Fróðskaparrit - 01.01.2008, Page 152

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Parasites of three-spined stickleback,
Casterosteus aculeatus L., from Faroe
Islands
Sníkar íføroyskum kombikki, Gasterosteus aculeatus L.
Dánjal Petur Højgaard\ Petur Steingrund1 and Clenn Bristow2
1 Faroese Fisheries Laboratory, Tórshavn, Faroe Island.
Email: danjalp@frs.fo
2 Biological Institute, Universtity of Bergen, Norway
Abstract
ln the years 2002-2004 samples of three-spined stickle-
back, Gasterosteus aculeatus l., from Faroe Islands were
investigated from six different sites, three marine and
three freshwater. Ten parasites or disease conditions
were found in 1105 fish. The cestode Schistocephalus
solidus appeared in freshwater samples only (preva-
lence of infection 6.4-62.8 %). The nematode Hyste-
rothylacium aduncum (4.3 -5.7 %) and the copepod
Thersitina gasterostei (7.4-100 %) were only recorded
in marine samples. The ciliate Trichodina sp.(1.7-100
%) and the monogenean Gyrodactylus sp. (1.1-41.8 %)
were found in all localities. Of digeneans Diplostomum
sp.(5.0 %) was seen in one marine sample and an
unidentified species was seen at two localities in fresh-
water. Diseased conditions found were "fin rot", "white
spot disease" and "unidentified cysts.” Statistical
analyses suggest a significant difference in total para-
sitofauna between marine and freshwater localities
(p<0.01).
Úrtak
í tíðarskeiðinum 2002-2004 vórðu sýni tikin av kom-
bikki, Gasterosteus aculeatus L., á seks støðum í Føroy-
um: trimum støðum, har salt var í umhvørvinum, og
trimum, har einki salt var. Tíggju sløg av sníkum ella
sjúkrastøðu vórðu funnin í tilsamans 1105 fiskum.
Bendilormurin Schistocephalus solidus varð bert funn-
in, har einki salt var (6,4-62,8%). Rundormurin Hystero-
thy/acium aduncum (4,3-5,7 %) og krabbadýrið Thersi-
tina gasterostei (7,4-100%) vórðu bert funnin, har salt
var í umhvørvinum. Einkyknudýrið Trichodina sp. (1,7-
100%) og monogena iktan Cyrodactylus sp. (1.1-41.8
%) vórðu funnin á øllum støðum. Digena iktan Diplo-
stomum sp. (5,0%) varð bert funnin á einum stað, og
eitt ónavngreinað slag varð funnið á tveimum støðum,
har einki salt var. Funnar sjúkrastøður vóru: "fjaðrarot”,
"hvítblettasjúka" og "ónavngreiddar bløðrur". Hag-
frøðiligar kanningar vístu ein týðandi mun millum sølt
og ósølt støð í tali og tíðleika av sníkum (p < 0,.01).
INTRODUCTION
The three-spined stickleback, Casterosteus
aculeatus L. was first reported in the Faroe Is-
lands during the journeys of J.C. Svabo in the
years 1781-82 (Svabo, 1796). Its biology and
life-history in the Faroes are treated in Joen-
sen & Táning (1970), who also reported two
Fróðskaparrit 56. bók 2008:150-162