Free amino acid content in the skin mucus of goldfish, Carassius auratus L.: influence of feeding.
Free amino acid contents in skin extracts and influence of food and starvation on free amino acid content in skin mucus were analysed in sexually immature goldfish. Free amino acid concentration in skin mucus (91.1 mumol/g dry wt) was higher than in deep skin (54 mumol/g) or in whole skin (56.6 mumol/g) extracts. Free amino acid compositions were very similar in the latter extracts. They both differed from skin mucus extract in taurine, glutamic acid, glycine and histidine relative contents. Free amino acid composition in zooplankton used to feed goldfish was close to the composition found in corresponding skin mucus extracts, except in taurine content. Goldfish weighing 3 g (6 months old) and 17 g (1 year old) reared on zooplankton showed similar patterns of free amino acid composition in skin mucus. Comparison with free amino acid composition in skin mucus from goldfish fed on commercial food had big differences in glutamic acid, valine, methionine and lysine relative contents. During fasting, we observed an increase in the amount of mucus secreted and a concomitant decrease of the free amino acid concentration in the secretion. The origin of free amino acids found in skin mucus and their possible role in pheromonal and allelochemical communications of goldfish are discussed.
Saglio
P
P
Fauconneau
B
B
D000596:Amino Acids / Q000032:analysis*; D000818:Animals; D004032:Diet; D005215:Fasting; D006054:Goldfish; D009093:Mucus / Q000032:analysis*; D012867:Skin / Q000032:analysis*
D000596:Amino Acids