Family LYCOTEUTHIDAE

Museums

Museum list

Regional Maps

Family LYCOTEUTHIDAE

Compiler and date details

C.C. Lu, National Chung Hsing University, Taichung, Taiwan

Introduction

The family Lycoteuthidae Pfeffer, 1908 contains small to medium-sized squid (less than 200 mm mantle length) that inhabit the pelagic and benthic zone of the upper slope of the continental shelf from the tropical to the warm temperate region. Five species in four genera are known worldwide, assigned to two subfamilies. Lampadioteuthinae Berry, 1916 comprises a single genus, Lampadioteuthis Berry, 1916, diagnosed by presence of four light organs on the eye. Lycoteuthinae Pfeffer, 1908 has five light organs on the eyes and comprises three genera: Lycoteuthis Pfeffer, 1908; Selenoteuthis Voss, 1958; and Nematolampas Berry, 1913 (Roper et al. 1969; Toll 1983).

Pfeffer (1912) described a specimen of Lycoteuthis diadema (Chun, 1900) from south of Western Australia. Lycoteuthis diadema and L. lorigera (Steenstrup, 1875) were recorded for the first time from south-eastern Australian waters by Lu & Phillips (1985). No lampadioteuthine species have been recorded from Australian waters.

The considerable sexual dimorphism in this relatively rare family, until recently when until additional specimens of both sexes were examined, gave rise to taxonomic confusion (Toll 1983). The two nominal species, L. diadema and L. lorigera, are now recognised as conspecific, with Lycoteuthis lorigera having nomenclatural priority (Toll 1983; Forch & Uozumi 1990). Male L. lorigera (reported as L. diadema) diverge from the typical oegopsid pattern in having paired genital ducts (G. Voss 1962), but whether this is characteristic of all lycoteuthids is unknown. No information is available on life histories of any lycoteuthids.

Studies on the feeding biology of a fish, Macruronus novaezelandiae (blue grenadier), from the continental slope around Tasmania, have shown that lycoteuthids are a significant component of the diet of this species (Bulman & Blaber 1986). Around New Zealand, petrels commonly feed on lycoteuthids (Imber 1975), and elsewhere they are preyed upon by sperm whales and dolphins (Clarke 1966). In turn, lycoteuthids feed on fish, including myctophids, and on pelagic crustaceans (G. Voss 1962).

G. Voss (1962) considered that Lycoteuthis lorigera (reported as L. diadema) in the Gulf of Mexico occurs mainly at depths of 300 to 600 m and its larvae in the upper 50 m. Occurrence of this species in demersal trawl catches off eastern Tasmania suggests that it may be associated with the bottom during part of the day. Extensive diel vertical migration is characteristic of the genus Selenoteuthis elsewhere; Roper & Young (1975) suggested that diel migration is typical of the family. Of the four recognised genera, only Lycoteuthis occurs in Australian waters, from off southern New South Wales and eastern Tasmania; worldwide this genus occurs in subtropical oceanic waters.

Diagnosis

The funnel locking cartilage is simple and straight. The arms have biserial sharp-toothed suckers and the tentacular clubs have tetraserial suckers. The buccal connectives attach to the dorsal border of the ventral arms and light organs are present on the viscera, at the apex of the mantle and in some genera on the ventral surface of the eyes. Sexual dimorphism is highly developed in some genera, males having brachial photophores and the mantle photophores larger and more numerous than in the female; in males, the posterior mantle and the dorso-lateral arms are elongate.