| Summary: | Reproduction in fishes is an energetically costly but vital process that is important to nearshore fisheries and proper ecosystem functioning. Successful fish reproduction is generally limited to a narrow breadth of specific environmental conditions, and variation in these conditions may affect the ability of fish to allocate energy towards reproduction. In particular, ocean acidification (OA) is generally assumed to be a major threat to fish reproduction, but past studies on the effects of OA have produced variable results. To examine how OA affects bluebanded goby (Lythrypnus dalli) reproduction, female reproductive output and male reproductive behaviors were quantified under two experimental treatments that represent differences between present-day (ambient) and future OA (decreased by 0.2 pH units) conditions. To do this, sexually mature bluebanded gobies were placed in laboratory mesocosms for continuous seven-day trials and allowed to reproduce in artificial nests. Four artificial nests were placed in each of the four mesocosms to provide fish with similar nesting habitats to encourage reproduction. Each mesocosm included similar fish size structures and numbers of female gobies to control for any size- or sex-dependent responses. Male reproductive behavior was quantified daily through visual assessment of their movement patterns within each mesocosm. Female reproductive output was quantified by checking the nests for the presence of eggs, which were photographed to evaluate egg quantity, size, and development. Results indicate that future OA conditions did not significantly affect any of the reproduction metrics examined in this study. These results suggest that future changes in environmental factors such as seawater pH may not have dramatic effects on the reproductive output and behavior of bluebanded gobies. San Diego State University
|
|---|