Figure 1.
Map displaying locations sampled in this study.
(1) Marianne, (2) Arima, (3) Guanapo, (4) Aripo, (5) Quare, and (6) Turure. All streams were located in the Northern Range Mountains of Trinidad and Tobago (location shown in inset).
Table 1.
Environmental characteristics among Rivulus hartii sites.
Table 2.
The distribution of elemental composition in all Rivulus hartii individuals collected in this study compared to the distribution of elements and elemental ratios of 31 fish species compiled in a recent review [14].
Figure 2.
Correlations between body size, elemental composition or organismal stoichiometry of adult Rivulus hartii.
Table 3.
Analysis of elemental composition and stoichiometry of adult Rivulus hartii using a general linear model (GLM) and variance decomposition (η2).
Figure 3.
The effect of community composition (i.e. life history phenotype) on the elemental stoichiometry of adult Rivulus hartii.
Fish community composition predicts life history phenotype of this species, as well as a small component of its elemental composition and organismal stoichiometry. Bars are least squares means (standard error) of elemental composition and elemental stoichiometry generated from a general linear model (Table 3). They are standardized to body size = 35 mm. Community designations are RO = Rivulus Only, RG = R. hartii and Guppies, HP = High Predation sites. Bars surmounted by a star are significantly different using Tukey post hoc HSD test at P<0.05.
Figure 4.
Spatial variability in the organismal stoichiometry of adult Rivulus hartii.
Stream and the interaction of stream×community are the strongest predictors of elemental composition and organismal stoichiometry of R. hartii. Values are least squares means generated from a general linear model (Table 3). They are standardized to body size = 35 mm. Community designations are RO = Rivulus Only, RG = R. hartii and Guppies, HP = High Predation sites. ARM is the Arima, ARP is Aripo, GUA is Guanapo, MAR is Marianne, QUA is Quare and TUR is the Turure.
Table 4.
Analysis of elemental composition and stoichiometry of Rivulus hartii using a general linear model (GLM) and variance decomposition (η2).
Figure 5.
Correlations between resources and organismal stoichiometry of adult Rivulus hartii.
Different aspects of the organismal stoichiometry of adult R. hartii are significantly correlated with the invertebrate standing stocks (a), with the stoichiometry of epilithon (b), and with the stoichiometry of benthic organic matter (c).
Table 5.
A statistical assessment of how much of the stream effect in organismal stoichiometry is described by the quality of benthic resources or by the overall availability of resources.