Protoancylodiscoides combesi Bassock Bayiha, Nack & Pariselle

Bassock Bayiha, Etienne D., Nack, Jacques, Pariselle, Antoine & Bilong Bilong, Charles F., 2016, Two new species of gill parasites assigned to Protoancylodiscoides (Monogenea, Ancyrocephalidae) from Chrysichthys spp. (Siluriformes, Claroteidae) in River Sanaga (Cameroon), Zootaxa 4170 (1), pp. 178-186 : 183-184

Protoancylodiscoides combesi Bassock Bayiha, Nack & Pariselle

( Fig. 4 )

Type host. Chrysichthys auratus Geoffroy Saint-Hilaire.

Site. Secondary gill lamellae.

Type locality. Nachtigal (4°21'10.5'' N; 11°37'34.9'' E, alt. 432 m).

Other localities. Mbandjock (4°28'21.3'' N; 11°53'5.7'' E, alt. 543 m), Nanga-Eboko (4°44'36.4'' N; 12°25'41.9'' E, alt. 578 m) and Belabo (4°57'47.3'' N; 13°17'36.1'' E, alt. 615 m).

Other hosts. Chrysichthys nigrodigitatus (Lacépède) and C. longidorsalis Risch & Thys van den Audenaerde.

Prevalence. 66.6% in C. auratus , 3.4% in C. nigrodigitatus and 33.3% in C. longidorsalis .

Mean intensity. 10.2 ± 20 in C. auratus , 5 ± 0 in C. nigrodigitatus and 42 ± 14.2 in C. longidorsalis .

Etymology. The name combesi was given to this species by Dossou in 1985, but not officially published nor illustrated, in honor of Professor C. Combes from the University of Perpignan / France for his great contribution to the knowledge of parasites.

Specimens deposited. 1 Holotype MRAC n° 37931 and 4 paratypes MRAC n° 37932.

Description (based on 31 individuals). Dorsal anchor with long and thick guard, with distal end thinner and outwardly curved, short shaft, and conical blade arched with a long point. Presence of a thick filament. Transverse dorsal bar slightly curved with rounded ends pierced with circular holes. Ventral anchors having short shaft and perpendicularly developed triangular guard with eccentric triangular fenestration. Presence of a diagonal hull and a thick filament attached to its posterior extremity. Blade ending with a short fine tip. Ventral bar made up of two symmetric arms separated medially. Haptoral hooks with the same organization as in the previous species: medioventral hook pairs I [I] and IV [VII] with a thick and long shaft; latero-ventral hooks II [V] and hooks V [IV], VI [III], VII [II] with similar shape and size (thin, without shank); latero-dorsal hooks III [VI] with poorly developed shank. Presence of a longer than wide dorsal onchium. Copulatory complex formed by a tubular penis (Pe) associated with a complex globular oval accessory piece. Vagina sclerotized spiral flared at its base and distal part.

The measurements of haptoral and reproductive systems are provided in Table I.

Remarks. Protoancylodiscoides combesi resembles P. mansourensis , P. chrysichthes and P. auratum by the general morphology of the hard parts of the haptor and of the accessory piece. However, it differs from P. mansourensis by the size of the ventral bar 34 (29–38) vs 41(38–43), of the dorsal anchor 66 (61–73) vs 88 (81–93), and of the penis 228 (132–299) vs 325 (302–347). Protoancylodiscoides combesi also differs from P. mansourensis , P. chrysichthes and P. auratum by the morphology of the vagina which, in P. combesi , is spirally coiled with 2–3 rings (diameter 10 to 13 µm), unlike the other three species where there are 4 to 5 rings for P. mansourensis (diameter 24 to 27 µm), P. chrysichthes (diameter 13 to 20 µm) and P. auratum (diameter 8 to 12 µm). These three species may also be differentiated from one another by the shape of the distal third of the vagina which is coiled in P. chrysichthes , turned up and cup shaped in P. auratum , and straight in P. combesi .

Figures

FIGURE 4. Protoancylodiscoides combesi n. sp.: DB, dorsal bar; VB, ventral bar; DA, dorsal anchor; VA, ventral anchor; I to VII, haptoral hooks; DOn, dorsal onchium; AP, accessory piece; Pe, penis; Vg, vagina. Scale bar = 20 µm. WM, whole mount parasite. Scale bar = 200 µm.