Growth, development and behaviour of Persian sturgeon Acipenser persicus larvae in different light regimes

Abstract

The effects of five different light regimes on growth performance and behaviour of Persian Sturgeon larvae were examined. Larvae were reared under five different photoperiods (24L, 12L:12D, 16L:8D, 8L:16L and 24D), from hatching (25.8 ± 8.1 mg; 12 ± 0.6 mm) to 28 days post‐hatch (dph). Except the last week, there was no significant difference in growth parameters among the experimental groups. Growth performance significantly improved in larvae reared under a continuous light regime. The highest final length (34.5 ± 1.7 mm) was measured in 24L and the lowest one (29.5 ± 0.4 mm) in the constant darkness. Relative to other experimental groups, the continuous darkness had a retarding impact on the yolk sac absorption and swarming behaviour. Among the whole body compositions, the lowest body moisture content was measured in the continuous light group. Persian Sturgeon pre‐larvae and larvae were not completely dependent on light regimes (in 1–21 days), whereas on the basis of measured parameters (total length, wet and dry weight and digestive fullness index) a continuous light regime played a decisive role on growth performance beyond 21 dph.

The feeding/fasting strategy, size heterogeneity, and stocking density impact on body performance and cannibalism rate of Persian sturgeon ( Acipenser persicus ) larvae

“…The nature of species makes the extrinsic source as a chance or challenge onto body performance (Millán‐Cubillo et al, 2016). The mortality rate for Persian sturgeon might be ranged from 2% to 50% in different conditions (Falahatkar et al, 2017; Fashtomi & Mohseni, 2006). Our results indicate that mortality has a high relationship with feeding strategy.…”

Vitellus utilization under concurrent variations in temperature and light intensity in Ussuri catfish, Pseudobagrus ussuriensis

“…To maximize the seed quality in larviculture, the provision of optimal environment is undoubtedly of great significance, especially at the critical transition from endogenous to exogenous nutrition. Otherwise, sub‐ or supra‐optimal conditions may cause deformities and mortalities (Boeuf & Le Bail, ; Fukuhara, ; Hart & Purser, ; Villamizar et al., ) or decreased growth and development (Falahatkar et al., ; Lee et al., ; Martin et al., ; Peña et al., ; Wang et al., ). It should be mentioned that although in some other aquatic species the optimal temperature or light intensity for yolk absorption/utilization has been reported (Hart & Purser, ; Vidal et al., ; Stuart & Drawbridge, ), those optima were not obtained via the optimization of reliable models, as in our study.…”

“…In aquaculture, the yolk‐sac fry stage is a crucial link during the transition from consuming endogenous reserves (proteins and lipids) to exogenous nutrients, in which vitelline absorption and utilization are closely associated with variations in ambient milieu (Boeuf & Le Bail, ; Bromage, Porter & Randall, ; Villamizar et al., ; Wang et al., ). Due to environmental sub‐ or supra‐optimality, failure to perform vitelline absorption and utilization often immediately causes morphological malformations, inability to swim and feed (Falahatkar, Poursaeid, Efatpanah & Meknatkhah, ; Martin‐Robichaud & Peterson, ), vulnerability to diseases or readily falling victims to cannibalism, resulting in a depressed growth/high mortality (Fukuhara, ; Vidal et al., ). Information on early fish ontogeny is especially essential for a better understanding of larval dynamics and the mechanisms of adapting to variable environmental conditions, as it is of important relevancy to seed production.…”