Development of Herdmania has been described by Sebastian (1953) and Das (1957). Development is indirect involving a free swimming tadpole larva. Herdmania (a tunicate) is the most appropriate one of the best examples of retrogressive metamorphosis in which the highly developed tadpole larva undergoes retrogressive changes to become the most degenerated and sedentary adult. The phenomenon of retrogressive metamorphosis is [...]
The animal is hermaphrodite or bisexual and protogynous, i.e., ovary matures first, thus, self-fertilisation is avoided. Gonads: There are two large gonads embedded in the mantle, the left one lies in the loop of the intestine and the right one dorsal to the heart. Each gonad is about 3 × 1 cm, and consists of 10 to 25 lobes lying [...]
Urochordata includes about 2000 fixed and 100 pelagic species. It has been divided into the following three classes: Class 1. Larvacea (Appendicularia): 1. Small (5 mm long solitary) free-swimming pelagic forms. 2. Neotenic forms which retain the larval form throughout adult life with persistent tail, nerve cord, notochord. 3. Test is temporary and renewed periodically. 4. Single pair of gill-slits [...]