Small-scale shark and ray fisheries are conducted throughout Central America's Caribbean coast. Yet, there is limited information regarding catch composition and diversity of these fisheries, especially in Guatemala. Surveys of catch landings were conducted in two of Guatemala's primary Caribbean coastal shark and ray fishing communities, El Quetzalito and Livingston, between January 2015 and July 2017. Biological data from 688 landed chondrichthyans were collected, with 31 species (24 sharks, six rays and one chimaera) identified. The four most frequently captured species included Carcharhinus falciformis (30.2%), Sphyrna lewini (12.7%), Hypanus guttatus (12%) and Rhizoprionodon spp. (6.7%). Landed sharks contained most size classes with a high proportion of juveniles of species with low productivity. The large-bodied species C. falciformis and S. lewini were often recorded at sizes below known maturity; 96.6% and 85.1%, of the captured individuals were immature, respectively. This study can serve as a baseline to determine future trends in the elasmobranch fisheries conducted by Guatemala's Caribbean coastal communities and support assessments on the persistence of the fisheries. OPEN ACCESS Citation: Hacohen-Domené A, Polanco-Vásquez F, Estupiñan-Montaño C, Graham RT (2020) Description and characterization of the artisanal elasmobranch fishery on Guatemala's Caribbean coast. PLoS ONE 15(1): e0227797. https://doi.org/ 10.

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Considering the prey habitat, S. lewini is an oceanic predator which consumed oceanic prey, mainly cephalopods; whereas the juvenile sharks can predate on oceanic cephalopods and also on coastal prey from benthic habitat such as fish and crustaceans. IntroducciónLa falta de información y conocimientos biológico sobre tiburones en el Ecuador y en el mundo no permite establecer planes de manejo o conservación adecuados para la protección de las especies de tiburones más explotadas comercialmente. Por ello es importante realizar investigaciones que favorezcan el incremento de los conocimientos de las especies de tiburones en cada país, los cuales deben incluir el estudio de su biología básica tales como reproducción, edad, crecimiento, hábitos alimenticios y comportamiento.El estudio de los hábitos alimenticios permite comprender el papel funcional de los organismos dentro de las comunidades marinas y aporta información de zonas importantes de alimentación y crianza de tiburones para poder recomendar, junto con otros estudios biológicos, medidas de conservación o manejo adecuado de especies de tiburones (Galván et al. 1989).Los tiburones actúan como carroñeros ayudando a eliminar de las aguas los animales muertos y enfermos, manteniendo el equilibrio ecológico trófico de los ecosistemas marinos. A pesar de la importancia ecológica que los tiburones desempeñan en su ambiente, solo se cuenta con información biológica de algunas especies de tiburones a nivel mundial. En este contexto, el presente Material y métodosSe recolectaron estómagos de 116 tiburones martillo provenientes de aguas ecuatorianas durante enero a diciembre de 2004. El área de estudio estuvo comprendida entre 02ºN y 02ºS y desde la costa hasta 84ºW. El puerto de desembarque de tiburones fue Manta, en Ecuador. De cada ejemplar se registró su longitud total (LT). Posteriormente se extrajo el tracto digestivo de cada ejemplar mediante la disección de los organismos. Los contenidos estomacales fueron tamizados a través de una red de 1,5 mm de luz de malla, y posteriormente depositados en bolsas de plástico y preservados en hielo para su traslado al laboratorio. En el momento de la disección, se determinó el estado de madurez sexual de los tiburones, el que fue clasificado como juveniles y adultos, basado en observaciones directas del aparato reproductor y según la escala de madurez propuesta por Bejarano (2007).El contenido estomacal fue separado y las presas fueron clasificadas según su grupo taxonómico, identificándose hasta el menor taxón posible, dependiendo del grado de digestión que éstas presentaban. Para la determinación taxonómica se utilizaron diferentes claves de identificación, en el caso de los peces se utilizaron las claves de Clothier (1950), Rubio (1988), Fischer et al. (1995, Chirichigno (1998), García-Godos (2001); mientras que para identificar cefalópodos, se usaron las claves de Wolff (1984) y Clarke (1986). Debido al estado de digestión avanzado de los cefalópodos, la identificación se basó en las estructuras del aparato mandibular...

Sharks are apex predators in marine ecosystems and play an important role in regulating prey populations at lower trophic levels (e.g., fish, invertebrates, reptiles, mammals and birds) (Ellis et al., 1996).The bull shark, Carcharhinus leucas (Müller and Henle, 1839), and the tiger shark, Galeocerdo cuvier (Péron and Lesueur, 1822), are common worldwide in tropical and subtropical coastal areas (Compagno, 1984). The bull shark grows to a large size (over 340 cm) (Compagno, 1984) and frequently inhabits shallow water (max. depth 30 m) (Compagno, 1984). It is one of the few shark species that is physiologically capable of spending time in fresh water (Pillans and Franklin, 2004) and has been reported in rivers and lakes (Thorson et al., 1973;Thomerson et al., 1977;Montoya and Thorson, 1982; Simpendorfer et al., 2005). The tolerance of bull sharks for low-salinity conditions allows them to frequent areas close to shore and near river mouths, where they may interact with other shark species (Carlson et al., 2010). The tiger shark reaches a larger size than the bull shark (over 550 cm) (Compagno, 1984), with a wide tolerance for different marine habitats at depths ranging from the surface to 140 m. This species

We analysed the stomach contents of 69 silky sharks Carcharhinus falciformis, 44 blacktip sharks Carcharhinus limbatus and 24 whitenose sharks Nasolamia velox caught in the Ecuadorian Pacific from August 2003 to December 2004. Prey included bony fishes, elasmobranchs, molluscs, crustaceans and turtles, with bony fishes being the most important to the diets of all three sharks, suggesting they are piscivorous predators. Based on the index of relative importance, the C. falciformis diet includes Thunnus albacares, Thunnus sp. and Auxis thazard, as well as some squid, fish and turtles. Similarly, the C. limbatus diet was dominated by T. albacares, Exocoetus monocirrhus, A. thazard, Katsuwonus pelamis, members of the Ophichthidae family and other elasmobranchs. Meanwhile, N. velox consumed mainly Dosidicus gigas, Larimus argenteus, Cynoscion sp. and Lophiodes spilurus. There is little competition for food between these tertiary carnivores: C. limbatus prefers prey from coastal-oceanic habitats; C. falciformis consumes mostly oceanic prey and N. velox focuses on prey from coastal habitats. The lack of information on the biology of sharks in Ecuador hinders the development of appropriate management and conservation plans to protect shark resources. This study increases our knowledge and understanding of sharks in Ecuador, thus contributing to their conservation.

Changes in feeding habits during ontogeny show that organisms can present shifts in foraging behavior during their life cycle, which can alter local trophic dynamics. Therefore, describing diet across species ontogeny clarifies the ecological niche and ecosystem role of marine predators. In this study, diet tracers (stable isotope analysis) were analyzed in 16 scalloped hammerhead sharks Sphyrna lewini, using δ13C and δ15N values of collagen in vertebral cross-sections to reconstruct diet across their ontogeny. Our results suggest that S. lewini occupies a broad isotopic niche due to the consumption of prey belonging to different trophic levels (δ15N: 7.6-13.0‰) of the food chain in both coastal and oceanic zones (δ13C: -17.2 to -14.1‰) during their lifetime. Accordingly, ontogenetic changes in diet and habitat use were suggested by differences in δ13C and δ15N across age groups, indicating high consumption of coastal prey at 0-2 yr, oceanic prey at ~2-4 yr, a shift to high coastal prey at >4 yr, and a shift to high coastal prey, along with the consumption of prey from multiple trophic levels through feeding ontogeny (estimated trophic position: 2.9-6.5). This study showed migration from coastal to oceanic zones in juvenile S. lewini, and their return to coastal habitats as adults, potentially related to the use of coastal zones (i.e. mangroves) in the Eastern Tropical Pacific, both as important feeding areas for neonates and as feeding and breeding grounds for adults.

As apex predators, sharks are known to play an important role in marine food webs. Detailed information on their diet and trophic level is however needed to make clear inferences about their role in the ecosystem. A total of 335 stomachs of smooth hammerhead sharks, Sphyrna zygaena, were obtained from commercial fishing vessels operating in the Ecuadorian Pacific between January and December 2004. A total of 53 prey items were found in the stomachs. According to the Index of Relative Importance (%IRI), cephalopods were the main prey (Dosidicus gigas, Sthenoteuthis oualaniensis, Ancistrocheirus lesueurii and Lolliguncula [Loliolopsis] diomedeae). Sphyrna zygaena was thus confirmed to be a teutophagous species. The estimated trophic level of S. zygaena was between 4.6 and 5.1 (mean ± SD: 4.7 ± 0.16; males: 4.7; females: 4.8). Levin's index (BA) was low (overall: 0.07; males: 0.08; females: 0.09), indicating a narrow trophic niche. We found that sharks <150 cm in total length consumed prey of coastal origin, whereas sharks ≥150 cm foraged in oceanic waters and near the continental shelf. The analyses indicate that S. zygaena is a specialized predator consuming mainly squids.

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