Geology Reports⌕ Search

Geology topics

R.C. Simon

Publications and source records attributed to R.C. Simon.

17 recordsLinked to original sources
USGS1992

Performance of nine external tags on hatchery-reared rainbow trout

We evaluated nine commercially available tags to determine their suitability for marking yearling rainbow trout Oncorhynchus mykiss reared in raceways and circular tanks. The tags tested were Floy vinyl tubing tags FD‐67 anchor, FT‐2 dart, FT‐4 cinch‐up, and FT‐4 lock‐on; modified Carlin; modified Petersen disk; Monel strap 4‐1005; Monel butt end 4‐1242; and Stoffel fish seal. After 9 months, tag losses from raceway fish were lowest (8%) for the FT‐4 lock‐on tag; in tanks, none of the FT‐2 dart, FT‐4 cinch‐up, FT‐4 lock‐on, or the Monel butt end tags were lost. At 90 d after tagging, raceway fish marked with the Monel strap or the modified Carlin tags showed significantly less growth than did fish marked with the FD‐67 anchor tag; the converse was true for fish in tanks. After 9 months, raceway fish marked with the Monel butt end tag and tank fish marked with the FD‐67 anchor tag were least injured. Injury was greater in raceways than in tanks for all tag types. Judged by overall performance, the FD‐67 anchor was the most effective tag for fish maintained in raceways and the FT‐4 cinch‐up was a suitable alternative; the FT‐2 dart, FT‐4 cinch‐up, and Monel butt end tags were equally suitable for fish in tank culture.

Transactions of the American Fisheries Society↗
USGS1992

The study of relatedness and genetic diversity in cranes

The U.S. Fish and Wildlife Service (Service) is responsible for recovery of endangered species in the wild and, when necessary, maintenance in captivity. These programs provide an immediate measure of insurance against extinction. A prerequisite inherent in all of these programs is the preservation of enough genetic diversity to maintain a viable population and to maintain the capacity of the population to respond to change. Measures of genetic diversity examine polymorphic genes that are not influenced by selection pressures. Examples of these techniques and those used to determine relatedness are discussed. Studies of genetic diversity, electrophoresis of blood proteins, relatedness, blood typing, and restriction fragment length polymorphisms which are being used by the Patuxent Wildlife Research Center are discussed in detail.

Book chapter↗
USGS1988

Selection to increase survival of smolts in four successive broods of coho salmon

Survival from smolt to adult for full and half-sib families of coho salmon Oncorhynchus kisutch was used to identify families with the highest survival rates at Big Creek Salmon Hatchery in Oregon. Adult fish from families with high survival were bred selectively for four consecutive generations in an attempt to increase smolt survival. A significant improvement in survival in the select line compared to the control after two generations of selection was not maintained in subsequent generations. We concluded that selection was not an effective method for increasing survival of smolts released at Big Creek Hatchery.

Transactions of the American Fisheries Society↗
USGS1986

Family size and effective population size in a hatchery stock of coho salmon ( Oncorhynchus kisutch )

Means and variances of family size measured in five year-classes of wire-tagged coho salmon ( Oncorhynchus kisutch ) were linearly related. Population effective size was calculated by using estimated means and variances of family size in a 25-yr data set. Although numbers of age 3 adults returning to the hatchery appeared to be large enough to avoid inbreeding problems (the 25-yr mean exceeded 4500), the numbers actually contributing to the hatchery production may be too low. Several strategies are proposed to correct the problem perceived. Argument is given to support the contention that the problem of effective size is fairly general and is not confined to the present study population.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS1977

Reassociation and hybridization properties of DNAs from several species of fish

Reassociation and hybridization properties from spectrophotometric studies of DNAs from 10 species of fish indicate: 1. Great diversity in the amounts of repeated sequences in the genomes of different species - more specialized fish had less redundancy. 2. Large differences in the complexities of the DNAs - more specialized fish had less information. 3. Little homology between sequences of remotely related species but substantial homology between sequences of closely related species.

Comparative Biochemistry and Physiology, Part B: C↗