Effects of ocean warming on larval development of Patella ordinaria from the Canary Islands

Abstract

Ocean warming is causing Sea Surface Temperature (SST) to rise, which is projected to reach +2 to +4.5°C by the end of the 21st century. Temperature is considered the most important factor controlling the distribution, physiology, morphology and behavior of marine invertebrates. Early life history stages appear to be particularly sensitive to ocean warming. Effects of ocean warming on larval development have been documented in a wide range of invertebrate species; however, few studies have tested the effects of temperature on gastropod larvae. Here, we assessed the effects of two seawater temperature treatments: control (20 °C) and high (25 °C), on survival and larval development of Patella ordinaria through manipulative experiments. Data were analyzed using two-way ANOVA by permutations. To evaluate the effects of temperature and time on larval development, at each larval stage (oocyte, 2 cells, 4 cells, morula, trochophore, veliger, pediveliger), two-way permutational multivariate analysis of variance (PERMANOVA) was performed. In both analyses, temperature (20 °C vs. 25 °C) and time (3, 6, 19, 24, 28, 32 and 42 h) were used as fixed factors. The results showed a negative impact of high temperature on larval development and survival of P. ordinaria, and the implications are discussed. The early developmental stages of P. ordinaria larvae are studied for the first time.