Genetic Variation and Population Structure of Lingcod

Abstract

We analyzed allozymes from 13 collections of lingcod Ophiodon elongatus representing over 1,100 individuals throughout most of the species' range from Alaska to central California. Data were gathered from 41 presumptive gene loci of which 19 loci (46%) were polymorphic (Po.99 criterion, whereby the frequency of the most common allele is 0.99 or less in at least one collection). Average observed heterozygosity was 0.050 (SE, 0.001). Significant differences in genotype frequencies were found between sexes at the AH-2* locus for aconitate hydralase. Although lingcod populations are genetically similar throughout the range, significant allele frequency differences suggest that lingcod in Puget Sound are partially isolated from those along the open coast.

Allozyme and Microsatellite DNA Analyses of Lingcod from Puget Sound, Washington, and Adjoining Waters

“…These five regional groups were south Puget Sound, north Puget Sound, Deception Pass, San Juan Islands, and Strait of Juan de Fuca. An additional collection of 100 fish from Cape Flattery, Washington, was included as an outlier and, combined with the data presented in Jagielo et al (1996), to test for temporal differences in allozyme allele frequencies ( Figure 1). Made in conjunction with an ongoing tag and release study, the Cape Flattery lingcod were collected during the spawning season in February and March of 2001 by WDFW staff using hook-and-line.…”

“…Genetic studies by Withler et al (2003), who using several of the DNA markers developed in this study, have shown that multiple males can fertilize the eggs in a single egg mass guarded by a single male and that adoptive nest guarding (i.e., a male guarding one or more egg masses that is not the paternal parent of any of the attended embryos) may occur. Although adult lingcod are considered nonmigratory alongshore, some tagged individuals have been shown to move considerable distances in coastal waters, and there is some evidence that females are more nomadic and may undergo seasonal bathymetric migrations (Jagielo et al 1996 and references therein). Nevertheless, tagging studies suggest only limited movements between the Washington coast and waters of greater Puget Sound (Jagielo et al 1996).…”

“…Although adult lingcod are considered nonmigratory alongshore, some tagged individuals have been shown to move considerable distances in coastal waters, and there is some evidence that females are more nomadic and may undergo seasonal bathymetric migrations (Jagielo et al 1996 and references therein). Nevertheless, tagging studies suggest only limited movements between the Washington coast and waters of greater Puget Sound (Jagielo et al 1996).…”

“…In such habitats, reproductive isolation could develop for species with nonmigratory egg-laying adults, especially if larval dispersal is limited. Jagielo et al (1996) conducted a genetic study of lingcod population structure throughout much of the range of the species by analyzing 13 collections from Alaska to California grouped by four regions (northern, central, and southern coasts, and Puget Sound). They used starch-gel electrophoresis to characterize variation at 41 allozyme loci, 19 of which were polymorphic at the P 0.99 level (i.e., frequency of the most common allele 0.99 in at least one of the 13 collections).…”

“…Our study was undertaken to provide information regarding genetic aspects of population structure of lingcod in Puget Sound and the adjacent inland marine region and to further test for potential genetic differences (as first described by Jagielo et al 1996) between Puget Sound and the open coast. Specific objectives included (1) developing microsatellite DNA markers suitable for the study of lingcod populations, (2) collecting allozyme and microsatellite DNA data for lingcod from greater Puget Sound and adjacent regions, (3) determining whether or not there is evidence of genetically differentiated populations of lingcod within greater Puget Sound and, if so, what their interrelationships are, and (4) testing for allozyme allele frequency differences between the inland waters of greater Puget Sound and the adjacent coastal region.…”