Meeting Abstract
In a marine environment, attachment to substrate is vital to the success of many invertebrates, particularly those in the intertidal. Wave action, tidal flow, and predation are challenges that these organisms combat through a variety of mechanisms. Among these are attachment mechanisms, which help the animals stay in place. Chitons belong to the phylum Mollusca, which often use a mixture of suction and glue to attach to a substrate. In 1911 and 1916, G.H. Parker laid the groundwork for the study of chiton attachment forces. He made the assumption that chiton attachment “depends almost exclusively upon suction”. However, his observations did not involve formal testing, which left the questions of how and with how much force chitons attach to a substrate virtually unexplored. In this study we measured the attachment forces of the chiton species Mopalia muscosa. In order to investigate the contribution of suction specimens were allowed to attach to substrates with and without perforation. Perforation in the substrate inhibited the chiton’s use of suction. We were also interested in the impact of surface roughness on chiton attachment. Therefore, we performed the same experiment using substrates of three different grades of roughness: smooth, grain size of 0.267mm, and grain size of 1-2mm. On solid smooth substrates and substrates with a grain size of 0.267mm, M. muscosa attached with tenacities of 21 and 22 kPa, respectively, while tenacity upon the roughest surface was much lower (10kPa). On the perforated substrates, we found a significant decrease in tenacity, with only 30% and 50% of the tenacity depending on roughness. Our results show that suction plays a significant role in chiton attachment. Furthermore, the surface roughness of the substrate has a significant effect on total attachment force in chitons. Beside suction, other attachment mechanisms such as glue seem to play an important role.
