COLDWATER SCIENCE / FIELD GUIDE

Marine life

Meet the drifters, filter feeders and gelatinous predators that make the ocean a living world.

Ctenophora

Comb jellies

Comb jellies swim with eight rows of fused cilia, but the rainbow shimmer in a photograph and a flash of bioluminescence have different causes. Their body forms and feeding structures also vary widely.

Hydrozoa

Hydrozoans

Hydrozoans include attached hydroid polyps, small swimming medusae, and elaborate colonies such as siphonophores. Their varied forms share cnidarian stinging cells, but appearance alone rarely establishes a precise identification.

Pteropoda

Sea angels & butterflies

Sea angels and sea butterflies are pelagic snails whose modified foot helps them swim. Their different adult body forms matter when interpreting shell damage and ocean-acidification research.

Siphonophora

Siphonophores

A siphonophore is an integrated hydrozoan colony whose connected zooids perform different roles. Its coordinated appearance can resemble one long animal, but colonies vary in form and are not all built alike.

Scyphozoa

True jellyfish

A scyphozoan’s familiar swimming bell is one stage in a life cycle that often begins as an attached polyp. Its contractions, feeding structures, and seasonal abundance make sense when viewed as parts of that life history.

Tunicata

Tunicates

Tunicates include attached sea squirts and free-swimming forms such as salps and larvaceans. Their varied adult bodies share a chordate lineage, made especially visible in the larval stage of many tunicates.

Polychaete annelids

Bristle worms

Polychaetes share a segmented body plan, but their appendages and habitats reveal a wide range of ways to move and feed.

Anthozoa

Anemones & corals

Anthozoans live in a polyp form, using a mouth, oral disk, and tentacles without a free-swimming medusa stage.

Illustrations explain body plans and research methods. They are not species-identification photographs.