FTP, name this type of symbiosis, usually involving food, in which one organism benefits and the other either is unaffected or also benefits.
When it involves shelter, it is called inquilinism. In forests, one kind involves fungi which ascend trees in order to release spores from a higher vantage point. While it is most common among ocean invertebrates, such as between the oyster crab and bivalves, it also occurs on land; for example, between ants and aphids. FTP, name this type of symbiosis, usually involving food, in which one organism benefits and the other either is unaffected or also benefits.
When it involves shelter, it is called inquilinism. In forests, one kind involves fungi which ascend trees in order to release spores from a higher vantage point.
commensalism [prompt on symbiosis before it is mentioned]