The role of inshore areas as spawning grounds in Antarctic notothenioids

NOVILLO M; MOREIRA, EUGENIA; MACCHI, GUSTAVO; BARRERA-ORO, ESTEBAN

Congreso; Scientific Committee of Antarctic Research; 2022

The knowledge of reproductive biology in Antarctic notothenioids (Cryonotothenioidea) arises mostly from scientific surveys conducted in offshore areas of the continental shelf (>120 m depth), and considerably less from inshore shallower water sampling. Apart from prolonged gametogenesis, high gonadosomatic index at spawning, low fecundity and large yolky eggs, parental care and nest guarding seem to be also a sheared feature in some Cryonotothenioid species. Although reproductive aspects such as fecundity, spawning period, and size and age at sexual maturity have been described for many notothenioids, an important and basic reproductive feature like spawning ground remains unknown for the majority of the species. Elucidating this reproductive trait is essential because the protection of fish reproductive grounds is one of the most successful management strategies in the scope of sustainable exploitation and conservation of fish populations and marine ecosystems. In particular, logistic constraints caused by the harsh environmental conditions in Antarctica difficult the representative sampling of fish populations, and so the location and substrate type associated to spawning have been described only in a few notothenioid species. Moreover, how environmental factors that act as reproductive cues (particularly photoperiod and temperature) affect the spatio-temporal window in which notothenioids reproduction occurs have been scarcely explored. Coupling reproductive information from ichthyologic research conducted at Potter Cove, South Shetland Islands and at Paradise Bay, West Antarctic Peninsula, with literature data from nearby areas, we analyze biological, oceanographic and environmental conditions of these localities to evaluate the role of inshore areas as spawning grounds in Antarctic notothenioids.