Six Species of Lepidapedon Stafford, 1904 (Trematoda: Lepocreadiidae) from Deep-Sea Fishes

Abstract

Five new species and a new subspecies from deep-sea fishes (800 to 2,860 m) off Oregon are placed in the genus Lepidapedon: L. antimorae from Antimora rostrata; L. filiformis from Chalinura filifera; L. cascadensis, L. yaquina, and L. oregonensis from C. filifera and C. serrula; and L. luteum abyssensis from C. filifera, C. serrula, Hemimacrurus acrolepis, and Nematonurus longifilis. All new species have excretory bladders which reach only to the posterior edge of the hind testis and a key to the short-bladdered members of the species is presented. Lepidapedon elongatum reported from a variety of hosts and locations may be a composite of several species and should be restudied. Six species of Lepidapedon Stafford, 1904, were found in deep-sea fishes (Table I) collected in otter trawls off the coast of Oregon (Lat. 44? to 45? N, Long. 124? to 128? W). The fish were preserved at sea by injecting the mouth and anus with AFA and preserving them in 10% seawater-formalin as described by Eagle and McCauley (1965), and were later examined in the shore laboratory. Temperature data were not taken with the collections, but unpublished data from the Department of Oceanography, Oregon State University indicate the following low temperatures: 800 m depth, 4.00 C (3.80 to 4.12) 1,500 m depth, 2.49 C (2.42 to 2.55) 2,500 m depth, 1.76 C (1.75 to 1.78) These data are derived from three deep-sea stations sampled monthly for 18 months. Twenty-nine species have been placed in the genus: Lepidapedon rachion (Cobbold, 1858) Stafford, 1904; L. elongatum (Lebour, 1908) Nicoll, 1915; L. garrardi (Leiper and Atkinson, 1914) Manter, 1926; L. nicolli Manter, 1934; L. lebouri Manter, 1934; L. genge Yamaguti, 1938; L. sebastisci Yamaguti, 1938; L. gadi (Yamaguti, 1934) Yamaguti, 1938; L. coelorhynchi Yamaguti, 1938; L. luteum Yamaguti, 1938; L. hoplognathi Yamaguti, 1938; L. clavatum Linton, 1940; L. hancocki Manter, 1940; L. pugetensis Acena, 1947; L. calli Acena, 1947; L. levenseni (Linton, 1907) Manter, 1947; L. trachinoti Hanson, 1950; L. gymnacanthi (Issaitschikow, 1928) Yamaguti, 1954; L. microcotyleum (Odhner, mss.) Dollfus, 1953; L. australis Manter, 1954; L. congeri Manter, 1954; L. epinepheli BravoReceived for publication 9 February 1968. Hollis and Manter, 1957; L. truncatum Sogandares-Bernal, 1959; L. parepinepheli Sogandares-Bernal, 1959; L. holocentri Siddiqi and Cable, 1960; L. ptochus (Nicoll, 1915) Skrjabin and Koval, 1960; L. antarcticus Byrd, 1963; L. cambrensis Srivastava, 1966, and L. megalaspi Paruchin, 1966. In addition to these, McCauley, 1964, described a variety, L. luteium var. abyssensis. Manter (1954) transferred L. sebastisci and L. hoplognathi to Neolepidapedon. Hanson (1950) suppressed L. coelorhynchi and L. gadi and Ching (1961) suppressed L. pugetensis, all as synonyms of L. elongatum. Srivastava (1966) restudied the status of L. gadi and believes it to be valid. He also thought that L. microcotyleum is a synonym of L. gadi. McCauley (1964) suppressed L. holocentri as a synonym of L. truncatum and Nahhas and Cable (1964) concurred. Both Hanson (1950) and Byrd (1963) considered L. garrardi as incertae sedis. Ching (1960) considered L. clavatum as incertae sedis but Srivastava (1966) included it in his key without comment. Linton's (1940) description of L. clavatum lacks a discussion of the details of the seminal vesicle and I agree with Ching in considering it incertae sedis. Srivastava (1966) excluded L. ptochus from consideration until more is known. At the present, 20 species are accepted in this genus. This paper adds five new species and a new subspecies. Six species of Lepidapedon were found in five species of fishes: the gadid Antimora rostrata; and four macrourids; Chalinura filifera; C. serrula; Hemimacrurus acrolepis; and Nematonurus longifilis. The taxonomy of the macrourids is still in a state of flux and the