Skip spawning as a reproductive strategy in Antarctic fish species: the Antarctic silverfish (Pleuragramma antarctica) case study

The Antarctic silverfish Pleuragramma antarctica (Notothenioidei, Nototheniidae) is the most abundant pelagic fish inhabiting the frigid Antarctic coastal waters. It plays relevant roles in the local ecosystems, where it is often considered a keystone species connecting lower and upper trophic level...

Full description

Bibliographic Details
Published in:Frontiers in Marine Science
Main Authors: Eva Pisano, Stuart Hanchet, Marino Vacchi
Format: Article in Journal/Newspaper
Language:English
Published: Frontiers Media S.A. 2015
Subjects:
Q
Online Access:https://doi.org/10.3389/conf.fmars.2015.03.00071
https://doaj.org/article/7d6dd7445fe0443fb833b6d66e208066
Description
Summary:The Antarctic silverfish Pleuragramma antarctica (Notothenioidei, Nototheniidae) is the most abundant pelagic fish inhabiting the frigid Antarctic coastal waters. It plays relevant roles in the local ecosystems, where it is often considered a keystone species connecting lower and upper trophic levels within the coastal marine food web. Despite its ecological relevance, and although many aspects of the Antarctic silverfish biology have already been elucidated, knowledge on important components of its life cycle, including the reproductive features, is still poor. The available data on the reproduction of the Antarctic silverfish remains fragmentary and, in particular, information on the silverfish from the Ross Sea is lacking, in spite of the intensive ecological studies on this unique region and the fact that the only known nursery ground for this species is located in Terra Nova Bay (Ross Sea) where hatching occurs under the sea-ice. We present the here first description of the reproductive features of Antarctic silverfish from fish sampled in late Summer (mid February 2008) in the Ross Sea. The gross reproductive traits are consistent with those reported from other Antarctic sectors but, interestingly, widespread follicular atresia has been detected in the fish examined. The intensity and prevalence of such a follicular degenerative process suggest that skip spawning (not all adults spawn every year) could be a reproductive strategy of this Antarctic species. Such an hypothesis is discussed both on the short-term and on the evolutionary time-scale. Overall, the data presented also contribute to support the acknowledgment that skip-spawning is a diffuse phenomenon in fishes.