Effect of dietary l-tryptophan on cannibalism, survival and growth in pikeperch Sander lucioperca (L.) post-larvae

Abstract

The effect of supplemented commercial diets with crystalline L-tryptophan 10 and 20 g TRP kg -1 ) on cannibalism, survival and growth parameters of pikeperch postlarvae (Sander lucioperca) was evaluated. Fifteen-day-old pikeperch larvae (mean weight-6.8 mg) were reared during the next 28 days (20.5°C, 16L:8D) in glass aquaria in a recirculating aquaculture system. The enzyme-linked immunosorbent assay showed that TRP-supplemented diets were effective in increasing the levels of serotonin (5-HT) in the body tissue of pikeperch. TRP supplementation resulted in a slight decrease in both types of cannibalism, although the reduction in cannibalism impact did not amount to more than a few percent. TRP treatment had no significant influence on the final survival of pikeperch post-larvae (ranged from 20.1 ± 12.4 to 29.0 ± 12.9 %). However, contrary to the earlier studies conducted on other fish species, no significant difference in the growth rates and feeding behavior of pikeperch between TRP-fed and control group were found. The final body weight and growth rate ranged from 0.211 ± 0.014 to 0.243 ± 0.016 and from 12.19 ± 0.38 to 12.76 ± 0.35 % day -1 , respectively. To our knowledge, this is the first study reporting the effects of TRP supplementation on the cannibalism-survival-growth relations in fish in the post-larval stage.

Effect of L-tryptophan supplemented diets on serotonergic system and plasma cortisol inTotoaba macdonaldi(Gilbert, 1890) juvenile exposed to acute stress by handling and hypoxia

“…These data together suggest that Trp‐enriched diets could mediate an increase in 5‐HT synthesis through the increase in brain Trp availability in undisturbed totoaba juvenile. The increase in body 5‐HT proportional to dietary Trp has been reported in pikeperch, Sander lucioperca (Krol & Zakęś, ). Furthermore, brain Trp increased in line with body Trp increases in juveniles of Gadus morhua fed with a Trp‐enriched diet (Höglund et al., ); thus, elevated dietary intake of Trp appears to elevate brain Trp availability for 5‐HT biosynthesis in teleost.…”

“…The main limiting factor of 5‐HT synthesis, tryptophan hydroxylase (TPH) enzyme, works at medium saturation in physiological conditions; thus, higher Trp availability in the brain increases serotonin synthesis (Boadle‐Biber, ). Consequently, feeding with Trp‐enriched diets result in body and brain Trp increases, which then mediate the increase in 5‐HT content and function as was shown in Atlantic cod, Gadus morhua (Linnaeus 1758), (Höglund, Bakke, Øverli, Winberg & Nilsson, ) and in pikeperch Sander lucioperca (Linnaeus 1758) postlarvae (Krol & Zakęś, ). Moreover, in fish, Trp‐enriched diets decreased basal cortisol (Martins et al., ) and improved the stress response due to thermal (Tejpal et al., ), osmotic (Akhtar et al., ; Kumar, Saurabh, Pal, Sahu & Arasu, ) or crowding (Lepage et al., ) challenges.…”

Intracohort cannibalism and methods for its mitigation in cultured freshwater fish

“…The outcomes of these two types of cannibalism differ in the level of mortality. In the case of type I, it ranges between 1.5 and 12.0% of the initial stock of European perch (Perca fluviatilis) larvae (Baras et al 2003;Babiak et al 2004;Król and Zieliński 2015) and from 10 to 17% in the stock of pikeperch (Sander lucioperca) larvae (Zakęś and Demska-Zakęś 1996;Zakęś 2012;Król and Zakęś 2016) or even 40% in dorada (Brycon moorei) (Baras et al 2000b). Type II usually generates significantly higher losses and is mainly reported in a stock characterised by a large heterogeneity in size (Król and Zieliński 2015).…”

“…In these species, a prolonged period of darkness is associated with reduced activity and staying near the bottom of a tank, which leads to locally increased stock density and more severe aggressive behaviour (Baras et al 2000a). Therefore, for such species as pike (Szczepkowski 2009), pikeperch (Król and Zakęś 2016) or European perch (Tamazouzt et al 2000;Król and Zieliński 2015), the best rearing outcomes are obtained when fish are kept under a prolonged lighting period and at a proper light intensity for a given species.…”

Total and available tryptophan requirement of Nile tilapia,Oreochromis niloticus, fingerlings

“…Tryptophan is an essential amino acid and a precursor of several compounds, including serotonin (5‐hydroxytryptamine) (Le Floc'h, Otten, & Merlot, ), an important neurotransmitter that affects physiologic functions and behavioural responses of fish (Basic et al., ; Martins et al., ), being successfully supplemented in diets to suppress aggression (Harlıoğlu, Harlıoğlu, Mişe Yonar, & Çakmak Duran, ; Höglund, Bakke, Øverli, Winberg, & Nilsson, ; Hosseini & Hoseini, ) and cannibalism in fish (Król & Zakęś, ). Dietary tryptophan supplementation also improves growth performance of fish (Ciji, Sahu, Pal, & Akhtar, ; Farhat & Khan, ; Pewitt, Castillo, Velásquez, & Gatlin, ; Zaminhan et al., ; Zehra & Khan, ), and its deficiency may increase the incidence of scoliosis, lordosis and eye cataracts in salmonids (Walton, Coloso, Cowey, Adron, & Knox, ).…”