ANTIBACTERIAL AND ANTISETTLEMENT ACTIVITY OF THE DOGFISH (SCYLIORHINUS-CANICULA) EGGCASE

The dogfish eggcase protects the developing embryo for up to a year ag ainst predation and fouling. The mechanical protection is provided by the strength and resilience of the case. The aim of this study was to determine the mechanisms underlying the case's antifouling proficiency . The eggcase is constructed of oxidatively cross-linked proteins, whi ch are primarily collagen. Two main hypotheses were examined, firstly that the egg case scavenges heavy metals and these act as deterrents. Secondly, the tanning agents, particularly dihydroxyquinones, through reaction with Fe2+, produce hydroxy radicals that act as deterrents. T his process is called the Fenton reaction. Using ten different species of marine bacteria, Semibalanus cyprids and Enteromorpha zoospores, a variety of experiments were conducted to examine the effect of surfac e chelation, iron loading, changing the surface roughness, different c ollagen types and quinones, and the presence of antioxidants. The resu lts suggest that the photoactivated generation of free radicals is par tially responsible for the antifouling mechanism of the eggcase. Colla gen and quinone chemistry and surface integrity are also considered to be important in the antifouling process.