Figure - available from: Canadian Journal of Fisheries and Aquatic Sciences
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Density plot of flannelmouth sucker captures in the Grand Canyon between April 2012 and October 2018, faceted by reach. This plot is a smoothed histogram that shows proportions of flannelmouth sucker by fork length at first capture when they are administered a PIT tag for the first time. This figure represents only those fish that were caught and subsequently recaptured during our study duration.
Source publication
Individual growth can exert strong control on population dynamics but is constrained by resource acquisition rates. Difficulty in accurately quantifying resource availability over large spatial extents and at high temporal frequencies often limits attempts to understand the extent to which resources limit individual growth. Daily estimates of strea...
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Compensatory density‐dependent (DD) processes play an integral role in fisheries management by underpinning fundamental population demographics. However, DD processes are often assessed only for specific life stages, likely resulting in misleading evaluations of population limitations. Here, we assessed the relative roles of intra‐ and inter‐life s...
Citations
... These three disturbance-based hypotheses of community assembly and stability have not been evaluated equally well across ecosystem types. Recent studies without facilitation by ecosystem engineers found trophic niche compression from disturbances in aquatic ecosystems (Burdon et al., 2020;Gutiérrez-Fonseca et al., 2024;Hansen et al., 2023). Meanwhile, Rahman et al. (2021) found an increase in trophic niche area for ground beetles following disturbance. ...
Ecosystem engineering is a facilitative interaction that generates bottom‐up extrinsic variability that may increase species coexistence, particularly along a stress/disturbance gradient. American alligators (Alligator mississippiensis) create and maintain ‘alligator ponds’ that serve as dry‐season refuges for other animals. During seasonal water recession, these ponds present an opportunity to examine predictions of the stress‐gradient (SGH) and intermediate disturbance hypotheses (IDH).
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... Variations in somatic growth occur due to intrinsic and extrinsic differences of each individual. Thus, genetic and environmental factors (temperature, latitude, geographical distribution) and ecological interactions (competition, predation) act as determinants in growth rate (Winemiller, 1989;Shelton et al., 2013;Vincenzi et al., 2014;McDougall et al., 2018;Hansen et al., 2023). ...
The Amazon is one of the regions with the greatest fish diversity on the planet. In this vast biodiversity, there is Serrasalmus rhombeus, a predatory species that plays a vital ecological role in aquatic ecosystems. In order to generate biological data and valuable information to management efforts, we characterized the somatic growth pattern of S. rhombeus and identified its sources of variation. To achieve this, individuals of S. rhombeus were collected from two dams between October 2018 and November 2019. Analyzing the marginal increment based on data from 158 individuals revealed the formation of a single annual growth ring at the onset of the rainy season. Individual ages ranged from 1 to 6 years old. Among the considered models, the one that provided the best explanation for the variation in somatic growth of S. rhombeus integrated individual variation, sex, and sites. This highlights that the rate of an individual’s growth and the size it can attain are influenced by individual resource utilization, which is mediated by interindividual genetic diversity. Furthermore, this variation is associated with sex and the specific site where the individual is located.
... rates (Hansen et al. 2023), so other factors besides age and experience may be contributing to these timing patterns. The drivers of sex and length patterns in emigration timing in our system will require further investigation. ...
Objective
Handling and tagging migrating fish might alter their behavior, limiting inference from mark–recapture studies. Posthandling flight of tributary spawning Flannelmouth Sucker Catostomus latipinnis was previously identified in Coal Creek in the upper Colorado River basin. Our objective was to determine if similar issues were present at McElmo Creek in the San Juan River basin.
Methods
We compared emigration timing of Flannelmouth Sucker that had been handled and tagged with passive integrated transponder tags during their tributary spawning run to individuals tagged in previous years and detected both entering and exiting the tributary. Linear mixed‐effects models were used to examine intrinsic and extrinsic factors contributing to exit timing.
Result
Sex and tagging year were associated with emigration timing, but handling did not result in posthandling flight from McElmo Creek. Females exited the tributary ~3 days before males, and larger fish emigrated earlier than smaller adults.
Conclusion
Differences in capture technique and timing, available spawning habitat, and fish motivation across river systems may contribute to differences in posthandling emigration of tributary spawning Flannelmouth Sucker.
