PARENT SESSION
Poster Session #35: Reproductive Ecology.
Wednesday, August 7. Presentation from 5:00 PM to 6:30 PM. Exhibit Hall B & C, TCC

Body condition, reproduction and diet variation of Rana grylio as a function hydrology.

UGARTE, CRISTINA^*,1, ¹ Florida International University, Miami, Florida

ABSTRACT- Proposed wetland restoration efforts in south Florida will involve modifications in hydrology patterns to the Everglades. Changes in water level and hydroperiod are known to affect the native fauna. Most studies in south Florida concerned with hydrology effects have concentrated on mammals, birds, and fish, while amphibians have received little attention. Rana grylio, the pig frog, is the largest native frog found throughout long hydroperiod marshes of the Everglades. Since it primarily occurs in these long hydroperiod sites, and is an intermediate link in the Everglades food web, it is important to investigate its ecology and include this information in restoration decisions. I collected 600 Rana grylio, from March 1999 to February 2002. Frogs were collected from three areas with different hydrologic regimes. Fat body content, diet composition, and reproductive status were analyzed by season and site. Overall, more frogs had fat bodies in the dry season than in the wet season. Stomach content volume also was higher in the dry season than in the wet season. Diet varied seasonally as well, with high proportions of crustaceans in the diet during the dry season and a shift to insects and arachnids during the wet season. Females with mature ova were found mostly from February to June. Differences in the presence of fat bodies, gravid females, and volume of stomach contents varied between sites. Sites that completely dried during the dry season of 2001 showed a shift in recruitment of post-metamorphic frogs while a site that remained inundated did not show a similar shift. The diet results follow similar seasonal patterns as found in other aquatic taxa of the Everglades. The reproductive cycle corresponds to some other frogs that inhabit permanent water bodies in subtropical areas. This information is useful to water managers who can incorporate this information into their decision-making processes.

KEY WORDS: Rana, reproductive cycle, diet, hydrology