University of Tasmania, Australia

Labidocera cervi

Labidocera cervi Krämer,1895

Download a fact sheet for Labidocera cervi (PDF 447KB)

Taxonomy

Size

• Male: 2.75-3.15 mm
• Female: 2.80-3.48 mm

Distinguishing characteristics

• Cephalosome and 1st pedigerous somite separate
• Right A1 geniculate in male
• Rostrum deeply bifurcate
• Cephalosome with or without anterolateral hooks
• 1 pair of cuticular lenses
• Ventral eye extends anterioventrally between a deeply bifurcate rostrum
• Posterior of prosome with large pointed processes
• Female urosome 2-3 segmented; male 4-5 segmented
• Genital somite and caudal rami may be asymmetric in female, symmetric in male
• Female P5 biramous , each rami 1-segmented
• Male P5 uniramous with a chela , left P5 may have a rudimentary endopod

Male

• Anterior cephalosome rounded
• Right A1 geniculate
• Posterior prosome symmetrical
• Right P5 with a long thumb on the claw, which is set at an obtuse angle to the rest of the segment
• Urosome 4-5 segmented

Female

• Prosome with asymmetrical corners, larger on the right side
• Urosome asymmetrical, 2-3 segmented
• Genital somite swollen ventrally, more than 2x as long as wide; a rounded projection ventrally shows on left
• Posteriolateral knob on the right side of genital somite
• P5 has 3 small terminal spines and 2 outer edge spines on the exopod ; endopod spiniform

(Taw 1978, Bradford 1999)

Distribution

• Epipelagic
• Restricted distribution: south eastern Australia and New Zealand

Ecology

• Bright blue in colour when alive
• Occupies surface layers during the day when colouration protects it from predators
• Possibly neustonic
• Broadcast spawner
• Eggs can undergo diapause during unfavourable conditions
• Predator; feeding primarily on small copepods

References

• Bradford-Grieve, J. M. (1999). The marine fauna of New Zealand: pelagic calanoid copepoda: Bathypontiidae, Arietellidae, Augaptilidae, Heterorhabdidae, Lucicutiidae, Metridinidae, Phyllopodidae, Centropagidae, Pseudodiaptomidae, Temoridae, Candaciidae, Pontellidae, Sulcanidae, Acartiidae, Tortanidae. National Institute of Water and Atmospheric Research, Wellington, New Zealand.
• 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.