Revista De Biologia Tropical最新文献

{"title":"Southern Hemisphere humpback whales (Megaptera novaeangliae) (Artiodactyla: Balaenopteridae) singing activity at Caño Island Biological Reserve, Costa Rica before, during, and after COVID-19 lockdowns","authors":"Laura J. May-Collado, Sawyer Bottoms, Grace Durant, Jose David Palacios-Alfaro, Juan Jose Alvarado","doi":"10.15517/rev.biol.trop..v71is4.57280","DOIUrl":"https://doi.org/10.15517/rev.biol.trop..v71is4.57280","url":null,"abstract":"Introduction: Boat traffic is recognized as a major contributor of underwater noise. Increasing presence of boats in coastal habitats is predicted to have important repercussions on the communication of marine mammals. In Costa Rica, the waters of the Caño Island Biological Reserve are an important breeding area for humpback whales from the Breeding-Stock G (BSG). Their predicted and abundant presence has fueled the development of whale watching activities as an important component of the local economy, and while the country has norms of conduct for this activity, whales often interact with multiple boats at the same time. The lockdowns associated with the COVID-19 pandemic provided a unique opportunity to study the potential impacts of noise associated with boat traffic on the singing activity of humpback whales.
 Objective: Determine whether noise levels and boat acoustic presence around Caño Island Biological Reserve changed during the COVID-19 lockdowns, and if it did, what is the impact on song detection of BSG humpback whales.
 Methods: Acoustic recordings were made using a bottom-mounted autonomous underwater recorder for 30 days in September 2019, 2020, and 2021, resulting in a total recording effort of 480 hours.
 Results: Our results show that broadband underwater noise levels (dBRMS) during pre-lockdown were significantly higher, particularly at frequencies below 1kHz, than during and post-lockdown. This is likely due to a decrease in the proportion of boat acoustic presence during the lockdown. Although the proportion of whale songs detected did not vary among years, whale songs were detected similarly throughout the day during the lockdown, compared to pre-and-post lockdown where the proportion of whale song presence decreased during hours when more boats were present.
 Conclusions: This study shows a clear change in underwater noise levels during the COVID-19 lockdown, likely due to a decrease in boat presence. The study also highlights the potential impact of noise associated with boat traffic on humpback whale singing activity. The results of this study can inform the Conservation Areas of Osa (ACOSA) in charge of managing Caño Island Biological Reserve, to develop and implement mitigation measures to regulate underwater anthropogenic noise associated with tour boats.","PeriodicalId":21368,"journal":{"name":"Revista De Biologia Tropical","volume":"166 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136105368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"False killer whales (Pseudorca crassidens Cetacea: Delphinidae) along the Pacific coast of Central America and Mexico: Long-term movements, association patterns and assessment of fishery interactions","authors":"Annie B. Douglas, Frank Garita Alpízar, Alejandro Acevedo-Gutiérrez, Sabre D. Mahaffy, Kristin Rasmussen, Ester Quintana-Rizzo, Joëlle De Weerdt, Daniel M. Palacios, Damián Martínez-Fernández, Camila Lazcano-Pacheco, Christian Daniel Ortega Ortiz, Nicola Ransome, Astrid Frisch-Jordán, Francisco Villegas-Zurita, John Calambokidis, Robin W. Baird","doi":"10.15517/rev.biol.trop..v71is4.57189","DOIUrl":"https://doi.org/10.15517/rev.biol.trop..v71is4.57189","url":null,"abstract":"Introduction: Worldwide, false killer whales (Pseudorca crassidens) are infrequently encountered, yet long-term studies have shown strong site fidelity as well as long-term associations among individuals in several locations. Detailed studies of this species have primarily been conducted around tropical oceanic islands or in the subtropical southern hemisphere.
 Objectives: We assess movements and association patterns among false killer whales along the Pacific coasts of the USA, Mexico, Guatemala, Nicaragua, Costa Rica including Isla del Coco, and Panama, representing one of the longest-running (albeit non-continuous) studies of this species. We also examine photos for evidence of interactions with fisheries, a known source of mortality to false killer whales.
 Methods: From Central America, we selected 212 individuals (50 encounter groups) out of 244 individuals (56 encounters) for inclusion in analyses based on photo quality and distinctiveness. Photos were collected on dedicated surveys from 1991-1994 and dedicated and opportunistic surveys from 1998-2022. Other than the effort off the oceanic Isla del Coco (1993-1994), surveys were undertaken in continental shelf waters. Additionally, we selected by photo quality and distinctiveness 124 (33 encounter groups) out of 189 individuals from southern California and Mexico for inclusion in these analyses. Association patterns were analyzed in SOCPROG and movements were analyzed in R.
 Results: Of the 328 total individuals, 158 (48.2 %) were encountered more than once, and 114 (34.8 %) were re-sighted after a year or more. The longest individual sighting history spanned 26.2 years with six re-sightings over that period between southern Costa Rica and Panama. Association and movement analyses revealed that individuals identified off southern Costa Rica and Panama linked into a single social network, with extensive movements between the two countries. Three individuals encountered off northern Costa Rica were re-sighted off northern Nicaragua, and individuals encountered off Nicaragua were encountered off Guatemala and central mainland Mexico. Nine matches were found among false killer whales between central mainland Mexico and Central America. There were no matches between the mainland coastal waters and the 33 individuals encountered around Isla del Coco. Dorsal fin disfigurements consistent with interactions with line fisheries ranged from 0 to 21 % for individuals within social clusters identified by community division.
 Conclusions: The infrequency of sightings combined with a high re-sighting rate of individuals and groups from the same area, suggests multiple small populations with large home ranges that include coastal waters. Small populations are sensitive to environmental changes, and as the human population grows, so do the demands on fisheries and ecotourism, which could directly impact the different populations. Additional effort in offshore areas is needed to determi","PeriodicalId":21368,"journal":{"name":"Revista De Biologia Tropical","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136105359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Migratory destinations of endangered humpback whales, Megaptera novaeangliae (Cetartiodactyla: Balaenopteridae), from El Salvador","authors":"Nicola Ransome, Melvin G. Castaneda, Ted Cheeseman, John Calambokidis, Fred Sharpe","doi":"10.15517/rev.biol.trop..v71is4.57283","DOIUrl":"https://doi.org/10.15517/rev.biol.trop..v71is4.57283","url":null,"abstract":"Introduction: The study of many aspects of cetacean ecology is made possible by identifying individuals through space and time. Humpback whales (Megaptera novaeangliae) can be easily identified by photographing their ventral tail flukes’ unique shape and pigmentation patterns. The small and endangered distinct population segment (DPS) of Central America humpback whales visit El Salvador seasonally each winter; however, dedicated research has been extremely limited there. Before 2018, only 11 individual whales had been photo-identified, and the migratory destinations of Salvadoran humpback whales were unknown. In recent years, photo-identification efforts have increased, and today there are 92 individually identified humpback whales from El Salvador.
 Objective: To identify the main high-latitude feeding areas of Salvadoran humpback whales.
 Methods: Using the online matching platform Happywhale, Salvadoran whales were matched via automated image recognition to a global humpback whale fluke photo-identification catalog of 66 043 individuals.
 Results: In total, 80 (87.0 %) of the whales photographed in El Salvador were matched to individuals seen in North Pacific feeding areas. Sighting histories of Salvadoran whales resighted in feeding areas ranged from two to 29 years (average = 12.1, SD = 5.8). While we note that survey effort was likely very different between regions, the main feeding area of Salvadoran humpback whales on Happywhale was Central California (n = 70, 76.1 %). Of these whales, 21 (22.8 %) had also been sighted in Southern California, while just three (3.3 %) individual whales were registered only in Southern California. Additionally, two whales (2.2 %) were sighted in Southern British Columbia, Canada, and one whale was matched to a humpback whale from Southeast Alaska. This whale (of unknown sex) has a sighting history of 27 years but no prior documentation in a breeding area and is the first published sighting of a Southeast Alaskan humpback whale in the breeding area of the endangered Central America DPS.
 Conclusions: Our study shows that while Salvadoran humpback whales were matched to various feeding areas in the Eastern North Pacific, their primary migratory destinations are in Southern and Central California.","PeriodicalId":21368,"journal":{"name":"Revista De Biologia Tropical","volume":"166 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136105186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Initial characterization of mitochondrial DNA control region haplotypes of the Antillean manatee (Trichechus manatus manatus, Sirenia:Trichechidae) in Guatemala","authors":"Grecia Mendez, Susan Carney, Heidy Amelia Garcia, Ester Quintana-Rizzo","doi":"10.15517/rev.biol.trop..v71is4.57278","DOIUrl":"https://doi.org/10.15517/rev.biol.trop..v71is4.57278","url":null,"abstract":"Introduction: Small populations are at risk of losing genetic variability much faster than large populations; this subsequently decreases their ability to adapt when facing environmental changes. A small population of the endangered Antillean manatee (Trichechus manatus manatus) has been identified in Guatemala.
 Objective: This study explored the genetic diversity of the Antillean manatee in Guatemala by analysing mitochondrial DNA control region haplotypes in the two most important habitats for the species, Bahía La Graciosa, a coastal bay and Bocas del Polochic, a coastal wetland, both located in the Izabal State.
 Methods: Genetic samples were collected using non or minimally invasive sampling techniques: scraping of epidermal tissue, collection of floating feces, and collection of tissue from carcasses. DNA extractions, DNA amplification using polymerase chain reaction (PCR), and sequencing of the control D-loop region were used to process and analyse the samples.
 Results: Seven mitochondrial DNA sequences were obtained from 36 samples collected (minimum of four and maximum of seven individuals). Four haplotypes were identified, A01, A03, A04, and J01. No other Central American country has reported this number of haplotypes in a manatee population, and it is the first time that haplotype A01 has been reported for the region. The Guatemalan manatee population comprises at least two genetic lineages, the Florida/Greater Antilles lineage (haplotypes A01, A03, and A04) and the Mesoamerican lineage (J01).
 Conclusion: Further studies, with the use of nuclear markers, are necessary to understand the population dynamics between Bahia La Graciosa and Bocas del Polochic to identify the number of management units present in the country; also, the degree of relatedness with the Belizean population needs to be established to better coordinate conservation efforts.","PeriodicalId":21368,"journal":{"name":"Revista De Biologia Tropical","volume":"30 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136105187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"More pieces for the puzzle: novel information on the genetic diversity and population structure of Steno bredanensis (Artiodactyla: Delphinidae) in Central America and the Caribbean Sea","authors":"Dalia C. Barragán-Barrera, Camilo A. Correa-Cárdenas, María Alejandra Duarte-Fajardo, Lissette Trejos Lasso, Betzi Pérez-Ortega, Shakira G. Quiñones-Lebrón, Antonio A. Mignucci-Giannoni, José Julio Casas, Roberto Santamaria Valverde, Nohelia Farías-Curtidor, Susana Caballero","doi":"10.15517/rev.biol.trop..v71is4.57285","DOIUrl":"https://doi.org/10.15517/rev.biol.trop..v71is4.57285","url":null,"abstract":"Introduction: The rough-toothed dolphin (Steno bredanensis) inhabits oceanic waters of tropical latitudes and exhibits philopatry in some oceanic islands. However, the species has been observed in shallow coastal waters in a few areas. Particularly in Central America, the rough-toothed dolphin has been reported by occasional records and strandings. For instance, the first confirmed record of this species in the Panama’s Caribbean was on July 17, 2012, in a coastal region of the Chiriquí Lagoon during a bottlenose dolphin monitoring survey. Similarly, the first rough-toothed dolphin mass stranding reported for the Pacific of Panama was on April 20, 2016, at the Ostional Beach, where 60 dolphins stranded and ten died. These sightings and events offered a valuable opportunity to obtain samples to conduct genetic studies, which are scarce in the region.
 Objective: In this study, we present the first assessment of genetic diversity for rough-toothed dolphins based on mitochondrial DNA Control Region (mtDNA-CR) in the Panamanian Pacific and the Wider Caribbean.
 Methods: Samples were collected in Colombia (N=5), Panama (N-Caribbean=1, N-Pacific=9), and Puerto Rico (N=3) from free-ranging and stranded individuals. DNA was extracted from each sample, and a mtDNA segment of around 534 to 748 bp was amplified through the PCR reaction. The obtained sequences were compared with rough-toothed dolphin haplotypes previously published in NCBI (N=70), from the Atlantic, Indian, and the Pacific Oceans.
 Results: Our findings showed significant population structure among ocean basins (strong differentiation with ΦST data), and high genetic diversity within each phylogroup. Only the Atlantic Ocean showed high genetic differentiation within the basin, detecting three phylogroups: the Caribbean, northern, and southern Atlantic.
 Conclusions: These findings support previous genetic studies that indicate high levels of population structure among ocean basins, although this species seems to be widely dispersed. However, samples from Panama and the Caribbean appear to show connectivity between highly differentiated Atlantic and Pacific Oceans. Therefore, our results highlight the need for more research to assess the rough-toothed dolphin genetic and population status in Central America, as the piece of the puzzle needed to clarify its taxonomy and genetic differentiation worldwide. This information is needed due to the rough-toothed dolphin IUCN categorization as “Least Concern” and its classification into appendix II according to CITES. While individuals are potentially threatened by incidental fishing, no management units are currently used to conserve this species despite its high genetic differentiation.","PeriodicalId":21368,"journal":{"name":"Revista De Biologia Tropical","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136105195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characteristics and spatial identification of Antillean manatee (Trichechus manatus manatus Sirenia: Trichechidae) strandings in Guatemala","authors":"Oscar Machuca-Coronado, Ester Quintana-Rizzo, Tannia Sandoval, M. Fabiola Corona-Figueroa, Heidy Amely Garcia","doi":"10.15517/rev.biol.trop..v71is4.57274","DOIUrl":"https://doi.org/10.15517/rev.biol.trop..v71is4.57274","url":null,"abstract":"Introduction: Marine mammal strandings can be used to determine the impacts of anthropogenic activity on the species survival, population health, and levels of environmental pollution in ecosystems. In addition, these data can help design conservation and management strategies as well as identify priority areas for the species. The West Indian manatee (Trichechus manatus) is listed as endangered throughout its range. In Guatemala, it is distributed along the Caribbean coast. Anthropogenic activities appear to be having a direct pressure on the species, affecting the status of the population.
 Objective: The general purpose of this study was to analyze the 30 years of documented manatee stranding reports available for Guatemala. Two specific objectives were defined to: 1) conduct a spatial analysis of manatee strandings to identify the areas of high stranding concentration, and 2) determine whether there were sex differences in the number of strandings.
 Methods: Characteristics and areas of concentration of manatee strandings were described along the Caribbean coast between 1992 to 2022. Sites with the highest probable density of strandings were identified using a Kernel density analysis. We compared the number of stranding events that occurred in each protected area that included manatees in their management plans and each municipality of Izabal. We determined whether there were sex differences in the number of stranded manatees. We use the potential biological removal to estimate the maximum number of manatees that can be removed from the population due to anthropogenic causes without negatively impacting species survival.
 Results: Forty-three manatee stranding events were recorded throughout the species’ range in Guatemala (48 total individuals). The sites with the highest predicted density of strandings were Santo Tomás de Castilla bay, followed by Lake Izabal (including the limits of the Refugio de Vida Silvestre Bocas del Polochic) and Parque Nacional Río Dulce. The majority of the cases were registered in protected areas (60 %). Estimates of potential biological removal were equivalent to less than one manatee per year, which was exceeded by the annual average of stranded manatees recorded (three manatees).
 Conclusions: Anthropogenic activities cause mortality of manatees in this region, despite the implementation of protected areas. Poaching was identified as the main cause of manatee mortality in Guatemala. The implementation of management strategies focused on minimizing threats to the species, based on the application of environmental legislation and environmental awareness, is essential. The creation and implementation of a protocol for the stranding of marine mammals on the Caribbean coast of Guatemala is necessary, in order to obtain standardized records of these events and conduct rescue efforts and releases when possible.","PeriodicalId":21368,"journal":{"name":"Revista De Biologia Tropical","volume":"4 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136105191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mitochondrial DNA supports the low genetic diversity of Tursiops truncatus (Artiodactyla: Delphinidae) in Bocas del Toro, Panama and exhibits new Caribbean haplotypes","authors":"María Alejandra Duarte-Fajardo, Dalia C. Barragán-Barrera, Camilo A. Correa-Cárdenas, Betzi Pérez-Ortega, Nohelia Farías-Curtidor, Susana Caballero","doi":"10.15517/rev.biol.trop..v71is4.57291","DOIUrl":"https://doi.org/10.15517/rev.biol.trop..v71is4.57291","url":null,"abstract":"Introduction: The common bottlenose dolphin (Tursiops truncatus) is one of the most studied cetaceans worldwide; however, information about the genetic structure of wild populations is scarce in some regions like Central America and the Caribbean. There are two known genetic forms identified in the Caribbean based on mitochondrial DNA Control Region (mtDNA-CR) data: the ‘inshore (or coastal) form’ and the ‘Worldwide distributed form’. In general, the inshore form refers to coastal and highly philopatric populations that show low genetic diversity. Worldwide distributed form refers to highly mobile populations with coastal and oceanic individuals that do not show philopatry and usually display high genetic diversity.
 Objective: To determine the preliminary genetic status of common bottlenose dolphins in La Guajira, Colombian Caribbean, using a hypervariable portion of mtDNA-CR. The obtained haplotypes were compared with samples collected in Panama (likely ‘inshore form’) and with haplotypes previously found in other areas of the Caribbean.
 Methods: In 2016, a total of 26 skin samples were obtained by remote biopsy system (PAXARMS) in two locations, La Guajira (Colombia, N=7) and Bocas del Toro (Panama, N=19). DNA was extracted, samples sexed, and a segment of mtDNA-CR (~550-750 bp) was amplified by PCR. The successfully amplified DNA sequences were manually reviewed and cleaned, and subsequently compared with 44 haplotypes previously reported for the Caribbean.
 Results: The mtDNA-CR sequences from Bocas del Toro shared the same unique inshore haplotype previously reported for this population, while the samples from La Guajira represented six novel haplotypes, five belonging to the Worldwide distributed form and one to the ‘inshore form.’ Population structure analysis revealed two phylogroups for the Caribbean (FST=0.1353, ΦST=0.3330) with high haplotype diversity: Panama(Bocas del Toro)-Bahamas-Cuba-Mexico (h=0.8489, π=4.2536 %) and Colombia-Costa Rica-Honduras-Puerto Rico (h=0.8837, π=4.2423 %).
 Conclusions: These findings support the results previously reported for common bottlenose dolphins in Bocas del Toro-Panama and reinforce the need to protect this vulnerable ‘inshore’ population by treating it as a unique population management unit. Mitochondrial DNA analysis of samples collected from La Guajira dolphins provide the first insight into the genetic diversity of common bottlenose dolphins in this region, indicating the presence of both inshore and Worldwide distributed genetic forms. The potential connectivity of this last form among La Guajira-Colombia, Costa Rica, and Honduras in Central America highlights the need for more genetic and ecological studies to determine the appropriate management units for this species in Central America and the Caribbean.","PeriodicalId":21368,"journal":{"name":"Revista De Biologia Tropical","volume":"166 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136105188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First mercury and stable isotope assessment from an unusual mass stranding of rough-toothed dolphins (Steno bredanensis) (Artiodactyla: Delphinidae) in Azuero peninsula, Pacific coast of Panama","authors":"Dalia-C. Barragán-Barrera, Lissette Trejos-Lasso, Betzi Pérez-Ortega, José-Julio Casas, Roberto Santamaria-Valverde","doi":"10.15517/rev.biol.trop..v71is4.57188","DOIUrl":"https://doi.org/10.15517/rev.biol.trop..v71is4.57188","url":null,"abstract":"Introduction: Small cetaceans are good bioindicators of environmental contamination; however, knowledge about their ecotoxicological status in Central America is scarce. In Panama, access to samples from wild populations to determine the ecotoxicological status of oceanic dolphins is limited; therefore, stranding events provide an alternative for obtaining samples. In April 2016, a rare mass stranding event occurred in the Azuero Peninsula (Pacific coast of Panama), where 60 rough-toothed dolphins (Steno bredanensis) stranded, including ten which died on the beach.
 Objective: To assess total mercury (THg) concentrations, and δ13C and δ15N stable isotope values in rough-toothed dolphins for the first time in this region.
 Methods: Nine skin samples were collected from adults, stored in 70 % ethanol, and posteriorly analyzed to determine THg concentrations and stable isotope values.
 Results: THg concentrations ranged from 4 764 to 18 689 ng g-1 dry weight (dw) (mean = 12 841; SD = 5 083 ng g-1 dw), δ13C values ranged between −16.8 and −15.2 ‰ (mean = −16.2; SD = 0.6 ‰), and δ15N values ranged between 14.3 and 15.9 ‰ (mean = 15.0; SD = 0.5 ‰).
 Conclusions: High THg concentrations reported for this species in the Azuero Peninsula are consistent with values reported for rough-toothed dolphins in other areas worldwide, such as the central-northern Rio de Janeiro State in Brazil and La Guajira in the Colombian Caribbean. Elevated mercury (Hg) concentrations may be related to the rough-toothed dolphin diet, which according to δ15N values found here, appears to be based mainly on high trophic level prey that bioaccumulate more Hg in their tissues compared to lower trophic level organisms. However, additional dietary studies would be required to support these findings. Continuing monitoring of traditional dietary analysis, as well as contamination levels in fish and dolphins, is necessary to understand the dolphins’ ecotoxicology in Panama.","PeriodicalId":21368,"journal":{"name":"Revista De Biologia Tropical","volume":"166 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136105365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lobomycosis Like Disease in Bottlenose Dolphins Tursiops truncatus (Artiodactyla: Delphinidae) from Costa Rica Pacific Waters","authors":"Juan Diego Pacheco-Polanco, David Herra-Miranda, Lenin Oviedo Correa","doi":"10.15517/rev.biol.trop..v71is4.57292","DOIUrl":"https://doi.org/10.15517/rev.biol.trop..v71is4.57292","url":null,"abstract":"Introduction: Lobomycosis, is a chronic mycotic disease of the skin and sub-dermal tissue caused by Paracoccidioides ceti, which affects dolphins worldwide. In Costa Rica, the incidence of lobomycosis Like Disease (LLD) has been documented in inshore common bottlenose dolphins (Tursiops truncatus) from the waters of Golfo Dulce, South Pacific.
 Objective: Examine the prevalence pattern of LLD in inshore T. truncatus from Costa Rica Pacific waters, specifically in Golfo Dulce and Golfo de Nicoya.
 Methods: We examined over 20 000 photographs of T. truncatus, collected during long-term research on cetaceans in 2005-2020 (n = 476 surveys), in Golfo Dulce, as well of nine sightings T. truncatus from the Golfo de Nicoya , obtained during 17 samplings events in 2014-2022, these records for the presence of LLD allowed to calculate the prevalence rate with a confidence interval.
 Results: The prevalence rate of LLD in adult photo-identified individuals was 13.1 % (CI: 12 -14.2) in Golfo Dulce, and 100 % in Golfo de Nicoya, considering the size of the population for the period of 2022.
 Conclusion: The persistence and high prevalence levels of LLD in small, localized, communities of T. truncatus are a cause for serious concern.","PeriodicalId":21368,"journal":{"name":"Revista De Biologia Tropical","volume":"166 S1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136105370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heat loss or heat uptake? Skin temperature in Antillean manatees (Trichechus manatus manatus, Sirenia: Trichechidae) in Belize","authors":"Nicola Erdsack, Jamal A. Galves, James E. Powell","doi":"10.15517/rev.biol.trop..v71is4.57272","DOIUrl":"https://doi.org/10.15517/rev.biol.trop..v71is4.57272","url":null,"abstract":"Introduction: The two subspecies of the West Indian manatee (Trichechus manatus), Florida manatees (T. m. latirostris) and Antillean manatees (T. m. manatus), face different environmental challenges. While Florida manatees have to cope with winter water temperatures below their lower critical temperature of ~ 20 °C and air temperatures below freezing, Antillean manatees live in year-round warm Caribbean waters. Sirenians lack effective thermal insulation and have limited capability of controlling peripheral heat loss. Although severe cold related health issues and mortality are primarily known in Florida manatees, it can be assumed that Antillean manatees and other extant sirenians share the cold-sensitivity, but hardly ever experience it. Contrarily, during summer, Antillean manatees may face the opposite form of thermal stress by being exposed to water temperatures close to their body temperature. However, the upper critical temperature of manatees is not known.
 Objective: To improve understanding of the impact of high ambient temperatures on manatee physiology.
 Methods: We measured skin temperature in six Antillean manatees in two different habitats in Belize, and compared the results to skin temperatures measured in two captive Florida manatees.
 Results: We found a similar temperature distribution pattern over the body surface in both subspecies, but significantly higher temperatures and larger temperature ranges among measuring points in Antillean manatees as compared to Florida manatees. In one Antillean manatee, skin temperature was consistently lower than ambient water temperature by up to 2.5 °C. This implies potential heat uptake from the environment, in contrast to the heat loss experienced by Florida manatees at low water temperatures, apparent in skin temperatures above ambient water temperature.
 Conclusions: Our findings suggest that heat stress may be a more likely risk for manatees in warm tropical waters. Despite the small sample size, our results present important findings towards understanding thermal tolerance and impact of high ambient temperatures on manatee physiology.","PeriodicalId":21368,"journal":{"name":"Revista De Biologia Tropical","volume":"164 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136105200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}