Staurophora mertensii Brandt in the Firth of Clyde

Abstract

IT may be of interest to record the occurrence of considerable numbers of the arctic Leptomedusan, Staurophora mertensii Brandt¹, in the Firth of Clyde during the summer of 1951. Only two specimens have actually been examined; but reports were received on several occasions of medusæ described as having cruciform gonads of dark brown or black colour and 5–6 cm. in diameter when first seen at the end of May, increasing later to more than 15 cm. Since no other medusa with cruciform gonads exceeds about 5 cm. in diameter, there can be little doubt that these medusæ were Staurophora. From these reports it appears to have been common in the water around Bute and the Cumbraes from May to July; but it may have been more widely distributed, since one of the specimens examined was taken on May 30 ten miles south of Ailsa Craig, that is, nearly fortyfive miles south of Millport.