Life history traits of Patagonotothen cornucola (Richardson, 1844) in the Beagle Channel

Abstract

This study deals with the life history traits of Patagonotothen cornucola, a non-Antarctic notothenioid fish species inhabiting the Beagle Channel, focusing on key population parameters linked to the reproductive cycle, age structure and growth. P. cornucola is distributed in subtidal areas and intertidal microhabitats, exhibiting unique morphological adaptations suchas a dorso-ventrally flattened body and a small size ranging from 9 to 13 cm. No sex-related dimorphism was observed, as neither the length frequency distribution nor the length–weight relationship differed between males and females. Notably, this species is an oviparous, intertidal winter spawner that provides parental care, nesting, and guarding, with a synchronousreproductive cycle. Winter spawning would ensure better development conditions during springtime to the larval stage. The study reveals a potential impact of urbanisation on P. cornucola, with evidence of feminisation linked to endocrine-disrupting chemicals due to urban runoff and sewage effluents. We highlight the need for further research on population dynamics affected by environmental stressors. The Von Bertalanffy parameters were as follows: L∞ = 131.1, k = 0.52, L0 = 7.04, and an estimated lifespan of 5 years. Otolith microincrements analyses provided a back-calculated hatching period consistent with the austral winter reproductive season. These findings are crucial for understanding the adaptive strategies of P. cornucola and informing local conservation planners in the Beagle Channel.