Cestode parasites of Illex Illecebrosus Illecebrosus (LeSueur) (Decapoda: cephalopoda)

Ommastrephid squid of the subspecies Illex illecebrosus illecebrosus (LeSueur) were obtained during the months of July through September, 1966 and July through November, 1967, from numerous areas around the east coast of the province of Newfoundland. The specimens were obtained by jigging and immedi...

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Bibliographic Details
Main Author: Brown, Elizabeth Louise
Format: Thesis
Language:English
Published: Memorial University of Newfoundland 1968
Subjects:
Online Access:https://research.library.mun.ca/7139/
https://research.library.mun.ca/7139/1/Brown_ElizabethLouise.pdf
https://research.library.mun.ca/7139/3/Brown_ElizabethLouise.pdf
Description
Summary:Ommastrephid squid of the subspecies Illex illecebrosus illecebrosus (LeSueur) were obtained during the months of July through September, 1966 and July through November, 1967, from numerous areas around the east coast of the province of Newfoundland. The specimens were obtained by jigging and immediately upon capture they were placed in a styrofoam container of crushed ice and so transported to the Laboratory for examination. An incision was made in the median ventral mantle wall exposing the internal organs which were then examined for parasites. Helminths found were relaxed in 1 percent urethane (ethyl carbamate) and preserved in 70 percent ethyl alcohol, prior to staining with acid carmine. Histological sections of the parasites were made in situ, and stained with Mallory's Triple Stain. Measurements of total length and standard (mantle) length of the squid were made, and the sex and maturity of each were recorded. -- Helminths of five genera were found, namely, Phyllobothrium sp. and Dinobothrium plicitum (both of which had previously been recorded), Pelichnibothrium speciosum, Scolex polymorphus and Nybelinia sp. The last three represent new records from this Ommastrephid. All species of helminths were found free in the caecum of the host, except D. plicitum which was normally found encysted in the walls of the caecum and intestine. -- The incidence of these parasites was tested for correlation with standard length, and sex of the host animal, as were annual, and seasonal variations in degree of infestation. -- Also found in the various internal organs of the squid were nematodes of the genus Contracaecum. -- The incidence of these parasites is discussed in terms of what is known of the biology of the short-finned squid, as are postulated life-cycles for their helminth fauna.