Genus of fishes

Lutjanus is a genus of marine ray-finned pisces, snappers belonging to the family Lutjanidae. They are found in the Atlantic, Indian, and Pacific Oceans. They are predaceous pisces normally found in tropical and subtropical witwatersrand, and mangrove forests. This genus besides includes two species that entirely occur in fresh and brackish waters .

taxonomy [edit ]

Lutjanus was created in 1790 by the german doctor and zoologist Marcus Elieser Bloch with Lutjanus lutjanus as its type species by tautonymy. [ 1 ] It is the type genus of the subfamily Lutjaninae and the family Lutjanidae. The name is derived from a local anesthetic indonesian name for snappers, ikhan Lutjang. [ 2 ] Bloch mistakenly stated that the type vicinity for L. lutjanus was Japan when the name he gave it suggested that it was collected in the East Indies. [ 3 ] A taxonomic survey of snappers within the subfamily Lutjaninae in the tropical western Atlantic Ocean indicated that the at monotypic genus Ocyurus and Rhomboplites sit within the genus Lutjanus. [ 4 ] Lutjanus ambiguus is considered by some authorities to most likely to be a hybrid between L. synagris and Ocyurus chrysurus, supporting the near relation between the two genus. [ 5 ]

Species [edit ]

presently, 73 recognized species are placed in this genus : [ 6 ] [ 7 ]

Characteristics [edit ]

Lutjanus snappers are little to large in size with oblong determine bodies which vary from deep to slender and fusiform in form. They have relatively large mouths which is protractable. The teeth are arranged in one or more rows in the jaw and are pointed and conic in form with the outer row consisting of canine-like teeth with the anterior ones enlarged into more obvious canine-like fangs. The vomerine dentition are arranged in patches which may be chevron, triangular or crescent and may or may bot have a posterior extension, or be arranged in a rhombus. The space between the eyes is convex and they have a aserrated preopercle which has a deep incision on its lower margin. They sometimes jhave a osseous knob between the operculum and the preopercle which is most obvious in those species which have a deep incision in the preopercle. They have a continuous abaxial flipper, frequently having a slender incision between the spinous parcel and the soft-rayed assign. The barbed partially of the abaxial fin may have 10 or 11 spines while the soft rayed partially may have 11 to 16 rays. The anal fin has 3 spines and between 7 and 10 easy rays while the pectoral fins have between 15 and 18 soft rays. The abaxial and anal fins are scaled while the caudal fin may be emarginate, truncate or, rarely, forked. These snappers are highly variable in color frequently having a background color of red, jaundiced, grey, or brown overlie with a blueprint of dark stripes or bars. They are frequently marked with a large blackish spot on upper flanks underneath the front man soft rays of the abaxial fin. [ 12 ]

distribution and habitat [edit ]

Lutjanus snappers have a circumtropical and subtropical distribution and are found in the Atlantic, indian and Pacific Oceans. [ 12 ] The mangrove loss cracker ( Lutjanus argentimaculatus ), [ 13 ] and the dory cracker ( Lutjanus fulviflamma ) have been recorded in the Mediterranean as possible Lessepsian migrants having entered that sea through the Suez Canal from the Red Sea while the cad cracker ( Lutjanus jocu ), a western Atlantic species, has been recorded in the Ligurian Sea. [ 14 ] many species are associated with coral reefs where they are conspicuous members of the fish animal, while some of the larger crimson snapper species descend into deeper waters, at least to 200 megabyte ( 660 foot ) in depth. [ 12 ] 2 species, L. fuscescens and L. maxweberi, only occur in fresh and brackish waters. [ 7 ]

biology [edit ]

Smaller Lutjanus species are often observed in big, diurnal aggregations which stay near the reef, these disperse at night to feed. Their diet is largely made up of fishes and crustaceans. Group spawn has been obserbed in at least one species. Courtship is initiated by the males who peck and rub themselves on the females ‘ body and when early individuals are attracted to the initial match they all spiral towards the come on, releasing the milt and eggs merely underneath the surface. The eggs are minute and ball-shaped in form and take 18 hours or so to hatch into larva. [ 12 ]

Fisheries [edit ]

Lutjanus is a genus which contains many species, particularly the larger ones, which are crucial commercial fish and which are considered to be excellent food fish in the tropics. The trip up is taken using a variety of methods including handlines, traps, spears, nets and trawling gear. They are chiefly sold as bracing fish but may be preserved by freezing or dry-salted. [ 12 ]

References [edit ]

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