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Full-Text Articles in Life Sciences

A Study Of Water-Soluble Inhibitory Compounds (Algicides) Produced By Fresh-Water Algae, Denny O. Harris, Manhar C. Parekh Nov 1973

A Study Of Water-Soluble Inhibitory Compounds (Algicides) Produced By Fresh-Water Algae, Denny O. Harris, Manhar C. Parekh

KWRRI Research Reports

A complex system of growth inhibitors was observed in the green algae (Volvocaceae). Inhibitors were found in the culture filtrates of some genera which limit their own growth (autoinhibitors) while others in the family produce substances which check the growth of other genera (heteroinhibitors). These inhibitors were destroyed by autoclaving. It was decided that Pandorina morum, which produced the strongest inhibitor and Volvox tertius, the most sensitive to the inhibitor would make an excellent model system for a study of the chemical and physical properties of these naturally occurring algicides. The algicide could be removed from actively growing cultures about …


Enzyme And Tissue Alterations In Fishes: A Measure Of Water Quality, David E. Hinton, M. W. Kendall, J. C. Koenig Aug 1973

Enzyme And Tissue Alterations In Fishes: A Measure Of Water Quality, David E. Hinton, M. W. Kendall, J. C. Koenig

KWRRI Research Reports

A variety of freshwater fishes were studied by light and electron microscopy, enzyme histochemical and biochemical methods, The objective was to determine normal structure and function in specific target organs and to compare these to altered states in aquatic pollution. The basic question, "can fish tissues and enzymes serve as indicators of water quality?," was asked. Microscopic alteration in gill was indicative of copper toxicity at an exposure of 20 parts per billion, Gross and light microscopic alterations were indicative of a single exposure of channel catfish to 15 parts per million of methyl mercuric chloride (CH3HgCl). Microscopic …


A Zooplankton Study Of Stumpy Lake, Virginia Beach, Virginia, Jose E. Hernandez Jul 1973

A Zooplankton Study Of Stumpy Lake, Virginia Beach, Virginia, Jose E. Hernandez

Biological Sciences Theses & Dissertations

A one year study was made of the zooplankton composition in Stumpy lake, a reservoir in the city of Virginia Beach, Virginia. Quantitative and qualitative -parameters were investigated under field conditions. The analysis of the data presents information on the monthly dynamics or the zooplankton and other fluctuations in the lake environment. It is the intention or this study to emphasize the seasonal changes in the zooplankton community and their relationship to the ecological factors responsible for these variations.


Food And Feeding Of Fishes From Magothy Bay, Virginia, Joseph J. Kimmel Jul 1973

Food And Feeding Of Fishes From Magothy Bay, Virginia, Joseph J. Kimmel

OES Theses and Dissertations

No abstract provided.


Progress And Data Available For Investigations, D Tennant Jan 1973

Progress And Data Available For Investigations, D Tennant

Experimental Summaries - Plant Research

This report summarises progress and data available for the following investigations. 1. Fallow Re-assessment. 2. Root Penetration and Distribution in Wheat. 3. Moisture use by Lupins, Rape and Wheat. 4. Variety Investigations in respect of Root Growth. 72M29, 72MO41,


Summary Of 1973 Field Experiments With Advisers, M L. Poole Jan 1973

Summary Of 1973 Field Experiments With Advisers, M L. Poole

Experimental Summaries - Plant Research

SECTION I: Effect of times of planting x Benlate seed treatment on incidence of blackleg in Span and Zephyr rapeseed. SECTION II: Rapeseed Variety Trials 1973 including times of planting. This report provides a record of two series of trials carried out in 1973. Trials - 73A4, 73AL10, 73AL11, 73AL12, 73BR9, 73BR12, 73BR13, 73ES7, 73ES8, 73GE3, 73JE4, 73JE5, 73KA3, 73KA7, 73M2, 73MO11, 73MO13, 73MT5, 73MT6, 73NA6, 73NA7. Effect of times of planting x Benlate seed treatment on incidence of blackleg in Span and Zephyr rapeseed, series of 12 trials were set up, mainly in the southern agricultural areas, near previous …


1973_Pasture Species Investigations - Wheatbelt, N. R. Mckeown Jan 1973

1973_Pasture Species Investigations - Wheatbelt, N. R. Mckeown

Experimental Summaries - Plant Research

Results from trials comparing the growth and persistence of a number of annual pasture legumes in 1973 are presented in this report. Rainfall conditions during the year are described briefly and a table of annual and growing season rainfall at relevant centres is appended. The experiments are grouped as follows according to average annual rainfall:- Zone A - Average annual rainfall 400 mm. Zone B - Average annual rainfall 345 - 400 mm. Zone C - Average annual rainfall 345 mm. and then further on soil type. 70GE4, 70ME3, 70ME4, 70NA3, 70TS2, 70TS5, 71LG16, 71TS22, 72LG3, 72LG26,


1973 Rates Of Phosphate On Lupin Yield, G Walton Jan 1973

1973 Rates Of Phosphate On Lupin Yield, G Walton

Experimental Summaries - Plant Research

Comments on Results - New Land sites (Graphs 1, 2) - The three sites were very responsive with the point of inflexion about 600 kg/ha super rate (similar to 1972 result). The seed x super rate interaction shows the quicker response to super with higher seeding rates. Low Super Bank (800 kg/ha) (GRAPH 3) - The two sites showed very little response to super applied. On the Eradu sandplain no response to super for either Unicrop or Wheat. On the Watheroo yellow sandplain (73M015) the two lupin cultivers and the wheat gave different responses. High Super Bank (>1 OOOkg/ha) …


1973 Long Term Rotation Trials, Ian Rowland Jan 1973

1973 Long Term Rotation Trials, Ian Rowland

Experimental Summaries - Plant Research

The results shown are the yield of grain harvested from crops grown after various lengths of pasture ley. Experiments - W56H, 66M29, 67BA6, 68E5, 68SG5, 69GE20,


Final Report On Interrelationships Between Chemical, Physical And Biological Conditions Of The Waters Of Las Vegas Bay Of Lake Mead, James E. Deacon, Richard W. Tew Jan 1973

Final Report On Interrelationships Between Chemical, Physical And Biological Conditions Of The Waters Of Las Vegas Bay Of Lake Mead, James E. Deacon, Richard W. Tew

Publications (WR)

This program was a status study of the interaction between Las Vegas Wash, an enriched stream, and Las Vegas Bay, a wedge shaped arm of one of the world's deeper reservoirs. The program centered primarily on identification and counting of planktonic algae from several points in Las Vegas Bay. Additional work on nutrient enrichment of water samples was conducted to aid in interpretation of algal distribution related to nutrient input. Examination of a variety of physical, chemical, and biological parameters, both at many surface points in the bay, as well as in vertical profile, was also accomplished and further aided …


1973 Time Of Planting And Rate Of Seeding On Lupin Yield, G Walton Jan 1973

1973 Time Of Planting And Rate Of Seeding On Lupin Yield, G Walton

Experimental Summaries - Plant Research

Of the four time of planting trials two definitely showed superiority of earlier seeding (73BA5, 73E6). The two trials in the Southwest (73BR14 and 73MT7) gave highest yields with June sowing compared to May. Three trials (73BR14, 73E6 and 73BA5) appear to have a Variety x Time interaction for plant density, but no definite trend for either Uniharvest or Unicrop although later sowing reduced plant density. Seeding rates in excess of 82 kg/ha gave the highest yields in all trials. The rate of seeding experiments (73BA5 and 73MT7) show that the best crop density for yield (graph) lies between 8 …


1973 Lupin Cultivar Comparison, G Walton Jan 1973

1973 Lupin Cultivar Comparison, G Walton

Experimental Summaries - Plant Research

Comparison of lupin varieties - 73LG6, 73LG7, 73LG78, 73A15, 73BA6, 73C3, 73MT8, 73MT20, 73N3.


Relative Growth, Reproduction And Distribution Of The Rock Crab, Cancer Irroratus, In Chesapeake Bay During The Winter, Roy Tim Terretta Jan 1973

Relative Growth, Reproduction And Distribution Of The Rock Crab, Cancer Irroratus, In Chesapeake Bay During The Winter, Roy Tim Terretta

Dissertations, Theses, and Masters Projects

No abstract provided.


Distribution Of Foraminiferida In An Estuarine Marsh System, Charles Warren Norton Jan 1973

Distribution Of Foraminiferida In An Estuarine Marsh System, Charles Warren Norton

Dissertations, Theses, and Masters Projects

Foraminiferal faunas in marshes and distributary channels of the James River estuary, Virginia, disclose several facies. The channel facies, primarily Ammobaculites crassus, and A. sp. A, typical of estuaries in Chesapeake Bay and other brackish areas are readily distinguishable freom the march facies. Marshes are divisible laterally by changes in the relative proportions of marsh species such as Miliammina fusca, Ammoastuta salsa, and Haplophragmoides hancocki.Changes along the longitudinal estuarine salinity gradient are discernable in both tidal creeks and marsh. Channels exhibit a longitudinal gradient from a freshwater thecamoebinid facies through an upper and mid-estuarine Ammobaculites facies to a higher salinity …


The Comparative Ecology Of Two Species Of Pipefish (Syngnathidae) In The York River, Virginia, Linda P. Mercer Jan 1973

The Comparative Ecology Of Two Species Of Pipefish (Syngnathidae) In The York River, Virginia, Linda P. Mercer

Dissertations, Theses, and Masters Projects

No abstract provided.


1973 Pasture Species Investigations - High Rainfall Area, D. A. Nicholas Jan 1973

1973 Pasture Species Investigations - High Rainfall Area, D. A. Nicholas

Experimental Summaries - Plant Research

1. Clover cultivar grazing trial - North Bannister 2. Clover cultivar grazing trial - Chowerup 3. Pasture types x stocking rate trial - Denmark Research Station 4. Low oestrogen clover cultivar trial - Mobrup 5. Stocking rate and conservation for steer beef production - Mt. Barker Research Station. 6. Perennial versus annual grass grazing trial – Manjimup Research Station. 68NA1, 701BR15, 72D1, 68BR27, 71MTT46, 72MN5,


Optimum Age, Temperature, And Salinity For Estuarine Stocking Of Juvenile Striped Bass, Morone Saxatilis, Walter Steven Otwell Jan 1973

Optimum Age, Temperature, And Salinity For Estuarine Stocking Of Juvenile Striped Bass, Morone Saxatilis, Walter Steven Otwell

Dissertations, Theses, and Masters Projects

A 3n factorial design to evaluate the effects of an abrupt introduction of striped bass, Morone saxatilis from a closed-system rearing facility into a variety of experimental temperature and salinity combinations has demonstrated a considerable hardiness of juvenile fish. Striped bass less than two months old had over 80.0%, survival during seven days subsequent to acute introduction from an average ambient condition of 21.0 ± 3 C at 0.20 to 4.8% into temperatures of 18 C and 24 C and salinities of 4.0% and 12.0%. Relative growth in these treatments was significantly greater than in the 12 C treatment at …


The Effects Of Intrinsic And Environmental Factors On The Oxygen Consumption Of The Blue Crab, Callinectes Sapidus Rathbun, Chae E. Laird Jan 1973

The Effects Of Intrinsic And Environmental Factors On The Oxygen Consumption Of The Blue Crab, Callinectes Sapidus Rathbun, Chae E. Laird

Dissertations, Theses, and Masters Projects

No abstract provided.


Time Of Planting And Rate Of Seeding On Lupin Yield, G Walton Jan 1973

Time Of Planting And Rate Of Seeding On Lupin Yield, G Walton

Experimental Summaries - Plant Research

Of the four time of planting trials twodefinitely showed superiority of earlier seeding (73BA5, 73E6). The two trials in the Southwest (73BR14 and 73MT7) gave highest yields with June sowing compared to May. Three trials (73BR14, 73E6 and 73BA5) appear to have a Variety x Time interaction for plant density, but no definite trend for either Uniharvest or Unicrop although later sowing reduced plant density. Seeding rates in excess of 82 kg/ha gave the highest yields in all trials. The rate of seeding experiments (73BA5 and 73MT7) show that the best crop density for yield (graph) lies between 8 and …


1973 Time Of Planting And Rate Of Seeding On Lupin Yield, G Walton Jan 1973

1973 Time Of Planting And Rate Of Seeding On Lupin Yield, G Walton

Experimental Summaries - Plant Research

Comments on results - Of the four time of planting trials two definitely showed superiority of earlier seeding (73BA5, 73E6). The two trials in the Southwest (73BR14 and 73MT7) gave highest yields with June sowing compared to May. Three trials (73BR14, 73E6 and 73BA5) appear to have a Variety x Time interaction for plant density, but no definite trend for either Uniharvest or Unicrop although later sowing reduced plant density. Seeding rates in excess of 82 kg/ha gave the highest yields in all trials. The rate of seeding experiments (73BA5 and 73MT7) show that the best crop density for yield …


Variations In Major Cations And Certain Heavy Metals In The Serum Of The Blue Crab, Callinectes Sapidus, James Alden Colvocoresses Jan 1973

Variations In Major Cations And Certain Heavy Metals In The Serum Of The Blue Crab, Callinectes Sapidus, James Alden Colvocoresses

Dissertations, Theses, and Masters Projects

No abstract provided.


Biology Of The Rock Crab, Cancer Irroratus Say, In Coastal Waters Of Virginia, Lewis Roller Shotton Jan 1973

Biology Of The Rock Crab, Cancer Irroratus Say, In Coastal Waters Of Virginia, Lewis Roller Shotton

Dissertations, Theses, and Masters Projects

The commercial seabass notting fishery and the trawl fishery in the Blackfish Bank area east of the entrance to Chincoteague Bay were used to study the biology of the rock crab, Cancer irroratus Say. Highest relative abundance of rock crabs occured in February, March, and April when coldest inshore (<30m) bottom water temperatures occurred. Relative abundance during all other months was extremely low. The apparent seasonal change in relative abundance may be due to an inshore-offshore seasonal migration of mature crabs following the seasonal inshore-offshore shift of colder bottom water. Male rock crabs grow to a significantly larger size than females. The carapace width range of males captured in the potting fishery was 66 to 141 mm; and 25 to 106 mm for females. In the trawl fishery the width range for males was 20 to 137 mm; and 22 to 102 mm for females. In both pot and trawl catches the male to female ratio was biased in favor of males. Males comprised 92% of the pot catch and 84% of all crabs captured by trawl. From August through December all crabs were in the hard shell intermolt stage. Small percentages of soft crabs occurred from January through June. Papershell crabs predominated in February, March and April. It is probable that most crabs molted in January and the process of exoskeleton hardening took several months. Ovigerous females were captured in seabass pots in April and June and in trawls from February through April. All ovigerous crabs were in hard shell condition. Gondal inspection of males and the presence of eggs on females indicated that rock crabs mature at a relatively small size (30 mm carapace width). Female rock crabs have a deeper body and wider abdomen than equivalent width males. Abdomen width grows more rapidly for females after the onset of sexual maturity than before. Mature females have a longer carapace than equivalent width males. Male and female regressions of chela length on carapace width could not be compared statistically but plots of the equations suggest no sexual difference. This dissertation is from the Joint Program Degree from the College of William & Mary and University of Virginia and awarded by the University of Virginia.