The Influence of Adult Conspecifics and Shore Level on Recruitment of the Ribbed Mussel Geukensia demissa (Dillwyn)

The roles of recruitment variability and adult conspecifics on the distribution of Geukensia demissa (Dillwyn) in a Spartina alterniflora (Loisel) marsh were examined in a field study. Recruitment to experimental collectors was compared to recruitment onto the marsh surface at three shore levels. Peak recruitment of mussels in the smallest size class (O-5 mm) occurred in October. Recruitment was greatest on the marsh edge and to collectors containing adult mussels, suggesting that larval mussels either preferentially settle or have higher survivorship among adult conspecifics. Mussels in the largest size class (5- 15 mm) recruited to collectors in early July suggesting that the previous year's cohort was still actively involved in post-settlement microhabitat selection.