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John M. Casselman 《Environmental Biology of Fishes》2007,79(1-2):137-154
Growth and ultimate size can provide important population insights and a sound biological basis for setting length limits,
which can be the best single regulation for preventing overexploitation of muskellunge (Esox masquinongy) populations. A system was developed, using cleithral age and total length at age confidence limits (CL) data, to determine
reproductive and growth potential (ultimate size) for calculating and setting increased size limits based on minimum reproductive
size (upper 99% CL at age at first maturity + 2 year) and minimum ultimate size (MUS) calculated from the lower 99% CL—minimum
ultimate size limit (MUSL). MUS also provides a trophy standard and an index of relative size for comparing trophy potential
of individuals within and among populations. Guidelines are provided for determining minimum sample size (mean ± 95% confidence
interval = 12 ± 4) and minimum age (8–10 ± 2.0 year) required to produce valid von Bertalanffy growth trajectories. MUS, MUSL,
and trophy standards for both length and estimated weight are provided for female and male muskellunge from 14 Ontario sources.
Mean MUS, or trophy standard, for females was 115 ± 10.3 cm (MUSL range 75–135) and 11.1 ± 2.6 kg (2.5–17.5) and for males
was 95 ± 7.5 cm (66–110) and 6.1 ± 1.3 kg (1.9–9.2). These indices can precisely define growth and growth potential for muskellunge
populations and individuals and can be used to better manage and maintain or improve the quality of muskellunge populations
and fisheries.
Dedicated to the late Dr. E.J. Crossman. 相似文献
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Bett Nolan N. Hinch Scott G. Bass Arthur L. Braun Douglas C. Burnett Nicholas J. Casselman Matthew T. Cooke Steven J. Drenner S. Matthew Gelchu Ahmed Harrower William L. Ledoux Roxx Lotto Andrew G. Middleton Collin T. Minke-Martin Vanessa Patterson David A. Zhang Wenming Zhu David Z. 《Hydrobiologia》2022,849(2):385-405
Hydrobiologia - Many of the world’s rivers are dammed, altering the physiology, behaviour, ecology and survival of fish. Integrative research has the potential to improve our understanding of... 相似文献
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The Human G2 Checkpoint Control Protein hRAD9 Is a Nuclear
Phosphoprotein That Forms Complexes with hRAD1 and hHUS1 下载免费PDF全文
Robert P. St. Onge Christian M. Udell Richard Casselman Scott Davey 《Molecular biology of the cell》1999,10(6):1985-1995
Eukaryotic cells actively block entry into mitosis in the presence of DNA damage or incompletely replicated DNA. This response is mediated by signal transduction cascades called cell cycle checkpoints. We show here that the human checkpoint control protein hRAD9 physically associates with two other checkpoint control proteins, hRAD1 and hHUS1. Furthermore, hRAD1 and hHUS1 themselves interact, analogously to their fission yeast homologues Rad1 and Hus1. We also show that hRAD9 is present in multiple phosphorylation forms in vivo. These phosphorylated forms are present in tissue culture cells that have not been exposed to exogenous sources of DNA damage, but it remains possible that endogenous damage or naturally occurring replication intermediates cause the observed phosphorylation. Finally, we show that hRAD9 is a nuclear protein, indicating that in this signal transduction pathway, hRAD9 is physically proximal to the upstream (DNA damage) signal rather than to the downstream, cytoplasmic, cell cycle machinery. 相似文献
4.
Nathan G. Smith Charles C. Krueger John M. Casselman 《Environmental Biology of Fishes》2008,81(4):375-386
A growth chronology index was used to determine whether changes in ecosystem structure and function in lakes could be associated
with fish growth histories. Growth chronologies were compared for white suckers, Catostomus commersoni, from Little Moose (oligotrophic), Oneida (eutrophic), and Cayuga (mesotrophic) lakes (New York) from opercular bone growth
increments, and for lake trout, Salvelinus namaycush, from Little Moose Lake using otolith growth. The longevity of these species allowed the development of chronologies from
17 to 33 years in length using only contemporary collections. We used these chronologies to examine whether fish growth histories
could be used as an index for ecosystem-scale changes. Specifically, we examined whether zebra mussel, Dreissena polymorpha, invasion in Oneida and Cayuga lakes in the early 1990s, and treatment of sewage effluent from dwellings around Little Moose
Lake beginning during the late 1980s could be detected in white sucker and lake trout growth chronologies. White sucker growth
in Oneida and Cayuga Lakes did not differ before and after zebra mussel invasions. Neither white sucker nor lake trout growth
chronologies from Little Moose Lake reflect changes in growth expected with reduced productivity levels associated with improved
sewage treatment. Growth chronologies of these two species did not detect the ecosystem-scale changes that occurred in the
study lakes. 相似文献
5.
Strecker AL Casselman JM Fortin MJ Jackson DA Ridgway MS Abrams PA Shuter BJ 《Oecologia》2011,166(3):819-831
Species present in communities are affected by the prevailing environmental conditions, and the traits that these species
display may be sensitive indicators of community responses to environmental change. However, interpretation of community responses
may be confounded by environmental variation at different spatial scales. Using a hierarchical approach, we assessed the spatial
and temporal variation of traits in coastal fish communities in Lake Huron over a 5-year time period (2001–2005) in response
to biotic and abiotic environmental factors. The association of environmental and spatial variables with trophic, life-history,
and thermal traits at two spatial scales (regional basin-scale, local site-scale) was quantified using multivariate statistics
and variation partitioning. We defined these two scales (regional, local) on which to measure variation and then applied this
measurement framework identically in all 5 study years. With this framework, we found that there was no change in the spatial
scales of fish community traits over the course of the study, although there were small inter-annual shifts in the importance
of regional basin- and local site-scale variables in determining community trait composition (e.g., life-history, trophic,
and thermal). The overriding effects of regional-scale variables may be related to inter-annual variation in average summer
temperature. Additionally, drivers of fish community traits were highly variable among study years, with some years dominated
by environmental variation and others dominated by spatially structured variation. The influence of spatial factors on trait
composition was dynamic, which suggests that spatial patterns in fish communities over large landscapes are transient. Air
temperature and vegetation were significant variables in most years, underscoring the importance of future climate change
and shoreline development as drivers of fish community structure. Overall, a trait-based hierarchical framework may be a useful
conservation tool, as it highlights the multi-scaled interactive effect of variables over a large landscape. 相似文献
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Age of mature Oreochromis niloticus in Lake Awassa, Ethiopia, was estimated by analysing optical macrozones (translucent and opaque) in sagittal otoliths from fish sampled over a 12-month period. Seasonal record on the type of macrozone at the edge of otoliths suggested that two translucent macrozones associated with biannuli were formed each year; one during January and February and another during June and July. Formation of translucent macrozones coincided with minimum water temperature, spawning associated loss in condition and presumably with reduction in the quantity and quality of the food consumed by the fish. Relative marginal increment analysis showed that biannulus formation may be completed in March and in August each year. A concurrent study has confirmed a biannual recruitment in O. niloticus in Lake Awassa, from which mid-February and mid-August were taken as median hatch-dates. A procedure to assign otolith age is described which considers median hatch-dates and uses the number of biannuli in otoliths without discriminating between fish from the two recruitment cohorts. We also show a procedure to discriminate between the two cohorts by using the number of biannuli, conditions on the edge of the otolith and time of capture to assign age for the two recruitment cohorts separately. 相似文献
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