Green lanternshark Etmopterus virens, from the NOAA.

Belongs within: Selachimorpha.
Contains: Squalus.

The Squalidae, spiny dogfishes, are a group of sharks characterised by the lack of anal fin, with the two dorsal fins often preceded by a fixed spine. The majority of species are found in deeper waters, with shallower-water species mostly found in colder regions.

Just when you thought it was safe
Published 28 July 2011
Smalltooth cookiecutter shark Isistius brasiliensis, photographed by Joshua Lambus.

Sometimes, you can get pretty much everything you need to know from the title of an article alone. To whit:

First documented attack on a live human by a cookiecutter shark (Squaliformes, Dalatiidae: Isistius sp.)

The article itself is in a journal I don’t have access to, but I can read the abstract: the person attacked was a long-distance swimmer in Hawaii and was bitten twice. The bite was treated with skin grafts, but still took nine months to finish healing.

Cookiecutter sharks are one of the more fascinatingly evil fish out there. They are small, as sharks go (up to about 50 cm, tops) but have proportionately oversized teeth that are arranged in a tight, single-row array that can be protruded outwards to take a neat plug out of the flesh of a larger animal: hence the name of ‘cookiecutter’. The effectiveness of the cutting tooth row is maintained by being replaced all at once, rather than individual teeth being replaced piecemeal as in other sharks. Cookiecutters are rarely encountered by humans as they are generally deep sea fish, living below the light zone, but like many mesopelagic animals they appear to migrate closer to the surface at night (Papastamatiou et al. 2010). Bioluminescent photophores behind the head have been suggested to function as a lure, drawing larger fish, dolphins, etc. into range of an ambush. Cookiecutters have very catholic tastes, and evidence of bites has been recorded from just about any decent-sized pelagic animal. They will even bite the external insulation on submarines.

Fish with cookiecutter bites, from Rick Macpherson (who, it turns out, covered this event when it was first happened).

Given their lack of pickiness, it is hardly surprising that a cookiecutter would take a bite out of a human. Of course, humans very rarely venture into the pelagic environment in which cookiecutters can be found. The very fact that the Hawaii indicent is the first confirmed attack indicates how extremely rare this would be expected to be. The Wikipedia page on cookiecutters refers to possible attacks on shipwreck survivors (though the source page linked to does not provide citations for such reports), and the body of a drowned fisherman was recovered in Hawaii with cookiecutter bites. But unless you happen to be swimming in the open ocean at night, your chances of being bitten by a cookiecutter are low.

Systematics of Squalidae
<==Squalidae [Dalatiidae, Spinacidae]
| |--Dalatias licha (Bonnaterre 1788)G60b (see below for synonymy)
| `--Isistius Gill 1864CDZ93, O89
| |--I. brasiliensis (Quoy & Gaimard 1824)G60b
| |--I. plutodusB96
| `--I. trituratus (Winkler 1874)CDZ93
|--Oxynotinae [Oxynotidae]CDZ93
| |--Protoxynotus misburgensis Herman 1975CDZ93
| `--OxynotusG60b
| |--O. bruniensis (Ogilby 1893)G60b
| |--O. centrina (Linnaeus 1758)G60a
| `--O. paradoxus Frade 1929G60a
| |--Cretascymnus adonis (Signeux 1950)CDZ93
| `--SomniosusG60b
| |--S. antarcticus Whitley 1939G60b
| |--S. microcephalus (Bloch & Schneider 1801)B02
| |--S. pacificusB02
| `--S. rostratusB02
| |--Eoetmopterus Müller & Schollmann 1989CDZ93
| | |--‘Etmopterus’ hemmoorensis Herman 1982CDZ93
| | `--E. supracretaceus Müller & Schöllmann 1989CDZ93
| `--EtmopterusG60b
| |--E. baxteri Garrick 1957G60b
| |--E. brachyurus Smith & Radcliffe 1912G60b
| |--E. gracilospinousB96
| |--E. lucifer Jordan & Snyder 1902G60b (see below for synonymy)
| |--E. perryiB02
| |--E. princeps Collett 1904G60a
| |--E. spinaxPP64
| `--E. virensW92
|--Protosqualus albertsii Thies 1981CDZ93
|--Squalogaleus Maisey 1976CDZ93
| `--S. woodwardi Maisey 1976CDZ93

Squalidae incertae sedis:
Euprotomicrus bispinatus (Quoy & Gaimard 1824)G60b
Centroscyllium fabricii (Reinhardt 1825)G60b, B02
|--S. albicaudaVF21
`--S. sherwoodi (Archey 1921) [=Scymnodon sherwoodi]G60b
Heteroscymnoides marleyi Fowler 1934G60b
Cirrhigaleus Tanaka 1912G60b
`--C. barbifer Tanaka 1912G60b
|--S. laticaudus Smith & Radcliffe 1912G60b
`--S. sarmenti Noronha 1926G60b
|--C. coelolepis Bocage & Capello 1864B02
|--C. crepidater (Bocage & Capello 1864)G60b
`--C. owstonii Garman 1906G60b
|--S. ichiharaiC84
|--S. plunketi (Waite 1910)G60b (see below for synonymy)
|--S. rossiNM72
`--S. squamulosus [incl. S. obscurus]C84
|--D. calcea (Lowe 1839)G60b (see below for synonymy)
|--D. elegans Springer 1959G60a
|--D. natalense (Gilchrist 19220G60a
|--D. profundorum (Smith & Radcliffe 1912)G60a
`--D. quadrispinosa (McCulloch 1915)G60b
Centrophorus Müller & Henle 1833 [incl. Atractophorus Gilchrist 1922]NM72
|--C. acus Garman 1906G59
|--C. armatus (Gilchrist 1922) [=*Atractophorus armatus]NM72
|--C. granulosusBY99
|--C. harrissoni McCulloch 1915G60b
|--C. scalptratus McCulloch 1915G60b
|--C. squamosus (Bonnaterre 1788)G60b (see below for synonymy)
`--C. uyatoG59
Centropterus lividus Costa 1861CDZ93

Centrophorus squamosus (Bonnaterre 1788)G60b [incl. C. foliaceus Gunther 1877G59, Scymnodon foliaceusG59, C. nilsoni Thompson 1930G59]

Dalatias licha (Bonnaterre 1788)G60b [=Scymnus lichiaG60a; incl. Scymnorhinus phillippsi Whitley 1931G60a, Dalatias phillippsiG60a]

Deania calcea (Lowe 1839)G60b [=Acanthidium calceumG60a, Centrophorus calceusG60a; incl. A. aciculatum Garman 1906G60a, Deania aciculataG60a, D. eglantina Jordan & Snyder 1902G60a, Acanthidium hystricosum Garman 1906G60a, D. hystricosaG60a, Centrophorus kaikourae Whitley 1934G60a, D. kaikouraeG60a, Acanthidium rostratum Garman 1906G60a, D. rostrataG60a]

Etmopterus lucifer Jordan & Snyder 1902G60b [incl. E. abernethyi Garrick 1957G60a, Acanthidium molleri Whitley 1939G60a, E. molleriG60a]

Scymnodon plunketi (Waite 1910)G60b [=Centrophorus plunketiG59; incl. Centrophorus waitei Thompson 1930G60b, G59, Centroscymnus waiteiG59]

*Type species of generic name indicated


[B96] Bond, C. E. 1996. Biology of Fishes 2nd ed. Saunders College Publishing: Fort Worth.

[B02] Burgess, G. H. 2002. Spiny dogfishes. Family Squalidae. In: Collette, B. B., & G. Klein-MacPhee (eds) Bigelow and Schroeder’s Fishes of the Gulf of Maine 3rd ed. pp. 48–57. Smithsonian Institute Press: Washington.

[BY99] Burrow, C. J., & G. C. Young. 1999. An articulated teleostome fish from the Late Silurian (Ludlow) of Victoria, Australia. Records of the Western Australian Museum Supplement 57: 1–14.

[CDZ93] Cappetta, H., C. Duffin & J. Zidek. 1993. Chondrichthyes. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 593–609. Chapman & Hall: London.

[C84] 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 2—Carcharhiniformes. United Nations Development Programme, Food and Agriculture Organization of the United Nations: Rome.

[G59] Garrick, J. A. F. 1959. Studies on New Zealand Elasmobranchii. Part VII.—The identity of specimens of Centrophorus from New Zealand. Transactions of the Royal Society of New Zealand 86 (1): 127–141.

[G60a] Garrick, J. A. F. 1960a. Studies on New Zealand Elasmobranchii. Part XI.—Squaloids of the genera Deania, Etmopterus, Oxynotus and Dalatias in New Zealand waters. Transactions of the Royal Society of New Zealand 88 (3): 489–517.

[G60b] Garrick, J. A. F. 1960b. Studies on New Zealand Elasmobranchii. Part XII. The species of Squalus from New Zealand and Australia; and a general account and key to the New Zealand Squaloidea. Transactions of the Royal Society of New Zealand 88 (3): 519–557.

[L58] Linnaeus, C. 1758. Systema Naturae per Regna Tria Naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata. Laurentii Salvii: Holmiae.

[NM72] Nair, R. V., & S. L. Mohan. 1972. The deep sea spined dog fish Centrophorus armatus (Gilchrist) (Selachii: Sualidae) from the east coast of India, with a note on its taxonomy. Journal of the Bombay Natural History Society 69 (1): 193–199.

[O89] Ogilby, J. D. 1889. List of the Australian Palaeichthyes, with notes on their synonymy and distribution. Part II. Proceedings of the Linnean Society of New South Wales, series 2, 4 (1): 178–186.

Papastamatiou, Y. P., B. M. Wetherbee, J. O’Sullivan, G. D. Goodmanlowe & C. G. Lowe. 2010. Foraging ecology of cookiecutter sharks (Isistius brasiliensis) on pelagic fishes in Hawaii, inferred from prey bite wounds. Environmental Biology of Fishes 88 (4): 361–368.

[PP64] Peres, J. M., & J. Picard. 1964. Nouveau manuel de bionomie benthique de la mer Mediterranee. Recueil des Travaux de la Station Marine d’Endoume, Bulletin 31 (27): 5–137.

[VF21] Vullo, R., E. Frey, C. Ifrim, M. A. González González, E. S. Stinnesbeck & W. Stinnesbeck. 2021. Manta-like planktivorous sharks in Late Cretaceous oceans. Science 371: 1253–1256.

[W92] Wilson, E. O. 1992. The Diversity of Life. Harvard University Press: Belknap (USA).


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