Crazy about Crabs...

Crazy about Crabs...

From the intertidal rocky-shores to the deep sublittoral reefs of Alderney's waters, crabs are in an amazing abundance. Anecdotally, Alderney hosts a variety of crab species, from small cryptic species such as the Hermit Crab (Pagurus bernhardus), to large, lumbering species, such as the Chancre/Brown Crab (Cancer pagurus). 

Crabs are Decapod crustaceans, with a thick, hard exoskeleton, with three paired legs and two pincers (known as Chelae). They begin life hatching out of an egg, as small larvae. They then go through several stages of moulting before they resemble the typical crab body and will continue to moult until they are adults. 

They are an important group of species within the marine environment, with some recognised as climate change indicators (such as the Montagu's Crab, Xantho hydrophilus) as well as those selected for human consumption.

On Alderney, field-based surveys are currently being conducted to assess crab species presence, abundance and population structure (including shell size/sex) across Alderney's intertidal rocky-shores. These surveys aim to help identify new species (including non-native species) and monitor trends of resident crabs. 

If you would like to take part in a intertidal crab survey on Alderney, please contact Dr Mel Broadhurst-Allen at


A male (left) and a female (right) Chancre Crab, recorded during a crab survey.