Atlas of Atlantic Ostracods
Taxon details
Paraconchoecia mamillata (Müller, G.W., 1906)
- Order:
- MYODOCOPA
- Suborder:
- Halocypridina
- Family:
- Halocyprididae
- Subfamily:
- Conchoecinae
- Size range (females):
- 1.9-2.2 mm
- Size range (males):
- 1.5-1.8 mm
- Depth:
- bathy-/abyssopelagic
Notes
133 records
This is a characteristic species, which has its asymmetrical glands opening on the tips of tubercles on the posterior margins of the carapace. It was first described by Müller (1906) from the Atlantic and Indian Oceans. He classified it in his ‘spinifera group’, and noted there were two size groups. Poulsen (1973) re-classified it placing it in Paraconchoecia. Deevey and Brooks (1980) subsequently split off the smaller form as P. nanomamillata, and so earlier records may be of either species. There are a number of characters other than the unique positions of the asymmetrical glands, which suggest that this species and its sibling species P. nanomamillata should be split off from its current genus. The typical species is deep mesopelagic at high latitudes (>60°) but sinks to bathypelagic or even abyssopelagic depths at latitudes <40°. At these deeper depths it is often numerically dominant in the halocyprid populations. At mesopelagic depths at subtropical latitudes it is replaced by nanomamillata. In common with many deep-living species, this is a rather fragile species and good specimens are at a premium. The very occasional extra large specimens hint that there may be yet another sibling species.
| NE Atl | n | Mean mm | s.d. | Range mm |
|---|---|---|---|---|
| Female | 136 | 1.72 | 0.096 | 1.50-1.90 (1.94) |
| Male | 65 | 1.67 | 0.063 | 1.50-1.79 (1.94) |
| A-1 | 78 | 1.34 | 0.075 | 1.18-1.50 |
| A-2 | 16 | 1.09 | 0.048 | 1.02-1.16 |
| A-3 | 35 | 0.93 | 0.031 | 0.88-1.00 |
