How to Identify Nudibranchs & Sea Slugs
Practical tips for identifying nudibranchs and related sea slugs using body shape, colour, pattern, anatomy, food source, habitat and location.
Learn identificationSea Slug Identification Guide
Identify a sea slug from its colour, pattern, body shape, rhinophores, gills and other features.
Growing public collection
Identify a Sea Slug
Explore our growing collection of verified nudibranch and sea slug records, with photographs and practical identification details from the MacroDivers collection. New records will be added as the guide develops.
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Identification Basics
Identification Basics
These guides explain the practical features we use when identifying sea slugs and organising records in the MacroDivers identification guide.
Nudibranch & Sea Slug Body Types
Understand the practical body-shape categories used in the MacroDivers identification guide, including oval, elongate, robust, with appendages, with visible shell and other.
Explore body typesRhinophores
A visual guide to rhinophore shapes, from ringed and smooth to rolled, branched and pocket-like forms.
Study rhinophoresNudibranch Gills
Understand external gill plumes, cerata, hidden gills and how these breathing structures help with identification.
Explore gill types