The life history and morphology of free-living Pilayella littoralis (L.) Kjellm. (Ectocarpaceae, Ectocarpales) in Nahant Bay, Massachusetts

Publisher Website
Google Scholar
Abstract
A previously unreported free-living form of Pilayella is described. During all months of the year, drifting clouds of this plant may carpet up to half of the sandy bottom and beaches of Nahant Bay, a 15 km2 rectangular embayment on the north coast of Massachusetts. Four features distinguish the atypical free-living form from the typical attached form of this species: (1) a ball shape and a concomitant general lack of polarity in the development of the central axes; (2) a polystichous condition present throughout much of the central axes; (3) a dearth of reproductive organs; and (4) a peak summer-time abundance of hundreds of tonnes (live weight). Plant reproduction and growth appear to result from ball fragmentation and subsequent regeneration solely by vegetative cell division. Fragmentation results from seasonal senescence of the filamentous axes and from infection by the marine fungus Eurychasma dicksonii. The Pilayella drift community is characterized by its virtual monospecificity by weight, its great abundance and its persistence since at least the turn of the century.

This publication has 2 references indexed in Scilit: