Histological characterization of reproductive tract and fetal annexes of the West Indian Manatee (Trichechus manatus) from Brazil

Bezerra, A. R. A.; Salmito‐Vanderley, Carminda Sandra Brito; Bersano, Paulo R. O.; Carvalho, Vítor Luz; Meirelles, Ana Carolina Oliveira de; Attademo, Fernanda Löffler Niemeyer; Luna, Fábia de Oliveira; Silva, Lúcia D.M.

doi:10.1590/1678-5150-pvb-5707

Cited by 3 publications

(2 citation statements)

References 12 publications

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“…Previous studies on reproduction in male West Indian manatees are limited to basic ultrastructural and morphometric descriptions of the spermatozoa (13), seasonal and developmental changes in spermatogenesis (14), size of the testes and seminal vesicles in relation to sperm competition (15), limited hormonal monitoring (16,17), and most recently gross anatomical and histological descriptions of the reproductive tract (18,19). While these studies provide valuable information, many gaps still remain and no information on semen parameters is available for this, or any other sirenian species.…”

Section: Introductionmentioning

confidence: 99%

Manual Collection and Semen Characterization in a West Indian Manatee (Trichechus manatus)

et al. 2020

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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.

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Section: Introductionmentioning

confidence: 99%

Manual Collection and Semen Characterization in a West Indian Manatee (Trichechus manatus)

et al. 2020

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“…Para isso o estudo das doenças dos peixes-bois é importante para evitar a disseminação de patógenos dos animais de cativeiro aos animais em vida livre. Desta forma, as estratégias para minimizar as ameaças aos peixes-bois tornam-se essenciais para a garantia da biodiversidade do peixe-boi [13,48].…”

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Infectious and Non-Infectious Diseases in Manatees in Brazil

Attademo

Oliveira

Sousa

et al. 2020

Acta Scientiae. Vet.

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Background: Antillean manatee (Trichechus manatus) and Amazonian manatee (Trichechus inunguis) are the two species of manatees that occur in Brazil, and both are endangered. Studies on manatee disease in Brazil were previously based mainly on Florida manatees. In recent years, these studies have increased in Brazil. Thus, the objective was to carry out a survey of the publications of infectious and non-infectious diseases in the two species of manatees that occur in the country, to assist in the identification of threats to the species and in the health assessment of manatees in the country.Review: Regarding infectious and contagious diseases, parasites have affected both species of manatees in Brazil, such as Pulmonicola cochleotrema in wild T. manatus, Toxoplasma gondii in both species, and Cryptosporidium spp. also in both species, this being an important agent of zoonotic character. Giardia sp., another zoonotic parasite, has also been reported in both species of manatees in Brazil. Mycotic lesions caused by B. hawaiiensis have been described in calves of T. manatus in captivity. Meanwhile, Candida sp., Trichosporon sp., Rhodotorula sp., and Cryptococcus sp. have been identified in T. inunguis. Studies on viruses in manatees are still not widespread compared to other species; however, it has been verified that rotavirus is present in T. manatus in captivity. In studies carried out to identify bacteria in T. manatus, the following bacteria were isolated: Arizona sp., Bacillus sp., Corynebacterium equi, Corynebacterium pseudodiphteriticum, Corinebacterium sp., Edwasiella tarda, Enterobacter aerogenes, Enterobacter agglomerans, Enterobacter sakasakii, Escherichia coli, Leptospira spp., Proteus sp., Proteus vulgaris, Providencia rettgeri, Pseudomonas aeruginosa, Salmonella spp., Serratia marcescens, Staphylococcus sp., Staphylococcus aureus, Staphylococcus coagulase-negativa, Stenotrophomonas maltophilia, Streptococcus sp., and Streptococcus viridans. Regarding noninfectious diseases, food-related diseases stand out, where gastrointestinal complications in manatees and obesity in animals in captivity are among the highest occurrences. Intestinal tympanism was reported in a T. inunguis calf, causing death of the animal. Pollution and contamination have also been a concern for the health of these animals. In studies carried out with T. manatus in Paraíba state, accumulation of heavy metals in the animals was verified, possibly originating from sugarcane farms in the region. The ingestion of garbage has also been one of the greatest threats to the health of manatees, where it was registered as a possible cause of death of T. inunguis in Amazonas state. Regarding congenital diseases, although rare in manatees, two calves of T. manatus in Ceará state have been described as having congenital malformations in the heart and brain, without a well-defined etiology. Trauma has been affecting both species; in Brazil, 17.3% of manatees reintroduced by 2018 showed evidence of collisions with vessels. Hunting for T. inunguis still occurs frequently, which has been greatly reduced for T. manatus.Conclusion: Pathogens and other factors that affect manatees have a potential impact on both species. Some of the identified agents have a zoonotic potential and, therefore, are also public health issues. This survey demonstrates that the need for incentives for studies on health assessment and pathogens in these species, both in the wild and in captivity, should be encouraged.

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Reproductive Science Methods for Wild, Fully-Marine Mammals: Current Approaches and Future Applications

Lanyon

Burgess

2019

Reproductive Sciences in Animal Conservation

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Histological characterization of reproductive tract and fetal annexes of the West Indian Manatee (Trichechus manatus) from Brazil

Cited by 3 publications

References 12 publications

Manual Collection and Semen Characterization in a West Indian Manatee (Trichechus manatus)

Manual Collection and Semen Characterization in a West Indian Manatee (Trichechus manatus)

Infectious and Non-Infectious Diseases in Manatees in Brazil

Reproductive Science Methods for Wild, Fully-Marine Mammals: Current Approaches and Future Applications

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