Combined effects of temperature and salinity on growth, survival, gill morphology, and antioxidant capabilities in the horse mussel Modiolus modiolus

Abstract

Temperature and salinity are critical to the reproduction, growth, and survival of shellfish. We investigated the combined effects of temperature (15 °C, 20 °C, and 25 °C) and salinity [20, 30, and 40 practical salinity units (PSUs)] on the horse mussel Modiolus modiolus, which inhabits the northern Chinese coast. The specific growth rate of M. modiolus increased with salinity at a low temperature (15 °C). The interaction between temperature and salinity with respect to M. modiolus survival was significant (Two-Way ANOVA; p < 0.01). Across all temperatures tested, M. modiolus specimens kept at low salinity (20 PSU) had narrower gill filament lumens than those kept at moderate salinity (30 PSU); the gill filament lumens of specimens kept at high salinity (40 PSU) were wider than either of these. The combined effects of temperature and salinity on superoxide dismutase (SOD) activity, total antioxidant capacity (T-AOC), and glutathione peroxidase (GPx) activity in the gills of M. modiolus were significant (Two-Way ANOVA; p < 0.05). Our results suggested that temperature and salinity significantly affect the survival, gill morphology, and antioxidant capabilities of M. modiolus. Our findings not only enrich our knowledge of the interactions between temperature and salinity with respect to shellfish but also provide a framework for M. modiolus aquaculture development.