The life of crustacea / by W.T. Calman.

  • William Thomas Calman
Date:
1911
Catalogue details

Licence: In copyright

Credit: The life of crustacea / by W.T. Calman. Source: Wellcome Collection.

    144/392 page 96
    Crabs” (DromiidcB)^ of which one species, Dromia vulgaris (Plate IX.), occurs on the southern coasts of Britain, have also the last two pairs of legs elevated on the back and used in a similar way; but in this case the covering is usually a mass of living sponge, one of the Sea-squirts (Tunicata), or some similar organism. Even more remarkable are the “ masking ” habits of the Spider Crabs (Oxyrhyncha). In these the carapace is almost always covered with sea-weeds, zoophytes, and other organisms which afford a very effective disguise. For example, specimens of the British species of Hyas {H. araneus and H. coarctatus) and Maia (M. squinado—Plate XIIL), which are very common on our coasts, readily escape the notice of the collector, as they lurk in the rock-pools. They are slow-moving animals, and the carapace and limbs are usually quite hidden by dense tufts of growing sea-weed, sponges, and other organisms. By observing the Crabs in an aquarium, it has been found that they actually dress themselves, plucking pieces of weed and the like and placing them on the carapace, where they are held in position by numerous hooked hairs. The transplanted fragments continue to live and grow until the Crab appears like a minia- ture moving forest. Still more strange is the fact that the Crabs appear to be able in some degree to adapt the nature of their covering to their surround- ings. It has been found that specimens dressed in
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