Biotodomella mirospinata, Morey & Arimuya & Boeger, 2019

Morey, Germán Augusto Murrieta, Arimuya, Mariana Vásquez & Boeger, Walter A., 2019, Neotropical Monogenoidea 62. Biotodomella mirospinata gen. nov., sp. nov. (Polyonchoinea: Dactylogyridae): a parasite of the gills of Biotodoma cupido (Cichliformes: Cichlidae), from the Peruvian Amazon, Zoologia (e 38455) 36, pp. 1-5 : 2

Biotodomella mirospinata sp. nov.

http://zoobank.org/ D808CB11-6EFD-4903-ABAC-BCFBDF4F84E3

Figs 1-14

Type-host: Biotodoma cupido (Heckel, 1840) (Cichliformes: Cichlidae ).

Type-locality: “Shiruy caño” in the Nanay River (3°44’42.10”S, 73°16’46.89”W, Peru.

Type-material: Holotype: INPA 785 a. 16 Paratypes: INPA 785 b-g, INPA 797 a-j.

Site in host: Gill filaments.

Prevalence: 35% (7 fish parasitized of 20 sampled).

Mean intensity: 1.57.

Description (based on 17 specimens: 6 stained, 11 cleared): Body fusiform, 446 (418–496; n = 6) long, greatest width 124 (111–144, n = 6) at level of germarium. Cephalic region with two pairs of lobes, head organs. Eyespots 4, anterior pair smaller than posterior pair; granules small, ovate; accessory granules scattered in cephalic region. Pharynx spherical, 23 (18–27, n = 6) in diameter; esophagus short, inconspicuous. Testis ovate, 67 long (n = 1), posterior to germarium; vas deferens loops left intestinal caecum; seminal vesicle elongate; prostatic reservoirs 2, pyriform; smaller prostatic reservoir with thick walls. MCO 24 (20–27, n = 6) long, sclerotized, coiled, with about two clockwise rings, base with short sclerotized fringe, tip funnel-shaped. Accessory piece elongate, 19 (14–19, n = 6) long, with submedian thumb-like projection, articulated with MCO by delicate process. Germarium 39 long (n = 1), ovate. Uterus not observed. Vagina dextral, a sclerotized proximally funnel-shaped tube; atrium sclerotized; seminal receptacle immediately anterior to germarium, globose. Vitelline follicles dense, overlapping caeca, reaching peduncle. Haptor subcircular. Hooks of hook pair 1 more robust than remaining, with straight shaft, inconspicuous point, inconspicuous thumb, shank with fringe-like expansion on proximal, veil-like sclerotization on proximal portion of shank; hooks of hook pairs 2–7 with similar morphology of shaft, point, thumb (erected conspicuous thumb, slightly curved shaft, short point); shaft variably expanded among hook pairs through; hook pairs 2, 3, 6, 7 with sclerotized expansions on distal end, variable in length, especially long in hook pair 7 (longer than hook length); hook pairs 4, 5 lacking sclerotized expansions on proximal end; hook pair 5 comparatively more delicate than remaining hook pairs. Hook pair 1, 35 (32–37, n = 6) long (including cuticular expansion whenever present); hook pair 2, 23 (21–24, n = 6) long; hook pair 3, 15 (15–19, n = 6); hook pair 4, 15 (15–20, n = 6) long; hook pair 5, 14 (14–17, n = 6) long; hook pair 6, 20 (18–22, n = 6) long; hook pair 7, 42 (41–43, n = 6) long. Bars elongate, distinct. Ventral bar halter-shaped with anterior, posterior grooves, 54 (48–60, n = 6) long. Dorsal bar more delicate, with extremities slightly recurved posteriorly, 65 (62–68, n = 6) long. Ventral anchor 47 (42–51, n = 6) long, base 5 (3–6; n = 6) wide, with elongate superficial root, with slightly recurved tip, short round deep root, evenly curved shaft, point. Dorsal anchor, 30 (27–33, n = 6) long, base 17 (12–20, n = 6) wide, with robust superficial root with small digitiform tip, short deep root, shaft. Eggs not observed.

Etymology: The specific epithet “ mirunospinata ” (from the Latin mirun = wonderful; spinus = thorns) refers to the unique morphology of the hooks among Neotropical species of Monogenoidea.

Remarks: Species of five genera have been reported from native species of Cichlidae in the Neotropical region: Trinidactylus Hanek, Molnar & Fernando, 1974 ; Gussevia Kohn & Paperna, 1964 ; Sciadicleithrum Kritsky, Thatcher & Boeger, 1989 ; Tucunarella Mendoza-Franco, Scholz & Rozkošná, 2010 ; and Parasciadicleithrum Mendoza-Palmero, Blasco-Costa, Hernández-Mena & Pérez-Ponce de León, 2017 . Biotodomella mirospinata sp. nov. does not conform with the diagnostic features of any of these genera, nor to any other genus reported from cichlids worldwide (see Boeger and Vianna 2006, Pariselle et al. 2011, Mendoza-Franco et al. 2010).

Biotodomella mirospinata sp. nov. is the only known species of the new genus proposed herein. The putative most distinctive diagnostic feature of Biotodomella , i.e. hook pairs distinct from each other with morphology unique among Neotropical freshwater monogenoids, is not shared with any other known species in the region and justifies the proposal of the new genus. The morphology of the dorsal anchor (with a groove on the distal portion of the shaft and a bifid point) is also unique among Neotropical dactylogyrids and is putatively considered another key diagnostic feature for the genus. Finally, no other genus of Dactylogyridae from Neotropical Cichlidae present species with tandem gonads as Boitodomella.