Tope (Galeorhinus galeus) COSEWIC assessment and status report: chapter 3

Species Information

Name and classification

The tope (Galeorhinus galeus) is one of 39 species belonging to the family Triakidae or houndsharks. In Canada, tope is more commonly referred to as soupfin shark but is recognized by the American Fisheries Society as tope (Nelson et al. 2004). The genus Galeorhinus is derived from the Greek words "galeos" meaning a shark and "rhinos" which means nose. The tope is the only representative from the family Triakidae on Canada’s Pacific coast. The tope has many common names.  Countries in the southern hemisphere, in particular, Australia, New Zealand, and South Africa refer to tope as ‘school shark’. Other common names include eastern school shark, flake, greyboy, greyshark, Penny’s dog, schnapper shark, sharpie shark, Sweet William shark, tope oil shark, tope school shark, tope soupfin shark, and vitamin shark (Florida Museum of Natural History - Species Profile: Tope Shark). In French this species is referred to as milandre

Morphological description

The tope is a dark bluish grey in colour on its dorsal side which shades to white on the underside (Mecklenburg et al. 2002). They are reported to grow up to 195 cm in length. They have two dorsal fins, with the first dorsal fin well ahead of the pelvic fins and the second dorsal fin being about the same size as the anal fin (Figure 1). The caudal fin has a large subterminal lobe which is nearly as long as the lower lobe (Ebert 2003). Their snout is long and pointed and they have a large mouth. The eyes of tope are horizontally oval with conspicuous spiracles behind each eye.

Figure 1. Biological illustration of the tope. Source: Compagno 1984.

Figure 1. Biological illustration of the tope. Source: Compagno 1984.

Genetic description

The population structure of tope in Canadian waters and throughout the eastern Pacific is unknown. Conventional tagging studies in the 1940s reported two tope tagged off the California coast recaptured off Vancouver Island 3 and 26 months later (Herald and Ripley 1951). Tope are considered highly migratory, moving north during the summer and south into deeper waters during the winter (Ebert 2003). Assuming that tope found in Canada are part of a larger highly migratory population, genetic structure, if it exists would be restricted to behavioural mechanisms as there are no known geographical or ecological barriers to gene flow. Tope in Australia showed a high degree of mitochondrial DNA similarity throughout their range; however, there was evidence of significant differentiation between South Africa and western Tasmania, Australia and weak evidence of restricted gene flow between eastern New Zealand and Australia (Ward and Gardner 1997).

Designatable units

For the purposes of this document, tope in Canada’s Pacific waters are considered as a single designatable unit.

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