Elsman's Whipnose, Gigantactis elsmani Bertelsen, Pietsch & Lavenberg, 1981
Elsman's Whipnose Anglerfish
A second species of whipnose angler is also recorded from Australian waters. Paxton's Whipnose Angler G. paxtoni Bertelsen & Pietsch, 1983, was named after Australian Museum Research Fellow, Dr John Paxton.
Introduction
Adult female Elsman's Whipnose have a long whip-like lure attached to the tip of the snout and needle-like teeth. Adults live in the deep oceanic waters of most oceans, usually well above the bottom.
Identification
Female Elsman's Whipnose can be recognised by the length and structure of the long whip-like lure attached to the tip of the snout. This species has a relatively elongate body and a long caudal peduncle and caudal fin. The needle-like teeth are arranged in approximately five rows.
The genus Gigantactis contains 21 species, all of which show extreme sexual dimorphism (differences between males and females). The largest females grow to 40cm in length, whereas the largest males only grow to 2.2cm. Males have highly developed sense organs that are presumably used to find females.
Habitat
The species is rarely seen, with very few specimens in research collections. It lives in the deep oceanic waters of most oceans, usually well above the bottom.
The fish in the image is a 31 cm standard length female (AMS I.28742-001) that was collected by Australian Museum staff on HMAS Cook, April 1989, in the Tasman Sea off Sydney, New South Wales. The specimen was collected by midwater trawl between the surface and 1800m over a bottom depth of 1700m to 4856m. It is the only specimen of this species known from Australian waters.
Distribution
Very few specimens collected from the Eastern Atlantic, North-west Pacific and Australia.
The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums. Source: Atlas of Living Australia.
Other behaviours and adaptations
Moore (2002) reported on the first underwater observations of three whipnose anglerfish (G. vanhoeffeni or G. perlatus). The fish were recorded on video at a depth of approximately 5000 m in the North Pacific about halfway between California and Hawaii. All three fish were upside-down with their fins splayed and mouths slightly open. Their lures were "stiffly held in a slight arc out in front of the fish".
References
- Bertelsen, E., & Pietsch, T.W. 1983. The Ceratioid Anglerfishes of Australia. Records of the Australian Museum. 35: 77-99.
- Bertelsen, E., Pietsch, T.W. & Lavenberg, R.J. 1981. Ceratioid anglerfishes of the family Gigantactinidae: morphology, systematics, and distribution. Contribributions in Science. (Los Angeles) 332: 1-74.
- McGrouther, M.A. 2001. First record of Elsman's Whipnose Anglerfish, Gigantactis elsmani (Lophiformes: Gigantactinidae) from Australian waters. Memoirs of the Queensland Museum 46(2): 646.
- Moore, J.A. 2002. Upside-Down Swimming Behaviour in a Whipnose Anglerfish (Teleost: Ceratioidei: Gigantactinidae). Copeia (4): 1144-1146.
- Pietsch, T.W. 1999. Gigantactinidae. Whipnose anglerfishes (deepsea anglerfishes) In Carpenter, K.E & Niem, V.H. (eds) FAO species identification guide for Fishery purposes. The Living Marine Resources of the Western Central Pacific. Vol. 3. FAO. Pp. 2068.