Respiratory responses to temperature and hypoxia in the nonindigenous Brown Mussel, Perna perna (Bivalvia: Mytilidae), from the Gulf of Mexico

• Published in: Journal of experimental marine biology and ecology 2002-09, Vol.277 (1), p.61-78
• Main Authors: Hicks, David W, McMahon, Robert F
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Autoecology; Biological and medical sciences; Brown mussel; Fundamental and applied biological sciences. Psychology; Hypoxia; Nonindigenous species; Oxygen regulation; Perna perna; Protozoa. Invertebrata; Respiration; Temperature; Temperature acclimation
• ISSN: 0022-0981; 1879-1697
• DOI: 10.1016/S0022-0981(02)00276-9

The respiratory responses to increasing temperature and progressive hypoxia were examined relative to temperature acclimation in the nonindigenous, brown mussel, Perna perna (Mytilidae) from the Gulf of Mexico. When oxygen uptake rate ( V̇ O 2 ) was recorded at near full air O 2 saturation, rate–temperature curves for Texas specimens of P. perna were sigmoidal, V̇ O 2 generally increasing with increasing temperature but becoming suppressed as temperatures approached 10 and 30 °C, corresponding closely to this species' incipient thermal limits. At each tested temperature, V̇ O 2 did not differ among individuals acclimated to 15, 20, or 25 °C. Lack of thermal acclimation was also reflected in acclimatory Q 10 values>1.0 (range=1.34–2.14) recorded across acclimation groups at test temperatures equivalent to acclimation temperature. Low acute respiratory Q 10 values in all acclimation groups across 15–20 °C indicated a limited capacity for thermal regulation of V̇ O 2 within this temperature range. The ability of P. perna to regulate O 2 uptake with progressive hypoxia was temperature-dependent, increasing from poor O 2 regulation at 10 °C to good regulation at 30 °C. The O 2 regulatory ability of P. perna and other open-water mytilids in declining O 2 concentrations does not greatly differ from that of estuarine heterodont bivalves, suggesting that it is not a major factor preventing open-water species, such as P. perna, from invading estuarine environments. However, P. perna's inability to regulate O 2 uptake at temperatures>25 °C combined with its relatively low upper thermal limit of 30 °C will likely prevent it from establishing permanent estuarine populations on Gulf of Mexico shores.