Exploring carapace phenotypic variation in female Fiddler Crab Austruca annulipes (H. Milne Edwards, 1837): insights into adaptive strategies and ecological significance

Abstract

Fiddler crabs (Ocypodidae: Crustacea: Arthropoda) are globally documented but relatively understudied along the Indian coastline. Austruca annulipes, common across Indian mangrove habitats, remains insufficiently explored in terms of female morphology. While male fiddler crabs are recognized for their prominent chelae, females of A. annulipes exhibit notable polymorphism. In this short-term study conducted in the mangroves of Sauta Vaddo (Baga), Goa, we documented 14 distinct female morphs, alongside observations of male moulting. The study highlights the scope for future research into the adaptive significance of female phenotypic variation in this species.