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The resting metabolic rates ( R [ABSTRACT FROM AUTHOR]

The species composition of the benthic-slope fish fauna of the Middle Atlantic Bight is described from trawl catches taken from a depth of about 900 m in August, 1969. Two species associations and an intermediate area are apparent. The difference between the two associations is partially attributable to differences in species composition, but primarily to a difference in species dominance. The small number of samples precludes geographic and bathymetric delineation of these associations, as well as conclusions about their temporal stability. Diversity values appear to be relatively high for the benthic fishes of the upper slope, but comparison with values for temperate estuaries and coastal fishes indicates a narrow range for all of these habitats, and considerable overlap in values from the different environments. Environmental stability may be of less importance in determining the diversity of fish faunas than of benthic invertebrate faunas because of the mobility of fishes and ontogenetic changes in their habitat preference. [ABSTRACT FROM AUTHOR]

BSTRACT: Changes in cropping patterns, water use, and profitability of producing sorghum with the LID (Limited Irrigation-Dryland) furrow irrigation system were compared with conventional irrigation practices. A recursive linear programming model was used to assess the economic impacts over a ten-year period. The analysis of various water resource situations in the High Plains of Texas indicated the LID system increased irrigated sorghum acreage over conventional practices. Although less irrigated and dryland wheat was generally produced, present value of returns increased from about $18 per acre to $50 per acre. Water use was slightly higher in most situations when using the LID system. [ABSTRACT FROM AUTHOR]

Five dinucleotide markers were isolated and optimized from a microsatellite-enriched genomic library obtained from the sandbar shark, Carcharhinus plumbeus. Genotypic distributions of all markers were found to be in conformance with the expectations of Hardy–Weinberg equilibrium with four to 39 alleles present per locus. We amplified these loci in two female sharks and their litters. A maternal allele was recovered at each locus in all progeny indicating reliable amplification. More than two paternal alleles were recovered across both litters indicating genetic polyandry. Additionally, these markers were amplified across 10 carcharhiniform species to examine their utility in other studies. [ABSTRACT FROM AUTHOR]

Auditory capacities of the Atlantic Loggerhead (Caretta c. caretta) were assessed to develop a sound repelling system to be used in dangerous areas. To estimate sensitivity, auditory brain-stem responses (ABRs) were recorded in ten animals to clicks and tones (250, 500, 750, and 1000 Hz). Animals, removed from water, had electrodes implanted subcutaneously. Stimuli were presented to eardrum with a vibrator. Consistent responses occurred within the first 10 ms after stimulation, not unlike that recorded in nonmarine forms. ABR waveforms increase in latency with stimulus attenuation. Prior to ABR recording, sound-induced head movements were noted in most, but not all animals. Sound-induced swimming was also observed. A flight response within the artificial environment of a small tank may not predict natural behavior, hence animals will be placed in a saltwater pen and the experiments repeated with a sound source away from the animal. Finally animals fitted with transmitters will be released in the lower Chesapeake Bay. After settling into a selected area, they will be approached by a moving sound projector to determine if this sound induces flight. [ABSTRACT FROM AUTHOR]