Lembeh — 3 September 2026
- Location seen
- Lembeh, Indonesia
- Date seen
- 2026-09-03
Costasiella sp 1
© Di Syrett / MacroDivers.com
About this species
- Current scientific name
- Costasiella sp 1
- Order
- Sapsucking slugs (Sacoglossa)
- Type
- N/A
- ID confidence
- Probable
- Genus
- Costasiella
- Species
- sp 1
- Average size
- 5 mm
- Colours
- white, black, blue, yellow, orange, translucent
- Body shape
- Oval
- Rhinophores
- Smooth
- Gills
- Cerata
- Similar species
- Stiliger
Geographic Distribution
Indo-West Pacific.
Identification
Tiny slug. White body with cerata - white/translucent and within it has black stalks with two yellow pompoms. Some also have a blue ring and then white tip in addition to the yellow pompoms. The rhinophores are long, translucent with white spots. It also has two black eye spots typical of Costasiella. This is a very unusual slug.
General Notes
This species is not in the book - Sea Slugs and Nudibranch Identification. It was identified as Costasiella sp 1 by Sea Slug World. The Sea Slug forum has it as species 2 but agrees that it is a Costasiella. There are documented sightings in Sulawesi (as well as Bali, Romblon, Guam, Hawaii and South Africa. I have never seen this species before and at the time thought it was a Stiliger.
Our Sighting
About our records
All sightings and photographs on this page are from our own dives. Locations shown are places where we have personally recorded this species. About MacroDivers.