Featured Elasmobranch – Banded Guitarfish

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Featured Elasmobranch – Banded Guitarfish

Raya_copyPhotograph Courtesy of Maria del Pilar Blanco

 

Banded Guitarfish

September 2009

 

Zapteryx exasperata (Jordan & Gilbert, 1880)

 

Family Rhinobatidae (Guitarfishes)

Identification: A guitar-shaped ray with a broad disc that is about twice as wide as it is long. The dorsal surface is covered with numerous, small to large, scattered, stellate prickles and a single median row of enlarged thorns running along the mid-back. Coloration on the dorsal surface is a distinctive sandy brown to dark gray, with several prominent black bars, but lighter on the ventral surface.

Size: A moderate-sized guitarfish with females reaching a maximum total length of 97 cm and males a maximum length of 83 cm.

Distribution: This species ranges from southern California to at least Mazatlan, Mexico.

Habitat: A warm-temperate to tropical guitarfish species it is usually found on rocky reefs from the intertidal zone to a depth of 69 m.

Biology: A viviparous species with litters of 4 to 11 young, with the size at birth being between 15-22 cm. Males mature between 64-70 cm and females between 57-77 cm. mating takes place around March and birth takes place 3-4 months afterward, usually in July. Males and females appear to be highly segregated, with females tending to congregate in the shallower waters of bays and lagoons. The diet consists of crustaceans, including shrimps and crabs, and other benthic invertebrates. During the day they are usually found resting in caves or under ledges, but at night they become quite active as they forage for food.

General interest: Occasionally taken as by-catch by recreational and commercial fishers in southern California they are of no commercial importance, but in Mexican waters they are a commercially important species. These are relatively docile rays and may easily be approached by divers.

By David A. Ebert

Pacific Shark Research Center

Moss Landing Marine Laboratories

8272 Moss Landing Road

Moss Landing, CA 95039

debert@mlml.calstate.edu