Ocean research and the great fisheries . ketch of her work which the writer nowessays for the information of his brother laymen. Her methodis as follows. Tlie young fish are caught, by the research vesselOithona, either in the tow-nets, or in one of the young-fish trawls—the latter being most ingenious otter trawls with a mesh assmall as one-twelfth of an inch. On their arrival at the labora-tory Dr. Lebour dissects out the alimentary canals and examinesthe food which is in them. The smallest turbot thus dissectedwas 6 miUimetres long. That is to say : That is what is meant by the statement in
Ocean research and the great fisheries . ketch of her work which the writer nowessays for the information of his brother laymen. Her methodis as follows. Tlie young fish are caught, by the research vesselOithona, either in the tow-nets, or in one of the young-fish trawls—the latter being most ingenious otter trawls with a mesh assmall as one-twelfth of an inch. On their arrival at the labora-tory Dr. Lebour dissects out the alimentary canals and examinesthe food which is in them. The smallest turbot thus dissectedwas 6 miUimetres long. That is to say : That is what is meant by the statement in Chapter I, p. 15,that the world of these little fishes was a world which could beexplained only with the aid of a microscope. Dr. Lebour tells us that few fish are vegetarians ; and asa rule only the very youngest fish eat diatoms. Very youngherring and plaice and other fish, however, do undoubtedly eatthem, and we have seen in Chapter XVII that their absenceor presence in the sea at the right time projjably makes all the PLATE XVIII. PLANKTON CONTAINING FISH EGGS (Photograph by Mr. A. Scott.) Magnified about 5 diameters. P. 192 THE SMALL GAME OF THE SEA 193 difference between wholesale destruction of the brood and anabnormally large hatch of herring, cod, and haddock. A newlyhatched plaice in an aquarium has been observed feeding ona diatomic plant called Navicula which was growing at the])ottom of the glass tank. The diatoms are, however, equally important because theyundoubtedly furnish the food of the small game on whichfish feed. And Dr. Lebour has proved that httle herring andother babies take to eating the larvae of certain molluscs andsmall crustaceans before the yolk has all gone. It is herepossible only to compile quite a few notes about these smallanimals. By far the greater part of the food of very young fish consistsof the larvae of certain Crustacea called Copepods or Oar Jeet\These—in water north of the Bay of Biscay—consist of betweenforty and fifty diffe
Size: 1251px × 1997px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, bookpublisheroxfor, bookyear1921
