Pacific cownose ray – Rhinoptera steindachneri

The Pacific Cownose Ray, scientifically known as Rhinoptera steindachneri, is a fascinating species of ray found in the Pacific Ocean. It is a distinctive member of the Rhinopteridae family, which is characterized by its unique cow-like snout.

Description & Characteristics

The Pacific Cownose Ray is a relatively large species, reaching a maximum size of 91.6 cm. Its body is flattened and diamond-shaped, with a broad, wing-like pectoral fins that extend forward to form its distinctive cow-like snout. The ray’s tail is long and slender, with a single, venomous spine located near its base. This spine serves as a defense mechanism against predators. The coloration of the Pacific Cownose Ray varies depending on its habitat. The dorsal surface is typically a grayish-brown, while the ventral surface is a lighter shade of white or cream.

Habitat and Occurrence

The Pacific Cownose Ray is a demersal species, meaning it lives primarily on or near the seabed. It is commonly found in shallow coastal waters, bays, and estuaries, with a depth range of 0.0 – 65.0 meters. This species has been reported from the marine zones of the North Pacific Ocean. This includes the Eastern Pacific, extending from California to Chile, as well as the Western Pacific, where it ranges from the Sea of Japan to Australia.

Taxonomy

The species Rhinoptera steindachneri belongs to the Class: Elasmobranchii, which includes sharks, rays, and skates. This class falls under the Order: Myliobatiformes, which encompasses a wide variety of rays characterized by their flattened bodies and large pectoral fins. The Pacific Cownose Ray further belongs to the Family: Rhinopteridae, which includes other cownose rays with similar morphological features.

Feeding

The Pacific Cownose Ray is a carnivorous species that primarily feeds on crustaceans. Using its flattened body and cow-like snout, it digs into the sandy seabed in search of prey, primarily crabs, shrimp, and other small invertebrates. The ray uses its powerful jaws to crush its prey before swallowing it whole.