Temperature effects on growing, feeding and swimming energetics in the Patagonian blennie (Eleginops maclovinus, Perciform)

F. A. VANELLA; D. A. FERNÁNDEZ; C. C. BOY

POLAR BIOLOGY

SPRINGER

Lugar: Berlin; Año: 2012 vol. 35 p. 1861 - 1868

0722-4060

The Patagonian blennie Eleginops maclovinus is a coastal and estuarine species, important for recreational and commercial fisheries and with aquaculture potential. This study assessed the effect of temperature on feeding and the allocation of energy in growth and swimming in a sub-Antarctic population. For growth experiment, two groups of 8 juveniles were reared at 4 and 10 °C (winter and summer temperatures, respectively) for 3 months. Swimming experiments were conducted at 5 and 10 °C, measuring the oxygen consumption before and after forced swimming (1 minute at 10 Total Lengths (TL)/s). Temperature affects growth. TL increased 0.09 cm at 4 °C versus 0.30 cm at 10 °C. Body mass grew 0.49 g at 4 °C versus 1.65 g at 10 °C, whereas the Fulton´s Condition Factor increased 0.021 at 4 °C versus 0.080 at 10 °C. The ingested food was more than two-fold higher at 10 than at 4 °C, while the feces produced at 4 °C was about two-fold higher. The scope between baseline and peak oxygen consumption after forced swimming was affected by temperature (4.51 at 5 °C and 3.03 at 10 °C). The percentage energy expenditure until the return of baseline oxygen consumption values showed a marked temperature effect, being higher at 5 °C. We propose the existence of a trade-off in the allocation of energy between swimming activity and growth, with proportionally more energy being consumed at low temperatures for swimming, than for other physiological functions like growth.