Halavi Guitarfish: Glaucostegus halavi

Family: Glaucostegidae
Common name(s)

Halavi Guitarfish.

Identification

A large guitarfish with a relatively wide, short, pointed snout with a rounded tip. Rostral ridges joined along most of snout length. Rostral cartilage posterior margin sharply demarcated. Eyes small. Snout length 6.3-7.8 x orbit length. Spiracles with two short, widely separated skin folds. Nasal flaps barely extend posteriorly beyond nostril opening.
Anterior margins of disc straight or weakly convex. Pectoral apices broadly rounded. Skin covered in small denticles, appearing rough along rostral ridge, between eyes, on shoulders, and along centreline. Small thorns present around eyes, single larger thorn on each shoulder, and in a continuous row along medial ridge from nape to tail.
Tail robust, slightly longer than disc length. Dorsal fins large and well separated, with narrowly rounded apices. Caudal fin triangular, without a defined lower caudal lobe.

Colour

Dorsum yellowish to greyish-brown and unmarked. Rostral cartilage pale. Ventrum white.

Size

Maximum length 171cm. Size at birth ~29cm.

Habitat

Tropical seas. Benthic on sandy substrates and sea grass. From very shallow water to at least 100m.

Distribution

Northwestern Indian Ocean. The halavi guitarfish is present from Kenya to India, including the Arabian Sea and Red Sea.

Halavi Guitarfish

Conservation Status

CRITICALLY ENDANGERED

The Halavi Guitarfish is found over a small range within a heavily fished region on the Indian Ocean and Gulf of Arabia. It is a retained component of bycatch and a directly targeted species. Consequently, significant declines in landings have been reported in the United Arab Emirates; 80% population reduction over the last 30 years.

Halavi Guitarfish
Reproduction

Aplacental viviparous. Litter size ~10.

Diet

Diet consists mainly on benthic invertebrates.

Behavior

Enters very shallow water to feed. In the Red Sea, the halavi guitarfish reproduces from May to October.

Reaction to divers

Usually skittish.

Diving logistics

The halavi guitarfish is seen fairly regularly by divers and snorkelers in the Red Sea. For example at Gorgonia Beach off Marsa Alam, Egypt.

Similar species

Sharpnose Guitarfish Distinguished longer, more acutely pointed snout.