Star fish belongs to which phylum ?
AArthropoda
BMollusca
CAnnelida
DEchinodermata
Answer:
D. Echinodermata
Read Explanation:
Phylum Echinodermata:
- These animals have an endoskeleton of calcareous ossicles and hence, the name Echinodermata (Spiny bodied)
- All are marine with organ-system level of organisation.
- The adult echinoderms are radially symmetrical but larvae are bilaterally symmetrical.
- They are triploblastic and coelomate animals.
- Digestive system is complete with mouth on the lower (ventral) side and anus on the upper (dorsal) side.
- The most distinctive feature of echinoderms is the presence of water vascular system.
The functions of water vascular system:
- It helps in locomotion
- It helps to capture and transport of food
- It helps in respiration
- An excretory system is absent
- Sexes are separate
- Reproduction is sexual
- Fertilisation is usually external
- Development is indirect with free-swimming larva.
Examples:
- Asterias (Star fish)
- Echinus (Sea urchin)
- Antedon (Sea lily)
- Cucumaria (Sea cucumber)