The effect of supply and deprivation of food on the morphology, behavior and nutritional condition of Prochilodus lineatus early larvae

LLAMAZARES VEGH, S.; LOZANO, I.; DIAZ, M.V.; GÓMEZ, M.I.; SÁNCHEZ, S.; FUENTES, C.

MARINE AND FRESHWATER RESEARCH

CSIRO PUBLISHING

Lugar: Collingwood; Año: 2021 vol. 72 p. 1329 - 1339

1323-1650

Early life stages of river´s migratory fish rely on physical transport mechanisms to carry them from spawning sites to distant nursery areas where they find food and refuge conditions. The starvation after a prolonged downriver drift could severely affect the capabilities of colonisation and predator evasion of the larvae. In this study, we investigated the differences in the external morphology, nutritional condition, and swimming abilities of fed and unfed P. lineatus early larvae in experimental conditions. After yolk reabsorption on Day 6, larvae were either fed with nauplii of Artemia salina or unfed for up to ten days. Larvae from each feeding regime (FED-UNFED) were taken daily from three aquaria, and the morphometry and routine swimming activity were determined and analysed together with a previously published RNA/DNA index dataset. The results are coherent with the previous investigation that indicated the larvae of this species have starvation endurance; however, a prolonged food deprivation would be associated with a smaller body and anal depth, and head length, lower RNA/DNA indices and reduced swimming abilities. The effects of morphological, nutritional and behavioural changes on the distribution and survival of wild P. lineatus larvae are discussed.