Effect of light intensity on the foraging and growth of Atlantic cod larvae:interpopulation difference?

Abstract

ABSTRACT-Studies have been conducted on the geographic variation of growth and survlval among fish populations but little work has been done in this regard on the early larval stages of marine fish. We conducted expenments on larvae from 2 separate populations of Atlantic cod to determine their response to light. P r e h i n a r y experiments conducted in our laboratory suggested that the llght intensity under which larvae were reared may affect the growth performance of Atlantic cod larvae from the Scotian Shelf (SS) and Northeast Grand Banks (NF) differently. We conducted experiments to test the hypothesis that light intensity d~fferentially affects larvae from these 2 geographically distlnct populat i o n~. Cod larvae from each population were reared under low (0.19 pE m-' or 8.5 lx) and high (12.92 pE m-2 or 680 Ix) light intensities. Results showed that NF larvae foraged, grew and survived better under high light than low light, while the SS lal-vae performed better under low light conditions. In nature, the population of SS cod we used spawn during late fall/early winter while NF cod spawn In spring/ summer Thus, SS larvae likcdy experience low winter light levels and NF larvae high summer light levels during first feeding. These results support our hypothes~s and suggest that cod larvae from different latitudes arc adapted to local environmental conditions.

Process-based models of feeding and prey selection in larval fish

“…These studies used the frequency of larvae with prey in their guts ('feeding incidence') at different light intensities as an indicator of feeding. The prey concentrations in these and other (Puvanendran & Brown 1998, van der Meeren & Jørstad 2001 investigations on the effect of light on growth and survival in larval cod were very high (50 to 4000 l -1 ) compared to natural conditions. This may have caused the larvae to feed non-visually, and to reach satiation at artificially low light levels, even if visual range was reduced considerably.…”

“…Cod larvae are adapted to lower light levels, but the lowest values of roughly 0.005 µmol m -2 s -1 (Huse 1994) appear to be very low and we have used the intermediate value of 1 µmol m -2 s -1 in the model. This parameter will affect feeding rates only when light is limiting, and may vary between stocks experiencing different light intensities during early life (Puvanendran & Brown 1998). It is also likely to improve as the eye develops ontogenetically (Fiksen et al 1998, Job & Bellwood 2000.…”

Growth, behaviour and colour changes of juvenile King George whiting (Sillaginodes punctata) mediated by light intensities

“…Light has been correlated with a variety of responses such as growth (Wallace et al 1988;Downing & Litvak 1999), survival (Soderberg 1990;Cerqueira & Brugger 2001), swimming activity (Oppedal et al 2001;Marchesan et al 2005;Johansson et al 2006), cannibalism (Appelbaum & Kamler 2000;Han et al 2005), metabolism (Appelbaum & Kamler 2000), metamorphosis (Puvanendran & Brown 2002), swim bladder inflation (Battaglene et al 1994), and feeding behaviour (Puvanendran & Brown 1998;Noble et al 2005).…”

Effect of light intensity on growth, survival and skin color of juvenile Chinese longsnout catfish (Leiocassis longirostris Günther)

“…Gardner and Maguire (1998) used only two light intensity treatments and concluded that further research was required to clarify the effect of light intensity on survival and growth, especially with higher intensities. The effect of light intensity on the survival and growth of larvae or juveniles has been studied in flatfish larvae (Blaxter, 1986), cod larvae (Huse, 1994), Australian giant crab larvae (Gardner and Maguire, 1998), larval haddock (Downing and Litvak, 1999), Atlantic cod larvae (Puvanendran and Brown, 2000), sea bass post-lavae (Cuvier-Péres et al, 2001) and juvenile haddock (Trippel and Neil, 2003). Light intensity was also reported to affect swimming activity and feeding (Petrell and Ang, 2001;Almazán-Rueda et al, 2004), cannibalism (Hecht and Pienaar, 1993;Gardner and Maguire, 1998;Kestemont et al, 2003), skin color (Rotllant et al, 2003), physiological hormone (Boeuf and Le Bail, 1989), metabolism (Appelbaum and Kamler, 2000), initiation of ecdysis (Waddy and Aiken, 1991), and metamorphosis (Eagles et al, 1986;Puvanendran and Brown, 2002).…”