Age, Growth and Otolith Microstructure of the Spotted Lanternfish Myctophum punctatum Rafinesque 1810

Abstract

This study investigated, for the first time, the age and growth of the spotted lanternfish Myctophum punctatum through an analysis of otolith microstructure. A total of 377 individuals were collected from the Strait of Messina (central Mediterranean Sea), ranging between 20.3 and 73.7 mm of standard length. Their length–weight relationship was estimated, and these outputs indicated an isometric growth, for all specimens and when males and females were analysed separately. The sagittal otoliths were removed from 185 fish, although the microincrement readings were considered valid for only 173 otoliths. Microincrement counts ranged from 32 to 48 (average = 37.6) in the otolith central zone, 30 to 56 (average = 44.3) in the middle zone, and 36 to 384 (average = 165.5) in the external zone. Overall, total microincrements ranged between 106 and 469. Different growth models (Gompertz, von Bertalanffy and logistic models) were considered, to understand which one fit best in describing the growth patterns in M. punctatum. The Gompertz model was then selected as the best-fitting model and its parameters for all individuals were L∞ = 74.79, k = 0.0084 and I = 139.60.