For example, jellyfish are usually found in groups. However, they are not "social animals", they just end up together because of the current of the sea (or other physical phenomena).
What's an adjective to describe this "group" behavior without implying that they are social?
Example:
On one hand, you have the solitary hermit crabs; on the other, the [...] jellyfish.
(Is communal an appropiate word?)
Consider, group-oriented.
These weak-tie behavioral propensities do not impose impediments to building macro societies as they do for monkeys and other group-oriented animals. Theoretical Principles of Sociology, Volume 3: Mesodynamics
I hesitate to call it a collective noun, but the term for a spontaneous grouping of jellyfish is bloom, (as in an algal 'bloom').
"Bloom" is usually used for a large group of jellyfish that gather in a small area, but may also have a time component, referring to seasonal increases, or numbers beyond what was expected.[14] Another collective name for a group of jellyfish is a smack,[15] although this term is not commonly used by scientists who study jellyfish. Jellyfish are "bloomy" by nature of their life cycles, being produced by their benthic polyps usually in the spring when sunshine and plankton increase, so they appear rather suddenly and often in large numbers, even when an ecosystem is in balance.[16] (-- Wikipedia)
So in your sentence, I reckon you can use the same term ("the bloomy jellyfish").
I'm unaware of a verb to bloom in this sense, but on this basis you may feel able to coin it.
Group does not necessarily refer to people or animals that can be found in groups because they are social and love to stay together:
- number of people or things that are located, gathered, or classed together: I saw a group of people in the distance
I think that using group for jelly fish does not imply a 'social' behaviour, the grouped jelly fish.
Shoal refers to social behaviour:
- In biology, any group of fish that stay together for social reasons are shoaling.
