The Zooxantelae and the hard coral are in a mutualistic relationship. This means that both the hard coral and the algae benefit from this relationship. The coral gets extra nutrients produced by the photosynthesizing algae, and the algae gets protection and a stable environment by living inside the coral tissue.
The case of the remora and the manta ray is a perfect example of commensalism. In this type of relationship, one of the participants has benefits, and the other participant has no benefits, nor costs. The remora gets ''leftovers'' from the manta ray, and possible protection from larger predators and the manta ray does not benefit from this relationship.
The tiger shark prays on the green sea turtle, so this is a clear example of predation.
The trevallies and the dolphins are both apex predators, therefore they are competing against each other for pray.