Fróðskaparrit - 01.01.2004, Blaðsíða 272

270
The Gametogenic Cycle and Spawning
in Mytilus edulis in the Faroe Islands
Kynskyknu-búning og -gýting hjá kræklingi (Mytilus edulis)
í Føroyum
Gudrun G. Thorarinsdóttir1, Karl Gunnarsson1 and Maria Dam2
1 Marine Research Institute, Skúlagata 4, 101 Reykjavik, lceland. E-maiIs: gutho@hafro.is; karl@hafro.is
2 Food, Veterinary and Environmental Agency, Falkavegur 6, FO-IOO Tórshavn, Faroe Islands.
Email: mariad@hfs.fo
Úrtak
Tann árliga ringrásin í búningini av kynskyknunum í
kræklingi, Mytilus edulis L. í Eysturoy í Føroyum varð
kannað tíðarskeiðið juni 1996 til juni 1997. Vevnaðurin
av kynsgøgnunum vísti tekin um at búningin av
kynskyknum fór fram alt árið, tó var meginbúningin í
tíðini frá novembur til mars. Gýtingin fór fram yvir eitt
longri tíðarskeið, frá mai til tíðliga á vetri, tó við eini
høvuðsgýtingartíð í mai og juni, tá ið sjóvarhitan er um
7-8°C. Eitt búningarskeið av kynskyknum, sum líkist tí
í Føroyum, er fyrr sæð í eini røð av kræklingastovnum
í útsynningspartunum av Evropa, men er hetta nakað
annarleiðis enn tað, sum er sæð bæði í landsynnings- og
útsynnings-partunum av Islandi.
Abstract
The annual gametogenic cycle in the blue mussel,
Mytilus edulis L. on Eysturoy in the Faroe Islands was
investigated from June 1996 to June 1997. Histological
preparations of thc gonads showed evidence of gonad
development throughout the year with the main
development period between November and March.
Spawning was protracted lasting from May until early
winter with the main spawning in May and June at a sea
temperature of 7 and 8°C, respectively. A gametogenic
cycle similar to the one in the Faroe Islands has been
observed in a number of populations in Western Europe
but is somehow different from those observed both in
western and eastern lceland.
Introduction
Available information on the reproduction
and seasonality of the gametogenic cy-
cle of Mytilus edulis L. in the Atlantic is
particularly extensive reflecting its com-
mercial importance. However, in the Faroe
Islands the information on reproduction in
blue mussels unlil now is limited (Gaard,
1986).
The gametogenic cycle of M. edulis var-
ies, both spatially and temporally and the
timing and duration of the cycle probably
results from complex interactions between
several exogenous and endogenous factors.
Of the exogenous factors, sea temperature,
which varies seasonally and latitudinally,
and food supply seem to be the most im-
portant (Seed and Suchanek, 1992).
The present paper describes the annual
gametogenic cycle and spawning in Mytilus
edulis in the Faroe Islands in relation to sea
temperature. Furthermore, comparisons are
made with other populalions of M. edulis in
the North Atlantic.
Fróðskaparrit 51. bók 2004: 270-279