Genomic
Studies of Species-At-Risk: Wolffish (Anarhichas spp.)
(KA Johnstone, HD Marshall, & SM Carr. 2007. Can J Zool 85,
115)
Wolffish (Anarhichas spp.)
include the first marine fish species to be listed by COSEWIC as Threatened under
the Species-at-Risk Act (SARA).
Wolffish, which inhabit specialized habitat along the margins of the
Continental Shelf and Grand Banks, are taken as by-catch in other,
directed fisheries. Numbers in some species have declined >90% as a
result. Their biology is poorly known. As part of the
species recovery plan, we have investigated their population genomic
structure.
The project uses a novel genomic sequencing
strategy, which
identifies a few widely-dispersed, highly-conserved DNA sequences in
other fish species, with sufficient homology to target sequences in a
new, genetically unknown species. This provides "entry points" into the
new genome, and it is possible to use "long
range" PCR to amplify multi-kilobase regions [here: 4276, 4555,
& 6835 bp
amplicons)] that span the gaps in the genome, and then to “leap-frog” through these spans by
successive design of new primers. The complete 16,543bp mtDNA genome sequences
of Striped (Anarhichas lupus), Spotted (A. minor) and Broadhead Wolffish (A. denticulatus) have been
obtained.
Genomic analysis of the three species’ data will assist their recovery
plans.