids to 157 by a frameshift mutation, and that 14 of the 19 copies are now truncated to ≤88 amino acids. There was no compelling evidence of either positive or negative selection acting on these 88 codons, and the pattern of RTG accumulation fits a neutral model with a duplication rate of ~10−6 per generation. It is concluded that there is no evidence supporting the hypothesis that the 19 elephant RTGs spread to fixation by selection; instead, the evidence indicates that these RTGs accumulated primarily by segmental duplication and drift. It is shown that the evolutionary multistage model of carcinogenesis (EMMC) predicts the recruitment of 1–2 independently acting tumor suppressor genes to suppress the increased cancer risk in elephants, so it is possible that one or a few RTGs may have been favored by selection resulting in the known enhanced sensitivity of elephant cells to DNA damage. However, the analysis does not provide any support for either a direct (via conserved TP53 activity) or indirect (via supporting canonical TP53 function) role of the RTGs sequences, so that the presence of multiple copies of TP53 retrogenes in elephants needs to be further justified before being used as a classic example of tumor suppression in large‐bodied animals.

Although there is growing concern about ingestion of microplastics by marine organisms, little research has been conducted on marine herbivores. This is the first study to document microplastic ingestion within the family Sirenia. Subsamples were collected from five locations in the gastrointestinal tracts (GI) of 26 dead manatees (Trichechus manatus latirostris) from Tampa Bay, Florida. During gross necropsies, macroplastic pieces were found in seven individuals (26.9%). Careful visual examination of the subsampled portions of the GI contents indicated that 19 individuals (73.1%) contained plastic particles. As five individuals had both macro and microplastic pieces, the overall frequency of occurrence of plastic ingestion was 76.9%. Due to the large volume of cellulose-rich ingested material, it was not feasible to analyze the entire gut contents, nor was it feasible to conduct chemical or enzymatic digestion; therefore, it is very likely that many microplastic pieces were not detected. Despite these technical challenges, it is clear that manatees in Tampa Bay are routinely consuming microplastics in addition to larger plastic pieces. Currently, nothing is known about the physiological effects of microplastic ingestion in sirenians, however environmental plastics could be concentrated by manatees through ingestion and the subsequent production of microplastics-laden feces.

Herein, we report anecdotes of manatee (family Trichechidae) behavior based upon accounts made by experienced observers. We have categorized the anecdotes into the broad categories of Conservation and Management (interactions with boats, people, and capture nets; rehabilitation and release), Behavioral Ecology (navigation, mother-calf interactions, interactions with conspecifics, mating behavior and birthing, anti-predator behavior, foraging and eating), and Cognition (sensory perception; learning, memory, and knowledge; interactions with objects, other species, and people; and mimetic behavior). These are all subjects that pertain to the goals of the Florida Manatee Recovery Plan of 2001. We found that many accounts report similar behaviors, suggesting that these may be fruitful lines of further inquiry. One subcategory, Navigation, appears to offer many research areas amenable to systematic study. The apparent behavioral flexibility and knowledge shown in manatee actions in several domains suggest that investigations of manatee intelligence are likely to be revealing. [ABSTRACT FROM AUTHOR]

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Florida manatees (Trichechus manatus latirostris) and rock hyraxes (Procavia capensis) exhibit expanded tactile arrays of vibrissae that are distributed not only on the face but also on the entire postfacial body. In contrast, the vibrissae of most mammals are principally restricted to the face. These facial vibrissae may be associated with central nervous system representations known as barrels in the cerebral cortex, barreloids in the thalamus, and barrelettes in the trigeminal nuclei of the brainstem. To date, vibrissae representations found within the brainstem have been principally limited to facial vibrissae representations in the trigeminal nuclei. We hypothesized that the tactile specializations of the manatee and rock hyrax would produce a unique modification of typical mammalian central nervous system organization, with postfacial vibrissae representations appearing in the cuneate and gracile nuclei as "body barrelettes." Using histological and histochemical methods, including cresyl violet, myelin, and cytochrome oxidase processing, we first delineated the rostral, middle, and caudal zones of the cuneate and gracile nuclei. Within the middle zone, divisions were present, including extensive parcellation in the cluster region, particularly in manatees. These clusters were particularly densely distributed and distinguishable in the presumptive postfacial body representations in the cuneate and gracile nuclei but otherwise shared many attributes with the barrelettes found in the trigeminal nuclei of other species. This study represents the first characterization of postfacial body vibrissae representations, or "body barrelettes," in the brainstem of any species. Previous studies have predominantly focused on facial vibrissae representations, which have served for decades as a model for sensory organization and plasticity. Our results extend what is known about vibrissae representations in the central nervous system to include expansions related to peripheral specializations of the postfacial body. Unusual somatosensory adaptations in the manatee and rock hyrax are highly informative regarding how mammalian brain organization responds to evolutionary pressures on sensory systems. [ABSTRACT FROM AUTHOR]

Data on the demography and distribution of wildlife populations are important for informing conservation and management decisions; however, determination of life history traits and population trends often are elusive. All four extant species in the order Sirenia are deemed vulnerable to extinction; therefore, determining the demography and distribution for populations worldwide is crucial. Aerial surveys, radio-tagging and tracking, genetic sampling and analyses, health assessments, carcass examination, and photographic documentation are all techniques used to study sirenian populations. A 40 +-year computer-aided catalog of images and demography data collected on Florida manatees enables searches of individuals by descriptions of feature (scar) types and has enabled estimates of annual survival and reproductive rates, documented extra-limital movements, and advanced modeling designs. Photography is discussed as a method for the documentation of unique and acquired features specifically on Florida manatees. By means of these features, individual Florida manatees have been re-identified as far from their established range as Cape Cod, Massachusetts, Houston, Texas, and in Cuba, The Bahamas, and Mexico. The length of gestation (11–13 months) and calf dependency (1–3 years), and potential longevity in the wild (> 50 years), have been verified. To meet the challenge of an increasing number of images collected with the advent of digital photography, there has been an increasing interest and potential for new techniques to assist with individual identification. Several researchers are utilizing drones and artificial intelligence to find, photograph, and streamline the individual identification of sirenians as well as other marine mammal species. New techniques have potential to simplify the photographic identification of Florida manatees. Photographic documentation could be a model for demographic and distribution research of sirenian populations outside of Florida and as a tool to monitor the viability of sirenian populations, particularly as threats emerge due to anthropogenic pressures and global climate change. [ABSTRACT FROM AUTHOR]

Evolving to become bigger and/or longer lived should increase cancer susceptibility, but this predicted increase is not observed, a contradiction named Peto's paradox. A solution is that cancer suppression evolves to minimize cancer susceptibility, and the discovery of 19 retrogene (RTG) copies of the tumor suppressor gene TP53 in the African elephant (Loxodonta africana) is increasingly cited as a classic example of such adaptive suppression. However, classic examples need rigorous evaluation and an alternative hypothesis is that the RTGs spread by genetic drift. This study shows that before its duplication, the ancestral elephant RTG was already truncated from 390 amino acids to 157 by a frameshift mutation, and that 14 of the 19 copies are now truncated to ≤88 amino acids. There was no compelling evidence of either positive or negative selection acting on these 88 codons, and the pattern of RTG accumulation fits a neutral model with a duplication rate of ~10−6 per generation. It is concluded that there is no evidence supporting the hypothesis that the 19 elephant RTGs spread to fixation by selection; instead, the evidence indicates that these RTGs accumulated primarily by segmental duplication and drift. It is shown that the evolutionary multistage model of carcinogenesis (EMMC) predicts the recruitment of 1–2 independently acting tumor suppressor genes to suppress the increased cancer risk in elephants, so it is possible that one or a few RTGs may have been favored by selection resulting in the known enhanced sensitivity of elephant cells to DNA damage. However, the analysis does not provide any support for either a direct (via conserved TP53 activity) or indirect (via supporting canonical TP53 function) role of the RTGs sequences, so that the presence of multiple copies of TP53 retrogenes in elephants needs to be further justified before being used as a classic example of tumor suppression in large‐bodied animals. [ABSTRACT FROM AUTHOR]

The Indian River Lagoon (IRL) on Florida’s east coast is a biologically diverse estuary and an important habitat to the threatened Florida manatee (Trichechus manatus latirostris). An unusual mortality event (UME) was declared by the Working Group on Marine Mammal Unusual Mortality Events in 2013 after a marked increase in manatee deaths in the IRL of an unknown cause. This UME followed a dramatic reduction of seagrass coverage in the IRL due to chronic non-toxic phytoplankton blooms, with a resultant ecosystem shift to mixed macroalgal dominance. At least 199 manatee deaths fitting the UME case definition were documented in and adjacent to the IRL during 2012–2019; mortality was highest in 2013, when 111 of these deaths were documented. The case definition included carcasses in good nutritional condition, with multiorgan congestion or wet lungs consistent with drowning without trauma. The gastrointestinal compartments of manatee carcasses were filled with diverse macroalga species, and the contents were notably more fluid than usual. Gross intestinal findings included blebbing to segmental thickening of the wall. Microscopic lesions were primarily intestinal, including necrosis, edema, hemorrhage, mucosa-associated lymphoid changes, and inflammation, sometimes associated with Gram-positive bacterial rods. A multidisciplinary approach of environmental and carcass sampling found no causative evidence through tests for micro- and macroalgal biotoxins, trace metals, general toxin screening, or vitreum biochemistry. Microbiological, cytological, immunohistochemical, and molecular analyses of Clostridiales from intestinal samples identified Clostridioides difficile toxin A, toxins A/B and toxin A gene; Paeniclostridium sordellii lethal gene (and other potential virulence factors from a sequenced strain); and Clostridium perfringens alpha and epsilon toxin genes. The results from this 8 year-long investigation are indicative that the cause of death in this manatee UME was associated with clostridial infection, initiated by a shift to a predominantly macroalgal diet.

Per‐ and polyfluoroalkyl substances (PFAS) are environmental contaminants linked to adverse health effects in humans and wildlife. Marine mammals, particularly manatees, have shown potential as sentinels for evaluating the presence and effects of anthropogenic chemicals. However, traditional blood collection techniques with marine mammals can be challenging, highlighting the need for improved strategies. In the present study, four different methods for the extraction of PFAS from dried blood spots were evaluated. Environ Toxicol Chem 2021;40:2726–2732. © 2021 SETAC [ABSTRACT FROM AUTHOR]

• Sirenian reproductive hormone fluctuations are related to seasonal environmental changes. • Measuring progesterone alone is not sufficient for pregnancy determination in manatees. • There is a paucity of reproductive endocrinology data for Antillean manatees and African manatees. • A full characterization of Sirenian gonadotropin cyclicity and acyclicity is needed. Reproductive hormones are essential to mating systems, behavior, fertility, gestation, parturition, and lactation in mammals and understanding the role of hormones in these processes is essential for species conservation. Sirenia is a unique order of marine mammals that include manatees, dugongs, and the extinct Steller's sea cow. Extant Sirenian species are all listed as vulnerable due to habitat loss, cold stress, boat strike trauma, harmful algal bloom toxicity, entanglements, and illegal hunting. Therefore, successful reproduction is essential to maintaining and increasing Sirenian populations. Understanding Sirenian reproductive behavior, endocrinology, and mating strategies will aid conservation and management efforts to protect and provide the proper conditions for successful reproduction. The objectives of this review were to synthesize the current knowledge regarding reproductive cycles and endocrinology of Sirenians and identify knowledge gaps for future investigation. The current literature on Sirenian reproductive physiology reports reproductive seasonality, sexual maturation, estrous cyclicity and acyclicity, pregnancy, and sex differences. However, there remain significant knowledge gaps on the cyclicity and pulsatile release of gonadotropins, maturation in females, and characterization of pregnancy hormone profiles throughout gestation. To date, there is no explanation for confirmed pattern for ovarian acyclicity, nor understanding of the function of the numerous accessory corpus luteum described in manatees. Research including a greater number of longitudinal and postmortem studies on a wider variety of wild manatee populations are important first steps. Taken together, understanding the reproductive endocrinology of these vulnerable and threatened species is critical for policy and management decisions to better inform protection initiatives. [ABSTRACT FROM AUTHOR]

Abstract Morphophysiological species researches are fundamental, and diagnostic imaging is an excellent technique, already used in wild animals, with great application, not invasive and provide real-time information of each body. Amazonian manatees are on the list of endangered animals classified in the vulnerable category and knowledge of the normal pattern of ultrasound anatomy of organs and tissues is important for the maintenance and well-being of captive specimens contributing to reintroduction actions. The objective of the study was to standardize the examination technique and describe the ultrasound findings of the liver, gallbladder, stomach, urinary bladder and the subcutaneous tissue of the abdominal region in Trichechus inunguis, in order to contribute with the anatomical and sonographic knowledge and assist in the diagnosis and prognosis diseases. The study used 18 animals to describe the normal sonographic anatomy in the abdominal cavity of the Amazonian manatee. During abdominal scan, it was possible to visualize the features of the liver, gallbladder, stomach, urinary bladder obtained satisfactory results in this study. Therefore, other structures were not primarily identified by the reduced time, lots of fat and gases in intestines of animals.

Age estimation is useful for understanding population parameters and, in many vertebrates, relies on the principle that growth layer groups (GLGs) are deposited annually in specific tissues. In Florida manatees (Trichechus manatus latirostris), GLGs in earbones are used to estimate age at death. Opportunities to validate the rate of GLG deposition in earbones from manatees >15 years old are rare, yet important for ensuring accurate age estimation across the species' lifespan. Tetracycline injection is a useful method for validating GLG interpretations, particularly when the exact age of an animal is unknown. Since 1997, we collected earbones from 10 manatees that were ≥13–69 years old at death and had been injected with tetracycline 9–37 years before death. The number of years since injection (YSI) was estimated by photographing earbone cross‐sections under ultraviolet light, measuring the distance between the fluorescent tetracycline mark and earbone edge, processing the earbones to visualize GLGs, superimposing the distance to evaluate the marks' locations relative to GLGs, and counting the GLGs between the mark and earbone edge. Seven earbones had tetracycline marks, although 2 of the marks were dull or discontinuous. On average, estimated YSI was 5.6 (SD = 7.5) years less than the known YSI; however, the error was nearly always ≤2 years for manatees that had been injected <20 years before death, consistent with an annual rate of GLG deposition at younger ages. Resorption (i.e., bone turnover) that obliterated GLGs was likely why YSI was underestimated in old manatees with longer post‐injection intervals, although we cannot exclude the possibility that GLG deposition rate may slow in old age. We discuss how age, extrinsic stressors, life history events, and laboratory processing may affect tetracycline visibility, earbone growth, and GLG interpretation. Our study reinforces the challenges with accurately estimating the age of old individuals in long‐lived mammalian species. © 2021 The Wildlife Society. : We evaluated tetracycline marks in earbones from older Florida manatees (≥13–69 years old) that had been injected with tetracycline 9–37 years before death. Results for younger manatees support an annual deposition rate of growth layer groups, but we discuss variables (e.g., bone resorption, timing of injection, dose of injection, and extrinsic stressors) that could influence bone growth dynamics and the success of tetracycline marking for validating age estimates in older manatees. [ABSTRACT FROM AUTHOR]

Limited information is available regarding male reproductive physiology in West Indian manatees (Trichechus manatus). Currently, only basic ultrastructural and morphometric descriptions of the spermatozoon exist; however, there are no reports evaluating any seminal characteristics in this species. Therefore, the aim of the study was to fill current gaps in knowledge regarding semen parameters in West Indian manatees by collecting and characterizing multiple ejaculate samples from a single, adult West Indian manatee. Samples were analyzed for the following semen parameters: volume, agglutination, pH, osmolality, viscosity, concentration, total sperm number, motility and kinematic parameters, morphology, plasma membrane integrity, acrosome integrity, chromatin maturation, and chromatin condensation. All macroscopic semen parameters varied to some extent between samples. Total and progressive motility was high for ejaculates 2 to 5, exceeding 97 and 89%, respectively; however, these parameters decreased dramatically throughout ejaculates 6 and 7. Across all samples, curvilinear velocity, straight-line velocity, and average pathway velocity represented the largest significant differences (p < 0.001) between each of the progression velocity subgroups (rapid, medium, slow). Sperm characteristics, including acrosome integrity (79.8%), chromatin condensation (93.1%), and chromatin maturation (99.5%) were very high; however, high numbers of morphologically abnormal sperm were present (52.9%) and plasma membrane integrity was low (45.1%). These results are the first of their kind for this species and suggest high semen quality, based on multiple ejaculates, in this male West Indian manatee.

Research with captive manatees initiated as part of a New College of Florida class project at MoteMarine Laboratory has yielded a wide range of research with substantive implications formanagement and conservation. Our training program directly supported investigations of bloodchemistry, immune function, stress-related physiology, respiration, thermoregulation, and behavioralecology. Our investigations of sensory processes included studies of visual acuity, color vision,passive and active touch, auditory frequency detection thresholds, auditory temporal processing rates,hearing in noise, and sound localization. Undergraduate and graduate students involved in thisprogram have been successfully mentored in sensory processes, animal behavior, and conservation.Further validation of the educational benefits of studying captive manatees awaits formal research onattitude, behavior change, and public policy related to protecting manatees and other marinemammals in natural settings.

By the mid-eighteenth century, a distinctive maritime commerce in turtle and manatee products existed in the Caribbean. It was especially prevalent amongst English-speaking inhabitants, from the Cayman Islands and Jamaica to the outposts of Costa Rica, Nicaragua and the Colombian islands. Consumption patterns led to a variety of encounters between indigenous Indians, Europeans, Africans and Creoles. Commerce in these natural resources, especially turtles, grew steadily, creating prodigious consumer demands for medical uses, culinary and fashion trends in Europe and the North America by the late-nineteenth century. This study intertwines themes of environmental history, maritime cultural encounters, fisheries and food history. Topics such as indigenous hunting techniques, processing, transportation, marketization, utilitarian and luxury consumerism and evolution of social attitudes towards natural resources are addressed. It is based on contemporary sources and covers various aspects of the supply and utilization of these marine animals over the longue durée. [ABSTRACT FROM AUTHOR]

The Florida manatee, Trichechus manatus latirostris, is a fully aquatic, threatened marine mammal for which increased understanding of their physiology, reproduction, and nutrition supports management decisions. Manatees may use taste to distinguish saltwater gradients, toxin detection, food assessment, and social interactions. This study sought to locate and characterize manatee taste buds comparing location, structure, number, and size to other species. Entire heads from manatees (6 males, 4 females) of various ages were obtained. The muzzle, tissue surrounding the nares, oral cavity, and epiglottis were examined grossly for pits and papillae. Tissues were examined using light and transmission electron microscopy. Within the predominant taste bud location, the tongue root, taste bud number was estimated using samples from four animals. The average number of taste buds within the tongue root was 11,534 (range 2,711–23,237) with sparse taste buds located on the soft palate and epiglottis. The location along the lateral surface of the tongue root and bordered by grooves, through which tastants could be easily transported, has functional significance. Large numbers of taste buds within the tongue root suggest that taste is an important component of manatee sensory systems and behavioral research would clarify this. [ABSTRACT FROM AUTHOR]

As a fully aquatic mammal, the Florida manatee (Trichechus manatus latirostris) spends a limited amount of time at the water's surface. However, as a mammal that breathes air, they do need to filter, warm, and humidify that air, and anecdotal evidence indicates manatees have a sense of smell. This study characterized the nasal turbinate system, including identification of the olfactory epithelium, and compared it to other mammals using a combination of gross and micro-anatomic examination. Major turbinates were present, including nasal, maxillary, and ethmoturbinates, but with minimal convolution. The respiratory epithelium was found throughout much of the nasal cavity and covered maxillary and nasal turbinates, as well as the septum. Mucus-producing cells and cavernous veins were extensive. The olfactory epithelium was found in the dorsocaudal ethmoturbinates. As a herbivore that feeds predominantly underwater, the manatee likely relies on taste and touch for assessing food and, therefore, does not need to use smell in the same way as other marine mammals such as mysticetes (Bouchard et al., 2019) and pinnipeds (Kowalewsky et al., 2006). However, there are still substantial numbers of olfactory cells, especially considering the decreased amount of exposure time to odorants when breathing at the surface. Therefore, the question remains of why manatees have maintained their ability to smell while other fully aquatic species such as odontocetes have not. Future research should focus on a combination of behavioral and molecular techniques to fully understand the olfactory capabilities of the Florida manatee. [ABSTRACT FROM AUTHOR]

Streptococcus bovis bacteremia (currently called S. gallolyticus) represents an infrequent condition, but associated with a high rate of morbidity and mortality Amado et al. (2015). The clinical presentation is characterized by symptoms associated with disseminated infection and with a higher frequency of endocarditis and gastrointestinal neoplasms, often occult Amado et al. (2015), Olmos et al. (2016). Probable sources of infection and zoonotic transmission have not been explored in the literature. We present a case of disseminated infection after ingestion of a marine mammal.

The Florida manatee (Trichechus manatus latirostris Linnaeus 1758) actively selects and consumes the “chicken-liver” sponge Chondrilla caribensis. Manatees ate over 10% of C. caribensis on a sample dock, mostly from pylons that received no direct sunlight. Since manatees reportedly eat mostly seagrasses and algae, it was thought that the chlorophyll-a content of the symbiotic cyanobacteria in C. caribensis might be correlated to the amount eaten; however the correlation was not significant (P > 0.05). C. caribensis has variable chemical defenses and round spherasters (spicules), but these do not appear to be effective deterrents to predation by manatees. This is the first direct evidence that manatees actively seek out and consume a sponge.

Sirenians share with cetaceans and pinnipeds several convergent traits selected for the aquatic lifestyle. Living in water poses new challenges not only for locomotion and feeding but also for combating new pathogens, which may render the immune system one of the best tools aquatic mammals have for dealing with aquatic microbial threats. So far, only cetaceans have had their class II Major Histocompatibility Complex (MHC) organization characterized, despite the importance of MHC genes for adaptive immune responses. This study aims to characterize the organization of the marine mammal class II MHC using publicly available genomes. We located class II sequences in the genomes of one sirenian, four pinnipeds and eight cetaceans using NCBI-BLAST and reannotated the sequences using local BLAST search with exon and intron libraries. Scaffolds containing class II sequences were compared using dotplot analysis and introns were used for phylogenetic analysis. The manatee class II region shares overall synteny with other mammals, however most DR loci were translocated from the canonical location, past the extended class II region. Detailed analysis of the genomes of closely related taxa revealed that this presumed translocation is shared with all other living afrotherians. Other presumptive chromosome rearrangements in Afrotheria are the deletion of DQ loci in Afrosoricida and deletion of DP in E. telfairi. Pinnipeds share the main features of dog MHC: lack of a functional pair of DPA/DPB genes and inverted DRB locus between DQ and DO subregions. All cetaceans share the Cetartiodactyla inversion separating class II genes into two subregions: class IIa, with DR and DQ genes, and class IIb, with non-classic genes and a DRB pseudogene. These results point to three distinct and unheralded class II MHC structures in marine mammals: one canonical organization but lacking DP genes in pinnipeds; one bearing an inversion separating IIa and IIb subregions lacking DP genes found in cetaceans; and one with a translocation separating the most diverse class II gene from the MHC found in afrotherians and presumptive functional DR, DQ, and DP genes. Future functional research will reveal how these aquatic mammals cope with pathogen pressures with these divergent MHC organizations.

Cold-stress syndrome (CSS) is one of the leading natural threats to free-ranging Florida manatees (Trichechus manatus latirostris). Cold water exposure below the species' acceptable physiologic range is a frequent occurrence for manatees during cold weather months causing CSS-induced systemic illness and significant annual mortality. Although CSS is a commonly presented condition at manatee rehabilitation facilities, the core body temperatures in CSS manatees are currently unknown due to the lack of clinically applicable and accurate temperature measurement methodologies. Our objective was to establish a clinically applicable measurement methodology of core body temperature in manatees. A novel, minimally invasive temperature technique to obtain esophageal temperature by placing a temperature sensor through an oro-gastric tube was compared to current oral and nasal methods in 20 clinically healthy manatees. Results identified the esophageal measurement as the best performing and most precise temperature methodology. The superior performance of esophageal temperature measurements differed significantly from both nasal and oral measurements, while nasal and oral measurements did not differ when compared with each other. The esophageal measurements were consistent with manatee core body temperature, facilitating generation of a reference interval for core body temperature in healthy manatees (35.0–35.8 C). Four CSS medical cases were evaluated with the newly validated esophageal temperature method, facilitating diagnosis of hypothermia. The application of this temperature measurement technique to CSS manatees in field or rehabilitation settings will help in understanding CSS pathophysiology, improve medical assessments during rehabilitation, and contribute to conservation efforts. [ABSTRACT FROM AUTHOR]

The Florida manatee (Trichechus manatus latirostris Linnaeus 1758) actively selects and consumes the "chicken-liver" sponge Chondrilla caribensis. Manatees ate over 10% of C. caribensis on a sample dock, mostly from pylons that received no direct sunlight. Since manatees reportedly eat mostly seagrasses and algae, it was thought that the chlorophyll-a content of the symbiotic cyanobacteria in C. caribensis might be correlated to the amount eaten; however the correlation was not significant (P >0:05). C. caribensis has variable chemical defenses and round spherasters (spicules), but these do not appear to be effective deterrents to predation by manatees. This is the first direct evidence that manatees actively seek out and consume a sponge. [ABSTRACT FROM AUTHOR]

Ages of Florida manatees (Trichechus manatus latirostris) can be estimated by counting annual growth layer groups (GLGs) in the periotic dome portion of the tympanoperiotic complex of their earbones. The Florida Fish and Wildlife Conservation Commission manages an archive of more than 8,700 Florida manatee earbones collected from salvaged carcasses from 1989 to 2017. Our goal was to comprehensively evaluate techniques used to estimate age, given this large sample size and changes to processing protocols and earbone readers over time. We developed new standards for estimating ages from earbones, involving two independent readers to obtain measurements of within- and between-reader precision. To quantify accuracy, precision, and error, 111 earbones from manatees with approximately known ages (first known as calves: "KAC") and 69 earbones from manatees with minimum known ages ("MKA," based on photo-identification sighting histories) were processed, and their ages were estimated. There was greater precision within readers (coefficient of variation, CV : 2.4–8.5%) than between readers (CV : 13.1–13.3%). The median of age estimates fell within the true age range for 63.1% of KAC cases and was at least the sighting duration for 75.0% of MKA cases. Age estimates were generally unbiased, as indicated by an average raw error ± SD of −0.05 ± 3.05 years for the KAC group. The absolute error (i.e. absolute value of raw error) of the KAC data set averaged 1.75 ± 2.50 years. Accuracy decreased and error increased with increasing known age, especially for animals over 15 years old, whose ages were mostly underestimated due to increasing levels of resorption (the process of bone turnover that obscures GLGs). Understanding the degree of uncertainty in age estimates will help us assess the utility of age data in manatee population models. We emphasize the importance of standardizing and routinely reviewing age estimation and processing protocols to ensure that age data remain consistent and reliable. [ABSTRACT FROM AUTHOR]

Herbivorous animals have unique intestinal microbiota that greatly helps with plant digestion in the host; however, knowledge on the microbiota of marine herbivores is limited. To better understand the taxonomy of intestinal microbiota in manatees, and the possible effects of captive conditions on that, we characterized the fecal microbiota of captive Antillean manatee Trichechus manatus manatus and compared the bacterial community with that of wild Florida manatees Trichechus manatus latirostris. Fecal samples were collected from four captive Antillean manatees in Ocean Expo Park, Okinawa, Japan. The high-quality sequences of the V3–V4 region of bacterial 16S rRNA obtained using an Illumina MiSeq platform were assigned to 16 bacterial phyla, and the most dominant was Firmicutes (84.05 ± 3.50%), followed by Bacteroidetes (8.60 ± 1.71%). Seven of the top 20 bacterial genera were responsible for hydrolyzing cellulose and metabolizing bile acid. The microbiota composition was remarkably different from that found in wild Florida manatees and more diverse than the composition in wild Florida manatees; hence, this result may be dependent on a captive environment. Our results highlight the unique intestinal microbiota in captive manatees, reflecting their diet and possibly an impact of the captive environment. [ABSTRACT FROM AUTHOR]

Sirenians share with cetaceans and pinnipeds several convergent traits selected for the aquatic lifestyle. Living in water poses new challenges not only for locomotion and feeding but also for combating new pathogens, which may render the immune system one of the best tools aquatic mammals have for dealing with aquatic microbial threats. So far, only cetaceans have had their class II Major Histocompatibility Complex (MHC) organization characterized, despite the importance of MHC genes for adaptive immune responses. This study aims to characterize the organization of the marine mammal class II MHC using publicly available genomes. We located class II sequences in the genomes of one sirenian, four pinnipeds and eight cetaceans using NCBI-BLAST and reannotated the sequences using local BLAST search with exon and intron libraries. Scaffolds containing class II sequences were compared using dotplot analysis and introns were used for phylogenetic analysis. The manatee class II region shares overall synteny with other mammals, however most DR loci were translocated from the canonical location, past the extended class II region. Detailed analysis of the genomes of closely related taxa revealed that this presumed translocation is shared with all other living afrotherians. Other presumptive chromosome rearrangements in Afrotheria are the deletion of DQ loci in Afrosoricida and deletion of DP in E. telfairi. Pinnipeds share the main features of dog MHC: lack of a functional pair of DPA/DPB genes and inverted DRB locus between DQ and DO subregions. All cetaceans share the Cetartiodactyla inversion separating class II genes into two subregions: class IIa, with DR and DQ genes, and class IIb, with non-classic genes and a DRB pseudogene. These results point to three distinct and unheralded class II MHC structures in marine mammals: one canonical organization but lacking DP genes in pinnipeds; one bearing an inversion separating IIa and IIb subregions lacking DP genes found in cetaceans; and one with a translocation separating the most diverse class II gene from the MHC found in afrotherians and presumptive functional DR, DQ , and DP genes. Future functional research will reveal how these aquatic mammals cope with pathogen pressures with these divergent MHC organizations. [ABSTRACT FROM AUTHOR]

Unmanned aerial systems (UASs) are powerful tools for research and monitoring of wildlife. However, the effects of these systems on most marine mammals are largely unknown, preventing the establishment of guidelines that will minimize animal disturbance. In this study, we evaluated the behavioral responses of coastal bottlenose dolphins (Tursiops truncatus) and Antillean manatees (Trichechus manatus manatus) to small multi-rotor UAS flight. From 2015 to 2017, we piloted 211 flights using DJI quadcopters (Phantom II Vision +, 3 Professional and 4) to approach and follow animals over shallow-water habitats in Belize. The quadcopters were equipped with high-resolution cameras to observe dolphins during 138 of these flights, and manatees during 73 flights. Aerial video observations of animal behavior were coded and paired with flight data to determine whether animal activity and/or the UAS's flight patterns caused behavioral changes in exposed animals. Dolphins responded to UAS flight at altitudes of 11–30 m and responded primarily when they were alone or in small groups. Single dolphins and one pair responded to the UAS by orienting upward and turning toward the aircraft to observe it, before quickly returning to their pre-response activity. A higher number of manatees responded to the UAS, exhibiting strong disturbance in response to the aircraft from 6 to 104 m. Manatees changed their behavior by fleeing the area and sometimes this elicited the same response in nearby animals. If pursued post-response, manatees repeatedly responded to overhead flight by evading the aircraft's path. These findings suggest that the invasiveness of UAS varies across individuals, species, and taxa. We conclude that careful exploratory research is needed to determine the impact of multi-rotor UAS flight on diverse species, and to develop best practices aimed at reducing the disturbance to wildlife that may result from their use.

The Antillean manatee (Trichechus manatus manatus) is an endangered marine mammal that inhabits the Caribbean Sea and riverine systems in Central America. Their acoustic behavior is relevant for individual identification, mating and parental care. Manatees produce tonal sounds with highest energy in the second harmonic (usually 5 kHz), and their audiogram indicates sensitivity from 0.3 kHz to 90 kHz with lowest thresholds in the 16 to 18 kHz range. We recorded manatees in the San San River, a highly polluted riverine system in Panama, using a stereo array. Frequency transmission experiments were conducted in four subhabitats, categorized using riverine vegetation. Incidental interactions of manatees and small motorboats were examined. Acoustic transmission was linearly related to tonal vocalization characters: correlations were stronger in freshwater than in transition and marine environments. Two bands, 0.6 to 2 kHz and 3 to 8 kHz, attenuate similarly in all subhabitats, and these bands encompass F0 (tone) and peak frequency respectively of manatee tonal calls. Based on our data we conclude that frequency transmission depends mainly on river depth and bottom characteristics, also motorboat sounds mask signals from 3.5 kHz to 8 kHz, which overlaps the peak frequency of tonal calls. In spite of differences between acoustic transmission in subhabitats of the San San River, manatees utilize bands that transmit efficiently in all subhabitats.

A major goal of this study was to determine whether serum protein fractions of healthy Florida manatees differ with age, sex, or living environments (wild versus housed). A second goal was to determine which serum protein fractions vary in diseased versus healthy manatees. Serum protein fractions were determined using agarose gel electrophoresis. Healthy adults had slightly higher total serum protein and total globulin concentrations than younger animals. This largely resulted from an increase in gamma globulins with age. Total serum protein, albumin, alpha-1 globulin, beta globulin, and total globulin concentrations were slightly higher in housed manatees compared to wild manatees, but there was no significant difference in the albumin/globulin (A/G) ratio, suggesting a difference in hydration between these groups. No significant differences were attributable to sex or pregnancy. Serum albumin concentrations and A/G ratios were significantly lower for manatees with boat trauma, entanglements, emaciation, or cold stress compared to healthy manatees. Variable increases were seen in alpha-1globulins, alpha-2 globulins, beta globulins, and gamma globulins. These globulin fractions contain positive acute-phase proteins and immunoglobulins, and their increases may reflect acute or chronic active inflammation. Changes in serum protein fractions were not consistent enough to justify the use of serum protein electrophoresis as a routine diagnostic test for manatees. However, serum (or plasma) protein electrophoresis is required when accurate values for albumin and globulins are needed in manatees and in determining which protein fractions may account for a hyperproteinemia or hypoproteinemia reported in a clinical chemistry panel. [ABSTRACT FROM AUTHOR]

The long‐term viability of the Florida manatee is threatened in part by mortality from boat collisions. This study investigated manatee behavior during boat approaches to better understand factors that lead to manatee–boat collisions. Digital acoustic recording tags (DTAGs) and Argos‐linked GPS tags were deployed on 18 manatees in southwest Florida, and boat traffic around them was mapped. Suites of manatee behavioral, environmental, and boat‐related factors were recorded during opportunistic boat passes. We built generalized linear mixed models to determine which factors accounted for variation in occurrence, number, and timing of manatee behavioral changes during boat passes. Manatees responded to boats, changing their orientation, depth, and fluking behavior most often when a boat approached closely (<10 m). Manatees were also more likely to change their depth when not on a seagrass bed and when actively fluking before a boat pass. Boat speed did not affect the occurrence or intensity of manatee response. Compared to fast approaches, however, slower passes allowed the manatee more time to respond, and behavioral change occurred earlier relative to the time of the boat's closest point of approach. We conclude that faster boats likely pose a greater risk of collision with manatees than do slower boats. [ABSTRACT FROM AUTHOR]

The Florida manatee ( Trichechus manatus latirostris ) has limited diversity in the immunoglobulin heavy chain. We therefore investigated the antigen receptor loci of the other arm of the adaptive immune system: the T cell receptor. Manatees are the first species from Afrotheria, a basal eutherian superorder, to have an in-depth characterization of all T cell receptor loci. By annotating the genome and expressed transcripts, we found that each chain has distinct features that correlates to their individual functions. The genomic organization also plays a role in modulating sequence conservation between species. There were extensive V subgroup synteny blocks in the TRA and TRB loci between T. m. latirostris and human. Increased genomic locus complexity correlated to increased locus synteny. We also identified evidence for a VHD pseudogene for the first time in a eutherian mammal. These findings emphasize the value of including species within this basal eutherian radiation in comparative studies. [ABSTRACT FROM AUTHOR]

The Antillean manatee Trichechus manatus manatus is a cryptic mammal that inhabits, among other areas, murky rivers and estuaries of Central and South America. The difficulty in detecting and counting manatees is an obstacle to monitoring their population status, as traditional count sampling is unsuitable. We conducted a quantitative analysis of the distribution and abundance of the manatee across its known range in the rivers and estuaries of French Guiana, based on data from a range-wide line transect visual survey combined with a side-scan sonar survey, identification of feeding sites, and silent observations at fixed points. A total effective effort of 248 hours and 1,129 km of boat survey was completed. We used two relative abundance indices: the combined encounter rate, which combines encounters per km from either visual or side-scan sonar surveys, and the global detection index, which is defined as the sum of all evidence per unit time. Manatees were detected in all nine study units. Niche modelling was used to analyse the space selection by manatees, and helped to detect differential use of habitats according to the season. The model predicted that coastal areas are used more extensively during the dry season. In the absence of better techniques to detect wild manatees in complex habitats this monitoring protocol may be relevant and replicable in hydrological systems where manatee detectability is constrained by biogeographical characteristics. [ABSTRACT FROM PUBLISHER]

Cytokines have important roles in the mammalian response to viral and bacterial infections, trauma, and wound healing. Because of early cytokine production after physiologic stresses, the regulation of messenger RNA (mRNA) transcripts can be used to assess immunologic responses before changes in protein production. To detect and assess early immune changes in endangered Florida manatees ( Trichechus manatus latirostris), we developed and validated a panel of quantitative PCR assays to measure mRNA transcription levels for the cytokines interferon (IFN)-γ; interleukin (IL)-2, -6, and -10; tumor necrosis factor-α; and the housekeeping genes glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and β-actin (reference genes). Assays were successfully validated using blood samples from free-ranging, apparently healthy manatees from the east and west coasts of central Florida, US. No cytokine or housekeeping gene transcription levels were significantly different among age classes or sexes. However, the transcription levels for GAPDH, IL-2, IL-6, and IFN-γ were significantly higher ( P<0.05) in manatees from the east coast of Florida than they were from those from the west coast. We found IL-10 and β-actin to be consistent between sites and identified β-actin as a good candidate for use as a reference gene in future studies. Our assays can aid in the investigation of manatee immune response to physical trauma and novel or ongoing environmental stressors. [ABSTRACT FROM AUTHOR]

Manatees are a vulnerable, charismatic sentinel species from the evolutionarily divergent Afrotheria. Manatee health and resistance to infectious disease is of great concern to conservation groups, but little is known about their immune system. To develop manatee-specific tools for monitoring health, we first must have a general knowledge of how the immunoglobulin heavy (IgH) chain locus is organized and transcriptionally expressed. Using the genomic scaffolds of the Florida manatee ( Trichechus manatus latirostris ), we characterized the potential IgH segmental diversity and constant region isotypic diversity and performed the first Afrotherian repertoire analysis. The Florida manatee has low V(D)J combinatorial diversity (3744 potential combinations) and few constant region isotypes. They also lack clan III V segments, which may have caused reduced VH segment numbers. However, we found productive somatic hypermutation concentrated in the complementarity determining regions. In conclusion, manatees have limited IGHV clan and combinatorial diversity. This suggests that clan III V segments are essential for maintaining IgH locus diversity. [ABSTRACT FROM AUTHOR]

Bone artifacts are uncommon in Cuban archaeology, even though bone was a basic material used by the natives. The region of Banes, Holguin province in western Cuba, is characterized for its abundance in sites of agroceramist filiation, represented by 55 %, which in turn has made it historically attractable to collections and researchers for the richness and diversity of material evidence. This work provides new data to the understanding of bone artifacts discovered in the region of Banes, which are now dispersed in national and international collections. Presently, 68 artifacts are registered, of which the majority (38 %) are ceremonial relics. The ribs of the manatee (Trichechus manatus) appeared as a common material for the making of these ceremonial artifacts. With them were made vomic spatulas, portable figures, containers, and pendants. This research provides a fresh understanding of the regional and national archaeology, especially concerned with the use and origin of bone artifacts. [ABSTRACT FROM AUTHOR]