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Estimation Of Components Of Variance By Method 3 And Henderson's New Method, G. F. S. Hudson, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

An algorithm for Method 3 for estimation of components of variance in a mixed model including fixed herd-year-season, genetic groups, and random sires nested within groups is presented. Computational aspects of the algorithm are discussed and compared with those of a new method of Henderson's. The new method involves equating quadratic forms based on approximate best linear unbiased prediction solutions to their expected values. Relative computing effort for the two methods depended on the ease of eliminating equations for fixed effects and on the number of traits. Numerical estimates from the two methods were similar. When the Method 3 estimate …

Monte Carlo Study Of Genetic Groups In Sire Evaluation, T. R. Famula, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Fixed genetic groups have been defined arbitrarily in linear models for sire evaluation. This simulation examined genetic groups under several selection strategies. Sires with highest estimated transmitting abilities were selected to have sons and additional female progeny. The process of evaluation and selection of sires and dams was continued for four generations. Final estimates of transmitting ability were compared to actual transmitting ability for several sire evaluation models on 300 simulated data sets. Genetic groups defined by generation increased the accuracy of estimating sire transmitting abilities over ignoring genetic groups when selected dams and sires of young bulls were mated. …

Epizootiology Of Late Summer And Fall Infections Of Oysters By Haplosporidium Nelsoni, And Comparisons To Annual Life Cycle Of Haplosporidium Costalis, A Typical Haplosporidan, J. D. Andrews

VIMS Articles

The two haplosporidan parasites that cause diseases of oysters along the middle North Atlantic coast of North America differ in their habitats, in timing of oyster mortalities, and in their adaptations to the host. Haplosporidium nelsoni (MSX) kills oysters throughout the year over a wide range of salinities (about 15 to 30 ppt). It has a long infective period of nearly 6 months. This pathogen rarely completes sporulation in its life cycle in oysters. It is highly pathogenic and exhibits irregular activity suggesting that it is poorly adapted to the host species. In contrast, Haplosporidium costalis (SSO) has a short, …

The Acceptability And Digestibility Of Microcapsules By Larvae Of Crassostrea Virginica., Fu-Lin Chu, K. L. Webb, D. Hepworth, M. Roberts

VIMS Articles

The acceptability and digestibility of microcapsules with gelatin-acacia and nylon-protein walls to larvae of Crassostrea virginica were assessed. Larvae were observed to ingest and digest the microcapsules. Gelatin-acacia microcapsules were more digestible than the nylon-protein microcapsules. Results indicated that both types of microcapsules supported some growth of larvae. Larvae fed cod liver oil encapsulated by gelatin-acacia walls grew as rapidly as larvae fed algae. Results also indicated that microcapsule concentration affected growth rate.

Larval Development Of Citharichthys-Cornutus, Citharichthys-Gymnorhinus, Citharichthys-Spilopterus, And Etropus-Crossotus (Bothidae), With Notes On Larval Occurrence, John W. Tucker Jr.

VIMS Articles

No abstract provided.

Anadromous Fisheries Research Program, Virginia - Annual Report 1982, Joseph G. Loesch, William H. Kriete Jr.

Reports

This presentation is the third annual report for P. L. 89-304, AFC 10 project "Anadromous Fisheries Research, Virginia," for the period 1 November 1981 to 31 October 1982. The fishes of concern were the alewife (Alosa pseudoharengus), American shad (A. sapidissima), and the blueback herring (A. aestivalis).

The Alosa species were once an important component of the landings of Virginia fisheries. In the last decade, however, there has been a dramatic decrease in American shad and river herring landings. The 1981 landings of Alosa species in Virgin.ia were the lowest ever recorded. American shad and river herring are also sought …

Assessment Of Larval Striped Bass, Morone Saxatilis (Walbaum), Stocks In Maryland And Virginia Waters. Part Ii. Assessment Of Spawning Activity In Major Virginia Rivers. Segment 2. Distribution And Abundance Of Striped Bass Eggs And Larvae In The James And Chickahominy Rivers, Virginia, During Spring 1981 : Draft Final Report, George C. Grant, John E. Olney

Reports

• Segment 1. Distribution and abundance of striped bass eggs and larvae in the upper York River system, Virginia, during spring 1980
• Segment 2. Distribution and abundance of striped bass eggs and larvae in the James and Chickahominy Rivers, Virginia, during spring 1981 : draft final report
• Segment 3. Pt.A. Distribution and abundance of striped bass eggs and larvae in the Rappahannock River during spring, 1982 : final report
• Segment 3. Pt.B. Dorsal and anal pterygiophore interdigitation patterns in four species of Morone (Teleostei, Percichthyidae) : an aid to larval identification

Oyster Spatfall In Virginia Rivers: 1981 Annual Summary, Dexter S. Haven, Paul C. Kendall

Reports

The Virginia Institute of Marine Science (VIMS) conducts weekly surveys from June through early October to obtain oystet spatfall information, Spat counts are made from oyster shells strung on wire and suspended from stakes on public and private beds, The number of spat on shells are counted each week of the spawning season to determine the potential of a particular area for receiving a strike and to predict the most likely period the strikes will occur.

Transport Of Bivalve Larvae In The James River, Virginia, Jay D. Andrews

Reports

The James River is the primary source of seed oysters for planting private beds in the Chesapeake Bay. A sharp decline in setting rates after 1960 accompanied cessation of oyster culture on private beds in the lower sector of the river. These broodstocks were eliminated and the beds were barren after 1960. High salinities permitted a new oyster disease caused by Minchinia nelsoni (MSX) to make planting in the lower river hazardous because of high mortalities (Andrews, 1964 and in press).

Studies of larval transport mechanisms were begun in the James River in 1950, and extensive sampling was done from …

Development Of Oyster Resources, Katherine V. Leonard

Reports

During the 3-year project period, augmentation of cultch material and transplanting of seed oysters as a means of increasing oyster production was used. Sites were selected for the planting and transplanting. These sites were evaluated based on several criteria. One of the major considerations is the relative abundance of previous spatfall or production in a given area. Several additional factors reviewed for selection included approximate date of peak setting, substrate type (muddy, sandy, rocky, etc. bottom), impact of MSX, estimate of bar potential, gross fishing efforts and salinity regimes. It is important to plant a week or two prior to …

Nomini Creek, Study Of Some Leased Oyster Grounds In The Vicinity Of The Route 202 Bridge (Before Construction), Paul C. Kendall, Dexter S. Haven

Reports

A study of leased oyster planting ground at the site of the proposed new bridge for Route 202 across Nomini Creek was made in December 1981 by the Virginia Institute of Marine Science.

Deep-Sea Bottom Fishes Caught On The 14th Cruise Of The R/V Akademik Kurchatov, T. S. Rass, V A. Grigorash, V. D. Spanovskaya, Y. N. Shcherbachev

Reports

Captures of deep-sea fish in waters of the American Mediterranean Sea and adjacent Bahama-Bermuda region of the Atlantic Ocean prior to our work were performed by a series of expeditions: Coast and Geodetic Survey of the USA ("Blake," 1877-1880), New York Zoological Society ("Zaca" and "Arcturus," 1929-1931), Bingham Oceanographic Laboratory of Yale University, USA ("Pawnee," 1927), the Danish Carlsberg Foundation ("Dana," 1920-1922 and 1928-1930), Bureau of Commercial Fisheries, USA ("Oregon," "Oregon II" and others between 1950 and 1960), and the University of Miami ("Pillsbury," 1969). However, only the latter of these expeditions working in the region of the Puerto Rico …