Protoancylodiscoides dibambaensis Bassock Bayiha, Bahanak & Bilong Bilong, 2024

Bassock Bayiha, Etienne D., Mbondo, Jonathan A., Bahanak, Dieu Ne Dort & Bilong Bilong, Charles F., 2024, Description of three new species of Protoancylodiscoides (Monogenea: Dactylogyridae) and biogeography of those parasitizing Chrysichthys nigrodigitatus (Siluriformes: Claroteidae) in Sanaga and Dibamba rivers, Cameroon, Zoologia (e 23) 41, pp. 1-11 : 6-7

Protoancylodiscoides dibambaensis Bassock Bayiha, Bahanak & Bilong Bilong , sp. nov.

Fig. 5

https://zoobank.org/ 28E573E2-8C58-48A4-953A-E4738F1F64AC

Type host and locality. Chrysichthys nigrodigitatus ( Siluriformes : Claroteidae ), Dibamba River ( Cameroon), 3°55’31”N and 9°40’21”E.

Infection site. Gill lamellae.

Type material. Holotype RMCA _VERMES_44345 ; Paratypes RMCA _VERMES_44346-44349 .

Description based on 18 individuals. Dorsal anchors with long and thick inner root ending less thick and curved distal extremity, outer root with shallow dent, blade arched and ending by strong point, thick filament covers middle of blade. Dorsal bar in chevron slightly curved with rounded extremities each pierced with circular hole. Ventral anchors, smaller than their dorsal counterparts, have an outer root narrower, off-center triangular fenestration at the base of each inner root, hull, thick and slightly sclerotised filament covers the base of the blade which ends in a thin and short point. Ventral bar V-shaped, consisting of two arms joined medially. Presence of seven pairs of hooks in three types according to their shape, size and position. Latero-ventral hooks II, V, VI, VII of similar shape and size [i.e. thin, without shank (= distal subunit)], resemble those present in ancyrocephaline oncomiracidia (larval hook). They correspond to proximal subunit (= outer root +thumb+point) in Kritsky and Kulo (1999); medio-ventral hook pairs I and IV enlarged with thick and long shank; latero-dorsal hooks III with moderately developed shank; presence of dorsal pouch-like structure (onchuim) wider than long. Male copulatory organ consists of a long tubular penis (228 µm) associated with accessory piece, composed of two superimposed subunits, of unequal thickness, forming a body with their crumpled distal parts. The sclerotised vagina is coiled at its base and flared in the distal part.

The measurements of the parasite in toto, the haptor, and the copulatory sclerotised parts are shown in Table 1.

Etymology. dibambaensis refers to the River Dibamba where fish hosts were collected.

Remarks. By the lack of the onchium and morphology of some sclerotised parts of the haptor, mainly ventral bar and dorsal anchor, Protoancylodiscoides dibambaensis sp. nov. is close to P. ivoiriensis Bouah, N’Douba & Pariselle, 2021 from Clarotes laticeps (Rüppell, 1829) . However, it differs from this species by the morphology of: (1) the dorsal bar: presence of fenestrations and folds at the extremities in P. dibambaensis sp. nov. vs absence of these features in P. ivoiriensis , (2) the ventral anchor: presence of a fenestration at each extremity in P. dibambaensis sp. nov. vs lack of the fenestration in P.ivoiriensis ; (3) the hooks: all hooks keep the larval form (ancyrocephaline oncomiracidia) in P. ivoiriensis unlike only hook pairs II, V, VI and VII have retained the larval form in the new species. Protoancylodiscoisdes dibambaensis sp. nov. also differs from P. ivoiriensis by the size of: (1) the penis length = 155 (118–191) vs 103 (74–116); (2) the dorsal bar x = 42 (38–47) vs 29 (27–34); (3) the ventral anchor a=34 (31–36) vs 27 (24–28).

Figures

Figure 5. Protoancylodiscoides dibambaensis sp. nov.: (DB) dorsal bar, (VB) ventral bar, (DA) dorsal anchor, (VA) ventral anchor, (I to VII) haptoral hooks, (AP) accessory piece, (Pe) penis, (Vg) vagina. Scale bar: 20 Μm.