We investigated how the taxonomic and functional structures of fish assemblages in the lower Amazon River floodplain responded to seasonal hydrological variations. Fishes were sampled in 440 aquatic habitats across a floodplain area of 17,673 km2during periods of high, receding, low and rising water. In addition, we recorded local environmental and landscape variables known to affect fish assemblages in floodplains. Redundancy analysis indicated that the taxonomic and functional structures of the fish assemblages were associated with water levels as well as local environmental, landscape and spatial variables. Our results showed that piscivores, planktivores and omnivores, as well as species with periodic and intermediate life history strategies, dominated the floodplain fish assemblages during periods of high‐water levels, whereas herbivores, invertivores and detritivores, as well as species of large body size with an equilibrium life history strategy, dominated the fish assemblages during periods of low‐water levels. Hydrology strongly influenced the structure of the fish assemblages in the Amazon floodplains. Our results indicate that the maintenance of seasonal hydrological dynamics in the basin is essential for the conservation of the regional fish diversity.
10 - Adaptation and evolutionary responses to high CO2
The evolutionary history of fishes spans geological periods where atmospheric CO2 was much higher than the current-day, yet some extant species are now sensitive to high environmental CO2. Other species have adapted to live in habitats where they naturally encounter very high CO2 levels. This chapter explores the evolutionary history of fishes in relation to environmental CO2 and adaptations to high CO2 habitats. It then considers the potential for adaptive responses to predicted future CO2 levels from climate change among extant fishes. Despite a rich theory and well-developed experimental methods in quantitative genetics only a handful of studies have tested for genetic variation in CO2-sensitive traits, which might enable fish to adapt to projected future CO2 levels. This is a serious knowledge gap that needs a concerted research effort to overcome. Without basic information on genetic variation in fitness-associated traits and the strength of selection, it is not possible to make informed decisions about the impacts of elevated CO2 on fish populations over the timeframes that CO2 is changing.
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- Award ID(s):
- 1536165
- PAR ID:
- 10249934
- Editor(s):
- Grosell, Martin; Munday, Philip L.; Farrell, Anthony P.; Brauner, Colin J.
- Date Published:
- Journal Name:
- Fish physiology
- Volume:
- 37
- ISSN:
- 1557-8011
- Page Range / eLocation ID:
- 369-395
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1016/bs.fp.2019.07.006
