Calanus australis
Calanus australis Brodsky, 1959
Download a fact sheet for Calanus australis (PDF 549KB)
Taxonomy
| Phylum | Arthropoda |
| Subphylum | Crustacea |
| Class | Maxillopoda |
| Subclass | Copepoda |
| Order | Calanoida |
| Family | Calanidae |
| Genus | Calanus |
| Species | australis |
Size
- Male: 2.50-3.30 mm
- Female: 2.70-3.20 mm
Distinguishing characteristics
- Cephalosome and first pedigerous somite partly fused
- A1 exceeds the body length by a few segments
- Pereiopods without modification or ornamentation
- P5 inner margin of coxa serrated (toothed) in both sexes
- P5 endopods have 8 setae, in male both caudal rami 3- segmented
Male
- P5's are of unequal length, right P5 1.5 - 1.6x shorter than left P5
- Right P5 exopod extends more than half way along left exopod segment 2
- Left P5 endopod extends only slightly beyond segment 1 of the left P5 exopod
Female
- A1 just reaches the tip of the caudal rami
- P5 serrations convex, with 15-22 triangular teeth
- Terminal spine of P5 right exopod segment 3 is shorter than the segment
- Similar to Calanus agulhensis
- Differs from Nannocalanus minor in that N. minor is smaller, has a 5-segmented prosome and has a more indented prosome over the first urosome somite
(Bradford-Grieve 1994 & 1999, Taw 1978)
Distribution
- Epipelagic
- Inshore, coastal and oceanic waters of southeastern Australia and New Zealand
Ecology
- Often dominates copepod biomass in nearshore, temperate waters
- Maximum abundance occurs in summer, with copepodite stage C5 outnumbering adults (Taw and Ritz 1979)
- Undergoes diel vertical migration
- Prefers seasonally stratified coastal waters (Sabatini et al. 2000)
- Abundance declines as stratification weakens
- Summer breeding coincides with phytoplankton blooms
- Copepodite stage C5 often carries large lipid stores
References
- Bradford-Grieve, J. M. (1994). The marine fauna of New Zealand: Pelagic Copepoda: Megacalanidae, Calanidae, Paracalanidae, Mecynoceridae, Eucalanidae, Spinocalanidae, Clausocalanidae. National Institute of Water and Atmospheric Research, Wellington, New Zealand.
- Bradford-Grieve, J. M., E. L. Markhaseva, et al. (1999). Copepoda. South Atlantic Zooplankton. D. Boltovskoy. Leiden, The Netherlands, Backhuys Publishers. 1: 869-1098.
- Sabatini, M.E., Ramirez, F.C. and Martos, P. (2000). Distribution pattern and population structure of Calanus australis Brodsky, 1959 over the southern Patagonian Shelf off Argentina in summer. ICES Journal of Marine Science 57: 1856-1866.
- Taw, N. (1978). Some common components of the zooplankton of the southeastern coastal waters of Tasmania. Papers and Proceedings of the Royal Society of Tasmania 112: 69-136.
- Taw, N. & Ritz, D. 1979. Influence of Subantartic and Subtropical Oceanic Water on the Zooplankton and Hydrology of Waters Adjacent to the Derwent River Estuary, South-eastern Tasmania. Marine and Freshwater Research, 30, 179-202.