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Show 330 MR. R. COLLETT ON CERTAIN GOBIOID FISHES. [Mar. 5, large swimming-bladder, which occupies a considerable part of the belly, expands still further when the individuals are brought up to the surface, the somewhat fatigued fish not being able to compress it so as to make the specific weight of the body to decrease sufficiently to permit it again to descend under the water. The weight of the body is also diminished by the loss of the scales; consequently a great number of such individuals are driven about on the surface of the water in a still living state, till they are carried away by the stream or picked up by sea-birds and other enemies. They swim, however, not without a certain degree of rapidity. Their enemies are almost all other fishes who occupy the same locality. Especially the different kinds of Gadus devour large masses ; and even in the case of small specimens of Gadus morrhua, G. esmarkii, and G. merlangus, I have occasionally found the stomach crammed with them. When they float about in their helpless state on the surface of the water, Gasterosteus aculeatus and Spinachia vulgaris snatch large pieces out of their brittle bodies. As mentioned above, their food consists chiefly of microscopic copepoda and other small pelagic animals. In the specimens that I have examined in the Christiania Fjord, these principally consisted of the copepods Dias longiremis, Lilljeb., Temora velox, Baird, together with the larvae of decapods (Hippolyte and Paleemon), and mollusks in their swimming-stage (Cardium). The stomach contains this kind of food both in the summer and the winter. Distribution.-Taking for granted, that the forms from Southern, Western, and Northern Europe are identical, L. pellucidus has a very wide distribution, although our information touching this species is at present very incomplete. In this case it is met with (possibly in certain spots only) from the western coast of Norway, about 60° N. long., down along Western Europe to the Mediterranean, in the Adriatic, and right up to the innermost parts of the Black Sea. In Norway it is met with outside of Bergen, and in the Christiania Fjord. At the first-named place the late naturalist Mr. Stuwitz obtained four specimens in December 1834; it has, however, not since been found in this locality. In the Christiania Fjord I have found it in several places inside Doobak, chiefly amongst the islands outside Christiania; most likely it is to be found in the outer parts of the fjord also, and undoubtedly at other places along our southern coast, not mentioned here. In Sweden it has been found by Dr. Malm in Bohuslen. In Scotland Mr. Parnell has taken it in Sol way Frith, June 1836 ; and in his ' Catalogue' Dr. Gunther states that the British Museum also has specimens from the Frith of Forth. In the Mediterranean it is known, through Prof. Canestrini, from the Gulf of Genoa; and Prof. G. O. Sars found it in the beginning of 1876 at most of the places visited by him-e. g. in Sicily, at Messina, and Syracuse-everywhere in enormous masses. In the Adriatic, whence it was already described in 1824 by Nardo, and afterwards mentioned by several authors, he found it at Trieste. |