Papers by Carlos Alberto Niño Torres
Marine Mammal Science
Dorsal fins, one of the most notable dolphin's physical features, play important kinematic an... more Dorsal fins, one of the most notable dolphin's physical features, play important kinematic and hydrodynamic roles and are related to physiological and environmental adaptation processes. Differences in dorsal fin shape have been recently associated with geographic variation, habitat specialization between ecotypes, and ontogenetic factors. We studied dorsal fin variation across several common bottlenose dolphin populations in the Caribbean. A total of 252 dorsal fin photographs from eight coastal regions in the Caribbean were selected for analysis. Dolphin dorsal fin proportions were compared among regions and compared with data previously collected from Holbox, Mexico. Dorsal fin models were constructed for each region. We found that across the Caribbean, coastal bottlenose dolphins exhibit low variation in dorsal fin shape, with the most common dorsal fin pattern having low and triangular shapes, two traits that greatly contrast with the oceanic ecotype. Also, significant diff...
Environmental Biology of Fishes
Sustainability
The Mexican Caribbean is in one of the regions with the greatest diversity of elasmobranchs in th... more The Mexican Caribbean is in one of the regions with the greatest diversity of elasmobranchs in the world. However, the population status of most of the shark and ray species in this region is unknown. We used a citizen science program based on divers to collect data about the diversity, abundance, and distribution of elasmobranchs in this region. We visited dive centers in six locations and performed structured interviews with divemasters, instructors, and owners of the diving centers. In total, 79 divers were interviewed, of which 69% had more than five years’ experience diving in the Mexican Caribbean. Divers could identify 24 elasmobranch species for this region. Most of the divers (82%) reported a decrease in sightings of sharks and rays. Rays were the most frequently sighted species by divers (89%), and the spotted eagle ray (A. narinari) was the most common elasmobranch species reported in the region. Citizen science was a useful approach gathering for baseline information abo...
CBM - Cahiers de Biologie Marine, 2011
This study reports the occurrence of a morphological abnormality (pectoral fins not fused with th... more This study reports the occurrence of a morphological abnormality (pectoral fins not fused with the head) in a juvenile female of the diamond stingray Dasyatis dipterura (Jordan & Gilbert, 1880) from the Gulf of California. The animal was caught with a monofilament gillnet by the artisanal fishermen from Estero del Soldado, Sonora, Mexico. This work represents the first record of this condition in the diamond stingray.
Environmental Biology of Fishes, 2022
The present study includes a list of elasmobranch species present in the Mexican Caribbean and th... more The present study includes a list of elasmobranch species present in the Mexican Caribbean and the conservation status of each species with recommendations to improve the management strategies that are ongoing in the region. Since 2015, surveys were conducted in local fisheries, sighting reports were collected, and several published sources, including those from national and international collections and museums, were reviewed. Based on documents, collections, direct records by authors, and local sighting reports, we found 85 elasmobranch species (49 sharks and 36 rays) reported for the Mexican Caribbean, from which 65 species (37 sharks and 28 rays) have been confirmed. The present study increased the total number of elasmobranch species known to be in the Mexican Caribbean by 57. These species belong to 10 orders and 30 families. This represents 41% of the elasmobranch species known for Mexico and 47% of the species reported for the Wester Central Atlantic Ocean. This research provides important baseline information about elasmobranch biodiversity in the Mexican Caribbean with implications in the management and conservation of these species at national and international levels.
Se presenta una revision de las especies de mamiferos acuaticos para el Caribe Mexicano. Un gran ... more Se presenta una revision de las especies de mamiferos acuaticos para el Caribe Mexicano. Un gran numero de fuentes publicadas fueron consultadas para buscar informacion sobre mamiferos acuaticos reportados para el Caribe Mexicano. Ademas, se consultaron 29 colecciones y museos nacionales e internacionales. Basados en documentos, colecciones, registros directos y noticias locales, el presente trabajo reporta la presencia de 18 especies de mamiferos acuaticos en el area de estudio [Tursiops truncatus, Stenella clymene, S. frontalis, S. longirostris, Steno bredanensis, Grampus griseus, Globicephala macrorhynchus, Peponocephala electra; Pseudorca crassidens, Orcinus orca, Physeter macrocephalus, Kogia breviceps, K. sima, Ziphius cavirostris, Mesoplodon europaeus, Trichechus manatus manatus, Lontra longicaudis annectens and Monachus tropicalis (extincta)]. Para obtener informacion de linea de base que permita un manejo eficiente a largo plazo de este recurso, se recomienda realizar censo...
Endangered Species Research, 2019
Population assessments and species monitoring for many endangered marine megafauna are limited by... more Population assessments and species monitoring for many endangered marine megafauna are limited by the challenges of identifying and tracking individuals that live underwater in remote and sometimes inaccessible areas. Manatees can acquire scars from watercraft injury and other incidences that can be used to identify individuals. Here we describe a novel method for photo-identification of Antillean manatees Trichechus manatus manatus using aerial imagery captured during flights with a small multirotor drone. Between 2016 and 2017, we conducted 103 flights to detect and observe manatees in Belize, primarily at St. George's Caye (SGC) near the Belize Barrier Reef. Review of aerial videos from these flights resulted in 279 sightings of manatees (245 adults, 34 calves). High-resolution images of individual manatees were extracted and classified according to image quality and distinctiveness of individual manatees for photoidentification. High-quality images of manatees classified as sufficiently distinctive were used to create a catalog of 17 identifiable individuals. At SGC, 21% of all sighted adult manatees (N = 214) were considered photo-identifiable over time. We suggest that the method can be used for investigating individual site fidelity, habitat use, and behavior of manatee populations. Our photoidentification protocol has the potential to improve long-term monitoring of Antillean manatees in Belize and can be applied throughout clear, shallow waters in the Caribbean and elsewhere.
Mammalia, 2019
Oral pathological conditions are common in mammals and have been relatively well documented for s... more Oral pathological conditions are common in mammals and have been relatively well documented for some wild groups, but are rarely reported in marine mammals. Here, we report for the Mexican Caribbean the first case of mandibular osteomyelitis in a free-ranging dolphin. A bottlenose dolphin Tursiops truncatus adult male (256.5 cm total length) was found stranded dead in the west coast of the State Reserve “Chetumal Bay Manatee Sanctuary”. Herein, we discuss some plausible explanations about the origin of this lesion to improve the knowledge about the species biology.
Aquatic Mammals, 2016
Characterizing species occurrence, abundance, and distribution is critical to the management of n... more Characterizing species occurrence, abundance, and distribution is critical to the management of natural resources and the conservation of biodiversity. In the Western Caribbean, little information exists on the occurrence of aquatic mammals along the Mesoamerican Barrier Reef System and adjacent aquatic ecosystems. Herein, we present the first comprehensive review of aquatic mammals encountered in the marine and freshwater habitats of Belize. To determine which aquatic mammal species occur in Belizean waters, we conducted an extensive review of published and unpublished reports of aquatic mammals. We located 163 unique reports from museum and animal collections , journal articles, theses, news reports, conference proceedings, institutional reports, and verified accounts from personal observations. Our review confirms the presence of 17 aquatic mammal species in Belize: 15 cetaceans ((Trichechus manatus manatus), and one carnivore (Lontra longicaudis annectens). Our findings provide the most up-to-date list of aquatic mammal presence in Belize. Given the limited data points obtained for most identified species, we recommend that systematic studies be conducted to investigate the status of the variety of aquatic mammals in the region to effectively monitor populations and devise strategies to mitigate the negative impacts of anthropogenic activity and climate change-related ecosystem shifts.
Marine Environmental Research, 2010
Environmental Biology of Fishes, 2011
The feeding ecology and trophic level of the banded guitarfish, Zapteryx exasperata, from the Gul... more The feeding ecology and trophic level of the banded guitarfish, Zapteryx exasperata, from the Gulf of California, were assessed using stable isotope analysis (SIA) of carbon and nitrogen in muscle samples, and stomach contents analysis (SCA). Males and females showed similar diet preferences with a high diet overlap (Cλ=0.99) and similar values of δ 13 C and δ 15 N (ANOVA, F=0.0 p=0.94 for δ 13 C; F=0.1 p=0.78 for δ 15 N). The main prey groups found were demersal fishes dominated by the daisy midshipman, Porichthys margaritatus, (>90%IRI), however, pelagic fishes were also found (Engraulis mordax 2%IRI). An ontogenetic diet shift was found, indicated by the importance of crustaceans in the juvenile diet and the significant isotopic differences between juveniles and adults (δ 13 C, ANOVA, F=13.3 p=0.0004 and δ 15 N, ANOVA, F=4.7 p=0.03). An overall trend of increase in δ 15 N values with increasing body length (F=8.15 p=0.005) was observed. The mean trophic level estimated in this work by the two methods was~4.1, indicating that this species is a top predator in the Gulf of California. Zapteryx exasperata is a specialist feeder (Bi=0.11, H'=2.32), consuming mainly benthic fishes in coastal areas of the Gulf of California. The importance of this species in the benthic ecosystem equilibrium as a top predator is an important point to keep in mind when developing future management plans of the batoid fishery in the Gulf of California.
Diseases of Aquatic Organisms, 2014
Congenital defects in crocodilians have received little interest. In the context of global change... more Congenital defects in crocodilians have received little interest. In the context of global change and increasing threats to biodiversity, data on birth defects occurring in wildlife could be of importance for estimating the health of species populations and their ecosystems. Herein, we report the first case of amelia (i.e. absence of limbs) in Morelet's crocodiles Crocodylus moreletii from Mexico and the third on the southern Yucatan Peninsula. The crocodile in question was a juvenile (41 cm total length) captured in July 2012 in the Río Hondo, the river that forms the border between Mexico and Belize south of the state of Quintana Roo. The prevalence of this malformation in the C. moreletii population of Río Hondo (0.35%) is similar to that reported in 2 previous cases in Belize. Several causes of birth defects in crocodilians have previously been cited in the literature. Although we do not have relevant information to elucidate this case, we discuss some plausible explanations for this birth defect.
Wildlife Research, 2019
The Caribbean is a mega-diverse and bio-geographically important region that consists of the Cari... more The Caribbean is a mega-diverse and bio-geographically important region that consists of the Caribbean Sea, its islands, and surrounding coastlines. Among the billions of aquatic species inhabiting this region, the mega-vertebrates stand out for their social, economic and ecologic relevance. However, the Caribbean has been threatened by climate change, poverty, pollution, environmental degradation and intense growth of the tourism industry, affecting megafauna species directly and indirectly. Population monitoring plays a critical role in an informed conservation process and helps guide management decisions at several scales. The aim of the present review was to critically examine the methods employed for monitoring marine megafauna in the Caribbean, so as to create a framework for future monitoring efforts. In total, 235 documents describing protocols for the monitoring of sirenians, cetaceans, elasmobranchs, sea turtles and crocodilians in the Caribbean region, were reviewed. The ...
Marine Mammal Science, 2013
Diversity
The herpetofauna of the insular systems of Mexico is composed of 226 species, of which 14 are anu... more The herpetofauna of the insular systems of Mexico is composed of 226 species, of which 14 are anurans, two are salamanders, and 210 are reptiles, comprised of two crocodilians, 195 squamates, and 13 turtles. Although the surface of the Mexican islands is only 0.26% of the Mexican territorial extension, these 226 species constitute 16.1% of Mexico’s documented herpetofauna of 1405 species. We classified the Mexican islands into five physiographic regions: the islands of Pacific Baja California; the islands of the Gulf of California; the islands of the Tropical Pacific; the islands of the Gulf of Mexico; and the islands of the Mexican Caribbean. The highest species richness among these regions is in the Gulf of California, with 108 species, and the lowest richness is 40 for the islands of the Pacific Baja California and 46 for those of the Gulf of Mexico. We identified introduced species, risk of wildfires, climate change, and urban/tourist development as the main environmental threat...
Environmental Biology of Fishes
Characterizing species occurrence, abundance, and distribution is critical to the management of n... more Characterizing species occurrence, abundance, and distribution is critical to the management of natural resources and the conservation of biodiversity. In the Western Caribbean, little information exists on the occurrence of aquatic mammals along the Mesoamerican Barrier Reef System and adjacent aquatic ecosystems. Herein, we present the first comprehensive review of aquatic mammals encountered in the marine and freshwater habitats of Belize. To determine which aquatic mammal species occur in Belizean waters, we conducted an extensive review of published and unpublished reports of aquatic mammals. We located 163 unique reports from museum and animal collections , journal articles, theses, news reports, conference proceedings, institutional reports, and verified accounts from personal observations. Our review confirms the presence of 17 aquatic mammal species in Belize: 15 cetaceans ((Trichechus manatus manatus), and one carnivore (Lontra longicaudis annectens). Our findings provide the most up-to-date list of aquatic mammal presence in Belize. Given the limited data points obtained for most identified species, we recommend that systematic studies be conducted to investigate the status of the variety of aquatic mammals in the region to effectively monitor populations and devise strategies to mitigate the negative impacts of anthropogenic activity and climate change-related ecosystem shifts.
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Papers by Carlos Alberto Niño Torres