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

Growth

performance

, survival or/and cannibalism

rate

of

larvae

are directly affected by feeding strategies, hatchery management, etc. (Mohler, King, & Farrell, 2000; Deng et al., 2003; Leu et al., 2018; Uriarte et al., 2019) and

thus

knowing these key factors for

sturgeon

larviculture helps farmers to provide an appropriate condition. There are, though, a few studies on how

sturgeon

larviculture can be influenced by feeding/fasting, size sorting and stocking

density

. It is the

first

time given cannibalism nature of Persian

sturgeon

larvae

has been reported. The

growth

and survival

rate

drawn from

this

study have been proved by previous documents regarding fish feeding frequency. In

this

study, having the feeding/fasting strategy been considered initial factor on final

weight

of the

larvae

, it would be logical why in all starved treatments survival

rate

, in both hetero & homo-size conditions, is increased.

Besides

this

, the starvation sterategy has resulted in adverse effect on final

weight

when stocking densities were raised by two-fold. It is

therefore

can reach around six-times in the homo-size small

larvae

(B6: 39.3 ± 11.3 mg) and four-times in homo-large (B4: 98.6 ± 30.4 mg) and hetero-small (B2: 80.3 ± 19.6 mg) treatments. The effect of feeding on final

weight

and mortality of

sturgeon

, previously, is well-defined in Siberian

sturgeon

(Gisbert & Williot, 1997) and white

sturgeon

(Deng et al., 2003). The persian

sturgeon

function

therefore

alter depending on overcrowding situation.

This

is to say, the more fish maintained starved in high

density

the higher mortality

rate

would be seen. Predicted that the reduction of

growth

performance

in aquatic, during

larvae

phase

in particular

, it would cause by competition either for feeding or for space (Bolasina et al., 2006; Lee et al., 2016; Yadata et al., 2019).

Larvae

maintained at high stocking

density

require more food availability to have an optimal final

weight

.

Although

stocking

density

clearly influences Amur

sturgeon

(Ni, Wen, Li, Chi, Bu, Ren, Zhang, Song, & Ding, 2014), Atlantic

sturgeon

Acipenser oxyrinchus (Mohler et al., 2000) and Chinese

sturgeon

Acipenser sinensis (Ni, Wen, Li, Chi, Bu, Ren, Zhang, Song, & Ding, 2016) by provoking

growth

performance

, the nature of species can opt how body

performance

react in different stocking

density

(Millán-Cubillo, Martos-Sitcha, Ruiz-Jarabo, Cárdenas, & Mancera, 2016). .