Cichlidogyrus polyenso Jorissen, 2018

Jorissen, Michiel W. P., Pariselle, Antoine, Huyse, Tine, Vreven, Emmanuel J., Snoeks, Jos, Decru, Eva, Kusters, Thomas, Lunkayilakio, Soleil Wamuini, Bukinga, Fidel Muterezi, Artois, Tom & Vanhove, Maarten P. M., 2018, Six new dactylogyrid species (Platyhelminthes, Monogenea) from the gills of cichlids (Teleostei, Cichliformes) from the Lower Congo Basin, Parasite (Paris, France) 25 (64), pp. 1-21 : 8-10

Cichlidogyrus polyenso Jorissen ,

Pariselle & Vanhove n. sp.

urn:lsid:zoobank.org:act:C1165346-CFFB-45C7-951E-0D3E094084B9Type host: Hemichromis elongatus (Guichenot, 1861) . Infection site: Gills. Type locality: Pond near Kila Kindinga 5° 290700 S 14° 5303.800 E. Material: four whole-mounted specimens in Malmberg’s solution (including the holotype) and two in Hoyer’s medium.

Holotype: M. T. 38330.

Paratypes: M. T. 38314–15, 38332, NHMUK 2018.1 .31.3, KN10050 https://laji.fi/en/view?uri=luomus:KN.10050 .

Symbiotype: RMCA _Vert_2015.030.P.0021.

Paratype host vouchers: RMCA _Vert_2015.030.P.0019, RMCA _Vert_2015.030.P.0020 .

Etymology: Species epithet is derived from Zen Buddhism and the Japanese language where an enso is a hand-drawn circle. This refers to the shape of the penis, as it is coiled. Species epithet consists of a prefix and a noun.

Authorship: Note that the authors of the new taxon are different from the authors of this paper; Article 50.1 and Recommendation 50A of International Code of Zoological Nomenclature [13].

Description ( Table 4 , Figs. 4g –4h , 6 )

Dorsal anchors with guard length four to five times the shaft length. Guard elongated and narrow. Point short (e = 9 µm). Ventral anchors 6 µm smaller than dorsal ones. Base with shallow, but wide indentation. Point long (e = 15 µm). Hooks pair I elongated. Secondary shaft (see [35]) widens gradually and ends rounded. Hooks III-VII short. Dorsal transverse bar slightly concave with narrow auricles that are far apart (y = 23 µm). Ventral transverse bar V-shaped with small extension at 1/3 of the distal ends of each arm. MCO with long tubular penis, which is spirally coiled and makes two to three loops. Distally from the loops, the penis makes a 90° turn and continues straight before ending. Short, rectangular heel with rounded edges (He = 4 µm). Accessory piece attaches to basal bulb, proximally broad but narrows distally of the basal bulb. Accessory piece makes two to three loops within the loops of the penis. Distally from the loops, the accessory piece leaves the space within the loops of the penis, turns 120°, meets the penis again and forms a plate resembling the tail of cetaceans, but with asymmetrical lateral ends and sides. At the proximal side, closest to the basal bulb, the plate is convex and results in a sharp point. The distal side is partially concave and partially convex and ends in a hooklike structure. The penis overshoots the plate and ends further distally. The vagina is large, tubular. Most proximally it corkscrews once, after which it makes a short loop. Soon after this it turns 180° to stack two loops of tube after which it ends distally, shortly after leaving the coil.

Remarks

Cichlidogyrus polyenso n. sp. has multiple characteristics in common with C. euzeti Dossou & Birgi, 1984 . Similarities are that both species have elongated hooks pair I, short hooks pairs III-VII, dorsal anchors with a long guard and short point, ventral anchors with a long point, a spirally-coiled penis, accessory piece and vagina. The major difference with C. euzeti is that the penis of C. polyenso n. sp. has fewer coils, two to three, rather than the four to five in C. euzeti , and is shorter in length. Moreover, the accessory piece is less coiled. Additionally, the vagina in C. polyenso n. sp. is more compacted, because it coils, while the vagina of C. euzeti is a long tube that winds, but never coils. Also, C. polyenso n. sp. has slightly larger ventral anchors (b = 38 µm, e = 15 µm) and hooks (I = 43 µm, V = 24 µm) than does C. euzeti (b = 30–35 µm, e = 10–12 µm, I = 35–40 µm, V = 15–20 µm). Cichlidogyrus euzeti is reported from Benin and Cameroon [6, 22] and the ROC [35]. Other species that have a similar sclerite morphology are C. longicirrus Paperna, 1965 and C. sanseoi Pariselle & Euzet, 2004 , both from H. fasciatus Peters, 1858 and the former from Chromidotilapia guentheri (Sauvage, 1882) as well, but both parasites have a longer MCO with more coils than do C. polyenso n. sp. and C. euzeti .

Figures

Figure 4. Compound micrographs of (a–c) Cichlidogyrus bixlerzavalai n. sp. from Tylochromis praecox: haptor of holotype (a), MCO of holotype (b) and MCO of paratype (c); of (d–f) Cichlidogyrus calycinus n. sp. from Hemichromis elongatus: haptor of holotype (d), MCO of holotype (e), vagina of holotype (f); of (g–h) Cichlidogyrus polyenso n. sp. from Hemichromis elongatus: haptor (g), MCO (h). Scale bar 20 µm, except for (g) 50 µm.

Figure 6. Haptoral and genital hard parts of Cichlidogyrus polyenso n. sp. from Hemichromis elongatus. Accessory piece of the MCO in grey, to highlight the plate-like structure of the accessory piece. I–VII, hooks; AP, accessory piece; DA, dorsal anchors; DB, dorsal transverse bar; MCO, male copulatory organ; Pe, penis; VA, ventral anchors; VB, ventral transverse bar; Vg, vagina. Scale bar: 20 µm.