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Family BRACHIOTEUTHIDAE

Arm Squids


Compiler and date details

2012 - Updated by Julian Finn, Museum Victoria, Carlton, Victoria, Australia

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

Introduction

Members of the family Brachioteuthidae are small to medium sized squid (less than 100 mm mantle length (ML)), with slender muscular mantles, sometimes produced as a short tail.

The taxonomy of the family is presently unstable and a thorough revision is required (Roper & Jereb 2010). Prior to 2001, the family Brachioteuthidae was considered to be monogeneric with the five nominal genera synonymised with Brachioteuthis Verrill. Lipinski (2001) described a new genus Slosarczykovia, with 1 species, and a new species of Brachioteuthis. Seven species, in two genera, are currently recognised as valid (Roper & Jereb 2010), with one species recorded from Australian waters.

Brachioteuthis riisei (Steenstrup) was first recorded from Australian waters by Allan (1945). It has since been taken in midwater trawls in an eddy of the East Australian Current (Brandt 1983). Lu & Phillips (1985) listed only B. riisei from Australian waters, although Nesis (1979) assigned specimens in his net collections to B. behni (Steenstrup) and Clarke (1966) reported B. picta Chun from the southern Indian Ocean and around New Zealand.

Adult Brachioteuthis are rarely caught and the available information on the biology of the group is patchy. The larvae are distinguished from all other squid larvae, except those of chiroteuthids, by their unusually long neck. The neck appears to be a single muscular, fluid-filled tube continuous with a large fluid-filled reservoir within the mantle. In the doratopsis larvae of chiroteuthids the neck is also elongate but is supported by many separate chambers. Larval Brachioteuthis are believed to orientate in a head down position—a drifting bell with tentacles hanging ready to capture prey (Young et al. 1986).

The eggs of a Brachioteuthis species have been taken occasionally in plankton nets in Hawaiian waters, and Young et al. (1986) suggested that females spawn single eggs, as in the Enoploteuthidae. Unlike enoploteuthids, however, adult brachioteuthid females lack nidamental glands. The lack of seasonality in occurrence of larvae in eastern Australian waters suggests that this species spawns throughout the year (Allan 1945). The diet of Brachioteuthis is not known, but a species of Brachioteuthis forms part of the diet of sperm whales caught off Iceland following their migration north from the Southern Ocean (Martin & Clarke 1986).

Larval Brachioteuthis around Hawaii are diel vertical migrators, occurring in the upper 50 m at night and descending to 100 to 150 m during the day (Young et al. 1986). The distribution of adults is unknown although they have been caught in midwater trawls in subtropical oceanic waters off central New South Wales.

Eggs collected in plankton nets have been successfully hatched in onboard aquaria off Hawaii (Young et al. 1986). In East Australian Current waters north of 32°S, eggs at the hatching stage and early hatchlings have been caught in abundance during the summer months and may lend themselves to laboratory study of early growth and development.

 

Diagnosis

Brachioteuthids have a slender, muscular mantle, a simple, straight funnel locking cartilage and biserial suckers on the arms. Lateral arms in adults have swimming keels. The tentacular club is expanded with numerous small suckers in the carpal region, extending proximally along the club. The buccal connectives attach ventrally to the ventral arms. The terminal fins are rhombic, generally less than 50% of the mantle length. No light organs are present.

 

General References

Allan, J. 1945. Planktonic cephalopod larvae from the eastern Australian coast. Records of the Australian Museum 21: 317-350 pls 24-27

Brandt, S.B. 1983. Pelagic squid associations with a warm-core eddy of the East Australian Current. Australian Journal of Marine and Freshwater Research 34: 573-585

Clarke, M.R. 1966. A review of the systematics and ecology of oceanic squids. Advances in Marine Biology 4: 91-300

Lipinski, M.R. 2001. Preliminary description of two new species of Cephalopods (Cephalopoda: Brachioteuthidae) from South Atlantic and Antarctic waters. Bulletin of the Sea Fisheries Institute, Gdynia 152: 3-14

Lu, C.C. & Phillips, J.U. 1985. An annotated checklist of Cephalopoda from Australian waters. Occasional Papers of the Museum of Victoria 2: 21-36

Martin, A.R. & Clarke, M.R. 1986. The diet of sperm whales (Physeter macrocephalus) captured between Iceland and Greenland. Journal of the Marine Biological Association of the United Kingdom 66: 779-790

Nesis, K.N. 1979. A brief zoogeographic survey of the pelagic zone around Australia and New Zealand (Cephalopods). Trudy Instituta Okeanologii. Akademiya Nauk SSSR. Moskva 106: 125-139 [in Russian]

Roper, C.F.E. & Jereb, P. 2010. Family Brachioteuthidae. pp. 129-134 in Jereb, P. & Roper, C.F.E. (Eds). Cephalopods of the world. An annotated and illustrated catalogue of species known to date. Volume 2. Myopsid and Oegopsid Squids. FAO Species Catalogue for Fishery Purposes. No. 4. Rome : FAO Vol. 2 pp. 1-605.

Young, R.E., Harman, R.F. & Mangold, K.M. 1986. The eggs and larvae of Brachioteuthis sp. (Cephalopoda, Teuthoidea) from Hawaiian waters. Vie et Milieu 35(3/4): 203-209

 

History of changes

Note that this list may be incomplete for dates prior to September 2013.
Published As part of group Action Date Action Type Compiler(s)
20-Mar-2014 TEUTHIDA 20-Mar-2014 MODIFIED Dr Julian Finn (NMV)
12-Feb-2010 (import)