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Email the author (Login required) Biology of the guitar ray Rhinobatos leucorhynchus (Günther, 1867) (Rajiformes: Rhinobatidae) in the Colombian Pacific
DOI: https://doi.org/10.3856/vol39-issue2-fulltext-10
Abstract
The guitar ray Rhinobatos leucorhynchus is commonly caught as by-catch of industrial and artisanal shrimp trawling in the shallow waters of the Colombian Pacific. The biological aspects of this species were studied using 286 animals caught as by-catch between 2001 and 2007. The females were proportionally larger than males, although growth was similar (allometric) for both sexes. The embryos showed no significant differences by sex in either size or weight. The adult sex ratio was 2.4:1 (females-males), whereas in embryos this ratio was 1:1. 51.5% of males, 51.5% had developed, calcified claspers, and 56.5% of females were pregnant, carrying between 1 and 6 embryos of 3 to 19.5 cm, suggesting a size at birth of 19 to 19.5 cm TL. The median size at maturity for females was lower than that of males (48.48 cm and 51.18 cm TL, respectively), and the females had embryos starting at 44 cm TL. The feeding habits of this species showed 30 prey items, with shrimp from the Penaeidae family and especially Trachypenaeus sp. as main food. The diets of male and female guitar rays differed significantly, and the niche breadth indicated that this species has a specialist diet. The results of this study provide useful information for proposing management measures for R. leucorhynchus, a species that requires attention given its biological characteristics and its importance in terms of commerce and human consumption.
