1986/02/01 by ROSINA M. BIERBAUM, Rosina M. Bierbaum, Scott Ferson +1 · 71 citations
Environmental Science · #Aquatic Invertebrate Ecology and Behavior #Biology #Bivalvia #Blue mussel #Botany #Carapace #Condition index #Crustacean #Crustacean biology and ecology #Ecology #Fishery #Infestation #Marine Bivalve and Aquaculture Studies #Mollusca #Mussel #Mytilus #Nutrient #Population #Zoology
paper · pdf · doi:10.2307/1541380
published in Biological Bulletin 170(1), 51-61 (Marine Biological Laboratory (MBL))
openalex publication_date 1986/02/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Pea crabs living within the mantle cavities of a variety of bivalve hosts have several adverse effects. In blue mussels (Mytilus edulis L.), the crab Pinnotheres maculatus (Say) steals food strands and causes gill lesions. We studied the long-term stress of P. maculatus on its host by measuring shell accretion in the field, and by numerically characterizing shell shape. Shell form in M. edulis is presumed to reflect environmental and physiological history. We computed growth increments in infested populations of mussels over a three-month period at two sites with high and low nutrient regimes. When growth was measured by change in shell length, significant differences between mussels with and without large pea crabs occurred at the low nutrient site, but not where mussels enjoyed a high nutrient regime. To integrate very long-term disparity in growth rates associated with infestation, we used mussels from a robust, naturally occurring population. We recorded and analyzed mussel silhouette shapes with a video digitizer. Elliptic Fourier approximation completely characterized the two-dimensional outlines of shells in such a way that the allometric dependence of shape variables on shell size could be easily removed. At this evidently favorable site, infested mussels displayed significant shell shape distortion characteristic of reduced growth rates. Thus, even in apparently benign environments, pea crab infestation appears to be a chronic stress to M. edulis.