The Influence of Salinity on the Growth of Juvenile Shortnose Sturgeon

Abstract

The shortnose sturgeon Acipenser brevirostrum is a promising aquaculture candidate, but optimal culture conditions remain to be defined. Given that salinity is known to affect the growth performance of fish, we examined the effect of salinity on the growth of juvenile shortnose sturgeon in aquaculture. Because the behavior and consequently the salinity exposure of juveniles in the wild is largely unknown, the optimal culture salinity for growth of juvenile shortnose sturgeon is difficult to predict. Juveniles (age, 16 months; mean weight, 273 g) were reared at four salinities (0, 5, 10, and 20‰) for 10 weeks at 18°C. Fish were fed a commercial salmon feed (49% crude protein, 20% crude fat, 4% crude fiber) continuously at a rate of 0.75% of their body weight per day. Weight gain and feed conversion rate (FCR) were significantly (P < 0.01) affected by salinity. Fish reared at 0‰ showed significantly more weight gain and greater FCR than the fish raised at all other salinities. Fish reared at 20‰ exhibited the poorest growth. Thus, we conclude that salinity may compromise the growth of juvenile shortnose sturgeon and suggest that, in commercial operations, salinity should be 0‰.

Age/size effects on juvenile green sturgeon, Acipenser medirostris, oxygen consumption, growth, and osmoregulation in saline environments

“…For example, Altinok and Grizzle (2001) found that juvenile Gulf sturgeon had higher specific growth rates and higher energy absorption efficiencies in 3& and 9& than in 0& and 1&, although hyperosmotic salinities were not tested. Jarvis et al (2001) found that juvenile shortnose sturgeon weight gain and feed conversion efficiency was the highest in FW, and the lowest at 20&, the highest salinity tested. Juvenile Adriatic sturgeon had lower specific growth rates and food conversion efficiencies at 20& than 0& and lower specific growth rates at 11& than 0& (McKenzie et al 2001a).…”

Hematocrit and plasma osmolality values of young-of-year shortnose sturgeon following acute exposures to combinations of salinity and temperature

“…Previous studies of shortnose sturgeon blood chemistry are limited to chronic salinity exposures of older juvenile fish (Jarvis et al 2001;Jarvis and Ballantyne 2003). Plasma osmolalities of fish exposed to brackish conditions returned to values similar to those of fish in freshwater, demonstrating physiological acclimation to brackish conditions (Jarvis and Ballantyne 2003).…”

Current growth, fat reserves and somatic condition of juvenile Baltic herring (Clupea harengus membras) reared in different salinities

“…There were differences among individual fish in all salinities except 12 psu, where all fish had rich fat deposits and their physical condition was significantly better than in other salinities. The differences in the fat reserves and fish condition may indicate an optimum of feed conversion rate (Jarvis et al 2001) in salinity of 12 psu or close to it. This could be linked to the lipid metabolism, which can be altered by salinity through enzymatic activity (Cordier et al 2002).…”

“…Many studies have shown that salinity affects euryhaline fish in multiple ways; e.g., their behaviour, intake of food, food conversion rate, somatic condition, fat reserves, growth and survival (e.g., Peterson-Curtis 1997;Boeuf et al 1999;Peterson et al 1999;Atwood et al 2001;Jarvis et al 2001;Cordier et al 2002). Euryhaline species usually tolerate a wide range of salinities as adults, but they have a given optimum, where they perform best growth.…”

“…These parameters have been determined in euryhaline fish species, in order to find out their optimum salinity at juvenile or adult stages (e.g., Hettler 1976;Boeuf et al 1999;Jarvis et al 2001;Imsland et al 2001Imsland et al , 2003. Experimental studies with adult or juvenile Baltic herring have not been made previously (Westin and Aneer 1987), partly because the herring is highly sensitive to handling stress and difficult to keep in captivity for long periods (Blaxter and Holliday 1963).…”