Pseudopecoeloides lesteri Aken'Ova & Cribb & Bray 2009

Autor: Aken'Ova, Thelma, Cribb, Thomas, Bray, Rodney
Rok vydání: 2009
Předmět:
DOI: 10.5281/zenodo.3792603
Popis: Pseudopecoeloides lesteri Aken’Ova, Cribb & Bray, sp. n. urn:lsid:zoobank.org:act: D5F80409-0968-4CFD-BC49-C8471ED6B9A2 Type-host: Pseudocaranx dentex (Bloch & Schneider) (Carangidae: Perciformes), white trevally. Other host: Pseudocaranx wrighti (Whitley) (Carangidae: Perciformes), skipjack trevally. Type-locality: Off Kingscote, Kangaroo Island, South Australia, 35°40’S, 137°39’E, December 1995. Other locality: Off North Mole, Fremantle, Western Australia, 32°03’S, 115°43’E, December 1994. * values derived from measuring published figures directly or calculated from published measurements. Site: Intestine. Material studied: Ex Pseudocaranx dentex: 4 off Kingscote; ex Pseudocaranx wrighti: 2 off North Mole. Type-material: Holotype: Queensland Museum, Reg. No. QM G 230452, paratypes: Queensland Museum, Reg. Nos QM G 230453 -4, BMNH Reg. No 2008.12.9.7-8. Description (Figures 7 -11): Based on 6 gravid, unflattened, laterally mounted worms from Pseudocaranx dentex and P. wrighti and 1 set of sagittal serial sections. Measurements are based on 3 gravid, unflattened, laterally mounted specimens from P. dentex; measurements of worms from P. wrighti are given in Table 3. Body elongate, slender, subcylindrical; maximum width in region of gonads, 1,373 -1,587 (1,482) × 158-170 (163); width to length ratio 1:8.5-10.0 (9.1). Oral sucker spherical to subspherical, opening nearly terminal, 85-95 (89) × 84-89 (86). Ventral sucker pedunculate, close to anterior end, larger than oral sucker, subspherical, 105-107 (106) × 119-125 (123); sucker width ratio 1:1.4-1.5 (1.4). Ventral sucker peduncle short, broad, 218-232 (225) × 132-158 (145), 14.6-15.9 (15.2) % of body length. Forebody relatively short, contains numerous gland cells, 261-323 (296) long, 19.0-21.7 (19.9) % of body length; peduncle to forebody length ratio 1:1.2-1.3 (1.3). Prepharynx distinct, short, feebly developed. Pharynx large, spherical to subspherical, 67-77 (72) × 76-77 (76); pharynx to oral sucker width ratio 1:1.1-1.2 (1.1). Oesophagus short, thin walled, surrounded by gland cells. Intestinal bifurcation dorsal to ventral sucker, 8-49 (28) posterior to anterior margin of ventral sucker peduncle. Caeca long, open into excretory vesicle close to posterior extremity to form uroproct (Figure 9). Testes 2, entire, subspherical, usually separated, contiguous in one specimen, tandem, in posterior half of body; anterior 136-147 (141) × 94-125 (113); posterior 146-165 (159) × 104-129 (120). Post-testicular area 289-384 (325) long, 19.4-24.2 (21.9) % of body length. Cirrus-sac absent. Seminal vesicle long, tubular, narrow and convoluted anteriorly, large and vesicular posteriorly; posterior portion 100-107 (103) × 50-60 (55). Pars prostatica distinct, large, surrounded by gland cells. Ejaculatory duct thick-walled, with distinct sphincter at anterior extremity (see Figure 8), surrounded by gland cells. Genital atrium small. Genital pore antero-sinistral to intestinal bifurcation, close to anterior extremity, 124-133 (129) from anterior end, 8.4-9.0 (8.7) % of body length. Ovary pre-testicular, entire, usually contiguous with anterior testis, separate in 1 specimen, spherical to subspherical, 71-77 (74) × 67-73 (69). Mehlis’ gland distinct, anterior to antero-dorsal to ovary. Uterine seminal receptacle present. Laurer’s canal present, thick-walled, opens dorso-sinistrally to ovary, at about level of its anterior margin. Metraterm distinct, thick-walled, with distinct sphincter at anterior extremity, surrounded by gland cells; thick-walled muscular structure appears to enclose anterior extremities of ejaculatory duct and metraterm (Figure 8). Eggs relatively large, operculate, 64-75 (69) × 27-44 (34). Vitelline follicles restricted to hindbody, extend from 499-623 (553) from anterior extremity, 33.8-41.9 (37.3) % of body length, to 26-40 (35) from posterior extremity; fields confluent dorsally and ventrally in post-testicular area, dorsally or not between posterior margin of posterior testis and anterior limit with interruptions in areas around gonads, separate ventrally, with follicles lying lateral, ventral and dorsal to caeca; anterior limit slightly posterior to posterior margin of seminal vesicle. Excretory pore terminal. Excretory vesicle I-shaped, long; posterior extremity forms short narrow duct surrounded by gland cells; vesicle reaches to ovary. Etymology: This species is named for Professor R. J. G. Lester for his contributions to marine parasitology. Comments: The specimens from Pseudocaranx wrighti are almost identical to those from P. dentex in general appearance and in all metrical features (Tables 2, 3) and are considered to be conspecific. Pseudopecoeloides lesteri sp. n. can be accommodated in Group B. P. mugilis and P. gracilis can immediately be distinguished from all the other worms in the group; P. mugilis has the shortest post-testicular area relative to the body length and P. gracilis is the least elongate and has the largest ventral sucker relative to the size of the oral sucker (Table 2). P. lesteri can be distinguished from the remaining species by its greater sucker ratio, larger pharynx relative to the oral sucker, longer forebody and shorter post-testicular area relative to the body length. It is more elongate than P. akule but less so than P. scomberi, as shown in their length/width ratios. The genital pore of the new species is more posteriorly situated than in P. scomberi (Table 2).
Published as part of Aken'Ova, Thelma, Cribb, Thomas & Bray, Rodney, 2009, Seven species of Pseudopecoeloides Yamaguti, 1940 (Digenea, Opecoelidae) from temperate marine fishes of Australia, including five new species, pp. 1-32 in ZooKeys 5 (5) on pages 9-15, DOI: 10.3897/zookeys.5.54, http://zenodo.org/record/576427
{"references":["Parukhin, AM (1983) [New species of trematodes from commercial fishes of the Indian Ocean.] Zoologicheskii Zhurnal 62: 1106 - 1108. (In Russian).","Yamaguti S (1970) Digenetic trematodes of Hawaiian fishes. Keigaku, Tokyo, 436 pp.","Bartoli P, Bray RA, Gibson DI (2003) Opecoelidae (Digenea) from western Mediterranean fishes: three rare species. Systematic Parasitology 55: 81 - 95."]}
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