| Abstract: | The serpulid annelid Ficopomatus enigmaticus is a widely distributed invader of shallow‐water, brackish habitats in subtropical and temperate regions, where it has numerous damaging ecological and economic effects. Its distributional pattern suggests that temperature and salinity play important roles in limiting its distribution, but because other factors often covary with these, drawing strong conclusions from these patterns is difficult. In an effort to more clearly identify the effects of these factors, we examined tolerance to acute thermal (16–28°C) and salinity (0–35 psu) stress by larvae (5‐day exposure, unfed) and adults (14‐day exposure, unfed) of F. enigmaticus in the laboratory experiments. Larvae showed higher mortality at the highest temperature tested 28°C; adult survival was unaffected by temperature. Neither larvae nor adults survived exposure to pure freshwater (0 psu), but survived well at salinities ranging 3.5–35 psu. In addition, high salinity did not slow tube growth in adults. These results suggest that salinity stress, in particular, does not directly limit the distribution of F. enigmaticus to low‐salinity habitats. Experimental work on the distribution of F. enigmaticus is uncommon in the literature, but is likely needed to identify the abiotic or biotic factors that limit the distribution of this frequently invasive species. |
