Effects of Thermal Stress on Ascidian Larval Development

Abstract

Rising ocean temperatures caused by climate change have the potential to cause detrimental effects to the development of many marine organisms. Numerous species of ascidians have been shown to undergo faster rates of larval development when subject to heat stress. In this study, we investigated the effects of increased temperature on the development and survival of embryos in the species Boltenia villosa. B. villosa embryos were placed under three different temperature conditions, ambient (11-12°C), mid (14-15.5°C) or high (16.5-18°C), and rates of development to important stage markers were observed. Survival rate to larval stage was also recorded. Our results show that embryos subjected to higher temperatures develop faster than those at ambient temperatures but have lower survival rates. This suggests that while higher temperatures speed up development, they also have detrimental effects on the quality of development.