Identifier: annualreportof4189718newy (find matches)
Title: Annual report of the Commissioners of Fisheries, Game and Forests of the State of New York
Year: 1895 (1890s)
Authors: New York (State). Commissioners of Fisheries, Game and Forests
Subjects: Forests and forestry Fisheries Game and game-birds
Publisher: (Albany, N.Y. : The Commission)
Contributing Library: Smithsonian Libraries
Digitizing Sponsor: Biodiversity Heritage Library

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
d chiefly in theswimming bladder and were present in considerable numbers and in all stages ofdevelopment. They belong to the genus Ascaris of which there are 102 distinctspecies, and only a very few are known to produce fatal results. Each femaleindividual produces thousands of eggs which are retained until the embryo hasreached a considerable size. Each egg is surrounded by a thick capsule and iscapable of resisting heat or chemicals for a considerable time. They are passed outof the body either through the mouth or the anus and ultimately get into a new hostpossibly after passing through an embryonic period in some lower form such as aninsect or a mollusk. The parasitic Copepod, Traclicliastes sp., is also frequently found upon fresh-water fishes where, especially in old or in diseased fish, they become attached tothe gills, sometimes in great numbers (Plate I, figure of gill). When young, theseparasites bore into the soft tissues of the gill, where they retain their position by an
Text Appearing After Image:
FISHERIES, GAME AND FORESTS. 179 anchor-like enlargement at the extremity of the anterior appendages. The mouthis adapted for sucking and the parasite is nourished by the blood obtainedfrom the gills. None of these parasites were numerous enough to account for the trouble, and,although an occasional intra-cellular sporozoan parasite was found, they were notabundant enough to warrant continued search, for in fish with the most noticeableexternal indications of the disease, the organs within were apparently normal and cystsor other usual indications of Sporozoa were not forthcoming. In every section thatwas cut, however, a variable number of minute foreign bodies, which were so smallthat they were at first taken for bacteria, were found especially abundant in the lymphspaces surrounding the various organs and in the testis. These were so minute thatit seemed hardly possible that they could be the cause of the disease and yet theirnumbers were so constant and they were so widely distribu

Note About Images