The Systematics of Salmonid Fishes of Recently Glaciated Lakes

Abstract

The systematics of the subfamilies Salmoninae and Coregoninae of recently glaciated regions are reviewed. Interrelation between systematics and fisheries biology are stressed, pointing out the abundance of intraspecific genetic diversity of some salmonid fishes manifested in ecological and behavioral specializations, but not necessarily by morphological divergence. Innate, reproductive homing behavior of salmonid fishes may allow closely related populations to exist in sympatry and maintain reproductive isolation. Examples are cited to support the contention that many sympatric "sibling species" have evolved from a common ancestor in postglacial times. Closely related, sympatric populations are a major taxonomic problem, but this phenomenon which allows a species to consist of genetically discrete units with reproductive isolation between the stocks is of great significance for fisheries management. Postglacial salmonid communities are typically fragile and highly susceptible to disruption or destruction by introductions, eutrophication, and exploitation. Every effort should be made to protect the genetic diversity of a species.

Histological structure of the skin of Arctic charr, Salvelinus alpinus (L.) from Spitsbergen

“…This was confirmed by observations of Behnke (1972), after Noakes (1980): "the question of possible population differences is of particular interest, given the polytypic nature of this species, and the known variations from a number of different localities".…”

Restricted matrilineal gene flow and regional differentiation among Atlantic salmon (Salmo salar L.) populations within the Bay of Fundy, eastern Canada

“…The possibility cannot be dismissed. Studies show an abundance of intraspecific genetic diversity in salmonid fishes, including Atlantic salmon, manifested in ecological and behavioural specialisation not associated with obvious morphological divergence (Behnke, 1972). Furthermore, natural selection associated with the invasion of novel habitats, with new and evolving environmental conditions, appears to be linked to adaptive evolutionary divergence (Orr and Smith, 1998).…”

Genetic relationships among landlocked, resident, and anadromous Brown Trout, Salmo trutta L.

“…We discuss our findings in relation to the parallel evolution of different lifehistory types within a number of salmonid fishes (e.g. Behnke, 1972).…”

“…A number of salmonid species contain ecologically and morphologically different types whose evolutionary relationships remain uncertain (Behnke, 1972;Balon, 1980). Anadromous (sea-run migratory) individuals commonly coexist with individuals maturing sexually in fresh water without having been to sea (Ricker, 1972;Scott & Crossman, 1973).…”