Cannonball Jelly fish are excellent swimmers, and Portly Spider Crabs often hitch a ride on them. What type of relationship is that?

1. mutualism

   No. In mutualism, both organisms benefit. The jellyfish gets no benefit from the crab's hitchhiking.

2. commensalism

   Yes. In commensalism, one organism (the crab) benefits, and the other (jellyfish) is not affected. The crab gets free transportation, and the jellyfish is not helped or harmed.

3. parasitism

   No. For parasitism, one organism benefits, and the other is harmed. Neither the crab nor the jellyfish is harmed by this relationship.

4. predation

   No. In predation, one organism eats another. Neither the crab nor the jellyfish gets eaten in this relationship.

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