Passage IV

The tiger frog, Rana rugulosa, is a species of frog that is commercially farmed. A farmer conducted 2 experiments to help determine the optimum diet for the growth of R. rugulosa.

Prior to the experiments, 10 diets (Diets 1-10) were prepared. The diets differed in the percent by mass of protein, the number of calories per gram (cal/g), or both (see Table 1).

Experiment 1

Each of 5 identical outdoor 1 tanks was prepared as follows: First, the tank was filled with water to a depth of 20 cm. Next, 30 adult R. rugulosa, each with a mass of 3.3 g, were placed into the tank. Then the tank was covered with a fine wire mesh.

Each tank of frogs was assigned a different diet: Diet 1, Diet 2, Diet 3, Diet 4, or Diet 5. Each frog was fed 1,000 mg of its assigned diet, twice per day, for the next 12 weeks. At the end of 12 weeks, the average final mass of the frogs was determined for each diet (see Table 2).

Experiment 2

Five more of the outdoor 1 tanks were prepared as in Experiment 1, except that each of the R. rugulosa had an initial mass of 7.9 g instead of 3.3 g. Each tank of frogs was assigned a different diet: Diet 6, Diet 7, Diet 8, Diet 9 or Diet 10. Each frog was fed 2,000 mg of its assigned diet, once per day, for the next 12 weeks. At the end of 12 weeks, the average final mass of the frogs was determined for each diet (see Table 3).

Tables adapted from P. Somsueb and M. Boonyaratpalin, "optimum Protein and Energy Levels for the Thai Native Frog, Rana rugulosa Weigmann." @2001 by Blackwell Sclence Ltd.