Question

Siamese fighting fish, also called betta fish, are popular aquarium fish. Betta fish are territorial and very aggressive. When threatened, betta will respond by puffing out their gill covers to look bigger as a form of intimidation. Betta fish can become threatened by movement or a change of scene in their environments.



Wild betta fish are naturally drab colors such as grey, brown, and dull green. Wild betta fish will only turn bright colors when aggressive or during courtship. Betta fish that are sold at pet stores have been bred to permanently display their bright colors.



The table below shows the reactions of a brightly colored, male pet betta fish to stimuli or things placed on the outside of its aquarium to provoke a response.



The table shows five stimuli and the Betta Fish Response to each stimulus. The betta fish swims toward and away or shows no reaction to a plastic aquarium plant. The betta fish shows a flaring of gills to a mirror. The betta fish shows no reaction to white paper. The betta fish shows a flaring of gills to colored paper. The betta fish swims toward and away or shows no reaction to black paper.



Select a factor that should be considered when evaluating the methods used to collect information about the betta fish's reaction to stimuli.


Whether or not the mirror contains plastic material.


Whether or not the stimulus is moved when it is presented.


The temperature of the water in the aquarium and the air outside.


The volume of the aquarium.

Answer 1

Whether or not the stimulus is moved when it is presented.

Movement/change of scene can provoke a reaction in bettas, so inconsistent motion of the different stimuli would be a confounding variable and should be controlled.