bluuebunny/crossref_metadata_2025_split huggingface dataset:
On size and growth in freshwater fish
Authors: McDowall R. M. 
Published: July 2006

AbstractPatterns of growth and size achieved in freshwater fish are examined with relation to the issues of indeterminate and determinate growth and asymptotic growth. Various authors suggest minimum, average and maximum sizes attained by fish, variously pointing to very small gobies and very large sharks, with most fish being about 150 mm long. Growth in fish is distinctive in that typically it continues throughout life, even though it becomes slower with increasing age and the onset of sexual maturity. Growth rates and size achieved by fish are highly flexible and subject to both genetic and environmental controls, so that size reached may vary with environmental variables such as water temperatures and food availability (both food abundance and prey types and sizes). Frequency distributions of 5 disparate freshwater fish faunas (Papua‐New Guinea 267 species and tropical; North America 709 species and subtropical to Arctic; Australia 176 species and tropical to temperate; New Zealand and Great Britain 27 and 39 species and both warm to cool temperate) closely resemble distributions generated by the theoretical model of Hutchinson & MacArthur, and also data on diverse faunas. Frequency distributions in these faunas are closely similar, with a majority of species being small. This similarity would seem to suggest a general explanation. However, examination of the freshwater fish fauna of North America suggests that, rather than showing a predominance of large fish in the Arctic, the fauna has more large fish towards the tropics, though the proportion of large fish there is lower owing to the proliferation of small species in the tropics and a paucity of them towards the Arctic. Analysis shows a shift in the size composition of the fauna with latitude and shows that the general pattern for the whole of North America consists of a composite series of rather different patterns. This suggests that there is probably no meaningful general explanation of the overall patterns seen in these diverse and disparate faunas and that the similarity in overall size distributions between freshwater fish faunas of North America, New Guinea, Australia and New Zealand are of little ecological or evolutionary significance. The generality of Cope's rule is questionable, especially for fish, in which dwarfing and/or evolution towards smaller size are seen to be common phenomena.
The effect of lakes on the stream fish fauna
Authors: Degerman E. , Sers B. 
Published: July 2006

AbstractThe effect of natural lakes on the fish species distribution in surrounding streams was studied using electrofishing survey data from 3281 localities in streams throughout Sweden. The occurrence of lake fish (northern pike, European perch, roach and burbot) was significantly higher close to lakes, both up‐ and downstream, as compared to localities further up‐ or downstream of lakes. Correspondingly, the occurrences of stream fish (brown trout, grayling, European minnow and bullheads) were lower close to lakes. It is suggested that the lower occurrences of the latter close to lakes be due to biotic interaction with lake fish, especially predation from pike and burbot. The results strongly indicate that the effect of lakes on water temperature, drift of plankton and invertebrates or the moderating effect on water fluctuations and quality did not influence the stream fish fauna to the same extent as the presence of lake fish in a zone up‐ as downstream of the lakes. Lakes function as a reservoir of strong predators and competitors.
Microhabitat use by fish in the lower Rio Matarraña, Spain, 1984–1987
Authors: Grossman G. D. , De Sostoa A. 
Published: July 2006

AbstractWe quantified microhabitat use in Barbus graellsii, Cyprinus carpio, Chrondostoma toxostoma, Esox lucius, Gobio gobio and Leuciscus cephalus during 1984–1987 in the lower Rio Matarraña, Spain. Fluctuations in numerical abundances of assemblage members increased during 1986–1987. These increased fluctuations were due to decreases in the abundances of Ch. toxostoma, E. lucius and G. gobio during the latter 2 years of our study. Only C. carpio increased slightly in abundance during this period. An analysis of microhabitat availability data indicated that 16 seasonal samples could be assigned to 1 of 6 groups ranging from: seasons with zero velocities, shallower depths and an algal/debris substratum to those with high velocities and depths and a substratum composed of algae/debris, rubble and gravel. Most seasonal changes in the substratum were attributable to conditions inhospitable to the growth of benthic algae (i. e., high velocities or low oxygen levels) rather than to actual changes in the underlying lithospheric substratum. Principle component analyses indicated that most species were overrepresented in deeper microhabitats with depositional substrata. Ch. toxostoma, however, tended to occur over rubble substrata in both shallow and deep microhabitats. Most seasonal changes in microhabitat use were produced by seasonal variations in microhabitat availability. However, all species except E. lucius exhibited seasonal variations in microhabitat use that typically involved velocity, depth and substratum composition. Although smaller specimens of most species were found closer to the substratum in 1984–1985, they tended to occupy shallow areas in 1986–1987. Canonical analyses of discriminants and univariate data demonstrated that the distance from the substratum was the best predictor of interspecific differences in microhabitat use. Species could be arrayed along a vertical gradient with L. cephalus and Ch. toxostoma occupying mid‐water column positions, B. graellsii and C. carpio occurring in lower‐water column microhabitats and E. lucius and G. gobio strongly associated with the substratum. Changes in interspecific microhabitat use were not correlated with changes in species abundances, and hence, interspecific competition did not appear to strongly influence microhabitat use during our study.
Annual biomass and production of brook charr (Salvelinus fontinalis) introduced into a historically fishless lake
Authors: Kelso J. R. M. , Shaw M. A. 
Published: July 2006

AbstractBrook charr 15 months old were introduced in 1985 into one of two self‐contained basins of Batchawana Lake, Ontario, Canada, where they survived and reproduced. Population survival rates (ages ≥ 1) remained high (>50%) from 1986 to 1992. Annual growth rates peaked (Gx=3.1) the year following their introduction, and remained between 0.8 and 1.6 thereafter. Brook charr biomass (B) was highest, ∼ 55 kg ∼ ha−1in 1987 and 1990, and production (P) gradually declined from 80–90 in 1986–1987 to ∼ 30 kg‐ha−1‐year−1in 1990–1991. Initial high P:B ratios for brook charr, ∼ 3.0, declined and stabilized to ∼ 1.3 in the third year after introduction.
Fish species richness in lakes of the northeastern lowlands in Germany
Authors: Eckmann R. 
Published: July 2006

AbstractFish species richness was assessed by electrofishing and gillnetting in 16 lakes of the northeastern lowland in Germany (the Schorfheide biosphere reserve). The lakes range from 0.03 to 10.55 km2 and support between 5 and 14 fish species. Species richness is significantly correlated with lake area in an exponential and a power model. Richness is also correlated with shoreline development and total dissolved solids. This supports the hypothesis that larger areas contain more species within a taxonomic group due to increased habitat diversity. The slope of the species‐area curve is low compared with most other studies of fish species richness in lakes, and the intercept value is high. This is interpreted as the result of high habitat and food diversity, lack of stress from abiotic factors, and the small regional species pool from which these lakes can be colonized. Two species inventories, one from the beginning of this century and one from the 1950s, are available for comparison. Average species richness did not change during the last decades. Species turnover rates were not related to the degree of anthropogenic eutrophication or to the intensity of fishery exploitation in these lakes. On the species level, however, one effect of accelerated eutrophication is apparent, the disappearance of 4 bottom‐living species from one to 6 of the study lakes.
Food resource partitioning of Arctic charr, Salvelinus alpinus (L.) and three‐spined stickleback, Gasterosteus aculeatus L., in the littoral zone of lake Takvatn in northern Norway
Authors: Jørgensen L. , Klemetsen A. 
Published: July 2006

AbstractThe food resource partitioning of Arctic charr (Salvelinus alpinus L.) and three‐spined stickleback (Gasterosteus aculeatus L.) were investigated in the littoral zone of lake Takvatn in northern Norway in the ice‐free period June–November. Charr and sticklebacks had different feeding habits. Sticklebacks ate several small benthic prey items that were never eaten by charr, and the sticklebacks' diet were dominated by the benthic microcrustaceans Chydoridae and Ostracoda, chironomid larvae and stickleback eggs. Small charr (<17 cm) consumed a wide spectrum of chironomid pupae, terrestrial insects and zooplankton. Intermediate (17–20 cm) and small charr had quite similar feeding habits, while large charr (>20 cm) frequently ate both benthos, pelagic and terrestrial food. The diet overlap between small charr and sticklebacks was never larger than 0.6 (Schoener's index). The segregation in feeding habits indicates that small charr and sticklebacks are segregated in microhabitat when they are both in the littoral zone.
Phenology and spatial and temporal distribution of larval fishes in a partially channelized warmwater stream
Authors: Peterson M. S. , VanderKooy S. J. 
Published: July 2006

AbstractWe studied the phenology and spatial and temporal dynamics of larval fish abundance with light traps from 5 locations along the length of Luxapalilia Creek, a partially channelized warmwater stream in northeastern Mississippi over 2 spawning seasops (March through August 1992 and 1993). The dominant, early spring spawners were catostomids (early‐April to late‐May) and darters (mid‐March to early‐June) whereas summer spawners were mainly cyprinids (mid‐May to August) and centrarchids (late‐May to August). The relative abundance of larvae collections differed based on: 1) site, 2) location, 3) date, 4) year, and 5) in larval stage. Total numbers of larvae and CPUE were high in mid‐ to late summer in downstream locations in both years when: 1) temperatures were high, 2) water velocities were low, and 3) depths were shallow compared to upstream locations. More mature larvae (meso‐ and metalarvae) were more common in the downstream locations whereas less mature larvae (yolk‐sac and protolarvae) were more abundant at the upstream locations. The downstream channelized portion of Luxapalila Creek resembled a lentic habitat with littoral zones characterized by slow water velocities, shallow depths, fine sediments, and vegetation. Larvae of darters (Etheostorna and Pcrcina), which require gravel bars and swift currents, were not collected in great numbers downstream, although members of the Ictiobinae (Carpoides and Ictiobus), cyprinidae and centrarchidae (Lepomis spp., Pomoxis spp. and Micropterus spp.) were more abundant downstream than upstream. This suggests that the natural, upstream locations acted as sources of larvae for the channelized downstream location.
Year class variation in fluctuating asymmetry in perch (Perca fluviatilis L.) from an acidic aluminium‐rich lake
Authors: Øxnevad S. A. , Østbye K. , Vøllestad L. A. 
Published: July 2006

AbstractFluctuating asymmetry is the random deviation from perfect bilateral symmetry owing to developmental perturbation, proposed as an indicator of sublethal environmental effects. This was measured in perch (Perca fluviatilis L.) from an acidic aluminium‐rich lake. Eleven paired meristic and morphometric characters were scored for fluctuating asymmetry. Level of fluctuating asymmetry differed significantly between year classes for two of the meristic characters, lower extra gill rakers and upper extra gill rakers, and also for an index summarizing number of asymmetric meristic characters per individual. This year class variation in fluctuating asymmetry is probably due to large variation in water quality during early development of perch embryos in spring. For future work on fluctuating asymmetry on fish we recommend the use of as many year classes as possible in the analyses.
Diel patterns in the feeding and habitat use of O‐group fishes in a regulated river: the River Great Ouse, England
Authors: Garner P. 
Published: July 2006

AbstractFeeding and habitat use behaviour of juvenile O+ fishes, principally Rutilus rutilus (L.) and Leuciscus cephalus (L.) was analysed at 4‐h intervals for a period of 24 h on 29 June, 27 July, and 13 September 1994 at a regulated site on the River Great Ouse, UK. Twenty‐five random point samples were taken by electrofishing during each sampling period from a 250 m reach of the river. Catch per unit effort decreased at night for both R. rutilus and L. cephalus. The number of prey items in the gut and the number of taxa found also decreased at night except for R. rutilus on one occassion. Habitat use remained near constant, with only slight increases in depth and distance from the bank at night. Use of Nuphar lutea by roach increased at night. Chub tended to avoid Nuphar lutea and were positively associated with emergent macrophyte and algal cover both during the day and night.
Diet and dietary overlap in fishes of temporary waters of southwestern Australia
Authors: Pusey B. J. , Bradshaw S. D. 
Published: July 2006

AbstractThe diets of six species of fish occurring in seasonally inundated waters of the southern acid peat flats of southwestern Australia were studied over a 23 month period. Fishes could be allocated to a benthos/lower water column guild or a midwater column/water surface guild. Segregation on the basis of prey size was noted for one species only, and this species had a larger mouth than the remaining species. Seasonal variation in within‐ and between‐guild overlap was observed. Highest overlap occurred in the mid‐wet season when inundation was greatest and all species foraged in extensive areas of very shallow water. Little segregation based on feeding position within the water column was possible, and some prey species (e. g. simuliid larvae) were particularly abundant at this time. Dietary overlap decreased as the dry season progressed and fish became concentrated in smaller areas of habitat. As fish demonstrated lower levels of food acquisition, this change in overlap was suggested to be in response to increased competition for limited food resources.
Direct Hydrothermal Synthesis of Highly Ordered Sn–SBA-15 Mesoporous Materials
Authors: Shah Pallavi , Ramaswamy Arumugamangalam V , Ramaswamy Veda 
Published: July 2006

Abstract
Well-ordered Sn4+-incorporated mesoporous silica SBA-15 samples have been synthesized from tetraethyl orthosilicate (TEOS) and SnCl4 (Si/Sn = 114–15) using nonionic surfactants under a slightly higher pH medium (optimum H2O to HCl molar ratio) and characterized by XRD (an increase in lattice parameter), TEM (no SnO2 species) and UV–vis spectral (absorption at 211 nm) techniques to show that Sn4+ ions are in tetrahedral coordination in Sn–SBA-15.
Formation of a Stable Sulfenic Acid by Hydrolysis of a Thionitrate and a Sulfenyl Bromide
Authors: Goto Kei , Shimada Keiichi , Furukawa Shunsuke , Miyasaka Shinji , Takahashi Yusuke , Kawashima Takayuki 
Published: July 2006

Abstract
Alkaline hydrolysis of a thionitrate and a sulfenyl bromide bearing a bowl-type steric protection group produced a stable sulfenic acid. This provides a conclusive demonstration of these elementary processes. It was shown that a very efficient steric protection group is necessary to prevent the condensation of the sulfenate anion generated during the hydrolysis.
Determination of AsIII/AsV Ratio in Alluvial Sediments of the Bengal Basin Using X-ray Absorption Near-edge Structure
Authors: Itai Takaaki , Masuda Harue , Takahashi Yoshio , Mitamura Muneki , Kusakabe Minoru 
Published: July 2006

Abstract
In this study, we applied X-ray absorption near-edge structure spectroscopy (XANES) to the determination of the AsIII/AsV ratios in sediments in the Bengal Basin, where groundwater contamination of As causes serious health hazard. The depth profile of oxidation state of As in sediment shows that AsIII is dominant species in the depth where As concentration of groundwater is high. This result is consistent with the general understanding about mobility of inorganic As species in various field observations.
Locked Energy of Axial to Equatorial Transformation Monitored by Exciplex and Excimer Fluorescence
Authors: Kadirvel Manikandan , Bichenkova Elena V , D’Emanuele Antony , Freeman Sally 
Published: July 2006

Abstract
2-O-tert-Butyldimethylsilyl-4,6-bispyrenoyl-myo-inositol-1,3,5-orthoformate (1) and 2-O-tert-butyldimethylsilyl-4-[(4-dimethylamino)benzoyl]-6-pyrenoyl-myo-inositol-1,3,5-orthoacetate (2) adopt unstable chair conformations with five substituents axial, in which the aromatic esters participate in π-stacking, and give excimer and exciplex fluorescence, respectively. Upon addition of acid, the orthoformate/orthoacetate lock is cleaved, which allows the inositol ring to switch to the more stable penta-equatorial chair conformation, with loss of exciplex/excimer fluorescence.
Fabrication of the Silica Rod by Inner Sol–Gel Transcription
Authors: Jung Jong Hwa , Cho Eun Jin , Kang Jeung Ku 
Published: July 2006

Abstract
The rod-like silica structure was obtained by inner sol–gel polymerization of BTEB using the organic tube 1 as a template, and its gas-absorption property was characterized. The organic silica rod-like material absorbed 0.68 wt % of hydrogen at 78 K.
The First Synthesis of Thermally Stable Acylamino-substituted 1,2-Dioxetanes
Authors: Matsumoto Masakatsu , Sano Yusuke , Watanabe Nobuko , Ijuin Hisako K 
Published: July 2006

Abstract
Singlet oxygen added smoothly to N-acyl-5-aryl-4-tert-butyl-3,3-dimethyl-2,3-dihydropyrroles 1 to give the corresponding bicyclic dioxetanes fused with N-acylpyrrolidine 2, which possessed marked thermal stability.
The Absence of Top3 Reveals an Interaction Between the Sgs1 and Pif1 DNA Helicases inSaccharomyces cerevisiae
Authors: Wagner Marisa , Price Gavrielle , Rothstein Rodney 
Published: July 2006

AbstractRecQ DNA helicases and Topo III topoisomerases have conserved genetic, physical, and functional interactions that are consistent with a model in which RecQ creates a recombination-dependent substrate that is resolved by Topo III. The phenotype associated with Topo III loss suggests that accumulation of a RecQ-created substrate is detrimental. In yeast, mutation of the TOP3 gene encoding Topo III causes pleiotropic defects that are suppressed by deletion of the RecQ homolog Sgs1. We searched for gene dosage suppressors of top3 and identified Pif1, a DNA helicase that acts with polarity opposite to that of Sgs1. Pif1 overexpression suppresses multiple top3 defects, but exacerbates sgs1 and sgs1 top3 defects. Furthermore, Pif1 helicase activity is essential in the absence of Top3 in an Sgs1-dependent manner. These data clearly demonstrate that Pif1 helicase activity is required to counteract Sgs1 helicase activity that has become uncoupled from Top3. Pif1 genetic interactions with the Sgs1–Top3 pathway are dependent upon homologous recombination. We also find that Pif1 is recruited to DNA repair foci and that the frequency of these foci is significantly increased in top3 mutants. Our results support a model in which Pif1 has a direct role in the prevention or repair of Sgs1-induced DNA damage that accumulates in top3 mutants.
Effects of trans-acting Genetic Modifiers on Meiotic Recombination Across the a1–sh2 Interval of Maize
Authors: Yandeau-Nelson Marna D , Nikolau Basil J , Schnable Patrick S 
Published: July 2006

Abstract
Meiotic recombination rates are potentially affected by cis- and trans-acting factors, i.e., genotype-specific modifiers that do or do not reside in the recombining interval, respectively. Effects of trans modifiers on recombination across the ∼140-kb maize a1–sh2 interval of chromosome 3L were studied in the absence of polymorphic cis factors in three genetically diverse backgrounds into which a sequence-identical a1–sh2 interval had been introgressed. Genetic distances across a1–sh2 varied twofold among genetic backgrounds. Although the existence of regions exhibiting high and low rates of recombination (hot and cold spots, respectively) was conserved across backgrounds, the absolute rates of recombination in these sequence-identical regions differed significantly among backgrounds. In addition, an intergenic hot spot had a higher rate of recombination as compared to the genome average rate of recombination in one background and not in another. Recombination rates across two genetic intervals on chromosome 1 did not exhibit the same relationships among backgrounds as was observed in a1–sh2. This suggests that at least some detected trans-acting factors do not equally affect recombination across the genome. This study establishes that trans modifier(s) polymorphic among genetic backgrounds can increase and decrease recombination in both genic and intergenic regions over relatively small genetic and physical intervals.
Four Novel Suppressors of gic1 gic2 and Their Roles in Cytokinesis and Polarized Cell Growth in Saccharomyces cerevisiae
Authors: Gandhi Meghal , Goode Bruce L , Chan Clarence S M 
Published: July 2006

Abstract
Gic1 and Gic2 are two Cdc42/Rac interactive binding (CRIB) domain-containing effectors of Cdc42-GTPase that promote polarized cell growth in S. cerevisiae. To identify novel genes that functionally interact with Gic1 and Gic2, we screened for high-copy suppressors of a gic1 gic2 temperature-sensitive strain. We identified two pairs of structurally related genes, SKG6-TOS2 and VHS2-MLF3. These genes have been implicated in polarized cell growth, but their functions have not previously been characterized. We found that overproduction of Skg6 and Tos2 in wild-type cells causes aberrant localization of Cdc3 septin and actin structures as well as defective recruitment of Hof1 and impaired formation of the septum at the mother-bud neck. These data suggest a negative regulatory function for Skg6 and Tos2 in cytokinesis. Consistent with this model, deletion of SKG6 suppresses the growth defects associated with loss of HOF1, a positive regulator of cytokinesis. Our analysis of the second pair of gic1 gic2 suppressors, VHS2 and MLF3, suggests that they regulate polarization of the actin cytoskeleton and cell growth and function in a pathway distinct from and parallel to GIC1 and GIC2.