Largetooth Cookiecutter Shark, Isistius plutodus Garrick & Springer, 1964
Introduction
The Largetooth Cookiecutter Shark has a cigar-shaped body, a short conical snout and two low, spineless dorsal fins. It has a row of 19 huge teeth (proportionately the largest of any shark species) in the lower jaw. Its anteriorly placed eyes may enable binocular vision.
What do Largetooth Cookiecutter Sharks look like?
Identification
The Largetooth Cookiecutter Shark has a cigar-shaped body, a short conical snout and two low, spineless dorsal fins. It has a row of 19 huge teeth (proportionately the largest of any shark species) in the lower jaw. Its anteriorly placed eyes may enable binocular vision.
The species looks similar to the Smalltooth Cookiecutter Shark. The two species can be separated base on tooth size (25-32 rows in lower jaw in the Smalltooth Cookiecutter Shark), colouration and fin placement.
Where are Largetooth Cookiecutter Sharks found?
Distribution
This species is recorded off Australia from specimens caught off Newcastle, New South Wales and in the Coral Sea, Queensland. Known mostly from subtropical near shore waters in the Western Atlantic and Western Pacific Oceans. Found from surface waters to 1000m or deeper, this species is considered to migrate vertically towards the surface at night.
The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums. Source: Atlas of Living Australia.
What do Largetooth Cookiecutter Sharks eat and how do they mate?
Feeding and diet
The Largetooth Cookiecutter Shark feeds in a similar manner to the Smalltooth Cookiecutter shark, Isistius brasiliensis. It uses is large jaw and fleshy lips to bite plugs of muscle from the bodies of larger marine creatures. The shark clamps onto its prey and bites down with the large teeth of the lower jaw, twisting and moving its body in a circular motion to gouge out a ‘cookie sharped’ piece of flesh.
The Largetooth Cookiecutter Shark possibly, due to the size of the teeth, is able to gouge out a more elongate cone like plug. The Largetooth Cookiecutter also feeds on squid and bony fish.
Reproduction
Very little is known about the biology of these sharks as they are rarely found in trawls. Thought to be viviparous with similar size litters to that of the Smalltooth Cookiecutter of 9.
References
- Compagno, L.J.V. 1984. FAO species catalogue. Vol.4, Sharks of the world. An annotated and illustrated catalogue of shark species known to date. Part I - Hexanchiformes to Lamniformes: viii, 1-250. FAO Fisheries Synopsis 125: 1-249.
- Garrick, J.A.F & Springer, S. 1964. Isistius plutodus, a New Squaloid Shark from the Gulf of Mexico. Copeia (4): 678-682.
- McGrouther, M.A. 2001. First record of the Large-tooth Cookie-Cutter Shark, Isistius plutodus from Australian waters. Memoirs of the Queensland Museum 46(2): 442.
- Zidowitz, H., Fock, H.O., Pusch, C. & H. Von Westernhagen. 2004. A first record of Isistius plutodus in the north-eastern Atlantic. Journal of Fish Biology. 64: 1430-1434.
- Bray, D.J. 2018, Isistius plutodus in Fishes of Australia, accessed 29 Aug 2022, https://fishesofaustralia.net.au/home/species/3511
- Last, P.R. & Stevens, J.D. 2009. Sharks and Rays of Australia. Collingwood : CSIRO Publishing Australia 2, 550 pp.