330 research outputs found
Heterogenity of the Spawning Populations of Surf Smelt in the State of Washington
Biometric comparisons of three spawning populations of surf smelt, one from Pacific Coast and two from Puget Sound, were made. The Puget Sound populations (Hood Canal and Utsaladdy) were more similar to each other compared to the ocean populations. The Hood Canal and Utsaladdy smelt exhibited least distance function, D^2 , and greater overlap of meristic characters compared to the Lapush fish. It was postulated that the Puget Sound smelt populations were derived from the ocean smelt some 13,000 or more years ago
Growth and Production of Golden Shiner, Notemigonous crysoleucas, Under Different Stocking Densities and Feeding Rates
Experiments on the effects of stocking densities and feeding rates on growth and production of golden shiner were conducted under laboratory conditions. The stocking densities were 20, 28 and 36 fry per 60 gal of water. The fish in tanks with 28 fry were fed at 1, 3 and 5% feeding rates and the rest were fed at 5% feeding rate. A 5% feeding rate was found to be essential for good production. The stocking density of 20 fry (400 lb/acre production) with 5% feeding rate yielded better growth in weight and length and better production than the rest of the experimental conditions
Maturation, Spawning Period, and Fecundity of the White Crappie, Pomoxis annularis Rafinesque, in Beaver Reservoir, Arkansas
Gonosomatic indices and ovum diameter frequency distributions showed that the Beaver Reservoir white crappie spawns from late April through May. During the spawning season females release eggs more than once. Various stages of ovarian ovum development were described. Sexual maturity was found in 2-year-old females of 197 mm and 3-year-old and older fish. Regression analyses of fecundity on total length, weight and age of white crappie indicated that the fish weight was the best predictor of fecundity
Environmental Changes Produced by Cold-Water Outlets from Three Arkansas Reservoirs
Water qualities of two natural streams (Buffalo and Kings Rivers), one new coId-tailwater (Beaver), and two old coId-tailwaters (Norfork and Bull Shoals) in northwestern Arkansas were studied from July 1965 through October 1968. The essential difference between the old cold-tailwaters and natural streams is a change in water quality which allows the development of a new productive ecological environment. Features which typify the old tailwaters are as follows: (1) relatively homioithermal temperatures; (2) stream beds scoured by strong hydoelectric power generation currents; (3) abundant phytoplankton and benthic macroinvertebrates; and (4) absence of warm water game fishes. Environmental factors characterizing natural streams are as follows: (1) high summer temperatures; (2) seasonal and individual current fluctuations at the various stations; (3) a greater variety of benthic macroinvertebrates and ichthyofauna; (4) abundant zooplankters; and (5) a tendency toward an equal distribution of the phyla Chrysophyta, Cyanophyta, and Chlorophyta. By October 1968, the new Beaver coId-tailwater had lost all of its warm-water characteristics but had not developed the biotic features of the old tailwaters
Low power design of a 916 MHz Gilbert Cell Mixer and a Class-A Power Amplifier for Bioluminescent Bioreporter Integrated Circuit Transmitter
This thesis presents the low power design of a 916MHz Gilbert cell mixer and a Class-A power amplifier for the Bioluminescent Bioreporter Integrated Circuit (BBIC) transmitter.
There has been increased use in the man-made sensors which can operate in environments unsuitable for humans and at locations remote from the observer. One such sensor is the bioluminescent bioreporter integrated circuit (BBIC). Bioluminescent bioreporters are the bacteria that are genetically engineered in order to achieve bioluminescence when in contact with the target substance. The BBIC has bioreporters placed on a single CMOS integrated circuit (IC) that detects the bioluminescence, performs the signal processing and finally transmits the senor data. The wireless transmission allows for remote sensing by eliminating the need of costly cabling to communicate with the sensor.
The wireless data transmission is performed by the transmitter system. The digital data stream generated by the signal processing circuitry of the BBIC is ASK modulated for transmission. The direct conversion transmitter used in this design includes a PLL, Mixer and a Power amplifier. The PLL is used to generate a 916MHz frequency signal. This signal is mixed with the digital data signal generated from the signal processing circuitry of the BBIC. A double balanced Gilbert cell is used to perform the mixing operation. The mixer output is applied to a power amplifier which provides amplification of the RF output power. The Gilbert cell mixer and the power amplifier have been implemented in 90nm CMOS process available through MOSIS
Maturation and Fecundity of Redear Sunfish
Based on gonosomatic indices and ovum diameter frequency distributions, the redear sunfish spawns from May through July. Fast growing 2-year-old (above 150 mm) and older fish attain sexual maturity. Mature ovum diameter ranged from 0.60 to 1.30 mm. Fecundity • total length, • total weight, and • age relationships were: 1nF = 5.95242 + 0.01967L (r²= 0.90), LnF = 8.80328 + 0.00594W (r²= 0.92), and 1nF = 8.19332 + 0.50231 A (r² =0.83), respectively
Age Assessment of White Bass from Otoliths, Dorsal Spines and Scales
Otoliths, dorsal spines, and scales of 85 white bass collected in1987 from a pre-spawning group were used forage assessment. Agreement between spine and otolith ages were 78.3%, between scale and otolith ages was 68.2%. Unlike spine ages, percent agreement of scale ages with otolith ages decreased from small to large fish. Length-frequency analysis in conjunction with ages assessed by the three calcified structures showed that dorsal spines and scales underestimated white bass ages compared to the otoliths. Clarity of the otolith annuli, even of the older fish, makes them a reliable source for white bass age assessment
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