The combined effects of salinity and temperature on various aspects of the reproductive biology of the estuarine mysid, Mysidopsis bahia

A broad range of salinity-temperature conditions (salinities from 3-31 parts per thousand and temperatures from 19-31 degrees C) significantly influenced various aspects of the reproductive biology of the estuarine mysid, Mysidopsis bahia, reared in the laboratory from newly released juveniles through first brood production by mature adults. Response surface methodology was used to depict the combined relationships of salinity and temperature on several reproductive functions, and canonical analysis was employed to produce absolute maximum/minimum values for these functions at specific salinity-temperature conditions. Developmental rate functions related to reproduction were more influenced by temperature than by salinity. Timing of both appearance of the marsupium (indicative of sexual maturity) and release of the first brood was directly related to temperature. Salinity had a greater impact than temperature on the percentage of females that were reproductively active and on young production, both by individual females and by isolated populations. Progressively lower salinities reduced both of these ultimate measures of reproductive capacity. For all reproductive observations, salinity and temperature interacted so that the influence of varying either of these environmental factors on reproduction was governed by the level of the other factor.