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Email the author (Login required) Feeding habits of the Pacific sharpnose shark Rhizoprionodon longurio in La Paz Bay, Baja California Sur, Mexico
Submited: 2026-03-05 19:22:43 | Published: 2026-08-18 17:19:00
DOI: https://doi.org/10.3856/vol54-issue4-fulltext-3634
Abstract
The Pacific sharpnose shark, Rhizoprionodon longurio, is a small coastal carcharhinid widely distributed in the eastern Pacific and an important component of artisanal fisheries in Mexico. This study analyzed the feeding habits of R. longurio in La Paz Bay, Baja California Sur. Forty-two individuals were examined, with total length, sex, and capture site recorded. Stomach contents were extracted, and prey were identified to the lowest possible taxonomic level. Ecological and statistical analyses were applied to characterize the diet. Of the total individuals, 26 were males and 16 females. Twenty-one prey taxa were identified, with teleost fishes representing the dominant prey group based on frequency and numerical contribution. Calamus brachysomus (relative importance index, %RII = 18.87) and members of the family Hemiramphidae (%RII = 9.54) were the most representative prey. Females consumed mainly C. brachysomus (%RII = 54.47), whereas males showed higher consumption of Diodon hystrix (%RII = 18.62) and D. holocanthus (%RII = 18.20). The species exhibited a generalist trophic strategy (Bi = 0.83). Analysis of similarity indicated high dietary overlap between sexes (R = 0.084) and maturity stages (R = 0.021). This study documents, for the first time, the consumption of Hemiramphidae and Diodontidae by R. longurio in the Gulf of California, highlighting its dietary plasticity and ecological role as a coastal predator.
