As crabs go, parthenopids enjoy scant attention from people who savour meatier decapods, save the odd carcinologist and those who insist on exploring the margins of an island that is running out of elbow space and ecological sanity. Like portunids, the family honours a mythical figure from the Mediterranean Sea, though the siren who lent her name to the crabs would probably be mortified to be associated with a body of creatures with ungainly moves and shabby mien.
In form, the animals resemble caricatures; a crudely triangular or hexagonal carapace bears limbs that are overwhelmed by a pair of oft spiny chelipeds commanding a disproportionate share of the crab's bulk. Such elongated arms would come in handy for battling commuters who attempt to invade subway cabins without giving passengers a chance to alight. But the impressive span is constrained by joints that limit their punch to a narrow swing between edible morsels and a mouth tucked beneath a stubby rostrum. Instead of nipping foes in the butt, the crabs' primary defence lies in their stout armoury and the ability to remain inconspicious amid muddy bottoms and seagrass meadows.
Most parthenopids are encountered by chance, when a tiny shift in the intertidal continuum betrays the presence of a disguised crab. This individual, spotted at Cyrene Reef and identified as Rhinolambrus pelagicus, was curiously unsullied by sediment, which was likely the result of a recent moult, as conspecifics have been seen with far grubbier coats. Obscure in both hide and habit, the family is consequently overlooked and possibly undercounted by casual observers. But their rarity in the field and the perilous status of some local species is also the product of a preference for questionable habitats: seagrass beds, sandy flats and silty seabeds that endure the regular dredges of a maritime economy and the dismissal of visionaries who dream of artificial reefs and refuse to see what life survives in these straits of dire passages.
Comments