Environmental Biology of Fishes

, Volume 27, Issue 1, pp 33–41

Comparative life history of female mosquito fish, Gambusia affinis, in tidal freshwater and oligohaline habitats

  • Nancy Brown-Peterson
  • Mark S. Peterson
Article

DOI: 10.1007/BF00004902

Cite this article as:
Brown-Peterson, N. & Peterson, M.S. Environ Biol Fish (1990) 27: 33. doi:10.1007/BF00004902

Synopsis

Female Gambusia affinis were collected from low salinity/near-neutral pH and tidal freshwater/low pH localities to document life history variation between these two habitats. Mosquito fish were 2.7 times more abundant in low salinity/near-neutral pH (2.37 ± 0.72 ppt; pH = 5.73 ± 0.11) than in tidal freshwater/low pH (0.27 ± 0.19 ppt; pH = 4.46 ± 0.18) habitats in Old Fort Bayou, a black-water tidal river of the Biloxi Bay estuary, Mississippi. Fish were common in both areas from June 1985 through February 1986. There were no significant differences between habitats in the length-weight relationships during the reproductive season with the exception of February. However, there were significant differences in life histories, although the areas were only 4 km apart. Ovarian recrudescence was observed in fish from both areas in February, but ovaries of low salinity fish were more developed than ovaries of freshwater fish. All fish from both areas had regressed ovaries by late September. The monthly slopes of the brood size vs. standard length regressions were significantly different between areas throughout the reproductive season with the exception of June. Although freshwater fish produced heavier tail-free embryos, fish from low salinity had significantly higher GSI values and brood size throughout the reproductive season. These observations suggest that Gambusia affonis may have a greater reproductive effort in low salinity/near-neutral pH environments than in freshwater/low pH habitats.

Key words

FecundityBrood sizeLength-weight relationshipLife history theoriesSalinitypHReproductive biology

Copyright information

© Kluwer Academic Publishers 1990

Authors and Affiliations

  • Nancy Brown-Peterson
    • 1
  • Mark S. Peterson
    • 2
  1. 1.Florida Department of Natural ResourcesBureau of Aquatic PreservesFort PierceU.S.A.
  2. 2.Harbor Branch Oceanographic Institution, Inc.Fort PierceU.S.A.
  3. 3.Department of Biological SciencesMississippi State UniversityMississippi StateU.S.A.