Diving with Trinchesiidae Nudibranches

Lanta Marine Life | Trinchesiidae

Trinchesiidae Nudibranchs are a little less commonly spotted, but can still be found on our Koh Lanta dive trips.

Individuals are brightly coloured aeolid nudibranchs, and in keeping with other members of this group, Trinchesiidae species have many tapered blood-filled tubes called 'cerata' growing on both the back and side areas of the body.

The cerata are thin-walled, blood-filled tubes which perform several functions, as part of the digestive system and also a gill-like function. The diet can influence the colour of the cerata and as such, members of this family can have varying colours, depending on the diet.

1 species found on this page:

Siboga Cuthona (Cuthona sibogae)

Siboga Cuthona

(Cuthona sibogae)

Cuthona sibogae feeding on Hydroid @ Koh Haa

The Siboga Cuthona is a medium sized nudibranch with a pale lilac to purple body and numerous cerata arranged in clusters along the body. The cerata have yellow tapered tips, with a purplish ring below. The cerata on the side of the body having little or no purplish ring.

The rhinophores and moustache-like oral tentacles are also a dark purplish colour.

Siboga Cuthona grows up to 3.5 cm and is often found feeding on hydroids (as pictured here).