Striped guitarfish  (Zapteryx exasperata)

Classified as Data Deficient (DD) on the IUCN Red List (1).

In common with other guitarfish, the head and pectoral fins of the striped guitarfish are fused, forming a broad triangular-shaped disc (2) (3). While the mouth and the gill slits are located on the underside of the head, the eyes and the spiracles (large respiratory openings) are situated on the dorsal surface (3) (4). The positioning of the spiracles enables the ray to take in water clear of sand and silt, and pump it over the gills whilst resting on the bottom (4). The body is slender and shark-like, with two equal sized dorsal fins and a moderately large, rounded caudal fin. The dorsal surface is a sandy-brown to grey colour, with prominent dark bars and irregular blotches, while the underside is considerably lighter (3) (4). In addition, numerous star-shaped prickles are scattered over the dorsal surface, and a row of an enlarged thorns runs down the middle of the back (3).

The striped guitarfish occurs in the eastern Pacific, where is it reported from central California south to Peru. However, records of its occurrence south of Mazatlan, Mexico in Central and South American waters may actually be attributable to the southern banded guitarfish (Zapteryx xyster) (1) (2).

The striped guitarfish mostly inhabits rocky reefs, shallow, sandy lagoons and near shore waters, from depths of 2.5 to 10 metres, but can be found from the intertidal zone down to 200 metres (1).

The striped guitarfish is relatively inconspicuous during the day, remaining hidden in caves and under ledges. At night however, this docile ray becomes fairly active, foraging over rocky reefs for food. Crustaceans, such as crabs and shrimp, as well as other benthic invertebrates are thought to be its main prey (2).

Male and female striped guitarfish appear to be highly segregated, with mixed schools of adults only occurring during a short mating period from March to April. Mating generally occurs in shallow bays and lagoons, where the females tend to congregate from January through to August. After a gestation period lasting three to four months, the female gives birth to four to eleven live pups. Almost nothing is known about the movements of this species after breeding, although it appears to migrate into deeper waters (1) (2).

Aside from during the breeding season, when large aggregations of striped guitarfish are targeted by fisherman in the Gulf of California and Baja California, Mexico, this species is not commonly caught. However, it is not clear whether this is because the species is particularly uncommon, or rather that for a significant proportion of the year it occurs in areas that are not heavily fished. In addition to the episodic exploitation of this species, the modification of bays and estuaries to support shrimp farms could be having a negative impact on its breeding grounds in Mexico (1).

Although elasmobranch fisheries management legislation is currently being developed in Mexico, there is currently no formal management plan in place for the striped guitarfish. Given how little is known about this species, especially in relation to its geographic distribution and its movements outside of the breeding season, further research is extremely important. Data on its life history, movement patterns, and catch rates will be essential in determining the true conservation status of the striped guitarfish and the measures necessary to maintain its population (1).

View information on this species at the UNEP World Conservation Monitoring Centre.

To find out more about the conservation of rays and sharks, see:

• Save Our Seas Foundation:
  www.saveourseas.com
• IUCN Shark Specialist Group:
  www.iucnssg.org
• Shark Research Institute:
  www.sharks.org
• Shark Trust:
  www.sharktrust.org