Effects of acute temperature increase on performance and survival of Caribbean echinoids

Rendina, Francesco (2016) Effects of acute temperature increase on performance and survival of Caribbean echinoids. [Laurea magistrale], Università di Bologna, Corso di Studio in Biologia marina [LM-DM270] - Ravenna, Documento ad accesso riservato.
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Abstract

Climate change is occurring at a faster rate than in the past, with an expected increase of mean sea surface temperatures up to 4.8°C by the end of this century. The actual capabilities of marine invertebrates to adapt to these rapid changes has still to be understood. Adult echinoids play a crucial role in the tropical ecosystems where they live. Despite their role, few studies about the effect of temperature increase on their viability have been reported in literature. This thesis work reports a first systematic study on several Caribbean echinoids about their tolerance to temperature rise in the context of global warming. The research - carried out at the Bocas del Toro Station of the Smithsonian Tropical Research Institute, in Panama - focalized on the 6 sea urchins Lytechinus variegatus, L. williamsi, Echinometra lucunter, E. viridis, Tripneustes ventricosus and Eucidaris tribuloides, and the 2 sand dollars Clypeaster rosaceus and C. subdepressus. Mortality and neuromuscular well-being indicators - such as righting response, covering behaviour, adhesion to the substrate, spine and tube feet movements - have been analysed in the temperature range 28-38°C. The righting time RT (i.e., the time necessary for the animal to right itself completely after inversion) measured in the 6 sea urchin species, demonstrated a clearly dependence on the water temperature. The experiments allowed to determine the “thermal safety margin” (TSM) of each species. Echinometra lucunter and E. viridis resulted the most tolerant species to high temperatures with a TSM of 5.5°C, while T. ventricosus was the most vulnerable with a TSM of only 3°C. The study assessed that all the species already live at temperatures close to their upper thermal limit. Their TSMs are comparable to the predicted temperature increase by 2100. In absence of acclimatization to such temperature change, these species could experience severe die-offs, with important consequences for tropical marine ecosystems.

Abstract
Tipologia del documento
Tesi di laurea (Laurea magistrale)
Autore della tesi
Rendina, Francesco
Relatore della tesi
Correlatore della tesi
Scuola
Corso di studio
Ordinamento Cds
DM270
Parole chiave
Echinoids, Sea urchins, Thermal tolerance, Righting time, Climate change, Global warming, Caribbean Sea, Temperature
Data di discussione della Tesi
22 Marzo 2016
URI

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