Crab in Silent Valley found displaying both male and female biological traits

A tiny crab displaying both male and female biological traits on the same body has been discovered in the Western Ghats. Discovered from the forests of the Silent Valley National Park, this freshwater crab belongs to the species Vela carli and is both male and female at the same time. The dual-sex condition was observed in three crabs found in tree holes in Silent Valley.

Vela carli is an endemic freshwater crab found only in the forests and streams of the Central Western Ghats. The study documents the first instance of gynandromorphy (a rare condition in which individuals exhibit both male and female characteristics) in Vela carli. This phenomenon is rare in crustaceans and has never before been reported in the freshwater crab family Gecarcinucidae, according to the researchers.

The study was carried out by K.S. Anoop Das and K.T. Fahis from the Centre for Conservation Ecology, MES Mampad College, in collaboration with scientist and crab specialist Sameer K. Pati and Purnima Kumari from the Zoological Survey of India. Their findings were recently published in the international journal Crustaceana.

Mr. Das, Head and Assistant Professor at the Centre, said that while gynandromorphy has been documented in several marine and freshwater crab families, it has not been reported in the family Gecarcinucidae. “The bodies of the crabs displayed male reproductive structures, while other parts showcased female features, including gonopores,” said Mr. Das.

According to him, the likely cause for this gynandromorphism could only be from intrinsic developmental processes rather than external environmental pollution. “The crab’s habitat was free from environmental pollutants. So we think that the reason for the phenomenon could be related to survival tactics. This makes it possible for the crab to procreate in the absence of male or female members,” said Mr. Das.

The specimens were collected during biodiversity surveys conducted in the forest. Among the more than 120 crabs examined, only three crabs showed this dual-sex condition.

The study was funded by the Department of Science and Technology, Science and Engineering Research Board (presently Anusandhan National Research Foundation).

“These crabs were found inside tree holes. While they are found to live near streams, the fact that the crabs were observed from the tree holes points to the rich ecosystems inside tree holes and the many biological mysteries our forests hold,” he added.