Banded Guitarfish: Zapteryx exasperata

Family: Trygonorrhinidae

Common name(s)

Banded Guitarfish.

Identification

A fairly large guitarfish with a shovel-shaped body, and a short, obtusely pointed snout with a rounded tip. Rostral ridges widely separated throughout their length. Eyes large. Preorbital length 3-4 x orbit width. Spiracles without lobes or skin folds. Nostrils thin, transverse, and widely spaced. Nasal curtain absent. Nasal flaps extend slightly over nostril opening.
Anterior margins of disc weakly convex. Pectoral apices broadly rounded. Dorsum covered in granular denticles. Ventral denticles much smaller and less distinct. Small orbital thorns. Much larger thorns present in two short rows on each shoulder and in a continuous row on midline from nape to first dorsal fin.
Tail fairly robust. Dorsal fins closely spaced, with narrowly rounded apices and convex posterior margins. Caudal fin triangular, without a defined lower caudal lobe, but sometimes with a small notch in posterior margin.

Colour

Dorsum and fins beige or greyish-brown with many diffuse darker blotches that sometimes form vaguely transverse bars across disc. Blotches on snout and anterior to eyes often black. Rostral cartilage imperceptible; colour identical to dorsum. Ventrum mostly white with a dark blotch near pectoral apices.

Size

Maximum length 97cm. Size at birth 15-18cm.

Habitat

Tropical/warm-temperate seas. Benthic in sandy bays, around coral reefs, in kelp forests, and offshore on continental shelf. From very close inshore to 200m.

Distribution

Eastern Pacific. Found from central California to at least Mazatlán, México. Records from beyond southern Mexico probably refer to the Southern banded guitarfish (Zapteryx xster).

Conservation Status

DATA DEFICIENT

The Banded Guitarfish (Zapteryx exasperata) is taken in artisanal fisheries on the Pacific coast of Baja California and in the Gulf of California, México. In the directed batoid fishery on the Pacific coast of Baja California (in Bahía Almejas), fishermen target aggregations of primarily gravid females during late spring and early summer months in nearshore and inshore nursery grounds. Within the Gulf of California, it is rare in catches (however catch and landings data are scarce outside of Sonora). Exceptions may be during reproductive aggregations and possible large catches by shrimp trawlers, although information on indirect landings by commercial trawls and gillnets is lacking. It is not known if this is relatively uncommon species, as landings would suggest, or if it simply occupies areas that are not heavily fished. To confirm the status of this species, its distribution needs to be accurately documented and abundance data should be obtained at least along the Pacific coast of Baja California and in the Gulf of California. Due to a lack of certainty on geographic range, and a poor understanding of natural abundance, the Banded Guitarfish is assessed as Data Deficient. This species is potentially at threat due to targeting of reproductive aggregations and generally unregulated artisanal fishing across its Mexican range. When further information is obtained the species’ conversation status should be reassessed with priority.

Citation

Bizzarro, J.J. & Kyne, P.M. 2015. Zapteryx exasperata. The IUCN Red List of Threatened Species 2015: e.T60177A80673370. https://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T60177A80673370.en. Downloaded on 29 May 2021.

Reproduction

Aplacental viviparous. Litter size 2-13. Gestation length 5-6 months.

Diet

Adults feed mainly on benthic fishes.

Behavior

Enters shallow water (2-10m) during the summer months, retreating to deeper water in the fall and winter. Segregates by sex for much of the year.

Reaction to divers

Easy to approach. Can be skittish but generally tolerant of divers; remaining motionless unless harassed.

Diving logistics

Banded Guitarfish congregate in the lower Sea of Cortez during the winter months. In late February in Cabo Pulmo they were present during every dive on the reef at about 15m.