Protoancylodiscoides auratum 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 : 181-183

Protoancylodiscoides auratum Bassock Bayiha, Nack & Pariselle

( Fig. 3 )

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)

Prevalence. 58% (14 of 24 C. auratus infected).

Mean intensity. 3.4 ± 3.7.

Specimens deposited. Holotype MRAC n° 37929 and paratype MRAC n° 37930.

Etymology. The name auratum refers to the host and has been given to this species by Dossou in 1985, but not officially published (nor illustrated).

Description (based on 21 individuals). The new species belongs to Protoancylodiscoides Paperna, 1969 as diagnosed by N’Douba (2000). Dorsal anchor with long and thick guard (= outer root, superficial root), distal end thinner and outwardly curved; shaft (= handle, inner root, deep root) shorter than guard; sharp and curved blade with thick base; presence of a thick filament. Dorsal transverse bar slightly curved anteriorly; both bilobed extremities separated from the central section by a constriction, anterior lobe with a hook folded medially. Ventral anchors with fenestration between shaft and guard; guard longer than shaft, presence of a hull starting at the front end of the shaft, running diagonally up to the base of the blade, blade ending in a short point; presence of a thick filament fixed to the distal end of the hull. Ventral transverse bar made up of two straight symmetrical arms separated medially. Presence of 7 pairs and 3 types of haptoral hooks according to their shape, size and position: latero-ventral hooks II [V], V [IV], VI [III], VII [II] of similar shape and size [i.e. thin, without shank (= distal subunit)], resembling those present in ancyrocephalid oncomiracidia (larval hook), corresponding to the proximal subunit (= handle + thumb + point) in Kristsky and Kulo (1999); medio-ventral hook pairs I [I] and IV [VII] enlarged with a thick and long shank; latero-dorsal hooks III [VI] with poorly developed shank. Presence of a longer than wider dorsal onchium. Copulatory complex, close to the pharynx, formed by a thin tubular penis (Pe) associated with a very complex globular accessory piece. Vagina coiled at its proximal part, then folded at the anterior part terminating by a cup shaped structure.

The measurements of haptoral and reproductive sclerites are shown in Table 1 .

Specific names P. auratum P. combesi P. mansourensis P. chrysichthes

in El-Naggar (1987) in Kritsky & Kulo (1999) Remarks. By the general morphology of the haptoral sclerites and of the accessory piece, P. a ur a t u m is close to P. mansourensis and P. chrysichthes previously described from C. auratus and C. nigrodigitatus , respectively.

However it differs from P. mansourensis by the size of the ventral bar 36 (32–38) vs 41 (38–43) and of the dorsal anchor 64 (56–70) vs 88 (81–93). Protoancylodiscoides auratum also differs from these two species by the penis length 180 (141–217) vs 325 (302–347) and 255 (162–365) for P. mansourensis and P. chrysichthes respectively, and by the morphology of the vagina: its distal portion is simple but flared in P. mansourensis ; it is turned up and cup shaped in P. auratum , but coiled in P. chrysichthes .

Figures

FIGURE 3. Protoancylodiscoides auratum 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.

Tables

TABLE 1. Measurements of Protoancylodiscoides auratum n. sp., P. combesi n. sp. and the two species already described in the genus Protoancylodiscoides Paperna, 1969 from Chrysichthys spp.

Hosts	C. auratus	C. auratus C. auratus	C. nigrodigitatus
		C. nigrodigitatus C. longidorsalis
Total length	764 (520–925; n=21)	577 (390–872; n=31) 835 (710–1000)	637 (410–884; n=29)
Total width	118 (73–165; n=21)	111 (68–181; n=31) 187 (142–261)	90 (73–115; n=33)
Haptoral length	126 (84–171; n=21)	114 (83–184; n=31) 99 (79–140; n=29)
Haptoral width	147 (99–194; n=21)	121 (87–179; n=31) 94 (74–127; n=23)
Pharyngeal diameter	54 (30–64; n=21)	32 (22–63; n=31) 30 (23–43; n=35)
Peduncle length	11 (7–17; n=21)	12 (7–25; n=31) 30 (23–43; n=35)
Dorsal anchor
a	64(56–70; n=21)	66 (61–73; n=31) 88 (81–93)	64 (55–69; n=10
b	43(39–49; n=21)	50 (44–56; n=31)
c	6(4–9; n=21)	5 (3–6; n=31) 4 (4–5)
d	27 (20–32; n=21)	26 (22–29; n=31) 28 (25–32)
e	22 (18–25; n=21)	23 (20–26; n=31) 24 (22–25)	31 (27–36; n=6)
Dorsal transversal bar
x	37 (33–43; n=21)	37 (33–42; n=31) 45 (40–48)	41 (34–46; n=20)
w	5 (4–7; n=21)	5 (4–7; n=31)
Ventral anchor
a	36 (33–38; n=21)	35 (31–39; n=31) 44 (39–47)	33 (29–38; n=5)
b	34 (33–38; n=21)	31 (27–35; n=31)
c	8 (6–9; n=21)	5(3–7; n=31) 4 (3–4)
d	11 (9–14; n=21)	11 (9–13; n=31) 17 (16–19)
e	17 (14–19; n=21)	19 (16–23; n=31) 22 (19–24)	20 (17–22; n=3)
Ventral transversal bar
x	36 (32–38; n=21)	34 (29–38; n=31) 41 (38–43)	45 (35–69; n=15)
w	4(3–5; n=21)	4 (3–5; n=31)
Uncinuli length
I [I] (médio-ventral)	40 (35–44; n=21)	31 (28–38; n=31) 36 (32–35)	42 (38–45; n=3)
II[V] (latero-ventral)	17 (14–19; n=17)	16 (15–18; n=25) 14 (13–16)	18 (17–19; n=4)
III[VI] (latero-dorsal)	21 (19–22; n=21)	25 (23–27; n=31) 30 (28–32)	23 (20–26; n=6)
IV[VII] (médio-dorsal)	33 (29–35; n=21)	28 (25–31; n=31) 34 (33–35)	30 (22–35; n=4)
V[IV] (latero-ventral)	16 (14–17; n=21)	15 (13–16; n=31) 16 (14–17; n=12)
VI [III] (latero-ventral)	16 (14–17; n=21)	15 (14–18; n=31) 16 (14–17; n=12)
VII [II] (latero-ventral)	15 (14–17; n=21)	15 (14–17; n=31) 16 (14–17; n=12)
Medio-dorsal onchium
L	25 (16–33; n=21)	23 (20–31; n=31) 33 (29–36)
l	18 (12–27; n=21)	21(10–23; n=31) 33 (28–38)
Pe	180 (141–217; n=21)	228 (132–299; n=31) 325 (302–347)	255 (162–365; n=5)
Diameter of vagina	10 (8–12; n=10)	12 (10–13; n=21) 24–27(n=21)	16 (13–20; n=26)