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 [...]
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 [...]
In Herdmania, digestive system includes the alimentary canal and digestive glands. Lying in the atrial cavity inside the mantle is a large bag-like pharynx or branchial sac. The wall of the pharyx is fused to the mantle along the anterior and ventral sides, on account of this attachment the atrial cavity is divided into right and left halves which are, [...]