What is the collective noun for under water animals?

There isn't a single, universally accepted collective noun for underwater animals. This is because there's such a vast diversity of creatures living in the ocean, from tiny plankton to enormous whales.

Here are some options depending on the specific group of underwater animals:

* Shoal/School - Often used for fish, especially when they swim together in large numbers.

* Pod - Used for dolphins, whales, and sometimes seals.

* Colony - Often used for coral, sea anemones, and other sessile organisms.

* Bed - Used for oysters, clams, and other bivalves.

* Flock - Can be used for jellyfish or other invertebrates that move in large groups.

You could also use more general terms like a multitude, a throng, a mass, a swarm to describe a large gathering of underwater animals.

Ultimately, the best collective noun depends on the context and the specific species you're referring to.