New species of hermit crab discovered

THIRUVANANTHAPURAM: Science has discovered a new member in the family of those lonesome yet funny hermit crabs, that live in shells and carry their homes around with them.  The new member, scientifically called Ciliopagurus grandis, was discovered by the scientists of the Aquatic Biology Department of the University of Kerala. The scientists R Reshmi and A Bijukumar, also reported the presence of 4 species on the Kerala coast, for the first time in the country.“Hermit crabs are a group of interesting organisms that have been studied very little in our state. They are economically important as they often form the major source of food for carnivorous fishes,” said Bijukumar.With very soft abdomens, these crabs lead a hermit-like lonely life in abandoned shells. They twist into abandoned snail shells and when they grow too big for the shell, they go ‘shopping’ for bigger shells. Every hermit crab has certain preferences for the shell it wants to live in, and spends quite a lot of time checking out new shells, before moving into a new one. “Several hermit crabs use vacancy chain methods to find new shells, where they queue up for available shells. When the largest crab move into a new shell, the second largest moves into the newly vacated shell, making its previous shell available to a third crab and so on,” explained Bijukumar.The new species found from the sea off Sakthikulangara coast near Kollam, has a large body size, when compared to other members in the genus Ciliopagurus. It is orange in colour in the shield region with transverse ridges on the legs coloured red.The scientists reported the finding of the study, in the latest issue of the international taxonomy journal, Zootaxa. The taxonomic identification of the new crab was supported by renowned taxonomist Tomoyuki Komai of the Natural History Museum and Institute, Chiba, Japan. The project was supported by the Kerala State Council for Science Technology and Environment.The four other crab species discovered  include the species such as Calcinus morgani, Diogenes klaasi, Coenobita brevimanus and Coenobita rugosus. Calcinus morgani was collected from intertidal rocky pools of Thirumullavaram Beach,  Kollam and Diogenes klaasi was collected from the mangrove swamps of Dalavapuram in Kollam district.“Of these four species, Coenobita brevimanus was thought to have been existing in the African coast. The finding could also be linked to ancient times when the continents were one. Likewise the Diogenes klaasi were originally reported from Indonesia,” said Bijukumar.Hermit crabs also serve as bio-indicators to study changes in environment and as an organism to study environmental influences. While their shopping for houses may take time and their appearance may look funny, their selection of suitable homes is very intelligent, at least from the point of the environmental health.