How to recognize a Calocalanus female:
Using a binocular :
A1 much longer than boby (often broken)
3 or 4 visible thoracic segments.
Urosome 2 or 3-segmented.
The genital segment is ball shaped in dorsal view.
2 setae on the furca are much thicker than the others (often broken).
Using a microscope :
P5 is rather small, uniramous and symmetrical.
How to differenciate C. styliremis from other Calocalanus
Using a binocular :
3 visible thoracic segments.
Urosome short, 3-segmented.
Furca is divergent.
(Notes that body shape is very variable in this species.)
Using a microscope :
P5 3-segmented, with one long spine (slightly longer than the 3 segments together) and several spinules at the end of the third segment (see figures).
Ecological Notes :