Variation in Byssal Thread Production by Mytilus trossulus with Temperature

Abstract

Mussels attach to substrates by means of byssal threads. The amount of threads produced influences the strength of attachment. In this experiment, we looked at the effect of temperature on the number of byssal threads formed by the marine mussel species Mytilus trossulus. We predicted that higher temperatures would limit the number of byssal threads produced. Mussels were placed in a flume set to a controlled temperature for each trial. Trials were performed at 10, 14, 18, 20, 22 and 25 degrees Celsius. Threads produced by each mussel were counted 11 times over a 24 hour period. Scanning electron microscope photos were also taken of threads from each temperature to compare possible visual differences. Our results suggest that total mean threads produced by M. trossulus peak around 18 degrees Celsius, and decrease as temperatures increase or decrease. The importance of knowledge on factors that affect byssal thread formation becomes increasingly important as global water temperature is expected to rise. Mussel attachment is important for ecological reasons, because mussels and the ecosystem that they live in depend on the formation of thick mussel beds. This information is also useful for mussel aquaculture, as the raising of farmed mussels depends on the ability of mussels to attach to substrates.