First Insight into the Biological Aspects of the Crocodile Shark Pseudocarcharias kamoharai in the Eastern Pacific Ocean
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First Insight into the Biological Aspects of the Crocodile Shark Pseudocarcharias kamoharai in the Eastern Pacific Ocean Colombo Estupiñán-Montaño 1
&
Felipe Galván-Magaña 2
Received: 20 April 2020 / Revised: 18 August 2020 / Accepted: 19 August 2020 # Springer Nature Switzerland AG 2020
Abstract The crocodile shark Pseudocarcharias kamoharai (Matsubara, 1936) is a species caught incidentally off the coast of Ecuador with no commercial importance in the country. As with many elasmobranch species, very little is known about its general biology. The aim of this study was to provide baseline information to enhance the knowledge on various aspects of the biology of this species. During the years 2003–2009, a total of 59 individuals of P. kamoharai were landed by commercial fishing in Ecuadorian waters. The total length (TL) ranged 50–113 cm. On average, the females were larger than males (91.8 ± 2.2 and 84.1 ± 4.1, respectively) and the number of females captured was higher (sex ratio = 1.9F:1M). Based on the morphology of the claspers, males were considered mature at 80 cm TL and at a clasper length of 6 cm, and 70% of the males caught were mature. The squid Ancistrocheirus lesueuri was the only prey observed in two shark stomachs with food from 59 shark stomachs analyzed. This study provides biological information of P. kamoharai in Ecuador and will help as a baseline to generate data and increase our knowledge of the biology of this shark species in the eastern Pacific Ocean. Keywords Feeding habits . Pseudocarchariidae . Sex ratio . Maturity stage
Introduction The crocodile shark Pseudocarcharias kamoharai (Matsubara, 1936) (Fig. 1a) is a small shark of the order Lamniformes, and it is the only representative of the family Pseudocarcharhiidae. It has a distribution in all of the world’s oceans. It is an epipelagic and mesopelagic species, occurring from the surface to a depth of 590 m (Compagno 2001). In the eastern Pacific Ocean, P. kamoharai is distributed from Mexico to northern Chile (Bearez et al. 2001; Compagno 2001; Meléndez et al. 2006). The crocodile shark usually occurs offshore, although it is sometimes found inshore (Compagno 2001). There is scarce information regarding the biology of P. kamoharai in the eastern Pacific Ocean. It has been previously reported that it feeds on small pelagic fish * Colombo Estupiñán-Montaño [email protected] 1
Fundación Alium Pacific, Carrera 26 No. 5C–13, Santiago de Cali, Colombia
2
Centro Interdisciplinario de Ciencias Marinas, Instituto Politécnico Nacional, Av. IPN s/n., C.P. 23096 La Paz, Baja California Sur, Mexico
(Myctophidae, Gonostomatidae), benthic crustaceans, and mesopelagic cephalopods (Compagno 2001). Previous studies report that this species exhibits matrotrophic viviparity and oophagy (Fujita 1981; Gilmore 1993; Oliveira et al. 2010) with two embryos in each uterus (White 2007; Oliveira et al. 2010; Dai et al. 2011). Size at birth ranges from 35 to 46 cm total length (TL) (Fujita 1981; White 2007; Lessa et al. 2015), while males reach maturity
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