Fourteen new species of free-living marine nematodes from the Exe estuary

Abstract

Fourteen new species of freeliving interstitial marine nematodes are described from sandy habitats in the Exe estuary area, South Devon. They are all referable to existing genera. Enoplolaimus denticulatus sp. nov. is similar to E. connexus Wieser, 1953, but differs from it principally in the shorter cervical setae of the female, and in the form of the spicules in the male; Mesacanthion africanthijorme sp. nov. is characterized by the absence of a pre-cloacal supplement, by the presence of stout post-cloacal setae in the male, and by the unique structure of the spicules and gubernaculum; Epacanthion gorgonocephalum sp. nov. is related to E. enoploidiformis (Gerlach, 1952) comb. nov. and E. oliffi Inglis, 1966, differing from the former in the possession of a hirsute anterior end, and from the latter in the structure of the male copulatory apparatus and in the setal arrangement on the head; Axonolaimus orcombensis sp. nov. is closest to A. steineri Timm, 1954, but differs from it in the number of subcephalic setae and in the shape of the amphids, gubernaculum and spicules; Leptolaimus ampullaceus sp. nov. is characterized by the number of pre-cloacal supplements, by the structure of the spicules and gubernaculum, and by the presence of longitudinal files of papillae down the body-length; Camacolaimus barbatus sp. nov. is closest to C. prytherchi Chitwood, 1935, but has shorter cephalic setae, no alae on either side of the cloaca, a prominent post-cloacal supplement, lateral papillae in the oesophageal region, and a different setal arrangement on the tail; Paralinhomoeus uniovarium sp. nov. is characterised by its large amphids, long cephalic setae, and by the possession of a single anterior ovary; Theristus (Theristus) denticulatus sp. nov. is characterized by the typically complex structure of the gubernaculum and by the presence of stout ventral spines on the male tail; Theristus (Theristus) interstitialis sp. nov. is characterized by its long cephalic setae, by the position and size of the amphids, and by the structure of the male copulatory apparatus; Theristus (Trichotheristus) psammoides sp. nov. is closest to T. (T.) vicinus Riemann, 1966, but has larger amphids and differently shaped spicules and gubernaculum; Chromaspirina inglisi sp. nov. ( = C. pontica sensu Gerlach, 1951, nee. Filipjev, 1918) is characterized by a uniform covering of fine hairs over the entire body-surface; Microlaimus spirifer sp. nov. is characterized by the position and form of the amphids, by the form of the copulatory apparatus in the male, and by the long tail; Pomponema reducta sp. nov. is characterized by the possession of only six cephalic setae, and by the arrangement of denticles in the buccal cavity; Paracanthonchus opheliae sp. nov. is characterized by the distinctive structure of the gubernaculum and of the spicules.