CLASSIFICATION OF LEPIDOSTEUS (GARPIKE)
Phylum :- CHORDATA (Notochord and dorsal tubular nerve cord present and gill-slits present).
Group :- CRANIATA (Cranium with brain present).
Subphylum :- VERTEBRATA (Vertebral column present).
Division :- GNATHOSTOMATA (Jaws and paired appendages present).
Super class :- PISCES (Paired fins , gills and skin with scales)
Class :- OSTEICHTHYES (Bony fishes).
SUB-CLASS :- ACTINOPTYERGII (Ray finned fish).
SUPER ORDER :- HOLOSTEI (Bony ganoids).
Order :- Lepidostiformes (Vertebrae solid, opisthocoelous and ganoid scales in oblique rows).
FAMILY :- Lepidosteidae
GENUS :- Lepidosteus
Widely distributed in U.S.A. Fossilized gars have been found in Europe, India, South America, and North America
HABIT AND HABITAT
Lepidosteus is found in fresh-water rivers. It is a voracious feeder on small fishes. Sometimes, it also comes out of the surface to emit bubbles of gases. The heavily armoured predaceous gars usually occur in shallow weedy areas.
GENERAL CHARACTERSTICS OF LEPIDOSTEUS (GARPIKE)
- Commonly known as garpike, measures about 2 to 3 meters.
- Body is elongated with short caudal region and is divided into head, trunk and tail.
- Body is covered with thick rhombic ganoin-coated and articulated scales, about 50 to 65 along lateral line. Scales articulate with one another by peg-and-socket joints.
- Head is produced into snout. Both the upper and lower jaws are elongated to form a sort of gar.
- Eyes are developed. Gills are covered by operculum. Nostrils are found at the anterior end of beak.
- Dorsal fin with few rays. Dorsal and anal fins are far back near the tail. Caudal fin is rounded and semi-heterocercal. Paired pectoral and pelvic fins present.
- Vertebrae opisthocoelous and solid with convex anterior and concave posterior ends, as in some reptiles and unlike other fishes. Vomer paired.
- Tail symmetrical, spiracles closed.
- Air bladder is used as lung. It is vascularized and thus permits aerial respiration.
- Scales and skin of gars are used in the manufacture of hand bags and arts.
Lepidosteus shows a number of primitive features such as cellular air bladder, ganoin-coated scales, presence of fulcra, absence of jugal plate and closed spiracle. It also showsteleostian and advanced features such as branched pyloric caeca, reduced maxilla, presence of tooth-bearing infra-orbitals and opisthocoelous vertebrae.
Fish has toothed jaws, posterior dorsal fin and above features, hence it is Lepidosteus.