Variability of size characteristics and survival of the nauplii of Crimean brine shrimp Artemia spp. (Branchiopoda: Anostraca) feeding on different species of microalgae

Nauplii of brine shrimps Artemia spp. (Branchiopod: Anostraca) are one of the main species of live food used in marine fish larviculture. Specialized formulated enrichments or microalgae containing essential components for fish larvae are routinely used for improvement of biochemical composition of Artemia. Size, growth rate and survival of nauplii and metanauplii are important when Artemia is used as a live food. The goal of this study was to carry out comparative analysis of size characteristics and survival of metanauplii of the Crimean brine shrimp (produced by “Artemia cysts” company) feeding on different species of microalgae. Nauplii were hatched in accordance with the generally accepted procedure. Microalgae of different taxons – Isochrysis galbana, Prorocentrum micans, Gymnodinium wulffii, Prorocentrum cordatum, Tetraselmis suecica, Phaeodactylum tricornutum – were used for feeding metanauplii. The average diameter of dry Artemia cysts was 0.230 mm. The average length and width of nauplii were 0.473 and 0.150 mm, respectively. The average length of 1-day old metanauplii fed on T. suesica [(0,698 ± 0,014) mm] was significantly less than that of 1-day metanauplii fed on I. galbana, P. micans, G. wulfii, and Ph. tricornutum (P < 0.05). The average length and width of the 2-day and 3-days old metanauplii fed on I. galbana (1.19 and 0.324; 1.53 and 0.47 mm, respectively) were significantly larger than those of metanauplii fed on Ph. tricornutum, T. suesica, P. micans, and P. cordatum. Metanauplii fed on P. cordatum were significantly smaller than those fed on other diets. The survival of metanauplii fed on P. cordatum, P. micans, and T. suecica was the highest (above 95 %). The combination of the smallest sizes and highest survival rate of metanauplii fed on P. cordatum (microalgae with high DHA/EPA content) assumes the use on metanauplii as an experimental live food for marine fish larvae.