A new species of Lumbricillus, with a revised check-list of the British Enchytraeidae [Oligochaeta

Abstract

A new species of enchytraeid worm, Lumbricillus christenseni, is described and compared with some closely related members of the genus Lumbricillus.Twelve other species of enchytraeid, recorded in the British Isles for the first time, are listed.The habitats and localities in which these new records have been found in North Wales and Europe are also listed.A revised check-list of the British Enchytraeidae is given.Following the publication (Nielsen & Christensen, 1959) of a critical revision of the taxonomy of European enchytraeids, which resolved much of the confusion in the existing literature, the task of identifying the members of this family has been made much easier. Between 1961 and 1964, during an investigation of the littoral Enchytraeidae of the coasts of Anglesey and the Menai Straits, twelve species of enchytraeid new to the British Isles and one species new to science were identified. The new species, a member of the genus Lumbricillus Ørsted 1844, is hereby named Lumbricillus christenseni, after Dr Bent Christensen of the University Zoological Museum, Copenhagen, in recognition of his contribution to our knowledge of enchytraeid taxonomy.Lumbricillus christenseni sp.nov.Location and habitatThis worm has been found in only one location, namely, Porth Eilian, a small bay at the north-east corner of the island of Anglesey, North Wales. The worm was most common at about high-water mark of the neap tide, in a mixture of sand and pebbles with a sparse covering of undecayed weed. The specimens examined were all taken within 5 cm of the surface. There was a large proportion of mature specimens at the time of collection, that is, late spring and early summer of 1964.