Contribution to the knowledge of the biology of Diaphus Dumerilii (Bleeker 1856) of Gran Canaria (Canary island, Cental-East Atlantic)

Abstract

Diaphus dumerilii is one of the most abundant and poorly known mesopelagic species belonging to myctophids family, they are also known as lanternfishes. The individuals of Diaphus dumerilii were obtained from pelagic trawling surveys carried out by the vessel B/E ‘La Bocaina’ in the Canary Islands. The 1706 individuals of this species analysed in this work were measured and weighed, with a length of 17-87 mm and a weight varying from 0.028-4.12 respectively. Also, a subsample of 260 individuals was taken for morphological analysis. This study will also examine the sex-ratio (Chi-square) indicates an abundance of females 1:1,47, this species plays a fundamental role in the food chain and in energy transfer, as well, this species performs vertical migrations towards the surface (0- 100m) during the night and remains hidden in the depths during the day below 500m depth, other parameters such as the condition index (KN), gonadosomatic index (GSI) are calculated to know what could be the reproductive seasons. This study also includes the Modal Progression Analysis and total mortality estimation.