Journal of the Marine Biological Association of India

On a new species of Dendrodoris Ehrenberg from Goa : Mollusca - Nudibranchiata.

Volume 15 Issue 1

K. Virabhadra Rao and L. Krishna Kumary

Abstract

A nudibranchiate mollusc under the genus Dendrodoris Ehrenberg, subgenus Dendrodoris s. str obtained from a trawl catch in the Zuari River mouth off Dona Paula in Goa has been described as a new species, D. (D.) goani. Its dorsum is covered with large and small papillated tubercles irregularly scattered. The papillary portions are colourless and the tubercular portions dark gray. On the back and along the mantle edge there are grayish brown pigment spots. The general colouration of the dorsum is greenish yellow with a light shade of brownish tinge especially in front of the branchiae. The ventral surface of the mantle and the lateral surfaces of the body are colurless. The rhinophores are retractile with about 24 leaflets. The branchiae are five, tripinnately branched and retracctile into a branchial space bounded by raised walls. The foot is oval with a median, frontal cleft and bears anteriorly a narrow groove on either side. The pedal groove is dark gray and the sole of the foot is with a diffused gray in its anterior half. Mouth is porelike, buccal bulb is suctorial and the pharynx is divisible into a narrow looped anterior portion and an elongated dilated posterior portion. The bilobed ptyaline gland is much larger than the buccal bulb. The presence of small salivary glands, the position of the buccal ganglia and the nature of the short straight intenstine without the characteristic dorid loop in front of the digestive gland are as in other members of the subgenus Dendrodoris. The generative organs are complex. The hermaphrodite gland envelops the digestive gland completely and the hermaphrodite ampulla is a thick convoluted tube. The prostate is much elongated and lobed and the vas deferens is narrow and much coiled. The penis is with numerous recurved hooks. The male genital vaginal and oviducal openings are separate. An accessory gland is present. The spermatheca is large and roundish and spermatocyst is small and ovoid. The new species D. (D.) goani has a combination of characters separately met with in D. tuberculosa (Q & G) and a few other species under the genus.

Date : 31-08-1973