Giant Squid and Colossal Squid Fact Sheet (page 2 of 2)

By Dr. Steve O'Shea and Kat Bolstad -- Last updated: April 6, 2008

Dr. O'Shea and Kat Bolstad are members of the TONMO.com staff. You can communicate with them both in our Cephalopod Science forums.

<<< BACK TO PAGE ONE <<<

Size
Popular press has focussed on the size of this squid, and there has been considerable debate at an academic level as to whether the Colossal Squid is actually the largest squid, because the Giant Squid, Architeuthis dux, attains a greater total length.

There are several ways in which squid are measured (and in which their size or length may be exaggerated): Total Length relaxed (post mortem); Total Length when the animal is live (and outstretched); Standard Length, the length of the animal minus its two long tentacles; estimated length (the one that got away); weight; and, most inappropriately, length relative to a London double-decker bus.

As this Colossal Squid is likely to make international press, information often is misquoted. For your ease we've provided a few conversions below:

1 foot = 0.3048 metres (alternatively, 1 metre = 3.2808 feet)
1 kilogram = 2.2 pounds (alternatively, 1 pound = 0.5kg)

Therefore, a 2.5m ML Colossal Squid of 300kg is equivalent to an 8.202 foot ML Colossal Squid weighing 660 lbs; the 495kg Colossal Squid to be defrosted at the end of April 2008 weighs in at a colossal 1089 lbs.

The specimen reported on April 1, 2003 was a submature female of ML 2.5 m; despite it being extensively damaged it weighed ~300kg, and had a Total Length of 5.4m. At the time it was both the heaviest squid known to science, and squid with the longest mantle (reliable measures). The lower beak of this particular specimen had a rostral length (LRL) of 38mm. Lower beaks of Mesonychoteuthis are known to 49mm LRL, so we know that this species grows considerably larger. In late April we actually will be examining at least four Mesonychoteuthis: the 495kg specimen; a second, evidently extensively damaged specimen weighing ~150kg; and several considerably smaller specimens more recently taken in Antarctic waters.

Just how big does Mesonychoteuthis get? Well, we don't know; the largest LRL currently known measures 49mm. The first thing that we will do when this specimen is completely defrosted is measure LRL, and should this be less than 49mm we will know that Mesonychoteuthis gets even larger and heavier than the specimen we have.

Next we will determine the sex of the specimens (as a rule female squid attain a larger size than males), and their state of reproductive maturity will be appraised. Both sex and an indication of maturity provide insights into the realistic maximum size of a species.

Fig. 10

New Zealand reports based on analysis of stomach contents of long-distance foraging marine predators

Beaks attributed to this species have previously been encountered in stomachs of sperm whales caught in or proximal to northernmost eastern and western New Zealand waters (Clarke & MacLeod 1982), from one stranded specimen on Paekakariki Beach (Clarke & Roper 1998), and otherwise from numerous stranded specimens from beaches around New Zealand (Gomez-Villota 2007). They are also reported from wandering albatross chick regurgitations from Antipodes Islands (Imber 1992) and immediately south of New Zealand (Australian waters), Macquarie Island (Imber 1978, 1992). However, despite these five citations from local waters, and a sixth, as yet unpublished Macquarie Island record (an actual specimen trawled from 1143m), none of them confirms that the species occurs here, as wandering albatross, Diomedia exulans, average in excess of 1200 km from the nest site in search of prey (Jouventin & Weimerskirch 1990), and sperm whales, especially large males, undertake extensive migrations (O'Shea 1997). Mesonychoteuthis beaks have been reported from sperm whale stomachs captured off California (Fiscus et al. 1989), so the whales obviously retain some beaks in the stomach for considerable periods of time.

The occurrence of Mesonychoteuthis beaks in stomachs of female and small male sperm whales is intriguing, as these predators normally occur north of 40°S, while the squid are primarily reported from south of 40°S. Therefore Mesonychoteuthis, presently known from Antarctic waters, could extend as far north as 40°S, with the Subtropical Convergence delimiting the species' northern distribution (Clarke 1980). If true this would place this species in New Zealand waters, extending from a latitude equivalent to Christchurch through to the Chatham Islands.

In the southern hemisphere, female and young male sperm whales (to ~39 feet in length) are not normally found in latitudes higher than 40°S, while large males occur in Antarctic waters; large bulls must migrate from the lower-latitude breeding areas into colder Antarctic waters (the smallest male reported from the Antarctic was 35 feet in length (Clarke 1972). The male stranded on Mahia Peninsula 28/11/2002 was 13 metres (42 feet) in length, and its stomach contained 7 lower Mesonychoteuthis beaks. It had probably only recently migrated back from the Antarctic, and had likely made few migrations to the region in its life.

Closest record (unreported): between Macquarie Island and Stewart Island, ~140 n. miles south of New Zealand waters, an immature female, ML (when fresh) 0.9m (coordinates 53°49.30'S, 159°04.44'E), from 1143m.

Reproduction: Unknown; mature male unknown.

REFERENCES

Cherel, Y.; Duhamel, G. 2004. Antarctic jaws: cephalopod prey of sharks in the Kerguelen waters. Deep-Sea Research I 51: 17–31.

Clarke, M.R. 1962. The identification of cephalopod "beaks" and the relationship between beak size and total body weight. Bulletin of the British Museum (Natural History), Zoology 8(10): 419-480.

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

Clarke, M.R. 1980. Cephalopoda in the diet of sperm whales of the southern hemisphere and their bearing on sperm whale biology. Discovery Reports 37: 324 pp.

Clarke, M.R.; MacLeod, N. 1982. Cephalopod remains from the stomachs of sperm whales caught in the Tasman Sea. Memoirs of the National Museum Victoria 43: 25-42.

Clarke, M.R.; Roper, C.F.E. 1998. Cephalopods represented by beaks in the stomach of a sperm whale stranded at Paekakariki, North Island, New Zealand. South African Journal of Marine Science 20: 129-133.

Engeser, T.S.; Clarke, M.R. 1988. Cephalopod hooks, both recent and fossil. The Mollusca 12: 133–150.

Fiscus, C.H.; Rice, D.W.; Wolman, A.A. 1989. Cephalopods from the stomachs of sperm whales taken off California. NOAA Technical Report NMFS 83: 1-12.

Gomez-Villota F 2007. Sperm whale diet in New Zealand. Unpublished MAppSc thesis. Division of Applied Sciences, Auckland University of Technology, Auckland, New Zealand. 221 p.

Herring, P.J.; Dilly, P.N.; Cope, C. 2002. The photophores of the squid family Cranchiidae (Cephalopoda: Oegopsida). Journal of Zoology 258: 73-90.

Imber, M.J. 1978. The squid families Cranchiidae and Gonatidae (Cephalopoda: Teuthoidea) in the New Zealand region. New Zealand Journal of Zoology 5: 445-484.

Imber, M.J. 1992. Cephalopods eaten by wandering albatrosses (Diomedia exulans L.) breeding at six circumpolar localities. Journal of the Royal Society of New Zealand 22(4): 243-263.

Kirk, T.W. 1887. Brief description of a new species of large decapod (Architeuthis longimanus) . Transactions and Proceedings of the New Zealand Institute 20: 34–39 + 3 Pls.

Klumov, S.K.; Yukhov, V.L. 1975. Mesonychoteuthis hamiltoni Robson, 1925 and its importance in the feeding of sperm whales in the Antarctic. Antarctica 14: 159–189. [Russian]

Lu, C.C.; Williams, R. 1994. Contribution to the biology of squid in the Prydz Bay region, Antarctica. Antarctic Science 6(2): 223–229.

McSweeny, E. 1970. Description of the juvenile form of the Antarctic squid Mesonychoteuthis hamiltoni Robson. Malacologia 10(2): 323–332.

Nesis, K.N. 2003. Distribution of Recent Cephalopoda and implications for Plio-Pleistocene events. Berliner Pal�obiologische Abhandlungen 3: 199-224.

O'Shea, S. 1997. Status of three Octopoda recorded from New Zealand, based on beaks recovered from long-distance foraging marine predators. New Zealand Journal of Zoology 24: 265–266.

Robson, G.C. 1925. On Mesonychoteuthis, a new genus of oegopsid Cephalopoda. Annals and Magazine of Natural History (series 9) 16: 272 –277, 2 figures.

Rodhouse, P.G.; Clarke, M.R. 1985. Growth and distribution of young Mesonychoteuthis hamiltoni Robson (Mollusca: Cephalopoda): an Antarctic squid. Vie Milieu 35(3/4): 223-230.

Voss, N.A. 1980. A generic revision of the Cranchiidae (Cephalopoda: Oegopsida). Bulletin of Marine Science 30(2): 365-412.

Xavier, J.C.; Croxall, J.P.; Trathan, P.N.; Rodhouse, P.G. 2003. Inter-annual variation in the cephalopod component of the diet of the wandering albatross, Diomedea exulans, breeding at Bird Island, South Georgia. Marine Biology 142: 611–622.

Young, J.Z. 1984. The statocysts of cranchiid squids (Cephalopoda). Journal of Zoology 203: 1–21.

<<< BACK TO PAGE ONE <<<

Note: Steve and Kat welcome discussion in the Physiology & Biology forum of the TONMO.com Message Board.