On the fecundity of some gammarids

Abstract

1. The number of species found in this investigation is six, of which four are marine and two brackish water.2. The mean value of the body weight and the fecundity varies with the species. The size of a species bears no relation whatever to the reproductive capacity.3. The fecundity is subject to seasonal variation, being generally higher in the spring than in the winter months.4. In general, a positive correlation exists between body weight and fecundity of the individuals of each species. This rule does not, however, apply to Gammarus duebeni, in which the fecundity appears to fall after reaching its maximum at the 19 mg. body-weight class.