Antarctic starfish, Odontaster validus, distinguish between fed and starved conspecifics

Experiments were carried out to study the behavioural responses of the Antarctic omnivorous starfish Odontaster validus to the chemical signals produced by undamaged conspecifics. Tested starved animals displayed the ability to distinguish between fed and starved conspecifics. Effluents of starved conspecifics were mostly ignored by O. validus, although they showed a strong and complex reaction to the smell of fed ones. This combination of responses may be expected both to decrease the risk of cannibalism in the feeding aggregations typical for O. validus, and to increase foraging efficiency by stimulating the searching behaviour in animals exposed to satiated conspecifics.