Photo by Peter Southwood Photo by Peter Southwood Photo courtesy Charles Griffiths	Hymenosoma crabs Peter Southwood photographed this crab at Long Beach, where it was found on a sandy bottom. He was not sure what it was, so asked Professor Griffiths for help. The reply was interesting: "Another interesting taxonomic problem is brewing in that it appears that what we have been calling the common crowned crab Hymenosoma (47.5 in Two oceans) is in fact at least two and possible three different and quite distinct species! We have definitively proven by genetic tests that the Natal and Cape forms are separate species. I also have old literature suggesting that the species found on 8-20 m on sandy bottoms in False Bay has very different features. (In the bottom picture) the large animal on the right is the 'classic' and real H. orbiculare and occurs in estuaries and shallow marine waters in the Cape. The long-legged small pale one top left is the Natal form and appears to be an un-described species. The small, hairy, short-legged form on the l-left is the deep water form from False Bay and was initially described as H. geometricum, but this was later synonymised with H. orbiculare. It seems very likely that we can now prove that it is indeed a quite distinct species"
References: Thanks to Professor Charles Griffiths (UCT) for information. Two Oceans, a guide to the marine life of Southern Africa, GM Branch, CL Griffiths, ML Branch and LE Beckley, 1994.
Previous	News Index	Next