Moller's Lanternshark, Etmopterus molleri (Whitley, 1939)

Introduction

Moller's Lanternshark Etmopterus molleri, is a deepwater shark found in the Southwest Pacific.

Etmopterus molleri is a species of shark from the family Etmopteridae, which is the largest family in the order Squaliformes. There are considered to be 46 species found worldwide in five genera. In Australia 12 species are known from the Centroscyllium (1) and Etmopterus (11) genera. Moller's Lantershark was recognised and described as a new species by Australian Museum Ichthyologist, Gilbert Whitley in 1939.

Lanternsharks are named as such because they can bioluminesce.

Identification

Moller's Lanternsharks have a fusiform (tapering at both ends; spindle-shaped) body, are slender and have a long caudal peduncle. The snout is short, eyes large, and the second dorsal fin is about twice the size of the first dorsal fin. Both dorsal fins have spines.

Generally, Moller's Lanternsharks are light brown dorsally and darker brown fading to black ventrally. The upper caudal fin tip is dark, usually with a pale strip extending from the pectoral fin to the pelvic fins.

Lanternsharks are very special fish as they can bioluminesce. This means they can produce and emit their own light. Lanternsharks, use their hormonally-controlled photogenic organs, called photophores, for bioluminescent signaling or to disguise their sillouette in the water column when viewed from below, a common pelagic camouflage tactic called “counter illumination”. They typically have bioluminescent flank markings (between the pectoral and pelvic fins).

Habitat

Moller’s Lanternshark has been recorded on the outer continental and insular shelves, and upper slopes at depths of 238 to 655 m. Thought to be born at around 15cm and maximum size is approximately 46 cm total length (TL). Little else is known of the biology of these fishes.

Distribution

Moller's Lanternshark has been found along eastern Australia off Sydney, New South Wales and New Zealand. They are found on the outer continental, insular shelves and upper slopes of the ocean from depths of 238 to 700m.

Lanternsharks are generally not threatened by fishing activities as they are small and have no commercial value. However, the Moller’s Lanternshark is likely taken as bycatch in deepwater trawl fisheries off eastern Australia. They are harmless to humans.