Pleuromamma gracilis
(Claus, 1863)
Download a fact sheet for Pleuromamma gracilis (PDF 515KB)
Taxonomy
| Phylum | Arthropoda |
| Subphylum | Crustacea |
| Class | Maxillopoda |
| Subclass | Copepoda |
| Order | Calanoida |
| Family | Metridinidae |
| Genus | Pleuromamma |
| Species | gracilis |
Size
- Female: 1.60 - 2.55 mm
- Male: 1.51 - 2.25 mm
Distinguishing characteristics
- Cephalosome with short, acute apical process
- Rostrum massive with 2 hairy filaments
- Typically have red/brown button on the side of body around the junction of first body somite - depending on species can be on left or right side
- Female P5 with 3 free segments and 3 long setae or with 1 free segment and 3 short spines on distal segment
- Male right P5, terminal segment strongly curved, round; preceding segment with long curved inner spine
- Urosome often asymmetrical with curved somites and setal bundles
Male
- Pigment spot on right side
- Left A1 geniculate, toothed ridges on segments 17, 18, 19-21, serrations variable
- P2 endopod segment 1 with denticles on right side only
- Distal segment of right P5 elongate, slightly less wide than other related forms, penultimate segment has a curved process with a double row of blunt tubercles
Female
- Pigment spot on right side
- Proximal segments of A1 with small low denticles
- P5 2-segmented (with 1 free segment); distal segment with 3 terminal spines and 2 thin outer spines
- Very similar to P. borealis and P. Piseki, look at form of P5 and size
(Bradford-Grieve 1999, Zheng 1982)
Distribution
- Mesopelagic - epipelagic
- Oceanic
- Widespread in all oceans
- Found throughout Australian oceanic waters
Ecology
- Produces 3-4 generations year-1
- Forms large swarms, up to 100 m in length
- Produces bioluminescence that is stronger at night; luminescent glands are present on prosome, the bases of the swimming legs and antennules
- Undergoes diel vertical migration over hundreds of metres
- Display negative phototaxis
- Suspension feeders
References
- Bradford-Grieve, J. M. and Markhaseva, E.L. (1999). Copepoda. South Atlantic Zooplankton. D. Boltovskoy. Leiden, The Netherlands. Backhuys Publishers. 1: 869-1098.
- Buskey, E.J., Baker, K.S. and Smith, R.C. (1989). Photosensitivity of the oceanic copepods Pleuromamma gracilis and Pleuromamma xiphias and its relationship to light penetration and daytime depth distribution. Marine Ecology Progress Series¡¡55(2-3): 207-216.
- Shmeleva, A.A. and Kovalev, A.V. (1974). Cycles biologiques des Copepods (Crustacea) de la Mer Adriatique. Bollettino Pesca Piscic Idrobiol 29: 49-70.
- Wiebe, P.H. (1970). Small-scale spatial distribution in oceanic zooplankton. Limnol. Oceanogr. 15: 205-217.
- Zheng, Z., Li, S., Li, S.J. and Chen, B. (1982). Marine planktonic copepods in Chinese waters. Shanghai Sc. Techn. Press.