Quadriacanthus aegypticus El-Naggar & Serag, 1986

Quadriacanthus aegypticus El-Naggar & Serag, 1986 View in CoL

Type-host and locality: Clarias gariepinus ; Lake Manzala and the Demietta branch of the Nile River, Dakahlia Governorate, Egypt ( El-Naggar and Serag 1986).

Other localities: Ammar drainage canal, Bahr Mouis, Damroo drainage canal, Mansoura drainage canal, Nawasa El-Gheit drainage canal, Telbanah drainage canal ( Egypt), Blue Nile, White Nile ( Sudan), Krugerdrift Dam, Gariep Dam, Lake Tzaneen, Middle Letaba Dam, Nwanedi-Luphephe Dams, Phalaborwa Barrage, Vaal Dam ( South Africa), Lake Tana ( Ethiopia), Lake Turkana ( Kenya) and Lake Kariba ( Zimbabwe) ( Truter 2022, Truter et al. 2023).

New host: Clarias ngamensis .

New localities: Lake Lubanda, Luapula River.

Prevalence: P = 6.7% (Lake Lubanda); P = 40% (Luapula River).

Mean intensity: MI = 1 ± 1 (Lake Lubanda); MI = 2.7 ± 3.3 (Luapula River).

Voucher specimens: 17 Voucher specimens XXII.3.”06; 15; 18; 23; 25; 26; 28; 29; 31; 35; 37–43” are deposited in the collection of the Research Group Zoology: Biodiversity & Toxicology, at Hasselt University (Diepenbeek, Belgium).

Diagnosis: Tubular and straight male copulatory organ (MCO), widest at base and narrowing towards distal extremity. Accessory piece ends in two distinctive lateral, club-shaped outgrowths projecting from its posterior half. Vagina partly sclerotized tube. Dorsal anchor without shaft nor guard, with broad base and short point. Dorsal bar with rectangular centre, funnel-like median process posteriorly directed and two lateral expansions. Large dorsal cuneus triangular. Ventral anchor without shaft nor guard, with regularly curved blade. Ventral bar with two lateral branches. Y-shaped ventral cuneus. Seven pairs of hooks: pairs IV, III, I (decreasing size) larger than pairs II, V, VI and VII, latter pairs almost equal ( Fig. 3 View Figure 3 ).

Remarks: The specimens are reminiscent of the morphological characters of the MCO of the original description of Q. aegypticus by El-Naggar and Serag (1986) (base of copulatory tube wider, anterior end pointed; accessory piece terminates in two hooks and possesses two distinctive, lateral club-shaped outgrowths, projecting from the posterior half) as well as the drawings/measurements provided by El-Naggar and Serag (1986), Kritsky and Kulo (1988), Douëllou and Chishawa (1995) and Francová et al. (2017). We consider

AP them conspecific, as the morphometrical characteristics of the sclerotized structures correspond to those reported for Q. aegypticus , i.e., AP (34–44) in this study vs (33–49), (36–44), (39–44) Kritsky and Kulo (1988), Douëllou and Chishawa (1995) and Francová et al. (2017) respectively; MCO (36–39) in this study vs (34–40), (36–40) following Douëllou and Chishawa (1995) and Francová et al. (2017). However the shafts of the ventral and dorsal anchors deviate from the original description outlined in El-Naggar and Serag (1986).