(The black objects are two adult specimens in a mangrove forest at the type locality; the second is an immature specimen) Images courtesy of Cornelis Swennen.
Name: Aiteng ater
Common Name: Aiteng
How it made the Top 10: Its discovery has resulted in a new family, Aitengidae. Although it shares nearly all characteristics with sacoglossans, it exhibits unusual eating habits. This sea slug eats insects, whereas nearly all sacoglossans eat algae and a few specialize in gastropod eggs.
Reference: Swennen, C. and S. Buatip. 2009. Aiteng ater, new genus, new species, an amphibious and insectivorous sea slug that is difficult to classify [Mollusca: Gastropoda: Opisthobranchia: Sacoglossa(?): Aitengidae, new family]. The Raffles Bulletin of Zoology 57(2):495-500.
Type Material: Holotype – Zoological Reference Collection (ZRC) of the Raffles Museum of Biodiversity Research, National University of Singapore. Paratypes – ZRC and Zoological Museum, University of Amsterdam.
Type Locality: Thailand, Gulf of Thailand, Pak Phanang Bay.
Etymology: "The name is derived from Ai Theng, which is the name of one of the popular puppets in shadow plays (wayang) in the southern part of Thailand. It is a jolly, smooth, black, male, who plays in the night. Statues and drawings of various famous puppets were seen along the roads in the area during our visits. The smooth Ai Theng with his large lateral eyes did remind us of the just discovered slug. The specific name is according the colour that looks black on the mud of its habitat."