Body condition and energy content of the shore crab Carcinus maenas L. in a temperate coastal system: the cost of barnacle epibiosis

Abstract

The impact of barnacle epibionts on the condition of the shore crab Carcinus maenas was studied for the western Wadden Sea population. Approximately 39% of the crabs were fouled with the barnacle Balanus crenatus. Although the morphological Fulton’s K condition decreased by 5.8% in fouled crabs, Linear Mixed-Effects Models (LMM) showed that only the energetic condition of the crabs was significantly affected by fouling. The energy density of fouled crabs was consistently poorer (4.1% in AFDW; 8.7% in dry weight) than that of non-fouled crabs, especially in females and green forms in dry weight (12.8% and 11.4% reduction, respectively). Cumulative infection with Sacculina carcini, detected in 4.5% of the fouled crabs, additionally reduced by 14.3% the energy density in dry weight and almost to half of the total energy of the fouled crabs. Impacts of energy density reduction on crabs’ growth and reproduction are discussed.

Keywords:

• Carcinus maenas
• fouling
• energy density
• fitness
• Balanus crenatus
• Wadden Sea

Acknowledgements

The authors acknowledge Sander Holthuijsen from the Royal Netherlands Institute for Sea Research (NIOZ) for his valuable assistance with bomb calorimetry.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was supported by national funds by FCT - Foundation for Science and Technology -, within the scope of UIDB/04423/2020 and UIDP/04423/2020, results from the project ATLANTIDA (ref. NORTE-01-0145-FEDER-000040), and was funded by the project Ocean3R (NORTE-01-0145-FEDER-000064), supported by the North Portugal Regional Operational Programme (NORTE2020), under the PORTUGAL 2020 Partnership Agreement and through the European Regional Development Fund (ERDF).