First record of stonefish metabolism: baseline respiration and spontaneous activity of tropical marine Synanceia verrucosa

ABSTRACT

For the first time oxygen consumption and spontaneous activity of 16 individuals of stonefish Synanceia verrucosa were determined simultaneously. The experiments were conducted in an intermittent-flow respirometer at 25°C, and salinity (PSU 32). Continuous measurements of fish activity and oxygen consumption were combined in order to calculate routine (RMR) and standard metabolic rate (SMR) and at the same time quantify spontaneous activity. The relationship between RMR and activity was found to be highly significant (P < 0.001). Relative SMR values varied between 24.0 and 54.4 mg O₂ h⁻¹ kg wet mass⁻¹ for large (> 500 g) and small (102–394 g) specimens, respectively. Spontaneous activity rates ranged between 4–6 and 40–75 movements h⁻¹ (mean), for large and small specimens, respectively. Absolute SMR for a standard mass of 100 g was calculated to be 3.58 mg O₂ h⁻¹, using a wet mass vs. oxygen consumption relationship of SMR [mg O₂ h⁻¹] = 0.0643*WM [g] ^0.873. The investigated stonefish is so far the most motionless fish found in coral reef/mangrove areas, with activity levels much lower than closely related scorpionfish (Scorpaenidae), and scorpaenids from lower latitudes (e.g. sculpins). SMR of fish in this study was extremely low in comparison with other marine tropical species.

KEYWORDS:

• Oxygen consumption rate
• scorpionfish
• physiology
• temperature
• Scorpaenidae
• SMR
• RMR

Acknowledgements

The support of Stefanie Bröhl in conducting experiments is gratefully acknowledged. Thanks also to Christian Brandt for logistic support in ZMT and anonymous reviewers for improving the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author.

Author contributions

AK conceived the study, conducted the experiments, analysed the data and wrote the manuscript.

Additional information

Animal Ethics: Animal ethics approval was granted from Der Senator für Gesundheit (Title: Temperaturabhängigkeit von Korallenrifffischen) and all experiments were performed according to the relevant guidelines and regulations.

Notes

1 Specimens larger than 2 kg are extremely rare, therefore only one specimen could be located.

Additional information

Funding

This work was supported by ZMT inhouse funding, CC 6800: [Grant Number CC 6800].