Fróðskaparrit - 01.01.1995, Page 108

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WHALEWORM IN THE FILLETS OF SAITHE FROM FAROESE WATERS
ters, Norwegian waters and the North Sea.
The present study showed prevalences
from 67.4 % to 96.9 % in the muscles, the
abundance ranging from 0 to 27 per fish.
The reason for these high values most like-
ly are explained by the main diet of the
adult saithe, which according to Joensen
and Táning op.cit. are: herring, scopelids,
euphausiaceans and cephalopods, who gen-
erally are infected with Anisakis simplex
(see e.g.; Davey 1972; Smith 1983, 1984).
Taking into account the high abundances
of Anisakis simplex found in the fillets of
saithe, and keeping in mind that the stock
of saithe is among the largest fish stocks in
the area, the question arises whether the
saithe contributes to the maintenance of
Anisakis simplex in population or not. If the
saithe can pass these nematode larvae to its
final host, then it may be considered to
have importance. If not, then it is a blind al-
ley or “wrong address” for the Anisakis
simplex larvae. Desportes and Mouritsen
(1993) found no saithe in the stomach of
the pilot whale, a common whale in
Faroese waters. In Canadian Pacific waters
Margolis and Pike (1955) found adult
Anisakis simplex in the stomach of the
killer whale, Orcinus orca. However, nei-
ther Bloch and Lockyer (1988) nor Sigur-
jónsson (1993) report saithe as a food item
for killer whales in European waters. Haug
et al. (1995), however, found adult saithe in
the mink whale, Balaenoptera acutorostra-
ta, from Lofoten-Vesterálen. Mink whale
from this area and from around Faroes is
considered to belong to the same, relative-
ly large North-East stock (Sigurjónsson
1993). This whale contains high infections
of mature Anisakis simplex (Aspholm
1995). Even if no records seem to exist of
adult saithe in mink whale in the Faroe-
area, the situation must presumed to be the
same as in other parts of the North-East At-
lantic. Then the infection of saithe with
Anisakis simplex third stage larvae most
likely will contribute to the completion of
the Anisakis simplex life cycle. Whether
this contribution is high or low the work of
Aspholm et al. (1995) should be kept in
mind. They showed that a low infection of
the final host of sealworm Pseudoterrano-
va decipiens appear to sustain a stable in-
fection in the surrounding fishes. A similar
mechanicm, too, may be working in the
Anisakis simplex-liic cycle.
Acknowledgements
Grunnurin fyri Vísindaligum Fiskivinnukanningum
(The Fund for Scientific Fish Industry Research), Vís-
indagrunnur Føroya Sparikassa (The Scientific Fund of
Føroya Sparikassa), Grunnurin Til Praktiskar Fiski-
royndir (The Fund for Fishery Research) and Ráfiska-
keyparafelagið are thanked for financial support. The
laboratory staff of the former fish processing plant Ba-
calao are thanked for help with the digestion analysis
and the crew of “Magnus Heinason” are thanked for the
task with the sampling. I am indebted to Paul Aspholm,
Oslo and (the now late) Dr. Jóhannes Jóhansen for his
comments and critics to the manuscript.
References
Aspholm, P.A. 1995. University of Oslo. Pers. comm.
Aspholm, P.A., Ugland, K.I., Jødestøl, K.A. and B.
Berland. 1995. Sealworm (Pseudoterranova
decipiens) infection in common seals (Phoca
vitulina) and potential intermediate fish hosts from
the Outer Oslofjord. Intemational Joumalfor
Parasitology 25(3): 367-373.
Bloch, D. and Lockyer, C. 1988. Killer whales
(Orcinus orca) in Faroese waters. Rit Fiskideildar
11: 55-64.