Fróðskaparrit - 01.01.2006, Blaðsíða 140

138
SOLITARY ASCIDIANS (TUNICATA, ASCIDIACEA
AND SORBERACEA) OF THE FAROES
BIOFAR station: Not recorded during BIOFAR.
EEZ area: Faroe-Shetland Channel.
EEZ depth range: 459 m.
Tempcratures: Ifsampled in summer4-6°C (Westcrberg,
1990).
EEZ water mass: AI (Westerberg, 1990) or East Iceland
Current (Hanscn and Østerhus, 2000).
North Atlantic/Nordic Seas distribution: Svalbard;
Faroes; western coast of Greenland, northem North
America (Millar, 1966).
General distribution: As above.
Gencral depth rangc: From 50-459 m (Hartmeycr, 1924;
Millar, 1966).
Remarks: C. borealis is a rare species which presumably
is indigenous to the Arctic region, from where it has
been recordcd only a few times (Kola Fjord, Sval-
bard, eastern and western coast of Greenland, and
Baffín Island) (Traustedt, 1886; Hartmeyer, 1903,
1923). In addition there is one record (Hcrdman,
1891) from the boreal eastem Atlantic region (Faroe-
Shetland Channel) and an uncertain record (Van
Name, 1912) from the boreal western Atlantic re-
gion (near Cape Ann, Massachusetts); a small and
mutilated specimen. The record from the slope of the
Faroc-Shetland Channel is evidently a result of south-
ern dispersal with the East Iceland Current or Nor-
wegian Sea Deep Water.
Family ASCIDIIDAE
Genus: Ascidia Linnaeus, 1767
Ascidia callosa Stimpson, 1852
Good description: Hartmeycr, 1924: 41-53; pl. 1, figs.
15-16;Van Name, 1945; Millar, 1966: 55, fig. 35.
Previous records: “Beskytteren” 1926: Miðvágur (Ám-
back-Christie-Lindc, 1952).
BIOFAR stations (number of individuals in parentheses):
1023(1); 1153(1); 1616(1).
BIOFAR area; Ørðavík; Kolturssund; Kaldbaksfjørður
(Fig. 5).
BIOFAR depth range: 5-60 m.
BIOFAR temperatures: Unknown.
BIOFAR water mass: AW.
North Atlantic/Nordic Seas distribution: Svalbard; coast
of Norway; westem coast of Sweden; Faroes; Ice-
land; coasts of Greenland; northem North Amcrica
(Van Name, 1945; Millar, 1966).
General distribution: Arctic basin; Bering Sea; Okhotsk
Sea; Northern Pacific.
Figure 4. Ascidia callosa (from Lutzen, 1967).
General depth range: From shallow water to about 300
m (Millar, 1966).
Remarks: The BIOFAR records seem to indicate that A-
callosa is sparsely distributed in the Faroese EEZ-
This trend is also apparent in Iceland, along the Nor-
wegian coast, and the westem coast of Sweden, while
this species is not present in the southem part of the
boreal eastern Atlantic. A. callosa is also rare in the
Sea of Japan (two records). This species is, on the
other hand, very common in the Arctic Basin, the
Bering Sca and the Sea of Okhotsk (Sanamyan,
2000); and A. callosa together with Boltenia echinato
and B. ovifera make up almost fifty percent of the
ascidian fauna in the Arctic waters of Canada (Tra-
son, 1964). It obtains largest size in the higher lati-
tudes (Hartmeyer, 1924).