Lembeh — 3 September 2026
- Location seen
- Lembeh, Indonesia
- Date seen
- 2026-09-03
Hydatina physis
Brown-lined bubble shell
© Di Syrett / MacroDivers.com
About this species
- Current scientific name
- Hydatina physis
- Common name
- Brown-lined bubble shell
- Previous names
- Hydatina filosa
- Previous genera
- Bulla
- Order
- Head-shield slugs (Cephalaspidea)
- Type
- N/A
- Genus
- Hydatina
- Species
- physis
- Average size
- 50 mm
- Colours
- white, blue, purple, brown, cream
- Pattern
- stripe, edged mantle
- Body shape
- With Shell
- Rhinophores
- None
- Gills
- Hidden
- Similar species
- Hydatina zonta
Geographic Distribution
Circumtropical.
Identification
A beautiful bubble shell. The shell is white/cream with thin dark brown/black lines spiralling around the shell. The soft body has folds that may be pink to brown with a margin that is blue to purple. Bubble shells do not have rhinophores but like all head-shield slugs had lobe-like tentacles. The hidden gills are inside the mantle cavity on the right side. Unlike snails bubble shells are unable to retract fully into the shell because the soft body is much too large.
Behaviour / Habitat
Mostly found on night dives.
General Notes
The shell size is between 40 and 60mm, the fully extended animal can reach 90mm.