THE FUNCTIONAL ROLE OF ASTERIAS VULGARIS VERRILL (1866) IN THREE SUBTIDAL COMMUNITIES
type: CreativeWork
description: The functional role of Asterias vulgaris has been investigated in three subtidal communities at the Isles of Shoals, New Hampshire, U.S.A., from 1975 to 1980. The three communities are located at depths of 8 m, 18 m, and 30 m along a transect from the intertidal to a depth of 35 meters on rocky substrate of an exposed shore. Components of the study based on in-situ observations included an analysis of population structures, feeding biology, flux rates, predators and natural history of Asterias vulgaris in the 3 communities. The feeding data shows a series of prey specializations by size such that a progression of specialization on increasingly larger prey seems to be required for the species to grow larger (i.e. ectoprocts to hydroids to small gastropods to echinoids . . . to bivalves for the largest individuals). The communities at 8 m and 30 m contain a variety of prey that are utilized, and normally distributed population structures of asteroids are found. The middle community at 18 m is anomalous in several ways; fewer asteroids are feeding at 18 m, a small species of Leptasterias is present in high densities which may be a direct competitor for food as well as a predator upon Asterias vulgaris, especially at the most critical small sizes, and the resulting population structure is strongly skewed to very small individuals, 90% of which are Leptasterias sp. The giant Asterias vulgaris, found only at 18 m feed almost exclusively on large Modiolus modiolus, and are probably migrants into the community from deeper, soft-substrate communities. Asterias vulgaris is a generalist species found in a wide range of communities, consuming the prey available in a community in relation to its size-limited abilities. Its role in the 3 communities is not that of a major structuring or controlling factor, but rather it is itself controlled by the characteristics of the community. Most of the species in the low diversity Gulf of Maine are opportunistic in nature and not competiti…
abstract: The functional role of Asterias vulgaris has been investigated in three subtidal communities at the Isles of Shoals, New Hampshire, U.S.A., from 1975 to 1980. The three communities are located at depths of 8 m, 18 m, and 30 m along a transect from the intertidal to a depth of 35 meters on rocky substrate of an exposed shore. Components of the study based on in-situ observations included an analysis of population structures, feeding biology, flux rates, predators and natural history of Asterias vulgaris in the 3 communities. The feeding data shows a series of prey specializations by size such that a progression of specialization on increasingly larger prey seems to be required for the species to grow larger (i.e. ectoprocts to hydroids to small gastropods to echinoids . . . to bivalves for the largest individuals). The communities at 8 m and 30 m contain a variety of prey that are utilized, and normally distributed population structures of asteroids are found. The middle community at 18 m is anomalous in several ways; fewer asteroids are feeding at 18 m, a small species of Leptasterias is present in high densities which may be a direct competitor for food as well as a predator upon Asterias vulgaris, especially at the most critical small sizes, and the resulting population structure is strongly skewed to very small individuals, 90% of which are Leptasterias sp. The giant Asterias vulgaris, found only at 18 m feed almost exclusively on large Modiolus modiolus, and are probably migrants into the community from deeper, soft-substrate communities. Asterias vulgaris is a generalist species found in a wide range of communities, consuming the prey available in a community in relation to its size-limited abilities. Its role in the 3 communities is not that of a major structuring or controlling factor, but rather it is itself controlled by the characteristics of the community. Most of the species in the low diversity Gulf of Maine are opportunistic in nature and not competiti…
author: HULBERT, ALAN WILSON
keywords: Biology, Zoology
date published: 1980-01-01T08:00:00Z
date modified: 2026-07-24T05:23:09Z
provider: University of New Hampshire
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of New Hampshire