Description of Tresuncinidactylus wilmienae gen. et sp. n. (Monogenea: Gyrodactylidae), from the gills of the bulldog, Marcusenius macrolepidotus (Peters) from Lake Kariba, Zimbabwe Author Přikrylová, Iva DSI-NRF SARChI Chair (Ecosystem Health), Department of Biodiversity, University of Limpopo, Sovenga, South Africa; & Unit for Environmental Sciences & Development, North West University, Potchefstroom, South Africa; Author Barson, Maxwell Department of Biological Sciences, University of Botswana, Gaborone, Botswana; Author Shinn, Andrew P. INVE Thailand Ltd., Samed Sub-district, Amphur Muang Chonburi, Chonburi, Thailand; & Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville, Australia text Folia Parasitologica 2021 025 2021-11-16 68 1 12 http://dx.doi.org/10.14411/fp.2021.025 journal article 10.14411/fp.2021.025 1803-6465 8143640 Tresuncinidactylus gen. n. ZooBank number for species: urn:lsid:zoobank.org:act: E36CE744-A54F-4531-8BA5-ECAFD4A4DFE3 Type and only species: Tresuncinidactylus wilmienae sp. n. Diagnosis (based on 8 specimens ). Body fusiform, comprising body proper (cephalic regions, trunk and peduncle) and opisthaptor. Body wall thin and smooth. Cephalic region bilobed, each lobe bears a spike sensillum. Cephalic gland present. Eye spots absent. Mouth situated ventrally. Pharynx spherical, comprised of two bulbs, anterior bulb presents finger-like pharyngeal processes. Oesophagus branching into two simple, blind-ended intestinal crura that extend beyond uterus. Viviparous, only one embryo in utero observed. Male copulatory organ consists of muscular pouch, positioned ventrally, close to bifurcation of intestinal crura, armed with approximately 30 gracile spines. Opisthaptor delineated from body, bearing a single pair of large, slender hamuli with constriction on outer edge between shaft and point regions on each hamulus. Hamuli root prominently flattened; ventral terminus of hamulus cap tapered. Large muscle masses and tendons associated with hamulus root caps evident. Small and simple ventral bar, without anterolateral processes; thin lingulate membrane present. Thin, simple dorsal bar. Sixteen marginal hooks with large falculate sickles of one morphological type , but of three different sizes, length of each sickle being approximately equal in length to that of their handle. Two largest pairs of marginal hooks positioned closest to opisthaptoral peduncle, neighbouring two pairs of medium-sized marginal hook sickles situated along lateral margins of opisthaptor, and remaining four pairs and smallest marginal hooks positioned along posterior margin of opisthaptor. E t y m o l o g y: Generic name refers to the presence of marginal hooks of three differing sizes.