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Global Animal Guide

Fish

The guide features 55 species in the fish class. Each profile answers the most-searched questions first.

What are fish?

Fish are aquatic vertebrates that breathe through gills and move with fins. They are the oldest and most diverse group of vertebrates, with over 34,000 known species — more than all other vertebrate groups combined. They range from gobies under a centimetre long to the whale shark at up to 18 metres, and live everywhere from deep-sea trenches to mountain streams.

Frequently asked questions

What are fish?

Fish are aquatic vertebrates that breathe through gills and move with fins. They are the oldest and most diverse group of vertebrates, with over 34,000 known species — more than all other vertebrate groups combined. They range from gobies under a centimetre long to the whale shark at up to 18 metres, and live everywhere from deep-sea trenches to mountain streams.

How many fish are in the Global Animal Guide?

The Global Animal Guide currently features 55 fish with full, answer-first profiles covering diet, habitat, size, and conservation status.