Effects of receptive females' secretion on some male reproductive behaviors in the amphipod crustacean Microdeutopus gryllotalpa

The use of a choice test apparatus has shown that receptive females of the tube-building amphipod crustacean Microdeutopus gryllotalpa (Costa) secrete a waterborne substance which attracts males. This substance (1) increases the level of activity of males, and (2) orients the males' movements towards its source. Males do not secrete this substance. In this species, females tend to remain inside their residential tubes, and males generally travel from receptive female to receptive female. Thus, in the field, the attractant may stimulate the male to accelerate his movements toward, and guide him directly to a receptive female. On the other hand, at the concentration tested, the substance alone does not elicit intermittent pleopod beats, a male-specific behavior that only occurs in a reproductive context. The expression of intermittent pleopod beats is shown to require the presence of a female plus its tube.