Seasonality in the condition of megrim and its somatic growth in Cantabrian Sea and Galician waters

Abstract

The megrim (Lepidorhombus whiffiagonis) is a bottom-living species, important part of the benthic community in the Cantabrian Sea, and commercially exploited by the European fisheries. Robust and updated biological information of megrim is required for a deeper knowledge of its life history traits and an adequate stock assessment process and management. Condition factor, weight conversion factors and length-weight relationships are analyzed in Cantabrian Sea and Galician waters based on 7458 specimens from a time-series of 22 years (1998-2019) of commercial landings and from a research survey (2017). The influence of factors as the season, year, multi-year period, fish sex and maturity in the Le Cren’s condition factor (K) were analyzed. A clear seasonal pattern in K, more prominent in females was found, with the lowest condition in April (after the spawning period), and a progressive increase to the highest values from November to February, showing the relevance of K as indicator of the nutritional / reproductive status of megrim. The linear weight conversion equation and the power length-weight equations were also estimated and sexual and temporal differences were found. The somatic parameters obtained here are available to be used in the annual assessment of the Atlantic Iberian stock. Our findings will contribute to facilitating better exploitation, management and conservation of this Iberian resource.