Hippocampus sea horse brood pouch fish
Hippocampus is mainly live in tropical and temperate water,marine water particularly in India, Bangladesh, and Atlantic sea, Japan, Malay, Archipelago and China.
Continue reading Sea horse (Brood pouch fish)
Systematic position of Dentalium
Phylum : Mollusca.
Genus : Dentalium
Habit and habitat:
Dentalium is marine. In shallow waters to depth they are found. Living partly buried obliquely in the mud and sand. The pointed foot protrudes from the larger ventral end of the shell for use in burrowing. Continue reading Description of Dentalium ( Elephant’s Tooth Shell)
GENERAL CHARACTERISTICS OF MOLLUSCA
- Body is short and partially or wholly enclosed by a fleshy outgrowth of the body wall called mantle.
- A shell if present secreted by the mantle and of one, two or eight parts.
- Head and ventral muscular foot closely allied with foot variously modified for crawling, burrowing , swimming, or foot capture.
- Digestive system complete, complex, with ciliary tracts for sorting small particles, mouth with radula bearing transverse rows of minute chitinous teeth, anus opening in mantle cavity.
- Circulatory is open type.
- Respiration by ctenidia (gills).
- Nervous system typically a circumesophageal nerve ring with various pairs of ganglia and two pairs of nerve cords.
- Sexes usually separated