Order : CALANOIDA
Family : Clausocalanidae

Next species

Clausocalanus furcatus (Brady,1883 )
 

Total length : 0.8 to 1.8 mm

How to recognize a Clausocalanus female:

Using a binocular :

The prosome shape is almost perfectly ovoid.

Only 3 thoracic segments are visible.

A1 as long or slightly longer than prosome.

The rostrum is short and bifurcated.

P5 is small, symmetrical and uniramous.

Urosome has four segments and a regular cylindrical shape.

Furca shorter than preceding segment.

Using a microscope :

P3 Basipod has a calyx like shape (see figures).

P5 is 3-segmented and bifurcated distally.

How to differenciate C. furcatus from other Clausocalanus

Using a binocular :

C. furcatus is usually bigger than C. paululus and C. pergens and slightly smaller than C. arcuicornis, C. lividus and C. mastigophorus.

The lenght of the genital segment is similar to next segment contrary to other Clausocalanus.

The genital pore is big and clearly visible.

Using a microscope :

The third segment of P5 is shorter than the 2 preceding segments together.

The genital pore has a typical shape (see figures).

Ecological Notes :

Very common. Maximum abundance in autumn.

Probably mainly herbivorous.


P5

Basipod of P3

Genital segment lateral
CopyRight © 2005 - Observatoire Océanologique de Villefranche sur Mer - Stéphane Gasparini