Elasmobranch species in the artisanal fishery of Sucre State, Venezuela

Abstract

A wide diversity of elasmobranch species has been reported for waters off Venezuela; however, information regarding this group is lacking for most coastal regions. This study aimed to determine the species composition in catches made by the artisanal fishery of Sucre State, Venezuela, and to analyze size structure by sex for the most common species. During the study period (January 2016-September 2017), visits were made to the main fish markets in the city of Cumaná, Sucre State, and a total of 2,167 elasmobranchs belonging to 24 species (15 sharks and 9 rays) were quantified. The most frequently captured elasmobranch species were Mustelus higmani (36.2%), Mustelus canis (18.0%), Hypanus guttatus (15.1%), and Hypanus americanus (7.1%). The size ranges for these species were 29.3-73.7 cm total length (TL), 34.0-86.0 cm TL, 17.0-138.0 cm disc diameter (DD), and 48.0-108.0 cm DD, respectively. Considering national conservation assessments (following International Union for Conservation of Nature criteria), 7 of the species reported for the study area (M. higmani, Carcharhinus limbatus, Carcharhinus falciformis, Isurus oxyrinchus, Alopias superciliosus, Prionace glauca, and Aetobatus narinari) are listed as vulnerable, and the remaining species (n = 17) have not been assessed. Current conservation efforts in Venezuela are deficient given the collapse of government institutions responsible for the management of fisheries. This has led to noncompliance with fishing regulations designed for elasmobranchs. In the future, great effort must be made to continue generating information; however, future advances in scientific research and conservation will depend largely on the recovery of the economic and political stability in Venezuela.

Age and growth of the shark, Mustelus higmani (Carcharhiniformes: Triakidae) from Venezuela

“…The size structure of M. higmani reported in the present study is similar to the pattern observed previously for this species in the Northeastern region of Venezuela (Macias, 2017;Márquez et al, 2019). The differential pattern by sex in relation to maximum sizes (i.e.…”

“…The differential pattern by sex in relation to maximum sizes (i.e. females larger than males) as observed for M. higmani is common in species of the genus Mustelus Sidders, Tamini, Pérez, & Chiaramonte, 2005;Farrell et al, 2010;Márquez et al, 2019), as well in other groups of sharks (Hoenig, & Gruber, 1990;Cortes, 2000). Regarding results on the general sex proportion of the specimens captured in artisanal fishery, we did not find a significant difference between sexes; however, a previous seasonal analysis by Macias (2017) revealed the presence of sexual segregation during some periods of the year.…”

“…Mustelus higmani is a viviparous placentotrophic species with an annual reproductive cycle; the litter size varies between 2 and 9 pups, and feeds primarily on crustacea, small bony fish and squid (Compagno et al, 2005;Tavares et al, 2010). In Venezuela, this species is particularly abundant in the Northeastern region, and is the most frequently captured in artisanal shark fishery (40.8-36.2 %, Tavares et al, 2010;Márquez, Tavares, & Ariza, 2019). Despite the commercial importance of M. higmani, this species has not been well studied in the region, and there is a lack of information regarding its biology and fishery, which has hindered the stock assessment.…”

Reproductive biology and placentotrophic embryonic development of the smalleye smooth-hound shark, Mustelus higmani, from the south-eastern Caribbean

“…The commercial landings of M. higmani in the study area comprised a wide range of lengths, 23.2–72.5 cm TL in females and 22.6–62.5 cm TL in males, but with a predominance of captures in the ranges of 52.0–66.0 and 46.0–56.0 cm TL for females and males, respectively. The pattern of size composition observed in this study is similar to those previously reported for the same species in other studies conducted in the north-eastern coast of Venezuela (Tavares et al ., 2010; Marquez et al ., 2019). The sexually dimorphic maximum sizes (favouring M. higmani females) appear to be a common characteristic of mustelid sharks, having also been reported for M. canis from the east coast of the USA (Conrath & Musick, 2002) and northern Brazil (Zagaglia et al ., 2011), M. schmitti in common waters of Uruguay and Argentina (Oddone et al ., 2005; Belleggia et al ., 2012), M. henlei from the Gulf of California, Mexico (Perez-Jimenez & Sosa-Nishizaki, 2008) and M. asterias in the north-eastern Atlantic (Farrell et al ., 2010; McCully Phillips & Ellis, 2015).…”

“…were commonly captured as bycatch by industrial trawl fleets targeting shrimp (FAO, 2001) until the prohibition of this fishery in 2005. Mustelus higmani is an abundant shark in the north-eastern region and around Margarita Island where it is the species most frequently caught by the artisanal shark fishery, accounting for 36.2–40.8% of the shark landings numerically (Tavares et al ., 2010; Márquez et al ., 2019). Nevertheless, due to the small size of Mustelus species, this group represents ~6% of the total elasmobranch production in the eastern Venezuelan Caribbean (Tavares, 2019).…”