The mouth contains an organ for feeding, called radula in animals belonging to which phylum ?
AMollusca
BArthropoda
CAnnelida
DCnidaria
Answer:
A. Mollusca
Read Explanation:
Phylum Mollusca:
- This is the second largest animal phylum
- Molluscs are terrestrial or aquatic (marine or fresh water)
- It has organ-system level of organisation.
- They are bilaterally symmetrical, triploblastic and coelomate animals.
- Body is covered by a calcareous shell
- Body is unsegmented with a distinct head, muscular foot and visceral hump.
- A soft and spongy layer of skin forms a mantle over the visceral hump.
- The space between the hump and the mantle is called the mantle cavity in which feather like gills are present. They have respiratory and excretory functions.
- The anterior head region has sensory tentacles.
- The mouth contains a file-like rasping organ for feeding, called radula
- They are usually dioecious and oviparous with indirect development
Examples:
- Pila (Apple snail)
- Pinctada (Pearl oyster)
- Sepia (Cuttlefish)
- Loligo (Squid)
- Octopus (Devil fish)
- Aplysia (Seahare)
- Dentalium (Tusk shell)
- Chaetopleura (Chiton)