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Responses of copepods to dissolved free amino acids

1988; Inter-Research; Volume: 43; Linguagem: Inglês

10.3354/meps043269

1616-1599

CW Gill, S. A. Poulet,

Marine and fisheries research

The first maxilla (Ml) beating frequency of Temora longicornis, which is considered to be an index of feeding behaviour, was measured using a computerized micro-impedance technique, in filtered seawater as a control, and after exposure to 9 different particle-free mixtures of equimolar (10-' M) amino acids dissolved in seawater.Mixtures containing 20 dissolved free amino acids (ASP, GLU, ASN, SER, THR, GLN, HIS, GLY, ARG, 0-ALA, TAUR, TYR, AABA, VAL.TRP, PHE, ILE, LEU, ORN and LYS) were all detected by this copepod.Mixture 8, containing SER, THR, GLY and TYR, caused an increase ctivity for only 30 % of copepods tested, so not all amino acids are stimulatory in copepods.a1 stimulation and responses were reflected in an increase in appendage beat frequency.On rage, strongest responses were recorded for Mixture 1, containing ASP, GLU, ASN, SER, GLN and IS.Mixture 2, containing GLY, TYR.PHE, LEU, ORN and LYS, and Mixture 7, containing ASP and 1 GLU.Responses corresponded to increases in frequency up to 5.6 Hz, and varied according to the number and combination of amino acids present in the mixture.Amino acids are among the bioactive molecules responsible for triggering chemosensory feeding responses in copepods.