Rhinoptera steindachneri
Pacific Cownose Ray [+]

Kingdom: Animalia
Phylum: Chordata
Class: Elasmobranchii
Order: Myliobatiformes
Family: Myliobatidae
Genus: Rhinoptera
species: steindachneri
+ITIS +WoRMS

Description & Behavior

A common stingray, the Pacific cownose ray, Rhinoptera steindachneri (Evermann and Jenkins, 1891), is a member of the Family Myliobatidae or eagle rays and is also called the golden or hawk ray. The Pacific cownose has a subrostral (below the front edge) lobe with a median notch. It has a single dorsal fin near the base of a long whip-like tail, and one or two stingers at the base of the tail. It is dark brown or golden on the dorsal side with a creamy white ventrum (underside). Maximum width 90 cm; reef-associated; marine; depth range 0-30 m. Often observed in small groups and sometimes in large schools.

World Range & Habitat

This is the only species in this genus known in the Eastern Pacific: Gulf of California to Peru and the Galápagos Islands. Found over soft bottoms, near rocky or coral reefs and reef drop-offs. Occasionally found near the surface and can jump out of the water. Often in schools, sometimes associated with Aetobatus narinari, the spotted eagle ray.

» GBIF occurrence data in Google Earth [Tips] | Ocean Biogeographic Information System (OBIS) (World Distribution) [about]

Feeding Behavior (Ecology)

Feeds on benthic crustaceans and mollusks. The soft subrostral fins are used to probe the substrate in search of bivalve prey and may serve to detect water expelled from a clam's siphon or the weak bioelectric field generated by a bivalve. To excavate their prey, they dig deep depressions up to 40 cm in depth in bottom sediment by flapping the pectoral fins and by sucking sediment through the mouth and expelling it out of the gill slits. The flat tooth plates, present on both jaws, are used to grind their hard shelled prey.