Atlas of Atlantic Ostracods

Taxon details

Discoconchoecia elegans (Sars, G.O., 1866)

Order:
MYODOCOPA
Suborder:
Halocypridina
Family:
Halocyprididae
Subfamily:
Conchoecinae
Size range (females):
1.1-1.9 mm
Size range (males):
1.0-2.0 mm
Depth:
epi-/mesopelagic

Notes

1343 records

This was one of the first halocyprids to be described by Sars from samples collected off the Lofoten Islands off northwestern Norway. Since then it has been the most frequently recorded of all halocyprid species. Müller (1906) classified it in his ‘elegans group of species, which he defined as those species with an oval pad of hairs as the armature on the e seta of the male first antenna, noting its similarity to D. discophora. Müller (1906) also stated that the species not only has an unusually wide range of carapace lengths (♀ - 1.1-2.1 mm; ♂ - 1.0-2.0mm) but also that the lengths decrease with decreasing latitude. Skogsberg (1920) gave a detailed description of specimens from the Southern Ocean and Deevey (1968) illustrated a small form collected off Bermuda. Poulsen (1973) placed the species in Claus’s genus Paraconchoecia and described a new closely related species P. tamensis from a single male specimen (1.1mm) sampled off Indonesia. Martens (1979) placed these species in a new genus Discoconchoecia. Attributing an adult male specimen to this genus is straightforward, but as the size data given below indicates, it is unlikely that all the specimens attributed to elegans are the same species. In the Atlantic typically sized specimens occur at high latitudes and in the cold water outflows from the Arctic in the Labrador Sea. At tropical and subtropical latitudes the adult carapace lengths are almost half the typical length, and the size distributions of adults and juvenile instars are well defined and the length/size distributions are disjunct. However, at temperate latitudes (see 44°N data) the length/size distributions are continuous so that it is impossible to separate the juvenile instars and even the adult females on the basis of carapace length. Angel (1977) likened this distribution of sizes to a hybrid swarm. Specimens caught at deeper depths to be larger, but this trend is too vague to suggest there is any sort of bathymetric segregation. This problem of identity of this abundant and often dominant mesopelagic species may only be resolved by a molecular genetics study.

Svalblad ~80°N N Mean mm s.d. Range mm
Female 20 2.01 0.082 1.92-2.22
Male 11 2.19 0.087 2.08-2.36
A-1 13 1.77 0.034 1.72-1.84
A-2 8 1.51 0.073 1.42-1.60
A-3 9 1.23 0.065 1.14-1.32
A-4 12 1.00 0.043 0.94-1.06
A-5 13 0.65 0.031 0.60-0.70
Labrador Sea N Mean mm s.d. Range mm
Female 72 1.90 0.066 1.76-2.04
Male 13 2.03 0.088 1.96-2.04 (2.16)
A-1 40 1.62 0.042 1.54-1.72
A-2 31 1.36 0.048 1.30-1.50
A-3 72 0.98 0.078 0.82-1.12
A-4 71 0.64 0.027 0.58-0.74
A-5 22 0.43 0.019 0.40-0.44
Raunefjord, Norway n Mean mm s.d. Range mm
Female 14 2.07 0.111 1.86-2.35
Male
A-1 21 1.54 0.126 1.35-1.74
A-2 40 1.02 0.064 0.86-1.14
A-3 115 0.67 0.032 0.63-0.74
A-4 248 0.44 0.021 0.42-0.51
A-5 186 0.31 0.020 0.28-0.35
60°N 20°W n Mean mm s.d. Range mm
Female 222 1.70 0.076 1.58-1.98
Female 215 1.86 0.057 1.68-1.98
A-1 218 1.49 0.052 1.34-1.56
A-2 211 1.23 0.056 1.06-1.30
A-3 263 0.97 0.052 0.88-1.04
A-4 143 0.83 0.039 0.64-0.86
53°N 20°W n Mean mm s.d. Range mm
Female 215 1.69 0.058 1.58-1.84
Male 209 1.81 0.052 1.58-1.94
A-1 241 1.48 0.044 1.34-1.56
A-2 203 1.19 0.047 1.06-1.30
A-3 137 0.95 0.038 0.88-1.04
A-4 95 0.82 0.038 0.74-0.86
A-5 3 0.68-0.70
44°N 13°W n Mean mm s.d. Range mm
Females + juvs 3267 0.70-1.66
Male 334 1.45 0.108 1.14-1.98
Canary Is. n Mean mm s.d. Range mm
Female 272 1.24 0.045 1.18-1.40
Male 58 1.17 0.032 1.10-1.25
A-1 210 1.06 0.042 1.00-1.15
A-2 31 0.94 0.025 0.88-0.98
A-3 1 0.75
30°N 23°W n Mean mm s.d. Range mm
Female 275 1.25 0.036 1.16-1.36
Male 175 1.23 0.053 1.12-1.34
A-1 222 1.06 0.032 1.00-1.14
A-2 148 0.93 0.028 0.86-0.98
A-3 3 0.74-0.76
11° 20°W n Mean mm s.d. Range mm
Female 226 1.27 0.038 0.88-1.08
Male 215 1.19 0.320 1.10-1.26
A-1 223 0.99 0.046 0.88-1.08
Equator n Mean mm s.d. Range mm
Female 2080 1.23 0.052 1.10-1.38
Male 545 1.24 0.057 1.02-1.38
A-1 310 1.03 0.029 0.98-1.08
A-2 440 0.90 0.049 0.70-0.96
Benguela (Small) n Mean mm s.d. Range mm
Female 150 1.36 0.055 1.20-1.46
Male 86 1.27 0.034 1.20-1.34
A-1 185 1.04 0.057 0.86-1.14
A-2 59 0.74 0.038 0.64-0.82
Benguela (Large) n Mean mm s.d. Range mm
Female 15 1.59 0.046 1.50-1.66
Male 26 1.60 0.049 1.46-1.68
A-1
A-2
Southern Ocean n Mean mm s.d. Range mm
Female 187 1.64 0.060 1.52-1.84
Male 92 1.76 0.070 1.50-1.88
A-1 174 1.45 0.019 1.36-1.56
A-2 113 1.20 0.045 1.10-1.32
A-3 71 0.94 0.064 0.74-1.02
A-4 2 0.61 0.60-0.62

Map

Distribution map for Discoconchoecia  elegans SST key

Bathymetry

bathymetry data for Discoconchoecia  elegans
bathymetry data for Discoconchoecia  elegans
bathymetry data for Discoconchoecia  elegans

Drawings

Drawings of Discoconchoecia  elegans

Outline

Outline of Discoconchoecia  elegans