Whitefin hammerhead

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Whitefin hammerhead
Sphyrna couardi.gif
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Superorder: Selachimorpha
Order: Carcharhiniformes
Family: Sphyrnidae
Genus: Sphyrna
Species: S. couardi
Binomial name
Sphyrna couardi
Cadenat, 1951
Sphyrna couardi distribution map.svg
Range of the whitefin hammerhead
Synonyms
  • Sphyrna lewini Griffith & Smith, 1834

The whitefin hammerhead (Sphyrna couardi) is a species of hammerhead shark, and part of the family Sphyrnidae, found in the tropical waters of the northeastern Atlantic Ocean, from Senegal to the Congo region.[1] According to Cadenat and Blanche (1981), some specimens associated with the smalleye hammerhead (Sphyrna tudes) are in fact of the whitefin hammerhead, which would extend the range of this species into the Mediterranean Sea.[2] McEachran and Serret (1986) synonymized this species with the scalloped hammerhead (Sphyrna lewini).[3]

In appearance the whitefin hammerhead is very similar to the scalloped hammerhead, with a moderately broad, narrow-bladed head (width 21-25% of total length). The front margin of the head is broadly arched, with prominent indentations in the middle and sides. The first dorsal fin is tall and falchate (sickle-shaped), while the pelvic fins are not falchate with straight or slightly concave rear margins. The anal fin is low and long, with a deep notch in the rear margin. The color is blue-grey or grey-brown above, white below. It is distinguished from the scalloped hammerhead in that its head lobes are longer and less wide, the origin of its first dorsal fin are over the pectoral fin midbases, and there are no dark tips on its pectoral fins. Its maximum size is said to be about 3 m long; adult males typically range from 141-184 cm, and adult (gravid) females 230-235 cm.[2]

The whitefin hammerhead mainly feeds on benthic bony fishes, such as eels and flatfishes, as well as cephalopods. As with other hammerheads, they are viviparous, with the young nourished by a yolk sac placenta. Litters range from 24-28 pups, measuring 30-32 cm long or more. It is not known to have attacked people. This species is caught by West African fisheries but details are unknown.[2]

References[edit]

  1. ^ Froese, Rainer and Pauly, Daniel, eds. (2006). "Sphyrna couardi" in FishBase. May 2006 version.
  2. ^ a b c Compagno, Leonard J. V. (1984) Sharks of the World: An Annotated and Illustrated Catalogue of Shark Species Known to Date. Rome: Food and Agricultural Organization. ISBN 92-5-101384-5.
  3. ^ Martin, R. Aidan. (February 24, 1998). Recent Changes in Hammerhead Taxonomy. ReefQuest Centre for Shark Research. Retrieved on October 18, 2008.

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