Question

amphiprion percula, a species of clownfish, are kept in many home aquariums. two experiments were conducted to determine how diet and stocking density (number of fish per liter of seawater, fish/l) affect the specific growth rate (sgr; percent increase in length per day, percent/day) in a. percula. experiment 1 each of 12 identical 15 l tanks received 10 l of seawater having a salinity of 33 parts per thousand (ppt), a temperature of 27°c, and a ph of 8.2. salinity, temperature, and ph were kept constant over the course of the experiment. a. percula of similar lengths were selected, and their lengths were measured, in cm, with a ruler. then they were equally distributed among the tanks at a stocking density of 1 fish/l. the tanks were then divided equally into 4 groups. for 4 months, each group was fed a different diet (diets q - t). each group was fed the same mass of food 3 times daily. at the end of 4 months, the length of each fish was measured, in cm, with a ruler, and the sgr of each fish was calculated. the average sgr was then determined for each group (see table 1). table 1 diet average sgr (percent/day) q 0.30 r 0.40 s 0.50 t 0.35 experiment 2 the procedures for experiment 1 were repeated except that each group was kept at a different stocking density, 0.5 fish/l, 1 fish/l, 2 fish/l, or 3 fish/l, and all fish were fed diet t. at the end of 4 months, the average sgr was determined for each group (see table 2). table 2 stocking density (fish/l) average sgr (percent/day) 0.5 0.50 1 0.35 2 0.25 3 0.20 tables adapted from joo chambel et al., effect of stocking density and different diets on growth of percula clownfish, amphiprion percula (lacepede, 1802). ©2015 by springer. 12. which of the following statements about the relationship between the number of a. percula per tank and the average sgr is consistent with the results of experiment 2? on average, as the number of a. percula per tank increased, the average sgr: f. increased only. g. decreased only. h. remained the same. j. varied with no general trend.

Explanation:

Step1: Analyze Table 2 data

In Table 2, when stocking density is 0.5 fish/L, average SGR is 0.50 percent/day; when 1 fish/L, it's 0.35 percent/day; when 2 fish/L, it's 0.25 percent/day; when 3 fish/L, it's 0.20 percent/day.

Step2: Observe the trend

As the stocking density (number of fish per liter, which is related to number of fish per tank as volume is fixed) increases from 0.5 fish/L to 3 fish/L, the average SGR decreases from 0.50 percent/day to 0.20 percent/day.

Answer:

G. decreased only.