NEOCERATODUS FORSTERI : AUSTRALIAN LUNG FISH

Contents hide

1) NEOCERATODUS FORSTERI : AUSTRALIAN LUNG FISH

1.1) CLASSIFICATION OF LEPIDOSIREN NEOCERATODUS FORSTERI : AUSTRALIAN LUNG FISH

1.2) GEOGRAPHICAL DISTRIBUTION

1.3) HABIT AND HABITAT

1.4) GENERAL CHARACTERSTICS OF NEOCERATODUS FORSTERI : AUSTRALIAN LUNG FISH

1.5) SPECIAL FEATURES

1.6) IDENTIFICATION

1.7) REFERENCES

CLASSIFICATION OF LEPIDOSIREN NEOCERATODUS FORSTERI : AUSTRALIAN LUNG FISH

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 :- CHOANICHTHYES ( Nostrils connected to mouth cavity. Paired fins with larger median lobe ).

SUPER ORDER :- DIPNOI ( Lung tish. Body long and slender. Premaxilla or maxilla absent. Air bladder (Dipneusti) lung like ).

Order :- CERATODIFORMES ( Body ell-like, scales. small, burrowing fish).

GENUS :- Neoceratodus

SPECIES :- forsteri

GEOGRAPHICAL DISTRIBUTION

Neoceratodus or Australian lung fish is found in Buret and Mary rivers of Australia and Queensland

HABIT AND HABITAT

Neoceratodus or Australian lung fish inhabits quiet pools that become stagnant during dry season, when the fish rises to the surface to engulf fresh air into lungs. It feeds on small crustaceans and worms. It does not aestivate.

GENERAL CHARACTERSTICS OF NEOCERATODUS FORSTERI : AUSTRALIAN LUNG FISH

It is a common Australian lung-fish (barramunda).
overlapping cycloid scales
Body is elongated, measuring 1 to 2 metres and covered with distinct large overlapping cycloid scales.
Mouth is small. Gill slits five pairs. Body divided into head, trunk and tail.
Paired fins placed low; paddle like paired pectoral fins are found near head and pelvic fins near anal fin.
Tail is diphycercal. Dorsal fin, caudal fin and anal fin continuous.
Single pulmonary vasculated air bladder (lung) opens into oesophagus by a long duct.
Kidneys more elongated. Lateral line present.
Male does not possess vascular filament on pelvic fin. Larva is devoid of external gills.

SPECIAL FEATURES

Neoceratodus Jorsteri is the only living species and is considered as living fossil. The paired fins are modified into paddles. The skeleton of these fins is peculiar, because in each fin there is a central axis bearing radials of different sizes on both sides. The internal surface of the lung is sacculated and contains a series of alveoli. Lung respiration supplements gill respiration. Like Protopterus and Lepidosiren, this fish also reveals presence of primitive and specialized characters.

It also shows resemblance with Amphibia in having internal nares, lungs and autostylic suspensorium. absence of ossification in the cranial cartilage, premaxillae and maxillae and presence of dental plates on the jaws. Lepidosiren shows resemblance with Amphibia in internal nostrils, lung respiration and autostylic suspension. autostylic suspensorium show similarity with Amphibians.