Cichlidogyrus calycinus Kusters, Jorissen, Pariselle & Vanhove, 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 : 5-8

Cichlidogyrus calycinus Kusters, Jorissen, Pariselle & Vanhove n. sp.

urn:lsid:zoobank.org:act:D4922EBE-7FBE-425C-BBF0-

C90E39DB7171 Type host: Hemichromis elongatus (Guichenot, 1861) . Infection site: Gills. Type locality: Pond near Kila Kindinga 5° 290700 S

14° 5303.800 E.

Other localities: Mvuazi River (Lower Congo) 5° 190 S 15° 70 E.

Material: Fifteen whole-mounted specimens of which six are fixed in Hoyer’s medium (including the holotype), the other nine in Malmberg’s solution.

Holotype: M. T. 38316.

Paratypes: M. T. 38312–13, 38317–18, 38321, 38326, 38329, 38331, 38333, 38335, KN10046–47, https://laji.fi/en/view?uri= luomus:KN.10046 and https://laji.fi/en/view?uri=luomus:KN. 10047 , SAMC-A090066 , NHMUK 2018.1.31.1.

Symbiotype: RMCA _Vert_2015.030.P.0020.

Paratype host vouchers: RMCA _Vert_2015.030.P.0019, RMCA _Vert_2015.030.P.0021, RMCA _Vert_2015.030.P.0022 .

Etymology: The species epithet in Latin refers to the cup-shaped distal end of the vagina (calyx, Latin: cup) and is an adjective.

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. 4d–4f , 5 )

Dorsal anchors, with long guard (d = 17 µm), which is more than twice the shaft length (d = 7 µm). Blade long and curved. Ventral anchors on average 4 µm smaller than dorsal anchors, but with longer point. Hooks I and V long. Hooks III –IV and VII–VII sometimes long, sometimes short. Ventral transverse bar with small extension at distal third of each arm. Dorsal transverse bar slightly concave, with developed, but rather short auricles (h = 15 µm). Penis long, thin, tubular and makes a long turn of almost 360° after leaving the basal bulb and ends near the middle of the distal plate of the accessory piece. Heel oval. Accessory piece proximally broader than penis and with bean-shaped extension at one sixth of the length, where accessory piece and penis meet. Further distally,

C. dracolemma . All measurements in µm as M. W. P. Jorissen et al.: Parasite 2018, 25, 64

7

the accessory piece narrows to the width of the penis and follows its trajectory, but ends further distally. Accessory piece ends distally in an irregularly-shaped plate. Distal plate with separate elongated structure in the middle. The plate itself is twice as long as it is broad and with rounded edges. Elongated structure longer than plate and reaches further proximally than plate. Proximal from where the elongation overshoots the plate, it touches the penis and narrow part of the accessory piece. Vagina large and tubular. Distally, the vagina has a forcepsshaped structure, engulfed by a semi-hollow structure, which resembles the cup of a flower. More proximally, the forceps-like structure thickens after which it narrows into a long and narrow tube. At the proximal end, the vagina makes a loop and broadens slightly.

Remarks

In general, the morphology of the haptor of species of Cichlidogyrus that infect species of Hemichromis hardly varies [22, 34]. Thus, the morphology and measurements of the haptoral sclerites of C. calycinus n. sp. are nearly identical to that of C. teugelsi Pariselle & Euzet, 2004 . The main distinction in these structures is that the dorsal bar of C. calycinus n. sp. is larger (x = 40 µm, 31–55 µm, n = 15) than that of C. teugelsi (x = 35 µm, 32–38 µm, n = 30). The major morphological differences between the two are found on the MCO and vagina. Both have a long tubular penis that almost makes a 360° turn and an accessory piece with a bean-shaped extension at 1/6 of its length. Both species differ at the distal end of the accessory piece. In C. teugelsi , at the distal end the accessory piece makes a loop, while in C. calycinus n. sp. it forms an irregularly-shaped plate with an elongated structure attached to it. Furthermore, the narrow part of the accessory piece in C. calycinus n. sp. reaches further distally than that in C. teugelsi , which broadens and forms the loop structure at 5/6 of the length of the penis. Also, the accessory piece is on average 22 µm longer in C. teugelsi than in C. calycinus n. sp., while the penes differ 5 µm in length, with C. calycinus n. sp. having the longer one (Pe = 104 µm). The heel of C. teugelsi is irregularly shaped, whilst that of C. calycinus n. sp. is oval shaped. In some specimens of C. calycinus n. sp., the heel seemed longer. The vaginae of both species are also similar in morphology and size as they are long, tubular structures that make a loop at their proximal end. However, the distal ends are different. In C. teugelsi the distal end is a slightly sclerotized plate, while in C. calycinus n. sp. there is a forceps-like structure and an overall cup shape.

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 5. Haptoral and genital hard parts of Cichlidogyrus calycinus 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.