Quadriacanthus macruncus Bahanak, Nack & Pariselle, 2016

Bahanak, Dieu ne dort, Nack, Jacques, Pariselle, Antoine & Bilong Bilong, Charles F., 2016, Description of three new species of Quadriacanthus (Monogenea: Ancyrocephalidae) gill parasites of Clarias submarginatus (Siluriformes: Clariidae) from Lake Ossa (Littoral region, Cameroon), Zoologia (e 20160044) 33 (4), pp. 1-8 : 2-3

Quadriacanthus macruncus Bahanak, Nack & Pariselle , sp. nov.

Fig. 3

urn:lsid:zoobank.org:act:2FE39BE9-F936-4BE4-A907-F8BDB8FEA566

Description (based on 9 specimens, all mounted in GAP): adults measure 428.3 (209.7-737.6) long, 83.4 (47.8-101.5) wide at level of ovary. Pharynx circular is 26. 9 (25.8-27.9) wide. Straight tubular penis widened at basal extremity and tapering at distal one, Pe = 28.7 (25.1-31.5) long. Accessory piece pointed, slightly curved and wider at median level, equipped with two subterminal, symmetrical and similar spines, Ap = 21.6 (18.1- 23.3). Vagina not observed. Hooklets pair I = 12.9 (12.2-13.7), II = 12.9 (11.8-13.8), III = 13.6 (12.9-13.9), IV = 25.6 (24.9-26.7), V = 13.4 (12.4-14.3), VI = 14 (13.1-15.9), VII = 13.5 (12.9-14.1). Dorsal bar composed of developed rectangular centre, Ct = 24.7 (24.1-25.7), w = 9.1 5 (6.5-14.2) wide, with one median triangular process posteriorly directed, h = 10.2 (8.6-11.6), and two lateral expansions, x = 35.6 (33.6-37.1). Dorsal anchor with curved blade, reduced guard and short point, a = 38.3 (36.8-41.6), ba = 10.6 (9.3-11.7), e = 2.5 (1.9-3.1). Dorsal triangular cuneus (or patch), i = 3.6 (2.1-4.6), j = 9 (6.1-12.5). Ventral bar V-shaped, made up of two branches medially articulated, x = 46.3 (41.9- 49.5) long, w = 6.5 (5.5-8) wide. Ventral anchor quite similar to dorsal one, a = 39.7 (37.3-41.5), ba = 9.2 (8.8-9.9), short point e = 3.9 (3.2-4.3). Slightly curved ventral cuneus with bilobed proximal extremity, i = 2.9 (2.2-3.9), j = 6.1 (4-7.5).

Type host. Clarias submarginatus Peter, 1882 .

Site. Gills.

Type locality. Lake Ossa , Cameroon (3°45’- 3°51’N, 9°58’- 10°03’E) .

Type specimens. Holotype deposited at the Royal Museum for Central Africa (Tervuren): #37935 . Paratype deposited at the Royal Museum for Central Africa (Tervuren): #37936 .

Parasitic indices. Prevalence = 18.2%, mean abundance = 0.2 ± 0.4.

Etymology. The specific name, macruncus , refers to the large size of the anchors of this species.

Remarks. The morphology of the male copulatory complex of Q. macruncus resembles Q. levequei Birgi, 1988 and Q. euzeti Nack, Pariselle & Bilong Bilong, 2015 ; Q. macruncus ) can be distinguished by its smaller size: (Pe = 25.1-31.5 vs 45-50, 36-40; Ap = 18.1-23.3 vs 30-35, 25-28), and by the morphology of the median process, directed posteriorly to the dorsal bar, triangular. This structure is in the shape of a stick in Q. levequei and a funnel in Q. euzeti .

Figures

Figure 3. Sclerotized parts of Quadriacanthus macruncus sp. nov.: (Cc) copulatory complex, (Da) dorsal anchor, (Db) dorsal bar, (Dcn) dorsal cuneus, (H) hooklets, (Va) ventral anchor, (Vb) ventral bar, (Vcn) ventral cuneus, (Vg) vagina. Scale bar: 20 µm.