What is a pack of jellyfish called?

A group of jellyfish is called a bloom, swarm, or smolt.

* Bloom is the most common term and refers to a large aggregation of jellyfish, often caused by favorable environmental conditions.

* Swarm is used less frequently but has a similar meaning to bloom.

* Smolt is less common and is primarily used in the context of salmon, but can also refer to a group of jellyfish.