| circular dichroism of rhodopsins and porphyropsins. | circular dichroism and absorption spectra were determined for digitonin extracts of three rhodopsins: cattle, grass frog, and pigeon; and three porphyropsins: channel catfish, bluegill sunfish, and redear sunfish. a comparison of these spectra shows the following: (1) porphyropsins, like rhodopsins, exhibit two positive cd peaks in the spectral region 320--700 nm: an alpha peak at about 520 nm and a small beta peak at about 355 nm. these peaks substantially diminish upon bleaching. (2) in the cd ... | 1976 | 1083248 |
| histopathological changes in selenium-exposed fish. | redear sunfish (lepomis microlophus) were collected from martin lake in east texas. for at least 8 months, 1 year earlier, aqueous selenium-laden effluent from man-made sources was released into this 5,000-acre reservoir (unpublished data). redear sunfish from a reference lake, 8 km upstream, were collected for comparison to martin lake fish. the hepatopancreas (i.e., liver and associated, disseminated exocrine pancrease), mesonephros (i.e., kidney), gonads, heart, spleen, stomach, and gill arch ... | 1983 | 6858996 |
| neoergasilus japonicus (poecilostomatoida: ergasilidae), a parasitic copepod new to north america. | adult, gravid female neoergasilus japonicus harada, 1930 are described from several species of fish from lee county, alabama. samples of bluegill lepomis macrochirus rafinesque (n = 25), largemouth bass micropterus salmoides lacépéde (n = 6), redear sunfish lepomis microlophus gunther (n = 5), and channel catfish ictalurus punctatus rafinesque (n = 1) were collected between november 1993 and may 1995. prevalence of infection was 100% in all fish collected. the dorsal fin was the site of infectio ... | 1998 | 9488343 |
| morphology predicts suction feeding performance in centrarchid fishes. | suction feeding fish differ in their capacity to generate subambient pressure while feeding, and these differences appear to relate to morphological variation. we developed a morphological model of force transmission in the fish head and parameterized it with measurements from individual fish. the model was applied to 45 individuals from five species of centrarchid fishes: lepomis macrochirus, lepomis punctatus, lepomis microlophus, micropterus salmoides and pomoxis nigromaculatus. measurements ... | 2004 | 15472018 |
| contrasting uptake routes and tissue distributions of inorganic and methylmercury in mosquitofish (gambusia affinis) and redear sunfish (lepomis microlophus). | high hg concentrations in freshwater fish are a concern for human health, yet we lack a clear understanding of the mechanisms that produce high hg concentrations in fish. controlled studies in natural surface waters that quantify the uptake and retention of hg in fish tissues following exposures from the aqueous phase and from invertebrate prey diets are rare. using 203hg, we contrasted the accumulation of inorganic hg (hgi) and methylmercury (mehg) from the dissolved phase and from invertebrate ... | 2006 | 16916033 |
| mercury in sport fish from the sacramento-san joaquin delta region, california, usa. | total mercury (hg) concentrations were determined in fillet tissue of sport fish captured in the sacramento-san joaquin river delta and surrounding tributaries, a region particularly impacted by historic gold and mercury mining activity. in 1999 and 2000, mercury concentrations were measured in 767 samples from ten fish species. largemouth bass (micropterus salmoides), the primary target species, exhibited a median hg concentration of 0.53 mug g(-1) (n=406). only 23 largemouth bass (6%) were bel ... | 2008 | 18063015 |
| spatial trends and impairment assessment of mercury in sport fish in the sacramento-san joaquin delta watershed. | a three-year study was conducted to examine mercury in sport fish from the sacramento-san joaquin delta. more than 4000 fish from 31 species were collected and analyzed for total mercury in individual muscle filets. largemouth bass and striped bass were the most contaminated, averaging 0.40 microg/g, while redear sunfish, bluegill and rainbow trout exhibited the lowest (<0.15 microg/g) concentrations. spatial variation in mercury was evaluated with an analysis of covariance model, which accounte ... | 2009 | 19482398 |
| a pilot study testing a natural and a synthetic molluscicide for controlling invasive apple snails (pomacea maculata). | pomacea maculata (formerly p. insularum), an apple snail native to south america, was discovered in louisiana in 2008. these snails strip vegetation, reproduce at tremendous rates, and have reduced rice production and caused ecosystem changes in asia. in this pilot study snails were exposed to two molluscicides, a tea (camellia sinensis) seed derivative (tsd) or niclosamide monohydrate (pestanal(®), 2',5-dichloro-4'-nitrosalicylanilide, cas #73360-56-2). mortality was recorded after exposure to ... | 2016 | 26687501 |