Archive image from page 532 of The depths of the ocean. The depths of the ocean : a general account of the modern science of oceanography based largely on the scientific researches of the Norwegian steamer Michael Sars in the North Atlantic depthsofoceangen00murr Year: 1912 INVERTEBRATE BOTTOM FAUNA 497 being extremely numerous in certain localities and absent in others ; no doubt the currents at the bottom are responsible for this, seeing that the depth and temperature are in themselves entirely favourable. These enormous quantities of small crustaceans must have an appreciable influence upo
Archive image from page 532 of The depths of the ocean. The depths of the ocean : a general account of the modern science of oceanography based largely on the scientific researches of the Norwegian steamer Michael Sars in the North Atlantic depthsofoceangen00murr Year: 1912 INVERTEBRATE BOTTOM FAUNA 497 being extremely numerous in certain localities and absent in others ; no doubt the currents at the bottom are responsible for this, seeing that the depth and temperature are in themselves entirely favourable. These enormous quantities of small crustaceans must have an appreciable influence upon the shoals of fishes, and in particular upon the young fishes, and this I have been able to confirm by direct observation. On the northern slope of the Dogger Bank we captured a number of young whitings and flounders with the trawl at a depth of 38 metres (temperature 10 C), and their stomachs at first sight seemed to contain only sand, but closer investigation revealed small amphi- pods (sand-hoppers) which thus formed their principal nourishment, the sand being swallowed simul- taneously with them ; the stomachs of the larger fishes generally con- tained hermit crabs and swimming crabs (Portunus). The caprellids seemed to be especially associated with a bottom overgrown with Fig. 350. Macrocliymm pomum, M. Sars. hydroids, and were found only exceptionally where hydroids were absent. The central portion of the North Sea is poorly supplied with pycnogonids (sea-spiders), there being only one widely distributed form [Pyaiogonum littorale), and it was only found in deep water (80 to 100 metres) at low temperatures (6°-7° C), where I sometimes found it, as described by Sars, clinging to large sea-anemones [Urticina crassicornis and Metridium diantkus), into the skin of which it bores its proboscis for sucking; a solitary specimen of Nyniphon stromi was the only other pycnogonid found in deep water. The ascidians (sea-squirts) are also poorly represented ; the monascidians (
Size: 1176px × 1701px
Photo credit: © Actep Burstov / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: 1900, 1910, 1912, _michael_sars_north_atlantic_deep_sea_expedition_191, appell_f_jakob_johan_adolf_1857_, archive, book, bookauthor, bookcentury, bookdecade, bookpublisher, booksubject, bookyear, drawing, gran_h_h_haakon_hasberg_1870_, helland_hansen_bj_rn_1877_, historical, history, illustration, image, london_macmillan, murray_john_sir_1841_1914, north_atlantic_ocean, oceanography, page, picture, print, reference, vintage
