Mazatlan Butterfly Ray, Longsnout Butterfly Ray.
A small butterfly ray with a wide, vaguely kite-shaped disc. Disc width approximately 1.6-1.9 x length. Pectoral fin apices angular. Snout short and broadly obtuse. Snout shorter and more rounded in females and juveniles, slightly longer and more angular in mature males.
Eyes very small. No tentacle present on posterior margins of spiracles. Spiracle has a deeply concave inner margin. Mouth arched with a convex symphysis on lower jaw.
Skin completely smooth. Tail short. Dorsal fin absent. Caudal sting absent.
Dorsum overall brownish-grey, pinkish-grey in juveniles. Usually with a pattern of very small, irregular, dark spots and paired larger diffuse dark blotches. Dorsum sometimes unmarked. Ventrum white with dark margin and pectoral fin tips. Tail subtly banded.
Maximum disc width 81cm. Disc width at birth unknown.
Tropical to warm-temperate water. On sandy or muddy substrates, often in shallow bays and estuaries, and on sandy slopes from intertidal to at least 30m.
Eastern Pacific Ocean. Sea of Cortez, Mexico, to northern Peru.
The Mazatlan Butterfly Ray (Gymnura crebripunctata) is captured in artisanal gillnets, beach seines, and longlines, and in industrial demersal trawl fisheries that target shrimp and hake. Artisanal fishing pressure is intense throughout most of its range, and there are trawl fisheries operating in the Gulf of California and off Pacific Mexico, in Costa Rica, and in Colombia. Landings of Gymnura species (G. crebripunctata and G. marmorata) in the Gulf of California have generally been stable between 1997 and 2014, although effort has been steadily increasing. There are no data on population trends further south, but intense fishing pressure and a lack of management are suspected to be leading to reductions, although this species is still relatively common in landings, and may have life history traits that make it productive enough to withstand some fishing. Overall, given the intensity of fishing pressure across its range and the stability in Mexican landings (although with increasing pressure), it is suspected that the Mazatlan Butterfly Ray has undergone a population reduction of 20–29% over the past three generations (45 years) based on levels of exploitation, and it is assessed as Near Threatened (nearly meeting Vulnerable A2d).
Pollom, R., Avalos, C., Bizzarro, J.J., Burgos-Vázquez, M.I., Cevallos, A., Espinoza, M., González, A., Herman, K., Mejía-Falla, P.A., Morales-Saldaña, J.M., Navia, A.F., Pérez Jiménez, J.C., Sosa-Nishizaki, O. & Velez-Zuazo, X. 2020. Gymnura crebripunctata. The IUCN Red List of Threatened Species 2020: e.T14134431A124549206. https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T14134431A124549206.en. Accessed on 06 February 2022.
Viviparous. Litter size unknown.
Diet unrecorded but probably feeds mostly on small fishes like other butterfly rays.
Sedentary. Camouflages its body with sand by flapping its fins while resting on the bottom.
Reaction to divers
Fairly tolerant but will bolt if approached closely or if divers attempt to waft sand away from its disc.
Relatively common in Guanacaste, Costa Rica. I have encountered this species in January in Playa El Jobo and Playa Del Coco. More common during the colder months from December to February.