D. Vega, K. Van Waerebeek, Joanna Alfaro-Shigueto, Julio C. Reyes, M. Van Bressem
The morphology and maturation process of gonads of 70 Burmeister’s porpoises Phocoena spinipinnis, with body lengths ranging 135 - 183 cm (n = 34 females) and 64.5 - 182 cm (n = 36 males) are described. Samples were collected in six ports of central and northern Peru from 1987 to 1999. In the field, sexual maturity was determined through macroscopic examination of gonads. Ovarian corpora indicated mature females (resting, lactating, pregnant). Semen in epididymides was considered evidence for mature males. The ovaries of Burmeister’s porpoises are ovoid or bean-shaped and flattened, with corpora modifying surface appearance. In the laboratory, ovaries were examined macro- and microscopically, measured, weighed and sliced. The number of corpora ovarica (lutea, albicantia, atretica) and their morphology were documented. The follicles, oocytes, and nuclei were measured. Follicular development was predominantly left-sided, but occurred in both ovaries in 16.3% of females, mainly in those with numerous corpora. Macroscopically, several corpora atretica with luteinization had characteristics similar to those of corpora albicantia, making microscopic determination essential. Inconclusive evidence of recent ovulation was reported for January. Two of three immature females showed good follicular development in March and April. The testes of Burmeister’s porpoise are elongated and cylindrical. Of 36 males examined macroscopically, seven were immature, five pubescent and 24 mature. The histological analysis allowed to confidently determine sexual maturity status. Field evaluation of maturity based on the presence of sperm in the epididymides is a useful but in 8.3% of cases not an exact method. No histological evidence of male reproductive seasonality was found. Spermatogenesis was perceptible year-round and tubule diameters showed stochastic monthly variations. The body length at 50% sexual maturity was estimated at 157 cm and 152.7 cm, for males and females, respectively. There was no evidence of reproductive senescence. This study is the first evaluation of the sexual maturation process in the Burmeister’s porpoise, using both macroscopic observations and elaborate gonads histology. It provides important new information on the natural history of the species, including parameters (e.g., mean body length at maturation, reproductive seasonality) highly relevant to its conservation.
{"title":"Macroscopic and histologic characteristics of sexual maturation in the Burmeister’s porpoise Phocoena spinipinnis from Peru","authors":"D. Vega, K. Van Waerebeek, Joanna Alfaro-Shigueto, Julio C. Reyes, M. Van Bressem","doi":"10.5597/lajam00317","DOIUrl":"https://doi.org/10.5597/lajam00317","url":null,"abstract":"The morphology and maturation process of gonads of 70 Burmeister’s porpoises Phocoena spinipinnis, with body lengths ranging 135 - 183 cm (n = 34 females) and 64.5 - 182 cm (n = 36 males) are described. Samples were collected in six ports of central and northern Peru from 1987 to 1999. In the field, sexual maturity was determined through macroscopic examination of gonads. Ovarian corpora indicated mature females (resting, lactating, pregnant). Semen in epididymides was considered evidence for mature males. The ovaries of Burmeister’s porpoises are ovoid or bean-shaped and flattened, with corpora modifying surface appearance. In the laboratory, ovaries were examined macro- and microscopically, measured, weighed and sliced. The number of corpora ovarica (lutea, albicantia, atretica) and their morphology were documented. The follicles, oocytes, and nuclei were measured. Follicular development was predominantly left-sided, but occurred in both ovaries in 16.3% of females, mainly in those with numerous corpora. Macroscopically, several corpora atretica with luteinization had characteristics similar to those of corpora albicantia, making microscopic determination essential. Inconclusive evidence of recent ovulation was reported for January. Two of three immature females showed good follicular development in March and April.\u0000The testes of Burmeister’s porpoise are elongated and cylindrical. Of 36 males examined macroscopically, seven were immature, five pubescent and 24 mature. The histological analysis allowed to confidently determine sexual maturity status. Field evaluation of maturity based on the presence of sperm in the epididymides is a useful but in 8.3% of cases not an exact method. No histological evidence of male reproductive seasonality was found. Spermatogenesis was perceptible year-round and tubule diameters showed stochastic monthly variations. The body length at 50% sexual maturity was estimated at 157 cm and 152.7 cm, for males and females, respectively. There was no evidence of reproductive senescence.\u0000This study is the first evaluation of the sexual maturation process in the Burmeister’s porpoise, using both macroscopic observations and elaborate gonads histology. It provides important new information on the natural history of the species, including parameters (e.g., mean body length at maturation, reproductive seasonality) highly relevant to its conservation.","PeriodicalId":17967,"journal":{"name":"Latin American Journal of Aquatic Mammals","volume":"50 40","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141384143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Priscilla Cubero-Pardo, César Castro-Azofeifa, Fabricio Quirós Corella, Sebastián Mora Ramírez, Elena Vargas Ramírez, Sebastián Bonilla Sánchez, Christian Vargas-Bolaños
The Antillean manatee is a poorly studied marine mammal in Costa Rica. Its distribution covers the entire Caribbean coast, but sighting reports are scarce. This research was conducted in three protected areas (PA) where the species is primarily observed. The objectives were to determine the density patterns of sightings and grazing spots; to explore the relationship between grazing spots and sightings with geographic and temporal variables, for PA separately; to study the frequency of sightings and grazing spots according to season, month, and period of the day, for PA together; and to determine the pertinence of using a marine ecology application MarEco to register manatee sightings by the public. Data on manatee sightings and grazing spots gathered with the MarEco app, under a citizen science mechanism, were complemented with data obtained by the Tortuguero Conservation Area Administration (TCAA) through other means. The number of sighting records registered through MarEco during nine months was alike to the number of records reported to the TCAA over six years in two of the PA studied. The areas with the highest density of grazing spots and sightings matched with studies conducted 10 to 20 years ago. In two of the PA, sightings were most often associated with the rainy season, while fresh grazing spots were specially counted from 6:00 h to 8:59 h. The results suggest that manatees exhibit high site fidelity in the three PA, that their increased presence during the rainy season is likely due to increased availability of food, and that they perform feeding activity predominantly at night.
{"title":"Antillean manatee (Trichechus manatus manatus) occurrence and grazing spots in three protected areas of Costa Rica","authors":"Priscilla Cubero-Pardo, César Castro-Azofeifa, Fabricio Quirós Corella, Sebastián Mora Ramírez, Elena Vargas Ramírez, Sebastián Bonilla Sánchez, Christian Vargas-Bolaños","doi":"10.5597/lajam00329","DOIUrl":"https://doi.org/10.5597/lajam00329","url":null,"abstract":"The Antillean manatee is a poorly studied marine mammal in Costa Rica. Its distribution covers the entire Caribbean coast, but sighting reports are scarce. This research was conducted in three protected areas (PA) where the species is primarily observed. The objectives were to determine the density patterns of sightings and grazing spots; to explore the relationship between grazing spots and sightings with geographic and temporal variables, for PA separately; to study the frequency of sightings and grazing spots according to season, month, and period of the day, for PA together; and to determine the pertinence of using a marine ecology application MarEco to register manatee sightings by the public. Data on manatee sightings and grazing spots gathered with the MarEco app, under a citizen science mechanism, were complemented with data obtained by the Tortuguero Conservation Area Administration (TCAA) through other means. The number of sighting records registered through MarEco during nine months was alike to the number of records reported to the TCAA over six years in two of the PA studied. The areas with the highest density of grazing spots and sightings matched with studies conducted 10 to 20 years ago. In two of the PA, sightings were most often associated with the rainy season, while fresh grazing spots were specially counted from 6:00 h to 8:59 h. The results suggest that manatees exhibit high site fidelity in the three PA, that their increased presence during the rainy season is likely due to increased availability of food, and that they perform feeding activity predominantly at night.","PeriodicalId":17967,"journal":{"name":"Latin American Journal of Aquatic Mammals","volume":"117 18","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140678281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gloria Katerin Arévalo-González, L. Cabrias-Contreras, Andrea Venturotti N. Carneiro, Jenny Cristina Palencia-Murillo, Cristhian Mejía-Rey, Carlos A. Saavedra-Rodríguez, Rodolfo Sánchez-Ruiz, Bibiana Paola Gómez-Castro, Juan Camilo Restrepo-Llano, Juan Carlos Pérez-Ochoa, James Anker Murillo-Osorio
The aim of this study was to conduct an analysis of reported events concerning Antillean manatee (Trichechus manatus manatus) strandings in the middle Magdalena Basin region of Colombia from January 2011 to December 2023. To achieve this, a literature search was conducted in newspapers, news broadcasts, as well as gray and published reports, complemented by interviews and workshops with various governmental and non-governmental organizations. This search resulted in reliable information regarding past experiences involving stranded manatees over the years. Cases attended to by the environmental authority and its partners were also considered. Forty-four stranding events were recorded, with 34 deaths and 10 live manatees. Of the cases discovered, 79.5% of the reported cases were addressed. This effort highlighted the current lack of an official database that would provide firsthand knowledge of Antillean manatee stranding events in Colombia, thereby hindering timely and appropriate territorial management during response to the challenges faced by this species in the region. Furthermore, it underscores the need to implement a standardized response pathway for manatee cases, following appropriate protocols, and promoting the coordination of stakeholders within the regional stranding network in the middle Magdalena Basin. This approach, in addition to supporting the capacity building of communities, institutions, and organizations for improving response knowledge, conservation, and manatee recovery, is of paramount importance for the long-term sustainability of manatee populations in the region.
{"title":"Stranding reports of the Antillean manatee in the middle Magdalena Basin, Colombia 2011 to 2023","authors":"Gloria Katerin Arévalo-González, L. Cabrias-Contreras, Andrea Venturotti N. Carneiro, Jenny Cristina Palencia-Murillo, Cristhian Mejía-Rey, Carlos A. Saavedra-Rodríguez, Rodolfo Sánchez-Ruiz, Bibiana Paola Gómez-Castro, Juan Camilo Restrepo-Llano, Juan Carlos Pérez-Ochoa, James Anker Murillo-Osorio","doi":"10.5597/lajam00330","DOIUrl":"https://doi.org/10.5597/lajam00330","url":null,"abstract":"The aim of this study was to conduct an analysis of reported events concerning Antillean manatee (Trichechus manatus manatus) strandings in the middle Magdalena Basin region of Colombia from January 2011 to December 2023. To achieve this, a literature search was conducted in newspapers, news broadcasts, as well as gray and published reports, complemented by interviews and workshops with various governmental and non-governmental organizations. This search resulted in reliable information regarding past experiences involving stranded manatees over the years. Cases attended to by the environmental authority and its partners were also considered. Forty-four stranding events were recorded, with 34 deaths and 10 live manatees. Of the cases discovered, 79.5% of the reported cases were addressed. This effort highlighted the current lack of an official database that would provide firsthand knowledge of Antillean manatee stranding events in Colombia, thereby hindering timely and appropriate territorial management during response to the challenges faced by this species in the region. Furthermore, it underscores the need to implement a standardized response pathway for manatee cases, following appropriate protocols, and promoting the coordination of stakeholders within the regional stranding network in the middle Magdalena Basin. This approach, in addition to supporting the capacity building of communities, institutions, and organizations for improving response knowledge, conservation, and manatee recovery, is of paramount importance for the long-term sustainability of manatee populations in the region.","PeriodicalId":17967,"journal":{"name":"Latin American Journal of Aquatic Mammals","volume":"28 18","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140696090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sarah Farinelli, Lucy Keith-Diagne, John Garnica, Jamie Keiman, David Luther
Detection of many threatened aquatic mammals, such as manatees (Trichechus spp.), using traditional visual observation methods is associated with high uncertainty due to their low surfacing times, cryptic behaviors, and the environmental heterogeneity of their habitats. Rapid advancements in technology provide an opportunity to address these challenges. In this study, we aimed to quantify survey effort of unoccupied aerial vehicles (UAVs) for detecting the Vulnerable Amazonian manatee (T. inunguis). Using a closed population of manatees that is being rehabilitated within a lake at the Rainforest Awareness, Rescue, and Education Center in Iquitos, Peru, we calculated the number of repeat surveys needed to detect at least one individual with 95% (n = 3.10) and 99% (n = 4.76) confidence. We used both generalized linear mixed-effect models and Bayesian single-species and single-season detection models to determine the effects of the environment (water depth, water transparency, cloud cover, wind speed), time of day, and behavior (breathing, foraging, milling) on the time-to-detection and detection probability, respectively. Both models indicated a significant interaction between water depth and water transparency, causing an increase in the time-to-detection (β = 0.032; 95% CI = 0.028, 0.037) and a decrease in the probability of detecting manatees (α = -0.65; 95% CI = -1.3, -0.007), which was calculated to be 0.62 (95% CI = 0.23, 0.94). Due to the similarities between the lake and in situ habitats, the results of this study could be used to design in situ UAV survey protocols for Amazonian manatees or other difficult-to-detect freshwater aquatic mammals and to monitor ex situ animals pre-and post-release, which should ultimately contribute to a better understanding of their spatial ecology and facilitate data-driven conservation efforts.
由于海牛（Trichechus spp.）浮出水面的时间较短、行为隐蔽以及栖息地环境的异质性，使用传统的肉眼观察方法探测海牛等许多濒危水生哺乳动物具有很高的不确定性。技术的快速发展为应对这些挑战提供了机会。在这项研究中，我们旨在量化无人驾驶飞行器（UAV）在探测亚马逊海牛（T. inunguis）方面的调查工作。我们利用秘鲁伊基托斯热带雨林意识、救援和教育中心（Rainforest Awareness, Rescue, and Education Center）湖泊中正在恢复的海牛封闭种群，计算了以 95% （n = 3.10）和 99% （n = 4.76）的置信度探测到至少一只海牛所需的重复调查次数。我们使用广义线性混合效应模型和贝叶斯单物种和单季节探测模型来确定环境（水深、水透明度、云层、风速）、一天中的时间和行为（呼吸、觅食、研磨）对探测时间和探测概率的影响。两个模型都表明，水深和水透明度之间存在明显的交互作用，导致海牛的探测时间增加（β = 0.032; 95% CI = 0.028, 0.037），探测到海牛的概率降低（α = -0.65; 95% CI = -1.3, -0.007），计算结果为 0.62 (95% CI = 0.23, 0.94)。由于湖泊与原生境之间的相似性，本研究结果可用于设计亚马逊海牛或其他难以检测的淡水水生哺乳动物的原生境无人机调查方案，以及放归前和放归后的原生境动物监测，最终有助于更好地了解它们的空间生态学，并促进以数据为驱动的保护工作。
{"title":"Quantifying minimum survey effort to reliably detect Amazonian manatees using an unoccupied aerial vehicle (UAV) at an ex situ soft-release site","authors":"Sarah Farinelli, Lucy Keith-Diagne, John Garnica, Jamie Keiman, David Luther","doi":"10.5597/lajam00319","DOIUrl":"https://doi.org/10.5597/lajam00319","url":null,"abstract":"Detection of many threatened aquatic mammals, such as manatees (Trichechus spp.), using traditional visual observation methods is associated with high uncertainty due to their low surfacing times, cryptic behaviors, and the environmental heterogeneity of their habitats. Rapid advancements in technology provide an opportunity to address these challenges. In this study, we aimed to quantify survey effort of unoccupied aerial vehicles (UAVs) for detecting the Vulnerable Amazonian manatee (T. inunguis). Using a closed population of manatees that is being rehabilitated within a lake at the Rainforest Awareness, Rescue, and Education Center in Iquitos, Peru, we calculated the number of repeat surveys needed to detect at least one individual with 95% (n = 3.10) and 99% (n = 4.76) confidence. We used both generalized linear mixed-effect models and Bayesian single-species and single-season detection models to determine the effects of the environment (water depth, water transparency, cloud cover, wind speed), time of day, and behavior (breathing, foraging, milling) on the time-to-detection and detection probability, respectively. Both models indicated a significant interaction between water depth and water transparency, causing an increase in the time-to-detection (β = 0.032; 95% CI = 0.028, 0.037) and a decrease in the probability of detecting manatees (α = -0.65; 95% CI = -1.3, -0.007), which was calculated to be 0.62 (95% CI = 0.23, 0.94). Due to the similarities between the lake and in situ habitats, the results of this study could be used to design in situ UAV survey protocols for Amazonian manatees or other difficult-to-detect freshwater aquatic mammals and to monitor ex situ animals pre-and post-release, which should ultimately contribute to a better understanding of their spatial ecology and facilitate data-driven conservation efforts.","PeriodicalId":17967,"journal":{"name":"Latin American Journal of Aquatic Mammals","volume":"86 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140709433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Antillean manatee in Guatemala faces multiple threats resulting from habitat loss and human interactions such as motorboat collisions and poaching. While some conservation efforts have been initiated in Río Dulce National Park (RDNP), there is a lack of studies examining the current perceptions of threats to the species. This knowledge gap may hinder the development of effective conservation strategies that consider both the species and local communities. Our objective was to analyze the perceptions of key local stakeholders concerning the Antillean manatee, including its distribution, threats, attention to strandings, and the current status of conservation in the protected area of RDNP. From July to October 2019, we conducted 50 semi-structured interviews with technicians and river users, such as fishermen and boat captains. Additionally, we held two workshops: one aimed at developing a participatory mapping exercise and another to validate the information. Each workshop was divided into two groups: one for technicians and another for river users. A total of 68 people participated in the workshops, the majority of respondents were male (n = 47), ranging in age from 19 to 71, and predominantly local to the area. Their activities in the river included fishing, biological monitoring, transportation, and providing tourism services. Perceived threats to the Antillean manatee included motorboat collisions, poaching, bycatch, habitat degradation, and water pollution. The focus groups also identified key observations, such as mother-calf sightings, specific areas of risk for manatee-boat collisions, areas with a higher presence of aquatic vegetation, and additional threats such as habitat degradation and poaching. Our results demonstrate that stakeholders possess a fundamental understanding of the manatee, its threats, and its distribution. They also highlight a noticeable lack of knowledge, specifically regarding the attention given to manatee strandings. It is recommended that conservation strategies include environmental education adapted to local conditions, as well as the promotion of manatee studies and their dissemination at the local level, including attention to strandings in the area.
{"title":"Perceptions on the distribution, threats, strandings, and conservation of the Antillean manatee (Trichechus manatus manatus) in the Río Dulce National Park, Izabal, Guatemala","authors":"M. F. Corona-Figueroa, J. Cifuentes-Espinosa","doi":"10.5597/lajam00328","DOIUrl":"https://doi.org/10.5597/lajam00328","url":null,"abstract":"The Antillean manatee in Guatemala faces multiple threats resulting from habitat loss and human interactions such as motorboat collisions and poaching. While some conservation efforts have been initiated in Río Dulce National Park (RDNP), there is a lack of studies examining the current perceptions of threats to the species. This knowledge gap may hinder the development of effective conservation strategies that consider both the species and local communities. Our objective was to analyze the perceptions of key local stakeholders concerning the Antillean manatee, including its distribution, threats, attention to strandings, and the current status of conservation in the protected area of RDNP. From July to October 2019, we conducted 50 semi-structured interviews with technicians and river users, such as fishermen and boat captains. Additionally, we held two workshops: one aimed at developing a participatory mapping exercise and another to validate the information. Each workshop was divided into two groups: one for technicians and another for river users. A total of 68 people participated in the workshops, the majority of respondents were male (n = 47), ranging in age from 19 to 71, and predominantly local to the area. Their activities in the river included fishing, biological monitoring, transportation, and providing tourism services. Perceived threats to the Antillean manatee included motorboat collisions, poaching, bycatch, habitat degradation, and water pollution. The focus groups also identified key observations, such as mother-calf sightings, specific areas of risk for manatee-boat collisions, areas with a higher presence of aquatic vegetation, and additional threats such as habitat degradation and poaching. Our results demonstrate that stakeholders possess a fundamental understanding of the manatee, its threats, and its distribution. They also highlight a noticeable lack of knowledge, specifically regarding the attention given to manatee strandings. It is recommended that conservation strategies include environmental education adapted to local conditions, as well as the promotion of manatee studies and their dissemination at the local level, including attention to strandings in the area.","PeriodicalId":17967,"journal":{"name":"Latin American Journal of Aquatic Mammals","volume":"25 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140709843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rebeca Taines do Nascimento Pinheiro, R. E. Oliveira, Augusto C B Freire, F. Attademo, F. D. O. Luna, Vitor Luz Carvalho, Flávio José de Lima Silva, Simone Almeida Gavilan
Morphological studies of the digestive tract are relevant to know the biology and understand the eating habits to conserve species. Our objective was to analyze macroscopically and microscopically the digestive tract of Antillean manatee (Trichechus manatus manatus). Samples were collected from 20 animals found dead stranded on the coast of northeastern Brazil or that died during the rehabilitation process in captivity between July 1995 and March 2017. The macroscopic analysis of the gastrointestinal tract was carried out from the in loco monitoring of the two necropsies. For microscopic evaluation, tissue fragments were collected during necropsy, fixed with 10% buffered formaldehyde and subjected to routine histological processing, with 5 μm thick slices, and subsequently submitted to the Hematoxylin-Eosin staining method, the Verhoeff method, and the periodic acid-Schiff method. Macroscopically, neonates and adults have the same digestive tract structures, namely esophagus, stomach, duodenum, jejunum, ileum, cecum, colon, and rectum. The microscopic analysis demonstrated that the digestive tract is formed by four histological layers (mucosa, submucosa, muscularis, and serosa or adventitia). In the esophagus, esophageal glands are absent and there are elastic fibers in the submucosal layer and between the external muscle and adventitial layers. The stomach has a structure called the cardiac gland, which microscopically presents ontogenetic differences regarding the depth of the lining epithelium and the orderly distribution of cells along the gastric gland. In the duodenal ampulla and in the diverticula, duodenal glands were identified in the submucosa. The luminal portion of the mucous layer of the cecal ampulla, colon, and rectum is lined by keratinized stratified squamous epithelium. The digestive tract of the species Antillean manatee is similar to what has been reported for the order Sirenia.
{"title":"Morphological analysis of the digestive tract of Antillean manatee (Trichechus manatus manatus, Linnaeus, 1758) in northeast Brazil","authors":"Rebeca Taines do Nascimento Pinheiro, R. E. Oliveira, Augusto C B Freire, F. Attademo, F. D. O. Luna, Vitor Luz Carvalho, Flávio José de Lima Silva, Simone Almeida Gavilan","doi":"10.5597/lajam00326","DOIUrl":"https://doi.org/10.5597/lajam00326","url":null,"abstract":"Morphological studies of the digestive tract are relevant to know the biology and understand the eating habits to conserve species. Our objective was to analyze macroscopically and microscopically the digestive tract of Antillean manatee (Trichechus manatus manatus). Samples were collected from 20 animals found dead stranded on the coast of northeastern Brazil or that died during the rehabilitation process in captivity between July 1995 and March 2017. The macroscopic analysis of the gastrointestinal tract was carried out from the in loco monitoring of the two necropsies. For microscopic evaluation, tissue fragments were collected during necropsy, fixed with 10% buffered formaldehyde and subjected to routine histological processing, with 5 μm thick slices, and subsequently submitted to the Hematoxylin-Eosin staining method, the Verhoeff method, and the periodic acid-Schiff method. Macroscopically, neonates and adults have the same digestive tract structures, namely esophagus, stomach, duodenum, jejunum, ileum, cecum, colon, and rectum. The microscopic analysis demonstrated that the digestive tract is formed by four histological layers (mucosa, submucosa, muscularis, and serosa or adventitia). In the esophagus, esophageal glands are absent and there are elastic fibers in the submucosal layer and between the external muscle and adventitial layers. The stomach has a structure called the cardiac gland, which microscopically presents ontogenetic differences regarding the depth of the lining epithelium and the orderly distribution of cells along the gastric gland. In the duodenal ampulla and in the diverticula, duodenal glands were identified in the submucosa. The luminal portion of the mucous layer of the cecal ampulla, colon, and rectum is lined by keratinized stratified squamous epithelium. The digestive tract of the species Antillean manatee is similar to what has been reported for the order Sirenia.","PeriodicalId":17967,"journal":{"name":"Latin American Journal of Aquatic Mammals","volume":"90 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140246126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ana Carolina Oliveira de Meirelles, Vitor Luz Carvalho, Cristine Pereira Negrão Silva
{"title":"Where there’s smoke, there’s fire: Hypotheses for the high incidence of West Indian manatee calf strandings on the Brazilian semi-arid coast","authors":"Ana Carolina Oliveira de Meirelles, Vitor Luz Carvalho, Cristine Pereira Negrão Silva","doi":"10.5597/lajam00323","DOIUrl":"https://doi.org/10.5597/lajam00323","url":null,"abstract":"","PeriodicalId":17967,"journal":{"name":"Latin American Journal of Aquatic Mammals","volume":"124 38","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140087933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Ramos, Marisa Tellez, Nataly Castelblanco-Martínez, Laura May-Collado
{"title":"Antillean manatees feed on floating Halophila baillonii in Placencia Lagoon, Belize","authors":"E. Ramos, Marisa Tellez, Nataly Castelblanco-Martínez, Laura May-Collado","doi":"10.5597/lajam00322","DOIUrl":"https://doi.org/10.5597/lajam00322","url":null,"abstract":"","PeriodicalId":17967,"journal":{"name":"Latin American Journal of Aquatic Mammals","volume":"7 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140409805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Helena G. Do Val, F. L. N. Attademo, I. C. Normande, João Carlos G. Borges, Alexandra F. Costa, Ana Emília B. de Alencar, Lucas Inácio dos S. Melo, Lauro H. de Paiva-Jr, F. D. O. Luna
The Antillean manatee is a threatened aquatic mammal subspecies which inhabits the northern and northeastern Brazilian coasts and estuarine areas. In this study we analyzed behavior data from rehabilitated and released manatees, to evaluate if sex and home range affect behavior richness and activity budget. Behavioral data from 29 manatees (15 females and 14 males) of northeastern Brazil was analyzed from 2006 to 2018. The animals were monitored by trained staff, who followed the animals using satellite and VHF telemetry systems. Six behavior states and 17 behavior events were recorded. The data was analyzed using GLM, ANOVA, and regression statistical tests. Behavior richness varied from three to 14 and activity budget indicated that individuals spent more time engaged in behaviors such as moving slowly and feeding in the bottom of the water body, but neither behavior richness nor activity budget were affected by sex. Behavior richness related to home range varied from five to 14 behaviors. Behavior richness and the activity budget for two social behaviors events - touch and interaction with wild manatees - were positively influenced by home range size, highlighting the importance of the use of space on behavior expression in manatees.
{"title":"Influence of sex and home range on released Antillean manatees’ behavior in Brazil","authors":"Helena G. Do Val, F. L. N. Attademo, I. C. Normande, João Carlos G. Borges, Alexandra F. Costa, Ana Emília B. de Alencar, Lucas Inácio dos S. Melo, Lauro H. de Paiva-Jr, F. D. O. Luna","doi":"10.5597/lajam00325","DOIUrl":"https://doi.org/10.5597/lajam00325","url":null,"abstract":"The Antillean manatee is a threatened aquatic mammal subspecies which inhabits the northern and northeastern Brazilian coasts and estuarine areas. In this study we analyzed behavior data from rehabilitated and released manatees, to evaluate if sex and home range affect behavior richness and activity budget. Behavioral data from 29 manatees (15 females and 14 males) of northeastern Brazil was analyzed from 2006 to 2018. The animals were monitored by trained staff, who followed the animals using satellite and VHF telemetry systems. Six behavior states and 17 behavior events were recorded. The data was analyzed using GLM, ANOVA, and regression statistical tests. Behavior richness varied from three to 14 and activity budget indicated that individuals spent more time engaged in behaviors such as moving slowly and feeding in the bottom of the water body, but neither behavior richness nor activity budget were affected by sex. Behavior richness related to home range varied from five to 14 behaviors. Behavior richness and the activity budget for two social behaviors events - touch and interaction with wild manatees - were positively influenced by home range size, highlighting the importance of the use of space on behavior expression in manatees.","PeriodicalId":17967,"journal":{"name":"Latin American Journal of Aquatic Mammals","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140426375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vera M F Da Silva, Fernando César Weber Rosas, José D'Affonseca Neto, Eliana Feldberg, Jorge Felipe Oliveira Franco-de-Sá, S. M. Lazzarini, Rodrigo De Souza Amaral
Since 1976, Amazonian manatees have been examined either alive or through necropsies as part of a long-term program to rescue and rehabilitate orphan manatee calves whose mothers were either victims of illegal hunting or accidental catch in fishing nets in the Brazilian Amazon region. Rescued manatees have been found to have several types of diseases, but to our knowledge, there is no record of a congenital anomaly of the face, known as an oral cleft, in Amazonian manatees. In this paper, we report the occurrence of an oral cleft in an Amazonian manatee calf, describing the clinical evaluation and discussing the potential causes.
{"title":"Oral cleft in an Amazonian manatee (Trichechus inunguis) (Mammalia, Sirenia)","authors":"Vera M F Da Silva, Fernando César Weber Rosas, José D'Affonseca Neto, Eliana Feldberg, Jorge Felipe Oliveira Franco-de-Sá, S. M. Lazzarini, Rodrigo De Souza Amaral","doi":"10.5597/lajam00320","DOIUrl":"https://doi.org/10.5597/lajam00320","url":null,"abstract":"Since 1976, Amazonian manatees have been examined either alive or through necropsies as part of a long-term program to rescue and rehabilitate orphan manatee calves whose mothers were either victims of illegal hunting or accidental catch in fishing nets in the Brazilian Amazon region. Rescued manatees have been found to have several types of diseases, but to our knowledge, there is no record of a congenital anomaly of the face, known as an oral cleft, in Amazonian manatees. In this paper, we report the occurrence of an oral cleft in an Amazonian manatee calf, describing the clinical evaluation and discussing the potential causes.","PeriodicalId":17967,"journal":{"name":"Latin American Journal of Aquatic Mammals","volume":"22 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139957227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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