FAMILY LAOPHONTIDAE

Sexual dimorphism is more highly developed here than in any other family. Because of this separate keys are given for males and females.

In the male the P.3 Endopod usually is modified extensively and the Endopod of P.2 and P.4 also may differ from those of the female. Similarly, the Exopods of P.2-P.4 may be modified in the male. The modification may be only a slight variation in proportion of the segments but, also, setae may be replaced by spines or be very reduced in size, or even totally suppressed. Because of this the results obtained from the keys to the males must be treated with caution.

A further factor which must induce caution is the variability of the setation of P.2-P.4 which is reported in both sexes of many species. Variation occurs between populations, within a population, between the sexes and sometimes between the right and left members of a pair of appendages in a single individual. While these keys take into account the present knowledge of these sources of variation its very existence means that any identification arrived at with the keys must be checked against good descriptions.