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 circulatory system of Herdmania includes heart and pericardium, blood vessels and blood. Blood: The blood is slightly reddish vacuole and transparent. It has colourless plasma, many pigmented and non-pigmented corpuscles, and a few colourless amoeboid leucocytes. Leucocytes are nucleated, amoeboid and colourless. Other corpuscles are round, of various sizes, some have vacuoles, and they may or may not be [...]
In the adult there is a brain or nerve ganglion which is about 4 cm long. It lies embedded in the mantle mid-dorsally between the two siphons. The brain lies below a neural gland in family Pyuridae to which Herdmania belongs, but in most ascidians the position of the brain is dorsal to the neural gland. The brain has bipolar [...]