Table 2. Species`differences in morphological traits related to feeding biology.

Morphological trait	N. krameri A	N. krameri B	N. spinulifemur A	N. spinulifemur B
maxilliped dactylus	double nail	double nail	single nail	single nail
carpal article of gnathopod II, extra setae forming filtering basket*	well developed	missing	well developed	well developed
ischium I, extra setae forming filtering basket	missing	missing	well developed	well developed

*diagnostic character between N. krameri A and N. krameri B.