The scoophead (''Sphyrna media'') is a little-known species of
hammerhead shark, part of the
family Sphyrnidae. It inhabits the
tropical waters of the western
Atlantic Ocean, from
Panama to southern
Brazil, and in the eastern
Pacific Ocean from the
Gulf of California to
Ecuador, and probably northern
Peru, as well. It is found in shallow, inshore habitats.
One of the smaller hammerheads, the scoophead measures 150 cm long; adult males measure 90 cm long and adult females 100–133 cm. It is distinguished by its moderately broad, mallet-shaped head (22–33% as wide as the body is long). The forward margin of the head is arched, with weak medial and lateral indentations and no prenarial grooves, traits that this species shares with the
scalloped bonnethead
The scalloped bonnethead (''Sphyrna corona'') is a rare, little-known species of hammerhead shark in the family Sphyrnidae. Its other common names include the mallethead shark and the crown shark. It is found in tropical and subtropical waters ...
(''Sphyrna corona''). It is distinguished from the scalloped bonnethead by its shorter snout, broadly arched mouth, and deeply concave
anal fin
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...
. The first
dorsal fin is moderately falchate, and the second dorsal fin is as tall as the anal fin. The
pelvic fin
Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods.
Structure and function Structure
In actinopterygians, the pelvic fin consists of two en ...
s are not falchate, with a straight to moderately concave rear margin. Its coloration is grey-brown above, light below, with no fin markings.
[Compagno, Leonard J. V. (1984) ''Sharks of the World: An Annotated and Illustrated Catalogue of Shark Species Known to Date''. Rome: Food and Agriculture Organization. .]
Off the coast of
Trinidad, the scoophead coexists with two other small hammerheads, the
bonnethead (''Sphyrna tiburo'') and the
golden hammerhead
The smalleye hammerhead (''Sphyrna tudes''), also called the golden hammerhead or curry shark, is a small species of hammerhead shark in the family Sphyrnidae. This species is common in the shallow coastal waters of the western Atlantic Ocean ...
(''S. tudes''). These species avoid competition by diet and habitat differences; the scoophead feeds on small
elasmobranchs,
octopus
An octopus ( : octopuses or octopodes, see below for variants) is a soft-bodied, eight- limbed mollusc of the order Octopoda (, ). The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttle ...
,
squid
True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting t ...
, and
flounder
Flounders are a group of flatfish species. They are demersal fish, found at the bottom of oceans around the world; some species will also enter estuaries.
Taxonomy
The name "flounder" is used for several only distantly related species, thou ...
s.
Like other hammerheads, the scoophead is
viviparous,
with the pups measuring 34 cm or less at birth. It is taken with bottom
longlines,
gillnet
Gillnetting is a fishing method that uses gillnets: vertical panels of netting that hang from a line with regularly spaced floaters that hold the line on the surface of the water. The floats are sometimes called "corks" and the line with corks is ...
s, and hook and line throughout its range. It is caught commercially and sold as fresh fish or turned into
fishmeal. The scoophead is also a common
bycatch
Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juve ...
of the gillnet
mackerel
Mackerel is a common name applied to a number of different species of pelagic fish, mostly from the family Scombridae. They are found in both temperate and tropical seas, mostly living along the coast or offshore in the oceanic environment.
...
fishery
Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place ( a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, both ...
off Trinidad.
References
External links
Species Description of Sphyrna media at www.shark-references.com
{{Taxonbar, from=Q1069185
Sphyrna
Fish of the Gulf of California
Fish of Mexican Pacific coast
Western Central American coastal fauna
Fish of Colombia
Fish of Ecuador
Fish of South America
Taxa named by Stewart Springer
Fish described in 1940