CLASSIFICATION OF POLYODON : PADDLE FISH
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 :- PALAEOPTERYGII ( Ancient fIshes ).
Order :- CHONDROSTEI ( Body covered with bony scutes or naked. Tail heterocercal. Skeleton largely cartilaginous. Notochord unsegmented. Vertebrae acentrous ).
FAMILY :- POLYODONTIDAE
GENUS :- Polyodon (PoJydora)
Polyodon is found in the rivers of South and North Americas, Mississippi, Ohio and Missouri.
HABIT AND HABITAT
- Polyodon is a marine fish, sluggish and feeding chiefly on mud with minute organisms. The long gill rakers form efficient filter for taking planktonic food. It eats small invertebrates.
GENERAL CHARACTERSTICS OF POLYODON : PADDLE FISH
- Commonly known as spoon bill or paddle-fish because of paddle-like spoon.
- Body is fusiform, measuring 5 to 6 feet. Head is produced into a paddle shaped bill or spoon.
- Spoon is exceptionally elongated, spatulate, conical with rigid axis and flexible margins.
- Mouth is wide and ventral.
- Teeth minute, spiracles present, gill cover greatly produced posteriorly.
- Paired pectoral and pelvic fins small.
- Dorsal fin opposite to anal fin.
- A poorly-developed sub-operculum is present in addition to a small-rayed operculum.
- Lateral line distinct.
- Tail heterocercal caudal fin bilobed. Upper fleshy to be larger
Polyodon also shows combination of primitive and advanced characters.
The fish has spatulate rostrum and above features, hence it is Polyodon.
- Book of Practical Zoology VERTEBRATE by S.S.LAL – Rastogi Publications.
- SOURCES OF IMAGES – https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww2.illinois.gov%2Fdnr%2Feducation%2FPages%2FWAFPaddlefish.aspx&psig=AOvVaw2jL_Erck7Kaux6FM8V2LEt&ust=1603943537708000&source=images&cd=vfe&ved=2ahUKEwiD4dq3sdbsAhWAyXMBHYB3BycQr4kDegUIARDBAQ