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SUMMARY
The feeding habits
of demersal
fish species in
Icelandic waters
by
Ólafur K. Pálsson
Marine Research Institute
P.O. Box 390, Skúlagata 4,
101 Reykjavík, Iceland
On the basis of material sampled in
1980-82 the feeding habits of seven demer-
sal fish species in Icelandic waters are
described.
The feeding of cod (Gadus morhua
morhua) is characterized by the preference
for fish prey, particularly pelagic species
such as capelin (Mallotus villosus) and
blue whiting (Micromesistius poutassou).
Pronounced seasonal, regional and year to
year variations are observed. With increas-
ing lengt of cod the food composition
changes clearly from planktonic and
benthic prey (Euphausiacea) over to small
Rae, B.B. 1968. The food of cod in Ice-
landic waters. — Mar. Res. 6: 3—19.
Rae., B.B. 1969. The food of the witch. —
Mar. Res. 2: 5—23.
Thompson, H. 1929. General features in
the biology of the haddock (Gadus
aeglefinus (L.)) in Icelandic waters in
the period 1903 — 1926. — Rapp. P.-v.
Réun. 57: 5-73.
Wagner, G. 1959. Untersuchungen tiber
die Tagesperiodizitát der Nahrungs-
aufnahme bei Pollachius virens L.-
Kurze Mitt. Inst. Fischereibiol., Univ.
Hamburg 9: 61-103.
pelagic fish (M. villosus), and finally to
large pelagic (M. poutassou) or demersal
fish (Sebastes, G. morhua ) in the largest
predator length groups. On an annual
basis M. villosus is by far the most impor-
tant prey and is estimated to yield 35—
40% of the food of cod.
With respect to prey preference redfish
(Sebastes marinus marinus ) may be classi-
fied as a zooplanktonic feeder, preying
mainly on Euphausiacea and Calanoida.
Saithe (Pollachius virens) may be
described as a predator of zooplanktonic
(Euphausiacea) and nektonic (M. villosus)
animals. Haddock (Melanogrammus aegle-
finus), plaice (Pleuronectes platessa), long
rough dab (Hippoglossoides platessoides
limandoides) and catfish (Anarhichas
lupus ), on the other hand, are preferably
benthic feeders, which mainly prey on
Ophiuroidea and Polychaeta, although
occasionally they are fish consumers.
From the point of view of general
trophic relationships the predatory impact
of cod is of greatest interest, particularly in
the context of quantifying relevant pre-
dator-prey interactions of commercially
exploited fish stocks.
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