Redescription of two species of cystidicolid nematodes (Spirurina: Cystidicolidae) from Notopterus notopterus (Osteichthyes) in Thailand

摘要

Two nematode species, Pseudoproleptus notopteri (Karve et Naik, 1951) and Spinitectus notopteri Karve et Naik, 1951 (both Cystidicolidae), are redescribed based on light and scanning electron microscopical studies of specimens collected from the digestive tract of the freshwater fish Notopterus notopterus (Pallas) (Notopteridae, Osteoglossiformes) in Thailand. Some new important morphological features, such as a detailed structure of the cephalic end and the presence of bifurcate deirids and a ventral median caudal protuberance in male, are reported for the former species (P. notopteri), which is provisionally assigned to Pseudoproleptus Khera, 1955; Notopteroides notopteri Chakravarty et Majumdar, 1962, Pseudoproleptus satendri Sahay, 1967, P. lamyi Le-Van-Hoa et Bui-Thi Lien-Huong, 1969, P. gomtii Gupta et Bakshi, 1984. P. sprenti Gupta et Masoodi, 1986 and P. thapari Gupta et Naiyer, 1992 are considered its junior synonyms. The first study of S. notopteri by SEM showed its morphological similarity with S. mastacembeli Karve et Naik, 1951, from which it clearly differs by the structure of eggs; Spinitectus alii Kalyankar, 1970, S. bengalensis Chakravarty, Sain et Majumdar, 1961, S. gomalensis Siddiqui et Kattak, 1984 and S. thapari Ali, 1957 are considered to be junior synonyms of S. notopteri. Pseudoproleptus notopteri and Spinitectus notopteri are reported from Thailand for the first time.