slug in pajamas is often seen on our Northern shores, burrowing in
sandy areas near seagrasses where there are sea
pens. Armina nudibranchs are more active at night.
Features: 2-6cm long. Body long,
narrow with narrow black-and-white stripes (which are actually ridges).
The blue foot has a yellow or orange border. The wedge-shaped flap
over its mouth (oral veil) is also blue with a yellow or orange border.
The oral veil has no bumps on it. Rhinophores with yellow or red tips
and fine black stripes. According to Bill
Rudman, the coloured wiggly lines seen on the underside of the
body are not gills although gas exchange may take place. These act
like the cerata of aeolids, a place where the digestive gland can
expand. These lines often are the same colour of their sea pen food.
Sometimes mistaken for the bumpy-faced
armina nudibranch, that has a plain oral veil and foot and has
bumps on its 'face'. The Tiny striped
nudibranch (Dermatobranchus sp.) is also striped but is
What does it eat? As a group,
the armina nudibranchs eat soft
corals and sea
Rudman has a post sharing how an armina nudibranch feeds on a
sea pen and is dragged down into the sand when the sea pen retracts.
oral veil without bumps.
Changi, Oct 07
Close up of lines
under the mantle skirt.
Pulau Sekudu, May 12
Photo shared by Toh Chay Hoon on facebook.
shared by Loh Kok Sheng on his
armina nudibranch on Singapore shores
- Tan Siong
Kiat and Henrietta P. M. Woo, 2010 Preliminary
Checklist of The Molluscs of Singapore (pdf), Raffles
Museum of Biodiversity Research, National University of Singapore.
Helmut, 2001. Nudibranchs
and Sea Snails: Indo-Pacific Field Guide
IKAN-Unterwasserachiv, Frankfurt. 321 pp.
Neville. 2001. 1001
Nudibranchs: Catalogue of Indo-Pacific Sea Slugs. Neville
Coleman's Underwater Geographic Pty Ltd, Australia.144pp.
- Humann, Paul
and Ned Deloach. 2010. Reef
Creature Identification: Tropical Pacific New World Publications.