Fróðskaparrit - 01.01.1995, Page 111

115
Experimental infection of macroplankton
from Faroese waters with newly hatched
Anisakis simplex larvae
Dánjal Petur Højgaard
Úrtak
f eini roynd at greina ein part av lívsringrásini hjá van-
liga fiskasníkinum Anisakis simplex (“sandmaðki”), varð
dýraplankton av Føroya-leiðini royndar-infiserað við
nýliga klaktum Anisakis simplex-Xsnum. Kannaðu sløg-
ini vórðu hesi: krabbadýrini Calanus finmarchicus, C.
hyperboreus, Thysanoessa sp., Meganychtiphanes nor-
vegica og Parathemisto sp., lindýrini Clione limacina
og Spiratella retroversa og pílormurin Sagitta elegans.
Tvey sløg sýntust at taka larvumar, og hesi vóm
ljóskrabbin Meganyctiphanes norvegica og snigilin
Spiratella retroversa. Við tað, at Meganyctiphanes
norvegica er týðandi partur av føðini hjá ftskasløgunum
sild, upsa, toski og svarkjafti, kann tað helst verða ein or-
søk til, at hesi fiskasløg era fongd við Anisakis simplex.
Abstract
Macroplankton from Faroese waters were exposed to
newly hatched Anisakis simplex larvae, to describe
modes of transmission in the early part of the parasitic
life cycle. The species used in the experiments were: the
crustaceans Calanus finmarchicus, C. hyperboreus,
Thysanoessa sp., Meganychtiphanes norvegica and
Parathemisto sp., the molluscs Clione limacina and Spi-
ratella retroversa and the chaetognath Sagitta elegans.
Only the euphausiacean Meganyctiphanes norvegica.
and the mollusc Spiratella retroversa were experimen-
tally infected.
As Meganyctiphanes norvegica has some impor-
tance as food for fishes like herring, saithe, cod and blue
whiting, the finding may explain infection of these fish-
es with Anisakis simplex.
Introduction
The life cycle of the parasitic nematode
Anisakis simplex (“whaleworm”) has been
investigated for several decades (Temple-
man 1990). The main paths of the life cycle
(“euphausiacean crustacean - fish - whale”)
are known from different field studies
(Smith and Wootten, 1978; Smith, 1983).
In Japanese waters Oshima et al. (1968) ex-
perimentally infected the euphausiaceans
Euphausia similis and E. pacijica with live
Anisakis -larvae. Apart from the work of
Køie (1993), experimental infection of Eu-
ropean plankton seems to be poorly docu-
mented.
This study concentrates on macroplank-
ton from the North Atlantic. Some prelimi-
nary results on experimental infection of
the euphausiacean Meganychtiphanes nor-
vegica are presented.
Materials and Methods
Different species of macroplankton was ob-
tained onboard RAV “Magnus Heinason”
during two trips, 20-26 April and 14-18
May, 1994 in Faroese offshore waters.
Tows were made at standard hydrographic
stations at depths between 100 and 1000 m.
Fróðskaparrit 43. bók. 1995: 115-121