II 



THE MARINE CRUSTACEA 

 BY MARY J. RATHBUN 



CRUSTACEA are the most conspicuous invertebrate animals on 

 the coast of Labrador by reason of their vast numbers, brilliant 

 colours, swift movements, and diversity of form. The shallow 

 water fauna is most abundant on the northern and southern shores, 

 especially in Ungava Bay and from Hamilton Inlet southward 

 and westward, where the harbours are enriched by, the silt of 

 numerous rivers and the land slopes gradually into the sea. Vari- 

 ous kinds of Amphipods and other small forms swarm under the 

 rocks and in masses of algae or in pools of water. Along most of 

 the Atlantic coast, however, the bays are barren and rocky, with 

 little seaweed, and there are few large streams carrying down 

 sediment to form muddy and sandy bottoms; the rocks at the 

 water's edge are precipitous, supporting a narrow line of Fucus, 

 which gives shelter only to the common sand-flea. In quiet eddies 

 in the passages between the islands which fringe the coast, condi- 

 tions are more favourable for the development of life. Here the 

 dredge rewards the collector with spidery crabs and darting shrimps. 1 



The species found in Labrador are not numerous, nor are they 

 peculiar to the peninsula, but in general range from Cape Cod to 

 Greenland, while many extend to Europe or are Arctic in distri- 

 bution, in not a few cases reaching into Bering Sea and the North 

 Pacific Ocean. 



The common shore-crab, or rock-crab (Cancer irroratus), of the 

 New England coast is also the shore-crab of Labrador, but has not 

 been found north of Hamilton Inlet. It occurs frequently under 

 stones in the Strait of Belle Isle. Occasionally it is caught and 

 eaten by the natives. The shell is broadly oval, with nine saw- 

 teeth on each side, and is speckled with fine red or brown dots; 

 the claws are stout and similar in size and shape, and there are 

 four pairs of smooth, flattened walking feet. 



Three other crabs inhabit the coasts of Labrador, but live offshore 

 in depths varying from a few fathoms to fifty or more. They 

 belong to the group popularly known as spider-crabs, on account 

 of their relatively long and slender legs, but differ widely from the 



1 Cf. Packard, The Labrador Coast. 

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