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 #9235
Note the 2 pink egg sacs of an internal parasitic copepod (Crustacea) alongside the gills.Comment from Richard Willan on photo #8446
A juvenile individualComment from Richard Willan on photo #6001
Two individuals displaying trailing behaviour, which is characteristic of all species of Risbecia.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
- Bali (47) Jan, Feb, Mar, Apr, May, Jul, Aug, Sep, Oct, Dec
- Lembeh (21) Jan, Mar, Jul, Aug, Sep, Oct, Nov
- Manado (8) Apr, Jul, Sep, Oct, Nov
- North Sulawesi (3) Mar, Apr, Jul
- Wakatobi (2) Dec
- West Java (2)
- Bunaken (2) Mar
- Raja Ampat (2) May, Oct
- Ambon (2) Jan
- Siladen (2) Jun
- Lombok (1) Aug
- Komodo (1)
- Walea (1) Dec
- Philippines
- Malaysia
- Perhentian (4) Mar, May, Oct
- Tioman (2) Jun
- Malaysia (1) Jun
- Aur - Dayang (1) Jun
- Kapalai (1)
- Mabul (1) Aug
- Kuching (1) Oct
- Vietnam
- PNG
- Taiwan
- North East Coast (2) Jul, Aug
- Long Dong (1)
- Taiwan (1)
- Australia
- New South Wales (1) Feb
- Queensland (1) Mar
- Cambodia
- Koh Rong (1) Dec
- French Polynesia
- Taha'a (1) Mar
- Vanuatu
- Vanuatu (1)
- 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.
