Fróðskaparrit - 01.01.1998, Page 81

CAPRELLIDEA (CRUSTACEA; AMPHIPODA) í FØROYSKUM SJÓGVI,
VIÐ EINUM LYKLI TIL ONNUR SLØG f NORÐURATLANTSHAVI
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7.Gnathopod 2 basis with distal and medial spines
C. carina
Gnathopod 2 basis without medial spine.... 8
8. Antenna 1 Flagellum longer than peduncle .... 9
Antenna 1 flagellum shorter than peduncle .... 10
9.Pereonite 1-4 omamentation consisting of spines
C. dubia*
Pereonite 1-4 ornamentation consisting of tubercles
C. microtuberculata *
10. Pereopod 5-7 propodus margin
without spines C. unica
Pereopod 5-7 propodus margin with spines .... 11
11. Pereonite 5 -7 without omamentation..... 12
Pereonite 5-7 with ornamentation.......... 13
12. Male gnathopod 2 propodus densely setose, female
pereonite 5 50% larger than pereonite 4
C. ciliata
Male gnathopod 2 propodus not densely setose,
female pereonite 5 not larger than pereonite 4.. 13
13. Head without spines...................... 14
Head with spines........................... 15
14.Head with 1 large elongate tubercle
C. septentrionalis var. punctata
Head without large elongate tubercule...... 18
l,.Headwithsinglespine.......................... 16
Head with at least one pair of spines........ 17
16.Eye diameter as large as antenna 1 thickness, body
densely covered with small tubercles C. rinki
Eye diameter smaller than antenna 1 thickness,
unpaired spines on pereonites
C. septentrionalis var. monocera
1 '.Head with clearly defined paired spines, body
densely covered with small unpaired spines
Metacaprella horrida
Head with weakly defined paired spines, body
smooth C. linearis
I .Male gnathopod 2 basis of same length as pereonite
3, Ratio of total length to length of basis
greater than 13. C.liniaris
Male gnathopod 2 basis shorter than pereonite 3,
Ratio of total length to length of basis less than 13
C. septentrionalis var. loveni
* As seen below, these 2 species are considered
variations of the same species.
Key 3: Genus Thorina
l.Body smooth T. elongata
Body with large spines 7. spinosa
Key 4: Genus Aeginina
l.Antenna 1 flagellum longer than peduncle.
A. aenigmatica
Antenna 1 shorter flagellum than peduncle
A. longicornis
Discussion
The faunistic đata show some correlations
between water temperature and species
composition. The fauna could be divided
into a warm water group and a eurytherm
species group. No exclusive cold water
species group were found, and even species
considered to be arctic or subarctic (Aegi-
nella spinosa. Caprella microtuberculata,
Metacaprella horrida) where found at tem-
peratures above 9.0°C. This is a compara-
tively high temperature for arctic species,
and may be an influence of the seasonal
variations in the dominant water masses. A
typically warm-water species, Phtisica
mariner, was found at an unheard of low
temperature of -0.85°C (although only
once), also suggesting very variable condi-
tions. As for the salinity, however, all the
Caprellidea from the BIOFAR cruises
where taken within a relatively narrow