Cichlidogyrus kmentovae 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 : 11-12

Cichlidogyrus kmentovae Jorissen ,

Pariselle & Vanhove n. sp.

urn:lsid:zoobank.org:act:8A9E340B-2B30-428E-B994-AB9E296F5DEC

Type host: Hemichromis stellifer Loiselle, 1979 .

Infection site: Gills.

Type locality: Mbola River near Tshianya Village 05° 52009.800 S 12° 39052.600 E.

Material: Six whole-mounted specimens in Malmberg’s solution.

Holotype: M. T. 38338.

Paratypes: M. T. 38336–37, NHMUK 2018.1 .31.5, SAMCA090068 .

Symbiotype: AB53952197.

Etymology: Species epithet refers to biologist Nikol Kmentová ( Czech Republic), an enthusiastic researcher on the monogenean fauna of Lake Tanganyika and is a noun (name) in the genitive case.

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. 7 , 8a–8b )

Dorsal anchors with elongated guard that is four to five times the shaft length. Indentation, smooth, convex up to the shaft. Short point (e = 9 µm). Ventral anchors of same size (a = 32 µm) but with a more robust blade and base. Guard shorter (d = 13 µm). Indentation at the base less convex than in dorsal anchors. Hooks pair I large with broad primary shaft and even broader secondary shafts. Hooks pair IV– V long. Hooks pair VII short. Hooks VI of variable size, some long, some short. Pair III short and sometimes differs less than 0.2 µm from twice the length of II. Dorsal transverse bar slightly concave with short extensions. Auricles developed, but short (h = 9 µm). Ventral transverse bar small (X = 31 µm) and narrow (W = 5 µm) with extension that starts halfway along the course of each arm and reaches almost to the distal tip. MCO large with a long, thin, tubular penis (Pe = 137 µm), which gradually narrows over its course and makes a large turn of 270° at about the middle of its length. More distally, the penis turns 90° and meets the accessory piece. Basal bulb with small rectangular heel with rounded edges (He = 3 µm). Accessory piece departs from the basal bulb and makes a short 180° turn after which it broadens and meets the penis. At the distal end, the accessory piece connects to a semi-circular plate with seven discernible grooves on its surface. At the junction between the semi-circular plate and the rest, two small, sharp extensions protrude towards the semi-circular plate. Vagina consists of a thick-walled bulbous structure connected to a tube.

Remarks

Cichlidogyrus kmentovae n. sp. closely resembles C. amieti Doussou & Birgi, 1983 ; C. bychowskii sensu Paperna, 1965 and C. dracolemma Řehulková, Mendlová & Šimková, 2013 . Cichlidogyrus bychowskii was originally described by Markevitch, 1934 [17] as Ancyrocephalus bychowskii from the Leningrad aquarium from Hemichromis bimaculatus Gill, 1862 . No type material was deposited and a drawing of the MCO and vagina was lacking [17]. However, the penis was described as a long tube that was coiled many times [17]. A redescription of C. bychowskii on new material from Southern Ghana from the same host species followed in 1965 by Paperna [25], this time with a drawing of all sclerotized structures. However, the penis was represented as a long tube that makes one large loop instead of multiple coils. Paperna did not address the difference in morphology of the penis and based his diagnosis on the total length of the animal and the morphology of some haptoral sclerites [25, 41]. Therefore, Messu Mandeng et al., Řehulková et al. [22, 41] and the present authors suspect that Paperna misidentified his specimens, which are different from C. bychowskii and represent a new species. Furthermore, because the description of Markevitch [17] is not sufficient to recognize the animal and fails to illustrate its key characteristics, Cichlidogyrus bychowskii is considered a nomen dubium. It was previously considered a nomen nudum [22], but the term was misused. In Messu Mandeng et al. [22] specimens were found that resembled the species of Paperna, 1965 and were considered as C. cf. bychowskii . The present authors will use C. cf. bychowskii for the specimens described by Paperna, 1965 and collected by Messu Mandeng et al. [22] and stress that the species would need a new name in time, preferably, based on a description of new material. No voucher material was deposited by Paperna [25]. The difference between C. kmentovae n. sp. (L = 29 µm) and C. amieti is that the vagina of C. amieti is longer (L = 65–70 µm from [5]) and the distal plate of the accessory piece is absent. Cichlidogyrus dracolemma and C. cf. bychowskii both have a distal plate, but the vagina of C. dracolemma is longer (L = 46 µm) and thicker than in C. kmentovae n. sp. (L = 29 µm). Both C. dracolemma and C. cf. bychowskii also have a broadened, irregularly-shaped distal plate with a large hook. In C. kmentovae n. sp. the distal plate is semi-circular and has grooves. Cichlidogyrus cf. bychowskii and C. kmentovae n. sp. both have a vagina with a circular, broadened proximal part, from which a thin, tubular structure extends to the genital pore, but in C. cf. bychowskii , this tube makes a 360° loop. With regard to the length of the hooks, there was a categorical size difference in length between pairs III –VII, which is not mentioned in the descriptions of other species. However, the average length of pairs III and VI were short, whilst pairs IV– VI were long for C. cf. bychowskii [22]. In C. kmentovae n. sp., some measurements of hook pair III differed less than 0.2 µm from twice the length of pair II. It is, therefore, not always straightforward to categorize the length of the hooks. Our sample size was limited, and thus a larger dataset of measurements should further clarify the discrepancy in hook lengths.

Figures

Figure 7. Haptoral and genital hard parts of Cichlidogyrus kmentovae n. sp. from Hemichromis stellifer. 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.

Figure 8. DIC micrographs of (a–b) Cichlidogyrus kmentovae n. sp. from Hemichromis stellifer: haptor (a), MCO (b); of (c–d) Cichlidogyrus omari n. sp. from Tylochromis praecox: haptor of holotype (c), MCO of holotype (d); compound micrographs of (e–f) Onchobdella ximenae n. sp. from Hemichromis elongatus: haptor (e), MCO (f). Scale bar 20 µm, except for (e) 50 µm.