Symmetry: have radical/bilateral symmetry,pentaradial, five planes of symmetry,
Germ cell layers: 3 germ cell layers; outer layer is epidermis; middle layer is thick called the dermis, composed of connective tissue and exoskeleton, third layer is a single layer is ciliated cells
Coelm: true coelom
Circulatory system: has poor open circulatory system
Feeding: feeds on fine particles in the water, detrrius, or other animals; filter eaters; gut is U- shaped with mouth and anus on the same surface
excretion: doesnt have excretion organs
Nervous system: includes circum- oesophageal rings, have complex nervous systems
crinoidea
ophiuroidea
asteroidea
echinoidea
holothuroidea
No comments:
Post a Comment