Cynoscion is a
genus of marine
ray-finned fishes belonging to the
family,
Sciaenidae, the drums and croakers. These fishes are found off the coasts of North and South America in the western Atlantic and eastern Pacific Oceans. Many fishes in this genus have been given the common name weakfish.
Taxonomy
Cynoscion was first proposed as a
monospecific genus in 1861 by the American biologist Theodore Gill with Johnnius regalis, a species originally
described in 1801 from
New York by Marcis Elieser Bloch and Johann G. T. Schneider, designated as its
type species.[1][2] This genus has been placed in the
subfamily Cynoscioninae by some workers,[3] but the 5th edition of Fishes of the World does not recognise subfamilies within the Sciaenidae which it places in the
orderAcanthuriformes.[4]
Etymology
Cynoscion is a combination of cyno, meaning "dog", a reference to the pair of canine-like teeth in the upper jaw, with scion, the modern
Greek name of Umbrina cirrosa, which Gill preferred over sciaena because he did not like the sound of Cynosciaena.[5] The common name, weakfish, is a reference to the easily torn membrane in the mouth of C. regalis.[6]
Cynoscion weakfishes have an elongate, torpedo shapes body which is compressed to give it an oval cross-section. The head is low, with the crown being firm to the touch rather than spongy with moderately sized eyes and a large oblique mouth. There is a pair of large, pointed canine-like teeth in the front of the upper jaw. There are no
barbels or pores on the chin. The
preoperculum is smooth and not serrated and the top corner of gill slit is incised. The
dorsal fin is long based and is deeply incised with between 7 and 9 thin spines and between 20 and 30 soft rays. The
anal fin is supported by 2 small spines, less than half the length of the first anal fin ray, and 7 to 13 soft rays. They have large scales, ctenoid on the body and cycloid on the head. The lateral line reaches to the middle of the end of the
caudal fin.[8] The largest species in the genus are C. albus which has a maximum published
total length of 130 cm (51 in) and C. xanthulus at 129 cm (51 in) while the smallest is C. nannus reaching 27 cm (11 in).[7]
Distribution
Cynoscion weakfishes are found off the Americas in the eastern Pacific and western Atlantic Oceans being found in tropical and warm temperate waters.[8]