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Temperature effect over ontogenetic patterns of feeding structures in scyphozoan ephyrae: functional and ecological implications

Grant number: 15/25142-8
Support type:Scholarships in Brazil - Master
Effective date (Start): June 01, 2016
Effective date (End): April 29, 2018
Field of knowledge:Biological Sciences - Zoology - Morphology of Recent Groups
Principal Investigator:André Carrara Morandini
Grantee:Mayara de Almeida Jordano
Home Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
Associated scholarship(s):16/24801-0 - Characterization of feeding structures along the development of Scyphozoa ephyrae, BE.EP.MS

Abstract

Jellyfishes of the class Scyphozoa (~200 spp.) have a wide morphological diversity apparently associated with their habits and feeding modes. Their early development imply a drastic morphological change from the ephyrae stage (juvenile) to the adult body form. It is not yet known if environmental factors (e.g. temperature, and consequently viscosity) could determine functional shapes/dimensions of feeding structures of these medusae. In filter-feeding organisms, depending on the distance between consecutive filtering elements, as well as fluid regime, an eventual superposition of boundary layers around adjacent structures could reduce/inhibit the flux through filtering spaces. In this way, even a porous structure could act as an almost continuous barrier, with low filtering efficiency. An environmental factor that affects such type of interaction is the ratio of importance between viscosity and inertial forces, expressed by the Reynolds number (Re). Changes in temperature modify water viscosity, in one hand at low temperatures (low values of Re) the thickness of the boundary layer increases, on the other hand at higher temperatures (higher values of Re), the boundary layers retreat which can increase the filtering performance. Although some organisms can compensate changes in the fluid environment through morphological and behavioural responses, nothing is known if filtering organisms can perform such responses. This project will describe the early developmental stages of three Rhizostomeae species (Lychnorhiza lucerna, Cassiopea andromeda, and Cotylorhiza tuberculata), and of one 'Semaeostomeae' (Aurelia sp.) focusing on the development of the filtering oral arms. It will be tested the hypotheses that different temperatures promote a different development of the oral arms, that would compensate the variations in viscosity. The species will be submitted to cultivation in different temperatures and will be documented from the early ephyra stage to adulthood morphology. Oral arms structures will be measured, compared, and analysed between the different experimental designs. Additionally, quantification of the interaction features between fluid and animal (e.g. velocity of feeding currents) during swimming and feeding of the different specimens under distinct experimental treatments.

Scientific publications
(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)
JORDANO, MAYARA DE A.; MORANDINI, ANDRE C.; NAGATA, RENATO M. Is phenotypic plasticity determined by temperature and fluid regime in filter-feeding gelatinous organisms?. Journal of Experimental Marine Biology and Ecology, v. 522, JAN 2020. Web of Science Citations: 0.
Academic Publications
(References retrieved automatically from State of São Paulo Research Institutions)
JORDANO, Mayara de Almeida. Development of scyphozoan ephyrae (Cnidaria, Medusozoa) and their interaction with the fluid environment. 2018. Master's Dissertation - Universidade de São Paulo (USP). Instituto de Biociências São Paulo.

Please report errors in scientific publications list by writing to: cdi@fapesp.br.