Relative contribution of water and diet to otolith chemistry in freshwater fish

ZA Doubleday; C Izzo; SH Woodcock; BM Gillanders

doi:10.3354/ab00511

Dietary Variation in a Freshwater Fish Species: Relative Contributions of Biotic Interactions, Abiotic Factors, and Spatial Structure

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f94-284 ◽

1994 ◽

Vol 51 (12) ◽

pp. 2856-2865 ◽

Cited By ~ 59

Author(s):

Pierre Magnan ◽

Marco A. Rodríguez ◽

Pierre Legendre ◽

Sylvain Lacasse

Keyword(s):

Spatial Structure ◽

Freshwater Fish ◽

Fish Species ◽

Environmental Variables ◽

Brook Trout ◽

Diet Composition ◽

Abiotic Factors ◽

Biotic Interactions ◽

Relative Contribution ◽

Dietary Variation

We used multivariate analyses to examine which variables among the environmental and spatial components can best account for dietary variation in a freshwater fish, brook trout, Salvelinus fontinalis. The diet composition of brook trout was quantified in 37 lakes of the Laurentian Shield, Québec, Canada. Among the 25 measured environmental variables, fish species composition, sampling date, macrophyte abundance, and trout body length were the best predictors of diet composition. The total variation in diet composition was partitioned into four components: pure environmental 21.6%, pure spatial 23.2%, shared 19.9%, and unexplained 35.3%. A significant spatial trend in diet composition existed even after accounting for the main effects measured by the environmental variables. The two sets of spatial variables, when combined with the environmental descriptors, extracted different components of the dietary variation. The study allowed us to (1) highlight the role of spatial structure in diet variation of brook trout, (2) determine the relative contribution of both environmental and spatial components, and (3) generate testable hypotheses concerning mechanisms underlying the observed structure. Dependent variables other than diet composition, such as the density of different species at different sampling sites, can be used within the same statistical framework in studies of community ecology.

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Otolith chemistry analyses indicate that water Sr:Ca is the primary factor influencing otolith Sr:Ca for freshwater and diadromous fish but not for marine fish

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f09-112 ◽

2009 ◽

Vol 66 (10) ◽

pp. 1790-1808 ◽

Cited By ~ 122

Author(s):

Randy J. Brown ◽

Kenneth P. Severin

Keyword(s):

Water Chemistry ◽

Freshwater Fish ◽

Marine Fish ◽

Marine Water ◽

Primary Factor ◽

Otolith Chemistry ◽

Freshwater Systems ◽

Diadromous Fish ◽

Low Levels ◽

Lower Variability

Water chemistry is thought to be the primary factor influencing fish otolith chemistry. Experimental results with freshwater and diadromous fish have been consistent with this paradigm, but with marine fish, they have often been ambiguous or contradictory. A review of water chemistry data indicated that Sr:Ca (mmol:mol) levels were higher in marine water than in most freshwater systems and that Sr:Ca variability was lower in marine water than in most freshwater systems. We therefore hypothesized that lifetime otolith Sr:Ca profiles of freshwater fish would exhibit low levels of Sr:Ca with moderate variability, of diadromous fish would exhibit highly variable Sr:Ca levels, and of marine fish would exhibit high levels of Sr:Ca with low variability. Otolith Sr:Ca profiles from 81 species of freshwater, diadromous, and marine fish revealed that freshwater fish had low levels of Sr:Ca and lower variability than expected relative to marine fish, diadromous fish had Sr:Ca levels and variability that were consistent with expectations, and marine fish had high maximum Sr:Ca levels, as expected, and high Sr:Ca variability, similar in magnitude to diadromous fish, which was not expected. These findings indicate that water Sr:Ca is the primary factor influencing otolith Sr:Ca variation for freshwater and diadromous fish but not for marine fish.

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Otolith chemistry to determine movements of diadromous and freshwater fish

Aquatic Living Resources ◽

10.1051/alr:2005033 ◽

2005 ◽

Vol 18 (3) ◽

pp. 291-300 ◽

Cited By ~ 81

Author(s):

Bronwyn M. Gillanders

Keyword(s):

Freshwater Fish ◽

Otolith Chemistry

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Multidimensional Anxiety and Content-specificity Effects in Preferential Processing of Threat

European Psychologist ◽

10.1027//1016-9040.8.4.252 ◽

2003 ◽

Vol 8 (4) ◽

pp. 252-265 ◽

Cited By ~ 9

Author(s):

Manuel G. Calvo ◽

P. Avero ◽

M. Dolores Castillo ◽

Juan J. Miguel-Tobal

Keyword(s):

Selective Attention ◽

Cognitive Biases ◽

Naming Task ◽

Color Naming ◽

Memory Bias ◽

Ego Threat ◽

Phobic Anxiety ◽

Relative Contribution ◽

Content Specificity ◽

Specificity Effects

We examined the relative contribution of specific components of multidimensional anxiety to cognitive biases in the processing of threat-related information in three experiments. Attentional bias was assessed by the emotional Stroop word color-naming task, interpretative bias by an on-line inference processing task, and explicit memory bias by sensitivity (d') and response criterion (β) from word-recognition scores. Multiple regression analyses revealed, first, that phobic anxiety and evaluative anxiety predicted selective attention to physical- and ego-threat information, respectively; cognitive anxiety predicted selective attention to both types of threat. Second, phobic anxiety predicted inhibition of inferences related to physically threatening outcomes of ambiguous situations. And, third, evaluative anxiety predicted a response bias, rather than a genuine memory bias, in the reporting of presented and nonpresented ego-threat information. Other anxiety components, such as motor and physiological anxiety, or interpersonal and daily-routines anxiety made no specific contribution to any cognitive bias. Multidimensional anxiety measures are useful for detecting content-specificity effects in cognitive biases.

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