Cichlidogyrus sigmocirrus, Pariselle, Antoine, Bitja Nyom, Arnold R. & Bilong Bilong, Charles F., 2014

Pariselle, Antoine, Bitja Nyom, Arnold R. & Bilong Bilong, Charles F., 2014, Four new species of Cichlidogyrus (Monogenea, Ancyrocephalidae) from Sarotherodon mvogoi and Tylochromis sudanensis (Teleostei, Cichlidae) in Cameroon, Zootaxa 3881 (3), pp. 258-266 : 261

Cichlidogyrus sigmocirrus n. sp.

( Fig. 3 )

Type host. Tylochromis sudanensis Daget.

Site. Gills.

Type locality. Cross River at Mamfé Cameroon (05°45'58" N; 9°18'38" E).

Other locality. Munaya River (Cross River tributary) at Akwen Bridge, Cameroon (05°45'50" N; 9°03'39" E).

Specimens deposited. Holotype n° 37772 and 6 paratypes n° 37774 RMCA; 6 paratypes n° HEL 512 MNHN.

Etymology. Refers to the sigmoid shape of the penis.

Description (based on 20 individuals). Adults 562 (466–650, 20) long. 105 (79–154, 20) wide at level of ovary. Pharynx globular 42 (32–48, 20) in diameter. Dorsal anchor with guard three times longer than shaft, blade regularly curved and hollow on the first two thirds: a = 35 ± 1.1 (32–37, 40), b = 32 ± 0.9 (30–33, 40), c = 3 ± 0.8 (1–5, 40), d = 9 ± 0.9 (7–11, 40), e = 10 ± 0.8 (8–12, 40). Thin and strongly arched dorsal transverse bar, very short auricles: x = 40 (32–48, 20), w = 4 (4–5, 20), y = 13 (12–16, 20), h = 7 ± 0.9 (5–9, 40). Ventral anchor similar to dorsal one but slightly smaller: a = 31 ± 0.8 (29–33, 39), b = 30 ± 0.7 (28–31, 39), c = 3 ± 0.7 (2–5, 39), d = 9 ± 0.7 (7–11, 39), e = 12 ± 0.9 (9–13, 39). Long, thin and V–shaped ventral transverse bar: x = 39 ± 1.7 (35–42, 40), w = 4 (3–5, 20). First and third to seventh marginal hook short: Mh I = 14 ± 0.5 (13–16, 39), Mh II = 12 ± 0.7 (10–13, 30), Mh III = 20 ± 1.1 (17–22, 34), Mh IV = 23 ± 0.9 (21–25, 35), Mh V = 24 ± 1 (21–26, 39), Mh VI = 22 ± 0.9 (20–25, 39), Mh VII = 21 ± 1 (18–23, 36). Tubular sinuous (slightly spirally coiled) penis starting in a bulb with reduced heel, accessory piece is a spirally coiled (1.5 turn) band wrapped round the penis and attached to the penis basal bulb by a very thin filament: Pe = 54 (49–60, 20), He = 2 (2–3, 20), AP = 44 (36–54, 20). No visible vagina.

Remarks. This new species resembles its five congeners already described from species of Tylochromis Regan, 1920 [i.e. Cichlidogyrus berrebii Pariselle & Euzet, 1994 ; Cichlidogyrus kothiasi Pariselle & Euzet, 1994 ; Cichlidogyrus pouyaudi Pariselle & Euzet, 1994 ; Cichlidogyrus mulimbwai Muterezi Bukinga, Vanhove, Van Steenberge & Pariselle, 2012 and Cichlidogyrus muzumanii Muterezi Bukinga, Vanhove, Van Steenberge & Pariselle, 2012 ]; in having small auricles of the dorsal transverse bar (described as ‘two small, hollow outgrowths on the anterior convex face’ by Pariselle & Euzet 1994). Its penis is not clearly spirally coiled and its accessory piece seems to be linked to the basal bulb of the penis by a thin filament, these features have not been mentioned for the other species harboured by Tylochromis spp., but they are hardly discernible. Cichlidogyrus sigmocirrus n. sp. resembles C. pouyaudi , C. berrebii , C. mulimbwai in having marginal hook I of small size (14 µm, 12.3 µm, 13.1 µm and 15 µm, respectively), while C. kothiasi and C. muzumanii have a more developed marginal hook pair I (20.6 µm and 24 µm, respectively). By the shape of the penis C. sigmocirrus n. sp. is easily distinguishable from C. mulimbwai : reduced heel (2 µm) and 41 µm long vs. developed heel (9 µm) and 54 µm, respectively. By the shape of the penis and that of the accessory piece (AP) C. sigmocirrus n. sp. is easily distinguishable from C. berrebii : reduced heel and AP a large ribbon vs. developed heel (massive) and AP a thinner ribbon, respectively, and from C. pouyaudi : reduced heel and smooth ending of AP vs. long heel and thickened AP with ending forming a beak, respectively.

Figures

FIGURE 3. Haptoral and genital hard parts of Cichlidogyrus sigmocirrus n. sp.. Ap, accessory piece; DB, dorsal transverse bar; DA, dorsal anchor; He, heel; Pe, penis; VA, ventral anchor; VB, ventral transverse bar; I to VII, marginal hooks. Scale bar = 20 µm.