Risbecia tryoni
(Garrett, 1873)

Photographed by: Hengky Dotulong
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Subclass: | Opisthobranchia |
| Order: | Nudibranchia |
| Suborder: | Doridina |
| Family: | Chromodorididae |
| Species: | Risbecia tryoni |
Comment from Richard Willan on photo #4617
It is interesting to see an individual (the larger one here), with open ‘leopard-like’ circles, a pattern like that of Chromodoris leopardus.Comment from Richard Willan on photo #2715
When individuals of this species are crawling, their body is high and narrow, but resting individuals (like this one) adopt a low and flattened body posture. It could be easy to interpret them as different species.Comment from Richard Willan on photo #2250
This animal is resting so its shape is circular, it would be elongate when it is crawling. In the similar-looking Chromodoris leopardus, the dark markings form definite open circles instead of closed spots.Locality:
- Indonesia
- PNG
- PNG (2) Oct
- Malaysia
- Tioman (2) Jun
- Malaysia (1) Jun
- Aur - Dayang (1) Jun
- Perhentian (1) Oct
- Mabul (1) Aug
- Taiwan
- Philippines
- Vietnam
- Vietnam (1)
- Australia
- New South Wales (1) Feb
- Queensland (1) Mar
- French Polynesia
- Taha'a (1) Mar
- Thailand
- Similan Islands (1) Nov
- Phuket (1) Nov
- Myanmar
- Myanmar (1) Nov
Pictures of Risbecia tryoni
Similar Species
Author: Nila Murti
Risbecia tryoni has somewhat longish body form compared to Chromodoris leopardus which is more oval like. It also has a reduced mantle overlap, while Chromodoris leopardus has a wide mantle overlap. Both have very narrow purple colour band at the mantle edge. However in Chromodoris leopardus there is a second, broader white border immediately inside.
Perhaps the clearest difference is in the markings on the purplish or brownish mantle; Risbecia tryoni has dark round spots encircled by whites, while in Chromodoris leopardus the white-haloed markings are hollow rings, like in its namesake, the leopard.