Reproductive strategies conferring species dominance in marine mysid (Peracarida, Mysida) species in coastal waters off Vancouver Island, BC

Abstract

Cold-water mysid species are key components of north Pacific coastal ecosystems and yet much of their life history remains unknown. In Clayoquot Sound, on the west coast of Vancouver Island, a dozen or so species have been identified, with four occurring consistently in samples: Holmesimysis sculpta (W. Tattersall, 1933), Neomysis rayii (Murdoch, 1885), Telacanthomysis columbiae (W. Tattersall, 1933) (Fukuoka & Murano, 2001) and Columbiaemysis ignota Holmquist 1982. In this article growth and reproduction of these species over a 24-month period (May 2010-April 2012) is described, showing recovery from annual removal by the eastern Pacific grey whale (Eschrichtius robustus (Lilljeborg, 1861)) over winter, when pressure from this main predator has been relieved. Holmesimysis sculpta dominates the species flock by employing different life history strategies. It is less seasonal than sister species, overcoming a presumed resource limitation scenario and exhibits year-round reproduction, thereby demonstrating more rapid population rebound following predation and, therefore, retain dominance.