Transcript The Family Dalatiidae

The Family Dalatiidae
Kitefin-Cookiecutter-Pygmy-Taillight-Sharks
Tiffany Adams
September 18, 2007
Elasmobiology
Taxonomy
• Squaliformes
– Dalatiidae
• 7 genera
– 9 species
Dalatias licha
Euprotomicroides zantedeschia
Euprotomicrus bispinatus
Heteroscymnoides marleyi
Isistius brasuliensis
Isistius plutodus
Mollisquama parini
Squaliolus aliae
Squaliolus laticaudus
Taxonomy changes? Most of these species were previously listed under the
families Scymnorhinidae or Squalidae, along with many other genera. Fishbase
(ref. Nelson 1994) lists Dalatiidae as including 18 genera and 39 species.
Taxonomy above is from our text (Carrier 2004.)
Sleeper sharks? Most references still label Dalatiidae as “Sleeper Sharks” even
thought the sleeper shark belongs to the genus Somniosus under the family
Sominiosidae. A couple websites refer to Dalatiidae as “Kitefin Sharks” which still
seems inappropriate given that this name fits only 1 of the 9 species.
Dalatiidae Species
Dalatias licha- kitefin shark
Euprotomicrus bispinatus-
pygmy shark
Euprotomicroides zantedeschia- taillight shark
Isistius brasiliensis- cookiecutter shark
Squaliolus laticaudus- spined pygmy shark
Squaliolus aliae- smalleye pygmy shark
Isistius plutodus- largetooth cookiecutter shark
Heteroscymnoides marleyi-
longnose pygmy shark
Mollisquama parini- pocket shark (not pictured)
Characteristics of Dalatiidae
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Most are small, all under 60 cm except Dalatias (up to 200cm)
Both dorsal fins generally without spines and similar in size
Caudal fin with subterminal notch
No anal fin
Five gill slits
No nictating eyelid
Unicuspid teeth in both jaws- upper are slender and lanceolate, lower are
broad and overlapping
Biology/Ecology
• Reproduction
– Ovoviviparous, relatively small clutch sizes ranging from 6-20
– No information available on reproductive age or interval
• Prey
– Small bony fish, cephalopods, crustaceans
– Dalatias (kitefin)- skates and sharks
– Isistius (cookiecutter)- large fish and cetaceans
• Population status
– Most species abundance not well known
– IUCN lists all as either DD (data deficient) or LC (least concern)
Distribution
• Oceanic, Pelagic-benthopelagic
• Circumglobal in temperate to tropical seas
Isistius brasiliensis
The cookiecutter shark, an ectoparasite
Although cookie cutter sharks only grow to be around 50-60cm, they are
known to take bites out of cetaceans, sea lions, larger fish and other sharks.
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“The cookiecutter shark has specialized suctorial lips and a strongly modified
pharynx that allow it to attach to the sides of it prey. It then drives its saw-like
lower dentition into the skin and flesh of its victim, twists about to cut out a
conical plug of flesh, then pull free with the plug cradled by its scoop-like
lower jaw and held by the hook-like upper teeth.” (Campagno 1984)
Works Cited
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Allen, T. 1999. Shark Almanac. Lyons Press, New York. Pp. 49-58.
Carrier, J,, Musick, J., and Heithaus, M. 2004. Biology of Sharks and Their Relatives. CRC Press,
Boca Raton. Pp. 56-58, 65-66.
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 1 - Hexanchiformes to Lamniformes. FAO
Fish. Synop. 125(4/1):1-249.
IUCN 2006. 2006 IUCN Red List of Threatened Species. <http://www.iucnredlist.org>. Downloaded
on 13 September 2007.
Nelson, J. 1984. Fishes of the World. 2nd Ed. John Wiley & Sons, Inc., New York. Pp. 56-58.
Parker, S. 1999. The Encyclopedia of Sharks. Firefly Books, Buffalo.
Perrine, D. 1999. Sharks and Rays of the World. Voyageur Press, Hong Kong. Pp. 80, 105-106.
Steel, R. 1985. Sharks of the World. Facts on File, Inc., New York. Pp. 140-150.
Related Articles
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Cunha, C. and Gonzalez, M. 2006. Pregnancy in Squaliolus laticaudus (Elasmobranch: Dalatiidae)
from Brazil. Environmental Biology of Fishes. 75(4):465-469.
Gadig, O. and Gomes, U. 2002. First report on embryos of Isistius brasiliensis. Journal of Fish
Biology. 60(5):1322-1325.
Myagkov, N. 1984. Unusual brain structure of luminous shark, Isistius brasiliensis (Dalatiidae).
Journal of Ichthyology. 24(2):109-112.
Perrotta, R. G. 2004. Kitefin shark Dalatia licha (Dalatiidae)fishery in the northeastern Atlantic and
some recommendations for elasmobranchs explotation. Revista de Investigación y Desarrollo
Pesquero, 16:97-101 <http://hdl.handle.net/1834/1501> Downloaded on 16 September 2007.
Yusuke, S. et al. 1999. First record of the pygmy shark, Euprotomicrus bispinatus (Dalatiiformes:
Dalatiidae) from Fiji. Journal of National Fisheries University. 47(4):139-143.