Journal Of The Marine Biological Association Of The United Kingdom

Author : U. K. Marine Biological Association
Publisher : Forgotten Books
ISBN 13 : 9780666614292
Total Pages : 646 pages
Book Rating : 4.6/5 (142 download)

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Download or read book Journal of the Marine Biological Association of the United Kingdom, 1910-13, Vol. 9 (Classic Reprint) written by U. K. Marine Biological Association and published by Forgotten Books. This book was released on 2018-02-28 with total page 646 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from Journal of the Marine Biological Association of the United Kingdom, 1910-13, Vol. 9 Systematic examination Of tow-nettings for pelagic fish-eggs began on February 11th, and in the early months before the steamer was in commission, owing to the exigencies Of weather and time which attend the use Of a small sailing-boat, samples were taken only inside the Sound or in its near vicinity. As will be seen from the analysis of the collections given in Table I, there was a break Of more than a months duration, beginning early in March. From April to the end of August the ss. Oithona was available, which not only rendered collections from the Open-sea areas possible, but also permitted the use Of the Petersen young-fish trawl, by which large quantities of fish-eggs could be Obtained. The quantities so Obtained were generally much too large to admit Of their individual examination, and therefore it was my practice to pick out a portion of the total eggs for careful examination and frequently for hatching in the laboratory, while the residue was scrutinized as carefully as possible so that the rarer specimens should not be omitted. After a certain amount of practice one can recognize many of the familiar species by size and other peculiarities even with the naked eye, SO that after a confirmatory microscopic examination it is possible to Obtain a fair knowledge as to the identity Of the majority Of the Species present in a plankton sample, and then exceptional eggs can Often - though not, of course, without exception - be discerned. In the case Of tow-net samples, which were taken with coarse (24 strands to the inch) or medium (50 strands to the inch) nets at various depths from'the surface to about 9 or 10 fathoms, care was taken to pick out every individual egg. The hauls were in most cases of 15 minutes' duration, SO that quantitative comparison is to some degree possible. Throughout this work I have conducted my Observations having in view practical fishery questions - cg. The locating Of spawning areas, the duration Of the Spawning period, and the relative extent of the breeding Of various Species of fishes in the Plymouth area - rather than'details of purely biological interest, and therefore my records of the characters Of eggs and larvae have had special regard to points for purpose Of ready identification at the various stages Of development; hence details of embryology have little place in this paper. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.