Examining the Relationship Between Rostanga pulchra and Clathria pennata Under Climate Extremes

Abstract

Intertidal species relationships are some of the most robust and well-studied examples of species adaptability and resilience. Due to climate change, increasing marine temperatures are altering relationships between marine symbiotic species. An important marine symbiotic species found in intertidal ecosystems is that between the nudibranch R. pulchra and the sponge C. pennata. R. pulchra spends most of its life on the sponge both feeding on and laying its eggs directly on the sponge. This symbiotic relationship could possibly be affected by climate change since R. pulchra larvae are temperature sensitive and adults use scent to find the sponge. To examine this, R. pulchra specimens were exposed to foraging time trials to observe how long it would take individuals to reach the symbiotic sponge, C. pennata under different temperatures. R. pulchra individuals were placed in enclosed containers with both C. pennata and Haliclona permollis, another common intertidal sponge species. There was a tank at an ambient temperature of around 10°C, a 13°C treatment, and 16°C treatment. The experiment revealed that temperature does not affect the ability of R. pulchra to find the symbiont sponge, C. pennata over the other sponge, H. permollis. R. pulchra reached each sponge species at a similar proportions in each of the temperature treatments. In addition, it took on average the same time for R. pulchra to reach C. pennata in each treatment. This indicates that even though marine temperatures are rapidly increasing and affecting many symbiotic relationships, it is possible that the relationship between R. pulchra and C. pennata is not as highly affected.