Ontogenetic changes in DNA and RNA contents of laboratory-reared Prochilodus lineatus larvae: use of RNA/DNA ratios as nutritional condition indicator

DIAZ, MARINA VERA; GÓMEZ, MARÍA INÉS; SÁNCHEZ, SEBASTIÁN; FUENTES, CARLOS

MARINE AND FRESHWATER RESEARCH

CSIRO PUBLISHING

Lugar: Collingwood; Año: 2018 vol. 69 p. 455 - 463

1323-1650

The aim of this study was to describe the ontogenetic performance of DNA and RNA contents as well as the assessment of the nutritional condition of Prochilodus lineatus larvae reared under different feeding treatments. The experiment consisted in two parts: between 6-14 days after hatching (DAH) and 15-21 DAH. In the first part of the experiment, larvae were under two feeding treatments: fed or starved. During the second part, larvae were under four treatments: fed, fed until 14 DAH and later starved, starved until 14 DAH and later fed and starved. It is noteworthy that larvae that starved during early development and later received food reached higher sizes and weights than larvae from other feeding treatments. They also had higher instantaneous growth rates and nutritional condition. The availability of food following a period of starvation seems to trigger larval metabolism and cellular division. Consequently, we recommend maintaining appropriate food provision in the aquaculture of P. lineatus larvae, especially in advanced developmental stages. We verified that RNA/DNA index is affected by the feeding condition as well as sensitive to reflect prompt changes in feeding larval condition of this species. It could be employed to assess nutritional condition of both wild and cultured P. lineatus larvae.