Question

On the Bahamian island of Andros, mosquitofish populations live in various, now-isolated, freshwater ponds that were once united. Currently, some predator-rich ponds have mosquitofish that can swim in short, fast bursts; other predator-poor ponds have mosquitofish that can swinm continuously for a long time. When placed together in the same body of water, the two kinds of female mosquitofish exhibit exclusive breeding preferences. The predatory fish rely on visual cues and speed to capture mosquitofish. Mosquitofish rely on speed and visual cues to avoid the predatory fish Which adaptations(s) might help predators survive in ponds that are home to faster mosquitofish? 1. directional selecfon for increased speed 2. stabilizing selection for speed that matches that of the mosquitofish 3. change in hunting behaviour that replaces reliance on visual cues with reliance on tactile cues, which can be used to hunt at night 4. change in hunting behaviour that eliminates speed in favour of better camouflage, which permits an ambush strategy a. 1 only Ob.either 2 or 3 Oc.1,3, or 4 Od.either 1 or 3 Oe.2 only

Answer 1

Answer:

1. directional selection for increased speed

3. change in hunting behaviour that replaces reliance on visual cues with reliance on tactile cues, which can be used to hunt at night

4. change in hunting behaviour that eliminates speed in favour of better camouflage, which permits an ambush strategy

Explanation:

Mosquitofish have adapted to escape the predatory fish by adapting for swimming in short and fast bursts. Predator fishes should exhibit directional selection for speed to be able to catch these mosquitofish. Directional selection favors one extreme phenotype over the intermediate and the other extreme phenotype. Selection for fast swimmer fishes would make the population of predatory fishes better able to catch the prey.  

Likewise, the predatory fishes should change the strategies from relying on visual clues to tactile cues or camouflage. The prey mosquitofish would not be able to escape from the predatory camouflaged predator fish since the former relies on visual cues only. The use of tactile receptors that sense touch and pressure could also help the predator fish to catch the prey.  

Answer 2

Answer:

c.1,3, or 4

Explanation:

It is given that the predatory fish relies on speed and visual cues to capture mosquitofish. So if the predator increases its speed more than the mosquitofish, it will be able to catch it. Thus, directional selection for increased speed would benefit the predator fish.

Relying on visual cues also has a disadvantage since at night time it will be difficult to see the prey. So shifting the reliance on tactile cues would also benefit the predator fish since it will be able to hunt using the sense of touch which has no dependence on light.

Apart from increasing the speed, the predator fish can also trade it off for better camouflage. Reliance on speed will finish and it will still be able to hunt faster mosquitofish because it will be able to hide and attack in a better way.

Hence, options 1,3 and 4 are correct.