University of Tasmania, Australia

Clausocalanus parapergens

Frost & Fleminger (1968)

Download an fact sheet for Clausocalanus parapergens (PDF 475KB)

Taxonomy

Size

• Female: 0.97 - 1.38 mm
• Male: 0.97 - 1.14 mm

Distinguishing characteristics

• Form of seminal receptacle
• Shape of forehead and rostrum
• Prosome : Urosome ratio
• Female is similar to C.brevipes, the body and structure of the seminal receptacle is the same but C. parapergens urosome is relatively shorter
• Male similar to C.arcuicornis

Male

• Rostrum knob like, protrudes ventrally (lateral view)
• Longer ramus of P5 and genital pore on left side
• Left P5 longer than urosome, often slender in lateral view
• Right P5 2-3 segmented, distal segments reduced in size
• Caudal ramus <1.6 times as long as wide

Female

• A1 segment 2 less than 1.4 times as long as segment 4
• Rostrum short, thick and curved ventroposteriorly (lateral view)
• Posterior margin of female prosome angular in lateral view
• P5 segment 3 more than twice as long as segment 1
• 3rd segment of P5 more than 2 times as long as 1st segment of P5
• Prosome:urosome ratio 3.10-3.61:1
• Ventral profile of genital somite in lateral view somewhat undulant
• Genital somite more than 1.5 times as long as urosome somite 3
• Ventral lobe of seminal receptacle in lateral view large, visible anterior to base of dorsal lobe
• Seminal receptacle dorsal lobe bulb shaped, constricted in attachment to ventral lobe

Distribution

• Tropical-subtropical, circumglobal

Ecology

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.
• 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
• Taw 1978, pp 90