Temperature effects on larval growth and survival in five species of Caribbean Echinoids

Perricone, Valentina (2016) Temperature effects on larval growth and survival in five species 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

Under the global change scenario, the possible effects of ocean warming were investigated on the larvae of five species of Caribbean Echinoids: Echinometra lucunter, Echinometra viridis, Clypeaster rosaceus, Tripneustes ventricosus and Lytechinus williamsi. Their thermal tolerance was evaluated rearing them for six days under different temperature regimes (26, 28, 30, 32, 34, 36°C). The larval sensitivity to the treatments was evaluated on the base of survival and growth. The rearing at higher temperatures has revealed a great suffering state of the larvae by inducing both reduction of live larvae and abnormality in their development. The extent of impact of the treatments varied from species to species, evidencing different levels of thermal tolerance. Anyway, higher temperature treatments have shown a general lethal threshold at about 34°C for most of the species. As an exception, the lethal threshold of Echinometra species was 36°C, few larvae of which being still capable of survive at the temperature of 34°C. The studies have also analyzed the effect of water warming on the larvae growth in terms of size and symmetry. The results put in evidence the presence of a critical upper temperature (about 32°C) at which the larvae of all species reveal a great suffering state that translates in the reduction of size (i.e., of body, stomach and postero-dorsal arm) and abnormalities (i.e., strong difference in the lengths of the two postero-dorsal arms). As sea surface temperatures are predicted to increase of 4-5°C by 2100, the high percentage of abnormal larvae and their scarce survival observed at 32- 34°C treatments indicate that the early stages of these species could be affected by future global warming.

Abstract
Tipologia del documento
Tesi di laurea (Laurea magistrale)
Autore della tesi
Perricone, Valentina
Relatore della tesi
Correlatore della tesi
Scuola
Corso di studio
Ordinamento Cds
DM270
Parole chiave
Echinoids, Caribbean, Larvae, Temperature effects, Survival, Growth, Global warming
Data di discussione della Tesi
22 Marzo 2016
URI

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