Initial Mortality of Black Bass in B.A.S.S. Fishing Tournaments

We studied the initial mortality of black bass Micropterus spp. that were captured, weighed in, and released in fishing tournaments conducted by the Bass Anglers Sportsman Society between 1972 and 1998. Mean annual initial mortality (i.e., mortality before weigh-in and release) ranged from 1% to 30%. Initial mortality was greatest during the 1970s (15.2%) and decreased during the 1980s (5.7%) and 1990s (1.9%). Because initial mortality was uniformly low ( ≤5%) after 1982, we used results for 1983–1998 to assess relationships involving initial mortality. Initial mortality was correlated with bag size, mean fish weight per angler, and number of fish per angler. Logistic regression showed that these three variables and their interactions explained significant portions of the variation in black bass initial mortality. Our results suggest that the initial survival of black bass caught in tournaments can be improved by reducing the number or total weight of fish that anglers can hold in their live wells during the day. This could be accomplished by decreasing tournament bag limits

Temporal and spatial variation in pelagic fish abundance in Lake Mead determined from echograms

Echograms have been used extensively to locate and estimate the relative abundance of marine fish stocks (Cushing 1973). In freshwater, echograms have been used to describe vertical (Netsch et al. 1971; Eggers 1978; O\u27Brien et al. 1984; Matthews et al. 1985), spatial (O\u27Brien et al. 1984; Wanjala et al. 1986) and temporal (Baker and Paulson 1983) patterns in fish abundance. Although most uses of echograms have been qualitative, Mullan and Applegate (1969) and Matthews et al. (1985) obtained relative estimates of fish abundance by counting targets (fish) on echograms. However, neither Mullan and Applegate (1969) nor Matthews et al. (1985) presented any statistical analysis of estimates obtained from echograms. Our purposes in this paper are to: 1) describe a procedure we have used for the scoring and statistical analysis of echograms as relative estimates of pelagic fish abundance; and 2) describe temporal and spatial variation in pelagic fish abundance in Lake Mead

Effects of ambient Lake Mohave temperatures on development, oxygen consumption, and hatching success of the razorback sucker

Spawning of razorback suckers, Xyrauchen texanus, in Lake Mohave occurred from 10-22° C and larvae were collected at water temperatures from 10-15° C in 1982 and 1983. In the laboratory, hatching success was similar from 12-20° C, but reduced hatching success was found at 10° C while none hatched at 8°C. Development rate and oxygen consumption were positively related to incubation temperature. Direct effects of ambient Lake Mohave water temperatures on hatching success of razorback sucker embryos are considered minimal. Historical spawning temperatures for the species are hypothesized based upon successful incubation temperatures and comparison to the white sucker, Catostomus commersoni

Genomic and biochemical approaches in the discovery of mechanisms for selective neuronal vulnerability to oxidative stress

<p>Abstract</p> <p>Background</p> <p>Oxidative stress (OS) is an important factor in brain aging and neurodegenerative diseases. Certain neurons in different brain regions exhibit selective vulnerability to OS. Currently little is known about the underlying mechanisms of this selective neuronal vulnerability. The purpose of this study was to identify endogenous factors that predispose vulnerable neurons to OS by employing genomic and biochemical approaches.</p> <p>Results</p> <p>In this report, using <it>in vitro </it>neuronal cultures, <it>ex vivo </it>organotypic brain slice cultures and acute brain slice preparations, we established that cerebellar granule (CbG) and hippocampal CA1 neurons were significantly more sensitive to OS (induced by paraquat) than cerebral cortical and hippocampal CA3 neurons. To probe for intrinsic differences between <it>in vivo </it>vulnerable (CA1 and CbG) and resistant (CA3 and cerebral cortex) neurons under basal conditions, these neurons were collected by laser capture microdissection from freshly excised brain sections (no OS treatment), and then subjected to oligonucleotide microarray analysis. GeneChip-based transcriptomic analyses revealed that vulnerable neurons had higher expression of genes related to stress and immune response, and lower expression of energy generation and signal transduction genes in comparison with resistant neurons. Subsequent targeted biochemical analyses confirmed the lower energy levels (in the form of ATP) in primary CbG neurons compared with cortical neurons.</p> <p>Conclusion</p> <p>Low energy reserves and high intrinsic stress levels are two underlying factors for neuronal selective vulnerability to OS. These mechanisms can be targeted in the future for the protection of vulnerable neurons.</p

VARIATION IN SPOTTED GAR (\u3ci\u3eLEPISOSTEUS OCULATUS\u3c/i\u3e) MASS-LENGTH RELATIONSHIPS IN TEXAS RESERVOIRS

Total length and mass were measured on 883 spotted gar, Lepisosteus oculatus, collected between 1984 and 1996 from 49 Texas reservoirs. Spotted gar mass was positively related to length (r2 = 0.92, p \u3c 0.0001). Mass-length relationships differed significantly (P \u3c 0.0001) among reservoirs, explaining an additional 2% of the variation in spotted gar mass

Survival of Foul-Hooked Largemouth Bass (\u3ci\u3eMicropterus salmoides\u3c/i\u3e)

We conducted a field experiment to determine the survival rate of foul-hooked (hooked external to the oral cavity) largemouth bass (Micropterus salmoides) caught and released by recreational anglers. Of 42 largemouth bass caught with hard-plastic baits containing three treble hooks, 15 were hooked only within the mouth and 27 had at least one hook penetrating the external surface of the fish (i.e., foul-hooked). There was no difference in survival of mouth-hooked (100%), foul-hooked (100%), or control (100%) largemouth bass