Saw Fish (কৰত মাছ)

Scientific Name: Pristis

Classification

Phylum: Chordata - Dorsal tubular nerve cord, notochord and gill slits present.

Subphylum: Vertebrata - Vertebral column present.

Superclass: Gnathostoma -Jaws and paired appendages present.

Class: Elasmobranchii - Endoskeleton cartilaginous. Scales usually placoid. Notochord rudimentary. Spiral valve in intestine. Opercula absent.

Subclass: Selachii - Bony fish proper.

Order: Euselachii 

Genus: Pristis

Habit and habitat: Pristis is a warm water marine type. It is predacious, feeding on small fishes and other marine animals by slashing them with its saw. It often ascends the river.

Characteristics:

1. Elongated, shark like body is slightly depressed and divided into head, trunk and tail.
2. Body shape is midway between a shark and a ray. The anterior part is flattened dorsoventrally and is ray-like while the posterior part, for more than half, is shark-like. It exhibits close relationship with rays.
3. Head contains a pair of eyes and a pair of spiracles behind the eyes. Water passes through the spiracles and goes out through the gill-slits.
4. Snout is anteriorly produced into a saw-like rostrum with large and small weakly embedded teeth.

Videos

Sawfish facts: sawing their way through the oceans. YouTube: Animal Fact Files

References

• Practical zoology vertebrates by S.S Lal
• The life of invertebrates by J.Z Young