Clausocalanus furcatus
Brady (1883)
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Taxonomy
| Phylum | Arthropoda |
| Subphylum | Crustacea |
| Class | Maxillopoda |
| Subclass | Copepoda |
| Order | Calanoida |
| Family | Clausocalanidae |
| Genus | Clausocalanus |
| Species | furcatus |
Size
- Female: 0.94 - 1.31 mm
- Male: 0.70 - 0.92 mm
Distinguishing characteristics
- The only Clausocalanus with genital somite shorter than next two somites in female
- Form of seminal receptacle
- Shape of forehead and rostrum
- Prosome: urosome ratio
- Males differ from all other species of Clausocalanus in the shape of the rostrum and in usually having the longer leg of the pereiopod 5 and genital pore on the right side.
Male
- Rostrum not well developed and not protruding ventrally
- Longer pereiopod 5 and genital pore usually on right side (sometimes left). This is different to most other Clausocalanus males
- Longer leg of pereiopod 5 longer than urosome; shorter leg of pereiopod 5 usually bimerous, distal segment small
- Prosome:Urosome ratio 2.24-2.50:1
- Urosome somite 2 a little longer than other urosome somites
Female
- Rostrum in lateral view is thick, short and slightly curve, bifurcated at tip
- Pereiopod 5 coxa very short
- Prosome:Urosome ratio 2.24-2.50:1
- Urosome longer than 4th legs
- Genital somite shorter than next two somites
- Genital somite profile in lateral view rather uneven
- Seminal receptacle is large and bulbous
- Caudal rami twice as long as wide
Distribution
- Epipelagic
- Inshore coastal, coastal and oceanic
- Australian distribution includes Tasmania, North West Cape, New South Wales and Great Barrier Reef
- World distribution: widespread in tropical and subtropical waters of the Pacific, Indian and Atlantic Oceans
Ecology
- Tropical-subtropical, circumglobal
- Can be found in temperate regions with warm water movement
- Found in Tasmania from February - July, most abundant between March and May, coinciding with the extension of the East Australian Current
- C. furcatus females carry their eggs in a cylindrical mass wrapping the abdomen
- C. furcatus feeds, reproduces and develops at low phytoplankton concentrations, ideal for open ocean environments
- Development times for C. furcatus from hatching to adulthood is 13 - 21 days at 20°C
- Herbivorous filter feeder
References
- Frost B, Fleminger A (1968). A revision of the genus Clausocalanus (Copepoda: Calanoida) with remarks on distributional patterns in diagnostic characters. Bulletin of Scripps Institution of Oceanography 12:1-235
- Razouls C., de Bovée F., Kouwenberg J. et Desreumaux N., 2005-2009. Diversity and Geographic Distribution of Marine Planktonic Copepods. Available at http://copepodes.obs-banyuls.fr/en
- Kimmerer et al (1985)
- Mazzocchi & Paffenhöfer (1998)