Schilbetrema bilongi Bassock Bayiha, Nack & Pariselle, 2025

Schilbetrema bilongi Bassock Bayiha, Nack & Pariselle sp. nov.

Fig. 3 View Figure 3 , Table 2

https://zoobank.org/ 47A10CE7-8BA9-4699-A8F3-42F4E2D3D2C3

Type host: Schilbe mystus (Linnaeus, 1758) .

Number of hosts examined: 10.

Site: Gill lamellae.

Prevalence: 40%.

Mean intensity: 2.3 ± 2.4.

Type locality: Nachtigal ( 04°21’10.5” N; 11°37’34.9” E, alt. 432 m).

Sp ecimens dep osited: Holotyp e RMCA _VERMES_43400 and Paratypes RMCA _VERMES_43401–43404 .

Description based on six individuals: Dorsal anchors (DA) each with a straight blade, a very short and thick outer root (deep root, dorsal root, shaft), an elongate inner root (superficial root, ventral root, guard) longer than the outer root, a thick filament that covers the blade, a curved tip. Dorsal bar (DB) in form of a dumbbell, presents a small me-

2. Mean and ranges of measurements of Schilbetrema bilongi sp. nov., Schilbetrema ducentesimum sp. nov., Schilbetrema sanagaensis sp. nov., Schilbetrema asambaensis sp. nov. and selected other species of Schibetrema. dio-anterior projection and a fenestration at each extremity. Ventral anchors (VA), smaller than DAs, with a long blade, a small knob at the base of the inner root, a curved point. Ventral bar (VB) with short bilateral, posteriorly directed horns, T-shaped antero-median process with accessory structure (V-shaped) articulated to the point. Haptor is armed with seven pairs of hooks, similar in shape (each with truncate thumb, delicate point, slender shank) (even in size). MCO coiled (4 turns). Accessory piece made up of a proximal curved part followed by a distal end composed of digitiform process (5 finger-shaped expansions). Coiled vagina (3 turns). The mean and range of measurements of the new species and the sclerotised parts are shown in Table 2.

Etymology: Epithet bilongi is given in honor of late Pr. Charles F. Bilong Bilong, who worked during decades on African (mainly Cameroonian) fish monogeneans.

Remarks. Schilbetrema bilongi sp. nov. is morphologically similar to Schilbetrema spirocirra Paperna, 1969 from S. mystus (syn. Eutropius niloticus ) by the morphology of the MCO (spiral shaped). However, the new species is mainly distinguishable by the morphology of the dorsal bar (lack of lateral projections in the new species vs presence of lateral projections in the other species; short median projection vs long median projection), the ventral bar (accessory sclerite point shaped associated with antero-median projection vs antero-median process with large sub-triangular accessory structure articulated to tip); and by the length of the dorsal anchor (80–83 vs 50–61), the accessory piece (30–45 vs 60–71), and (5) the number of turns of the MCO (4 vs 7–9), respectively.