Table 1.

Behavioural taste responses of blue gourami Trichopodus trichopterus to pellets of agar gel (2%) flavoured with free amino acids or their derivatives (0.1 М).

Taste substances	Latent period, s	Pellet consumption, %	Index of palatability	Number of grasps over the entire trial	Pellet retention time, s:		Number of trials
					after the first grasp	over the entire trial
L-α-Alanine	4.27 ± 0.42	92.0 ± 3.9***	31.4	1.20 ± 0.06***	7.74 ± 0.50***	8.51 ± 0.46***	50
D-α-Alanine	3.62 ± 0.43*	40.8 ± 7.1	−8.1	2.49 ± 0.23	4.71 ± 0.66	8.03 ± 0.79**	49
L-β-Alanine	3.35 ± 0.23	25.5 ± 6.2*	−30.6	2.16 ± 0.19	2.74 ± 0.28	4.71 ± 0.56	51
Glycine	4.46 ± 0.36	34.0 ± 6.8	−17.1	1.82 ± 0.16	4.45 ± 0.51	5.94 ± 0.54	50
Glycyl-glycine	3.68 ± 0.30	20.0 ± 5.7**	−41.2	2.40 ± 0.27	1.95 ± 0.24***	3.50 ± 0.42*	50
Methyl-glycine (=sarcosine)	5.08 ± 0.87	20.0 ± 5.7**	−41.2	2.20 ± 0.22	2.51 ± 0.30	4.30 ± 0.53	50
Dimethyl-glycine-HCl	5.40 ± 1.05	25.5 ± 6.2*	−30.6	2.25 ± 0.22	3.16 ± 0.45	7.99 ± 0.86*	51
Trimethyl-glycine (=betaine)	4.23 ± 0.91*	30.0 ± 6.5	−23.1	2.24 ± 0.22	3.80 ± 0.26	6.25 ± 0.78	50
Glycolic acid	5.36 ± 0.51	74.0 ± 6.3**	21.3	1.88 ± 0.23	5.78 ± 0.65**	7.77 ± 0.71**	50
Acetic acid	4.68 ± 0.51	10.0 ± 4.3***	−65.5	2.94 ± 0.40	1.57 ± 0.16***	4.09 ± 0.73**	50
L-Cysteine	4.25 ± 0.76	28.0 ± 6.4*	−26.3	3.08 ± 0.33*	3.19 ± 0.44	5.21 ± 0.52	50
L-Cystine	4.64 ± 0.70	66.0 ± 6.8	15.8	2.40 ± 0.40	5.83 ± 0.62***	8.71 ± 0.66***	50
Mosquito  larvae extracta	4.63 ± 0.56	100.0 ± 0.00***	35.1	1.14 ± 0.07***	7.41 ± 0.39***	7.72 ± 0.40***	51
Control (blank pellets)	5.15 ± 0.55	48.0 ± 7.1	—	2.16 ± 0.19	3.28 ± 0.39	4.89 ± 0.44	50

^aConcentration of water extract of mosquito larvae in pellets = 175 g. l⁻¹. Values are mean ± s.e.m. *P < 0.05, **P < 0.01, ***P < 0.001 relative to control (χ² test – for pellet consumption; the Mann-Whitney U test – for others).