Publication Abstract

Growth of the introduced razor-fish Ensis directus on the east coast of England

D.W. Palmer

Evidence from grab surveys conducted by CEFAS found that the introduced species Ensis directus was by far the most common razor-fish within the Wash and North Norfolk candidate Special Area of Conservation (cSAC). Following development of an experimental hydraulic dredge fishery for razor-fish (Ensis spp.), environmental concerns led to a ban being imposed within the cSAC. Shell samples collected from these surveys and from experimental dredging showed clear marks interpreted as annual growth bands. This interpretation was confirmed by following the growth of individual year-classes over several years and by the microscopic examination of shell sections. The shell length at each annual mark was measured and von Bertalanffy growth parameters estimated for E.directus on a number of grounds. Within the study area, populations appear to be slow growing compared to those studied elsewhere in Europe. This species appears to be short lived when compared with native species of razor-fish.

Reference:

D.W. Palmer (2004) Growth of the introduced razor-fish Ensis directus on the east coast of England.Journal of the Marine Biological Association, 84: 1075-1076