Biodiversity, distribution, feeding and trophic role of marine mysids (Crustacea, Peracarida, Mysida) (2014)
- Authors:
- Autor USP: MIYASHITA, LEONARDO KENJI - IO
- Unidade: IO
- Sigla do Departamento: IOB
- Subjects: CRUSTACEA; MYSIDACEA; BIODIVERSIDADE; CANANÉIA (SP)
- Language: Inglês
- Abstract: This thesis focuses on the role of mysids in coastal ecosystems. It considers aspects of their distribution, biology, and ecology, such as: zoogeographical distribution in the Southwest Atlantic; their population dynamics in the Cananeia estuary, exploring spatial and temporal distribution in relation to environmental variables and zooplankton abundance; reproductive traits, annual production and tolerance to salinity gradients; feeding rateso selectivity, and functional responses; inter- and intraspecific predation; and the suppression of mysid abundance by predators. Particular attention was put to the trophic role of mysids in the context of the Biodiversity and Ecosystem Functioning theory in ecology (BEF). Experimental approaches were employed to evaluate the effects of species richness of the mysid assemblage on their feeding selectivity and consumption fluxes. Also, the effect of species richness of the mysids predador assemblage was taken into account. Mysids are usually the dominant benthic epifauna in coastal waters, and thus they play a key role in marine coastal food webs. However, few studies focused on these organisms in the South American region: only 3l out of ll31 mysid species described worldwide have been registered in the Southwest Atlantic. In the Cananeia estuary, salinity and temperature were important factors influencing mysid spatio-temporal distribution. Higher abundance and production occuned in spring, when thermohaline conditions were more favorable and food availability was high. Metamysídopsis elongata atlantica was the numerically dominant species, probably because it is the single mysid species that effectively colonizes low salinity areas, where food is more abundant and other mysid species are absent, thus avoiding interspecific competition and intraguild predation. Metamysidopsis e. atlantica had high annual production values, confrrming the importance of mysids in the carbon flux of tropical and subtropical (Continua)(continuação) coastal waters. Chlamydopleon dissímile, M. e. atlantica, and Mysidopsis coelhoi had opportunistic feeding behavior on the natural zooplankton assemblage, but there was evidence of avoidance of medium-size prey (300-400 um), mostly comprised by Oithona spp. Ingestion rates showed a non-linear increase with increasing food concentrations, suggesting a type II functional response for the three mysid species. There were both positive (complementarity effect) and negative effects of species combinations on their feeding response. Negative interactions were probably linked to intraguild predation, resulting in a reduction of mysid predation over the zooplankton. An increase in the number of mysid predator species enhanced mysid suppression relative to the mean performance of predator monocultures, but not in comparison to the most effective predator. Positive effects of diversity increased with spatial heterogeneity, as it allowed interspecific complementarity effects between predators to be expressed. Moreover, mortality of predators was reduced in spatially heterogeneous treatments, most likely because it dampened intraguild predation and/or negative behavioral interactions between predators. Finally, trophic cascades were not observed, probably due to the omnivorous - generalist character of mysids
- Imprenta:
- Data da defesa: 06.08.2014
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ABNT
MIYASHITA, Leonardo Kenji. Biodiversity, distribution, feeding and trophic role of marine mysids (Crustacea, Peracarida, Mysida). 2014. Tese (Doutorado) – Universidade de São Paulo, São Paulo, 2014. Disponível em: http://www.teses.usp.br/teses/disponiveis/21/21134/tde-30032015-143135/. Acesso em: 12 jun. 2024. -
APA
Miyashita, L. K. (2014). Biodiversity, distribution, feeding and trophic role of marine mysids (Crustacea, Peracarida, Mysida) (Tese (Doutorado). Universidade de São Paulo, São Paulo. Recuperado de http://www.teses.usp.br/teses/disponiveis/21/21134/tde-30032015-143135/ -
NLM
Miyashita LK. Biodiversity, distribution, feeding and trophic role of marine mysids (Crustacea, Peracarida, Mysida) [Internet]. 2014 ;[citado 2024 jun. 12 ] Available from: http://www.teses.usp.br/teses/disponiveis/21/21134/tde-30032015-143135/ -
Vancouver
Miyashita LK. Biodiversity, distribution, feeding and trophic role of marine mysids (Crustacea, Peracarida, Mysida) [Internet]. 2014 ;[citado 2024 jun. 12 ] Available from: http://www.teses.usp.br/teses/disponiveis/21/21134/tde-30032015-143135/
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