Diet of bullfrog tadpoles Lithobates catesbeianus, Shaw 1802 an invasive species from Monte Desert

QUIROGA L.; OLIVENCIA, N.; RAY, M.; WETTEN P.; RODRIGUEZ, Y.; ARAGON, J.; PIÑEIRO M; SANABRIA, E. A.

JOURNAL OF HERPETOLOGY

SOC STUDY AMPHIBIANS REPTILES

Lugar: Salt Lake City; Año: 2022

0022-1511

The competitive effects among tadpoles makes the bullfrog a possibleagent of native amphibian population declines at its introduction sites. Our aim was toanalyze the dietary composition of an invasive population of Lithobates catesbeianustadpoles and to evaluate the degree of dietary changes among activity months. Wehypothesized that bullfrog tadpoles would exhibit temporal changes in diet, consistentwith the variation of tadpole size and availability of resources.We collected 94 bullfrog tadpoles and identified 50 taxa in their digestive tracts. Theitems most frequently consumed were microalgae of the genus Navicula spp . (Fo=19) and Cymbella spp . (Fo= 17). The trophic niche breadth was Nb= 8.13, which isconsidered moderate-high. The trophic habits of L. catesbeianus larvae changedseasonally, with the diets during October and December being numerically similar(Morisita´s quantitative index = 0.86). The composition of the diet had a similarity of63% (Jaccard´s qualitative index) between August and October. The larvae of L.catesbeianus collected during the different months showed significant differences intheir stages of development and body mass. On average, individuals were larger andmore developed in the month of December, which was to be expected given that theabundance of prey items is greatest during the summer season. Our results show thatL. catesbeianus tadpoles have a wide trophic niche with a diet that is not stronglyselective, thus, the aquatic life history stages play an important role in the structuring ofinvaded anuran larval communities.