Spacing patterns in terebellid polychaetes

Abstract

The spatial distribution of a terebellid polychaete, Thelepus crispus Johnson, living in an intertidal mudflat of San Juan Island, Washington, was examined. Statistical methods, which analyze spatial patterns of polychaete tubes on the mudflat surface, revealed even spacing ( P < 0.00073; 613 individuals). Three models of spatial competition were examined and compared with natural populations. The simplest model, introduced by Pielou (1960), produced distributions of nearest neighbor distances which differed from those measured in actual populations ( P < 0.0033). The two other models, which incorporate different, but more realistic growth dynamics, produced nearest neighbors distances that compare favorably with actual populations.