Reproduction and growth of Notacanthus bonaparte (shortfin spiny eel): insights into the life history of a deep-sea species in the NE Atlantic

This study investigates the reproductive biology and growth of Notacanthus bonaparte based on 158 specimens collected in October 2023 from the Porcupine area, NE Atlantic. The specimens measured between 172 and 495 mm total length. Sagitta otoliths were extracted, photographed, measured and sectioned, revealing age estimates ranging from 4 to 20 years. The growth rate coefficient (k) was calculated as 0.05±0.02 (1 year–1). Gonads were dissected and analysed histologically, confirming that Notacanthus bonaparte in the NE Atlantic is an iteroparous species with group-synchronous oocyte development. Length at maturity (L50) was estimated to be 280 mm of total length for both sexes combined. The parameters of the length-weight equation were a=15.15 and b=3.32, indicating positive allometric growth. This study offers new insights into the life history of Notacanthus bonaparte and provides valuable information on the population dynamics of this deep-sea species.