Distribution of eggs and adults of alaska plaice Pleuronectes quadrituberculatus and flathead sole Hippoglossoides elassodon (Pleuronectidae) in the Pacific waters of Kamchatka

Distribution and biological parameters are considered for eggs and adults of two flatfish species on the data of annual surveys conducted on the shelf of southeastern Kamchatka in summer of 2011–2014 and 2016–2019. The eggs of Pleuronectes quadrituberculatus were sampled mostly at the stage of a germinal strip forming, whereas the eggs of Hippoglossoides elassodon were mostly at the stage of embryo cleavage. The main congestions of the eggs were found in the Kronotsky Bay and northern Avachinsky Bay. The adults of both species concentrated mainly in the northern Kronotsky Bay, at Cape Povorotny. Old age groups prevailed in aggregations of P. quadrituberculatus, but middle-age and young fish — in the aggregations of H. elassodon.