The recent discovery of a new species of estuarine crab at the Mangroves of Parangipettai has brought forth intriguing revelations about the biodiversity in Tamil Nadu, India. Found near the Vellar River estuary – a region where the river meets the ocean – in the Cuddalore district, this species symbolizes a pertinent instance of new marine life being discovered in the subcontinent. The crab has been named ‘Pseudohelice Annamalai’ in honor of Annamalai University’s century-long contribution to education and research.
First Ever Record of Pseudohelice Genus
Pseudohelice Annamalai represents the first-ever documented occurrence of the Pseudohelice genus in the high intertidal areas around the Centre of Advanced Study (CAS). This genus was previously confirmed to encompass just two species – Pseudohelice Subquadrata and Pseudohelice Latreilli.
Geographical Distribution of Pseudohelice Annamalai
The geographical range of this newly discovered species expands beyond the Indian subcontinent to the eastern Indian Ocean. These crabs are not geographically restricted, thereby signifying a broader distribution pattern than that previously known for this genus.
Distinctive Features of Pseudohelice Annamalai
Marked by a unique dark purple to dark grey colouring, Pseudohelice Annamalai comes with irregular light brown, yellowish-brown, or white patches on its posterior carapace. In contrast, its chelipeds showcase a lighter brown shade. Being a small-sized marine organism, it reaches a maximum width of up to 20 mm. Despite its size, this crab species is speedy and non-aggressive, much like its other intertidal counterparts.
Habitat of Pseudohelice Annamalai
Pseudohelice Annamalai dwells in the muddy banks of mangroves. The crab’s burrows are primarily found near the pneumatophores of Avicennia mangroves. Characteristically, these burrows reach depths between 25-30 cm and are branched. Larger pellets surround their entrance, further differentiating the living spaces of these species.
Significance of Pseudohelice Annamalai Discovery
The unearthing of Pseudohelice Annamalai in India plays a crucial role in bridging the distribution gap between the western Indian Ocean and the western Pacific Ocean. This discovery serves as additional proof of geographic isolation in the eastern Indian Ocean for certain marine organisms. As such, it contributes significantly to our understanding of marine biodiversity, distribution patterns, and habitat differentiation among crustaceans.
