Answer:
1. Mutualism
2. Mutualism (it was previously thought to be a case of commensalism)
3. Predation
4. Competition
Explanation:
<u>1. Zooxanthellae and hard coral - </u><em><u>Mutualism</u></em>
These two organisms live in symbiosis. This means that both benefit each other. Zooxanthellae allow corals to gain energy through photosynthesis and, in turn, they receive important nutrients that are produced during the metabolism of the hard coral.
<u>2. Remora and manta ray - </u><em><u>Mutualism</u></em>
Remoras and manta rays benefit each other. Remoras attach to manta rays mainly for transportation and feeding, but they also do it for protection. In turn, they make sure manta rays are clear from harmful bacteria and parasites. Several years ago, it was thought that manta rays didn't gain any benefit from remoras, so this was thought to be a case of commensalism. However, research has shown that they both benefit from each other. Therefore, this is also a case of mutualism.
<u>3. Tiger shark and green sea turtle - </u><em><u>Predation</u></em>
In some areas (not everywhere) tiger sharks feed upon green sea turtles. For example, in Hawaii, have been observed to attack green sea turtles and feed on them. Researchers have spotted numerous sea turtles with characteristic tiger shark bites.
<u>4. Dolphins and school of trevallies - </u><em><u>Competition</u></em>
Trevallies are large species of fish that feed on small schools of fish like dolphins. They both have their own predatory strategies that involve planning and gathering to catch large amounts of fish. Therefore, trevallies and dolphins compete for small schools of fish.
