Thuridilla gracilis
- Kingdom
- Animalia
- Phylum
- Mollusca
- Class
- Gastropoda
- Order
- Sacoglossa
- Family
- Plakobranchidae
- Genus
- Thuridilla
- Species
- Thuridilla gracilis
Thuridilla gracilis is a sacoglossan, or sap-sucking sea slug, from the family Plakobranchidae. It is related to Elysia but is not a true nudibranch.
It is slender, with dark lengthwise lines on a pale blue-green body, and its rhinophores and parapodia are tipped in orange. Nudibranchs of the Philippines also shows a second colour variety.
Like other Thuridilla it grazes on algae and is often seen moving quickly across reef and rubble during the day.
Thuridilla rarely sit still, so be ready to take several shots as it crawls. A fast shutter and steady breathing help.
It appears on page 364 of Nudibranchs of the Philippines.
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