10.1.2 External features 1 Trunk 2 Tail
10.1.2 External features 1 Trunk 2 Tail
10.1.3 Internal features 1 Digestive system mouth → pharynx → esophagus → stomach → intestine → anus endostyle, buccal gland 2 Circulatory system 3 Reproductive system heramphrodite mouth esophagus stomach intestine anus buccal gland endostyle ovary or test
10.1.3 Internal features 1 Digestive system mouth → pharynx → esophagus → stomach → intestine → anus endostyle, buccal gland 2 Circulatory system 3 Reproductive system heramphrodite mouth esophagus stomach intestine anus buccal gland endostyle ovary or test
3 Nervous system cerebral ganglion caudal ganglion 5 Notochord and Muscle Bands urochord notochord cell subchord cell
3 Nervous system cerebral ganglion caudal ganglion 5 Notochord and Muscle Bands urochord notochord cell subchord cell
10.1.4 Classification One order, Urochorda with two families, the main characteristics for classification are： （ 1 ）the ratio of body to tail in size and their shape （ 2 ）the shape of the endostyle （ 3 ）the position of the gill opening （ 4 ）the shape of the gonads Family Oikopleuridae：O. longicauda Family Fritillaridae: F. pellucida
10.1.4 Classification One order, Urochorda with two families, the main characteristics for classification are： （ 1 ）the ratio of body to tail in size and their shape （ 2 ）the shape of the endostyle （ 3 ）the position of the gill opening （ 4 ）the shape of the gonads Family Oikopleuridae：O. longicauda Family Fritillaridae: F. pellucida