CHEMORECEPTION IN CIRRIPEDES

¹ Marine Science Laboratories, Menai Bridge, Anglesey, North Wales

1. Feeding responses were elicited when solutions of amino acids and of organic and inorganic cations were applied to the cirri and mouth parts of Lepas and other barnacles. Proteins, peptides, sugars, neutral organic molecules, and anions were without effect.

2. Of the common amino acids, Lepas anatifera was most responsive to L-glutamic acid and L-proline. It was very sensitive also to betaine and taurine.

3. The order of sensitivity to amino acids and to other zwitterionic substances did not correlate with any obvious physical or chemical property.

4. Inorganic and organic cations had to be applied at higher concentrations than many amino acids to produce a response and probably acted on different receptors. The potassium ion had the greatest effect of those tested.

5. The observed sensitivity to amino acids and to potassium ions is thought to enable the animal to recognize living prey after it has been pierced by the setae present on the cirri.