Fróðskaparrit - 01.01.1995, Blaðsíða 97

101
Parastenocaris glacialis
(Crustacea: Copepoda, Parastenocarididae)
in the Faroe Islands
Pehr H. Enckell
Úrtak
Fram við føroyskum vøtnum og áarløkum eru her og har
heilt smá sand-og eyrstrekki. Kortini rúma hesi strekki
stundum interstitiskum dýrum, sum halda til ímillum
komini á hesum sandunum. Leitað varð eftir tí harpacti-
cida smákrabbadýrinum, Parastenocaris glacialis
Noodt, sum frammanundan er funnið í Fennoskandia, í
íslandi og í Spitsbergen. Hetta dýraslagið varð funnið í
vøtnum og á smáum sandum við áarbakkar í Streymoy,
Vágum og á Sandi. Ikki er spumingurin loystur enn,
hvussu hetta lítla og viðkvæma slag (0.35 mm til longd-
ar) er komið til Føroya. Avísir møguleikar verða havdir á
lofti.
Abstract
Faroese freshwater lakes and brooks have very small
stretches of sand/gravel scattered along their shores. In
spite of this, these stretches sometimes contain exclu-
sively interstitial animals, living among the sand grains
in the small beaches. A search was made for the
harpacticid cmstacean, Parastenocaris glacialis Noođt,
which has previously been found in Fennoscandia, in
Iceland, and on Spitzbergen. The species was found in
lakes and small sand banks in brooks in Streymoy, Vá-
gar, and Sandoy. The question of how this small and de-
licate species (0.35 mm long) has reached the Faroes is
still unresolved. Certain altematives are discussed.
Introduction
One family of harpacticoids, Parastenocar-
ididae, (Crustacea: Copepoda, Harpacticoi-
da) does almost exclusively occur in inter-
stitial habitats (i.e., living in the water-
filled interstices between sand grains in
sandy beaches along lake shores, sand
banks in rivers and brooks, and sometimes
in the hyporheal habitat under river bot-
toms or in subterranean springs).
The distribution of the species of this
genus is interesting, since many of the nu-
merous species occurring in Central Eu-
rope do not appear to cross the southem
limit of the Wurm ice (the last glaciation).
This indicates that such subterranean
species disperse rather poorly (e.g., Dela-
mare Deboutteville, 1960). This is also
shown by the fact that one of the dominant
species in Fennoscandia, Parastenocaris
phyllura Kiefer, does not seem to occur
above the Highest Shore Line (HSL)
(Enckell, 1969: Fig.3), while it is not un-
common in brackish water in Baltic beach-
es. The other dominant species in the area,
Parastenocaris glacialis Noodt, does, how-
ever, occur from the sea level to high alti-
tudes and may be found on the mountain
heath in small isolated pools lacking in-
and outlets. It is widespread in Fennoscan-
dia and also occurs in Iceland and on
Spitzbergen (Fig. 1, from Enckell, 1969),
and probably on Novaja Zemlja, Bomtzky,
1952. There are only scattered finds south
Fróðskaparrit 43. bók. 1995: 101-105