Notes
521 records
This was one of the earliest species to be described from samples collected off the Lofoten Islands in the Atlantic off the northwest coast of Norway. It has been frequently recorded at high latitudes in the North Atlantic. Russian data show that it spreads far into the high Arctic probably advected there in the northward flow of Atlantic water. It has a relatively shallow bathymetric range, which appears to prevent it from becoming established as a permanent member of the mesozooplankton at very high latitudes. It may prove to be a good indicator of any climatic changes that lead to a general warming of the waters of the Arctic. It is extremely abundant at boreal latitudes but becomes progressively less abundant and smaller towards lower latitudes. It is rare at latitudes <40°N; the three records from south of 30°N in the Atlantic are all from Vavra (1906), many of whose identifications were erroneous (Skogsberg, 1920) and so should be disregarded. This species is a North Atlantic endemic. When sampling was first undertaken in the Southern Ocean, similar looking specimens were identified as a subspecies. Consequently obtusata was considered to have a bipolar distribution (Müller 1906). The Southern Ocean ‘subspecies’ (Müller 1906, Skogsberg, 1920) was raised to a full species rank as antarctica, by Martens (1979) who also placed both species in a new genus Both species have been redescribed by Angel and Blachowiak-Samolyk (2006), confirming their separate identities. The bathymetric profiles show that at 60°N its range was centred at 50-200m where it dominated the halocyprid assemblage. At 40°N its range had deepened to 100-300m and it had become a far less important component of the ostracod assemblage.
| 44°N
|
n
|
Mean mm
|
s.d.
|
Range mm
|
|---|
| Female
|
13
|
1.55
|
0.056
|
1.44-1.64
|
|---|
| Male
|
19
|
1.15
|
0.027
|
1.12-1.20
|
|---|
| A-1
|
12
|
1.00
|
0.036
|
0.94-1.06
|
|---|
| A-2
|
42
|
0.85
|
0.035
|
0.74-0.90
|
|---|
| A-3
|
52
|
0.62
|
0.030
|
0.56-0.68
|
|---|
| 53°N
|
n
|
Mean mm
|
s.d.
|
Range mm
|
|---|
| Female
|
206
|
1.74
|
0.054
|
1.58-1.86
|
|---|
| Male
|
289
|
1.21
|
0.031
|
1.14-1.30
|
|---|
| A-1
|
589
|
1.16
|
0.068
|
1.04-1.34
|
|---|
| A-2
|
648
|
0.90
|
0.043
|
0.82-1.02
|
|---|
| A-3
|
1121
|
0.70
|
0.050
|
0.56-0.80
|
|---|
| Labrador Sea
|
n
|
Mean mm
|
s.d.
|
Range mm
|
|---|
| Female
|
27
|
1.81
|
0.029
|
1.70-1.92
|
|---|
| Male
|
36
|
1.21
|
0.029
|
1.12-1.26
|
|---|
| A-1
|
6
|
1.13
|
0.046
|
1.04-1.18
|
|---|
| A-2
|
3
|
|
|
0.92-1.02
|
|---|
| A-3
|
2
|
|
|
0.62
|
|---|
