Eastern Shovelnose Ray: Aptychotrema rostrata

Family: Trygonorrhinidae
Common name(s)

Eastern Shovelnose Ray, Long-snout Guitarfish.

Identification

A medium-sized shovelnose ray with a very long, narrow, acutely pointed snout with narrowly separated rostral ridges. Eyes small. Snout length 5.7-7.6 x orbit length. Spiracles without lobes or skin folds. Nostrils transverse. Nasal curtain absent. Small, pointed nasal flaps barely extend posteriorly beyond nostril opening.
Anterior margins of disc weakly concave with subtle convexity at eye level. Pectoral apices angular, posterior margins broadly rounded. Skin covered in small denticles. 2-3 pre-orbital thorns, 1-2 thorns over spiracle, 2 groups of small thorns on each shoulder (poorly defined in adults), and 18-20 midline thorns along back and tail.
Tail robust, 1.2 x disc length. Dorsal fins large and well separated, with narrowly rounded apices. Caudal fin triangular, without a defined lower caudal lobe.

Colour

Dorsum greyish-brown with large, diffuse, darker brown, dusky blotches. Blotches on snout may be golden. Rostral cartilage pale. Ventrum white with irregular small dark flecks.

Size

Maximum length 120cm. Size at birth 13-15cm.

Habitat

Tropical/warm-temperate seas. Benthic on sandy beaches, estuaries, sometimes adjacent to coral reefs, and offshore on continental shelf. From close inshore to 220m but usually shallower than 100m.

Distribution

Southwestern Pacific. Confined to the east coast of Australia from Halifax Bay in north Queensland, southward to Merimbula in southern New South Wales.

Conservation Status

LEAST CONCERN

The Eastern Shovelnose Ray is a regular bycatch in a variety of commercial fisheries, particularly trawl fisheries, which operate across much of its range. It is either discarded or retained and marketed depending on location (in Queensland trawl fisheries it cannot be retained, whereas in New South Wales it can be marketed). This species is also regularly taken by recreational fishers. Despite high levels of bycatch and its occurrence within a geographic area which is subject to considerable fishing activities, this species is assessed as Least Concern, given its abundance in a wide variety of habitats. Refuges are available in some marine protected areas, in particular Moreton Bay Marine Park. Elsewhere, declines have been documented in inshore rhinobatids (for example, the Brazilian Guitarfish (Rhinobatos horkelii) in southern Brazil), and bycatch levels should be monitored to gain data on the species’ population status.

Citation

Kyne, P.M. & Stevens, J.D. 2015. Aptychotrema rostrataThe IUCN Red List of Threatened Species 2015: e.T161596A68609037. https://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T161596A68609037.en. Downloaded on 23 May 2021.

Reproduction

Aplacental yolksac viviparous. Litter size 4-18. Gestation length 3-5 months.

Diet

Feeds mainly on benthic crustaceans and small fishes.

Behavior

Enters shallow estuaries to feed. Rarely moves offshore; maximum recorded depth limit stems from only 2 individuals that were caught at 220m.

Reaction to divers

Easy to approach. Can be skittish but generally tolerant of divers unless molested.

Diving logistics

The eastern shovelnose ray is a common guitarfish (locally called a banjo ray) in Northern New South Whales. One particularly good spot to find this species is while shore diving on the main beach at South West Rocks. On one dive in July I encountered 5 individuals laying on the shallow sand between the coral heads.

Similar species

Western Shovelnose Ray Distinguished by slightly broader, shorter snout, and more westerly range from southern and western Australia.