Diet of three shark species in the Ecuadorian Pacific, Carcharhinus falciformis, Carcharhinus limbatus and Nasolamia velox

Abstract

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.

Trophic inference in two sympatric sharks, Sphyrna lewini and Carcharhinus falciformis (Elasmobranchii: Carcharhiniformes), based on stable isotope analysis at Malpelo Island, Colombia

“…These results agree with other studies that have estimated a high trophic position for sharks (Cortés 1999, Bornatowski et al 2014, Li et al 2014, Hussey et al 2015, Estupiñán-Montaño et al 2017.…”

“…The silky shark, Carcharhinus falciformis, feeds mainly on teleosts but also on cephalopods and crustaceans (Cabrera-Chávez et al 2010, Duffy et al 2015, Estupiñán-Montaño et al 2017) and, occasionally, on sea turtles (Estupiñán-Montaño et al 2017, Acevedo unpublished * ). This species is considered to be a selective predator in the ETP, with a preference for the scombrid genus Thunnus (see Duffy et al 2015, Estupiñán-Montaño et al 2017, which normally inhabits oceanic zones and forms schools near seamounts.…”

“…This species is considered to be a selective predator in the ETP, with a preference for the scombrid genus Thunnus (see Duffy et al 2015, Estupiñán-Montaño et al 2017, which normally inhabits oceanic zones and forms schools near seamounts. Previous results are in line with those of the present study, as the depleted 13 C values obtained here (Tables 1 and 2) are typical of oceanic areas.…”

“…Carcharhinus falciformis feeds on a large number of prey species, from pelagic and coastal fishes (e.g., tunas, mullets, mackerel) to cephalopods, crustaceans, and sea turtles (Cabrera-Chávez-Costa et al 2010, Duffy et al 2015, Estupiñán-Montaño et al 2017). This shark is considered a piscivorous predator, consuming mainly fishes of the Scombridae family (Duffy et al 2015, Estupiñán-Montaño et al 2017.…”

Description and characterization of the artisanal elasmobranch fishery on Guatemala’s Caribbean coast

“…Similarly, for the capture of rays, longlines were more frequently used Fishing gears used to catch Chondrichthyan fish landed in this study. Data were grouped according to the following authors: a. Compagno [28], b. Compagno [29], c. Estupiñan-Montaño et al [42], d. Estupiñan-Montaño et al [43], e. Estupiñan-Montaño et al [44], f. Estupiñan-Montaño et al [45], g. Carpenter [46] and Ebert [47].…”