Life-history Variation in Caribbean gambusia, Gambusia puncticulata puncticulata (Poeciliidae) from the Cayman Islands, British West Indies
Coastal Sciences, Gulf Coast Research Laboratory
We studied seasonal and spatial variability in the reproductive life-history traits of Caribbean gambusia, Gambusia puncticulata puncticulata, using collections representing dry and wet periods from eight pond sites located across the three Cayman Islands. Caribbean gambusia exhibited a seasonal life-history response over the 5-month interval between the relatively dry and wet periods, marked by shifts to larger adult sizes and smaller broods made up of larger offspring. This seasonal shift in the life-history pattern coincided with increased rainfall, lower salinity, lower water temperature, and higher food availability. Overall, there was a reproductive trade-off involving a reciprocal relationship between brood size and mean embryo mass, and a direct relationship between brood size and total embryo mass. Levels of various environmental variables, including salinity, submerged aquatic vegetation cover, and capture depth, were apparently unrelated to the life-history pattern. Furthermore, the life-history pattern did not reflect an island effect. However, a correlation between the seasonal difference in salinity and offspring size suggested that the Cayman Island life-history pattern may correspond in part with the environmental stability hypothesis.
Environmental Biology of Fishes
Abney, M. A.,
Rakocinski, C. R.
(2004). Life-history Variation in Caribbean gambusia, Gambusia puncticulata puncticulata (Poeciliidae) from the Cayman Islands, British West Indies. Environmental Biology of Fishes, 70(1), 67-79.
Available at: http://aquila.usm.edu/fac_pubs/3277