taxonID	type	description	language	source
03F14E3BFFF6FFB0FC98FBA15FE2F96A.taxon	description	Figs 1 – 7 Type host. Hassar orestis (Steindachner, 1875), Doradidae Site of infection. Gill filaments. Type locality. Xingu River, Belo Monte Community, municipality of Vitória do Xingu, Pará (03 ° 05 ’ 52.5 ” S, 51 ° 43 ’ 18.0 ” W). Prevalence. 100 % of 16 hosts examined. Mean intensity. 6.5 parasites per infected host. Mean abundance. 6.5 parasites per host. Other records. Hassar orestis (Prevalence: 100 % of 8 hosts; Mean intensity: 6; Mean abundance: 6), Xingu River, municipality of Vitória do Xingu, Pará (02 ° 47 ’ 27.1 ” S, 51 ° 59 ’ 50.0 ” W). Specimens deposited. Holotype 39055 a, and 9 paratypes, CHIOC 39055 b – g, INPA 770, MPEG 0135; 9 vouchers, CHIOC 39056 a – b, 39057 a – c, INPA 771 – 772, MPEG 0136. Description (based on 10 type specimens, 5 mounted in Hoyer, 5 stained with Gomori’s trichrome): Body fusiform, total length including haptor 356 (250 – 462; n = 10) long, 77 (62 – 95; n = 10) wide at level of germarium. Tegument smooth. (Fig. 1). Cephalic margin rounded, cephalic lobes inconspicuous; 3 or 4 bilateral pairs of head organs with rod-shaped secretion; cephalic glands unicellular, posterolateral to pharynx. Eyes, pigment granules (eye-spots), absent. Mouth subterminal; pharynx muscular, sub-spherical, 28 (24 – 33; n = 9) long, 23 (17 – 25; n = 9) wide; esophagus short, two intestinal ceca, confluent posteriorly; lacking diverticula. Haptor globose 67 (55 – 85; n = 9) wide. Anchors similar. Ventral anchor, superficial root, narrow triangular, well developed; deep root inconspicuous; slightly curved shaft and point, forming angle of approximately 90 °; point extending just past level of tip of superficial root, outer 27 (24 – 31; n = 10) long, inner 28 (25 – 32; n = 10) long, base 18 (11 – 22; n = 10) (Fig. 6). Dorsal anchor, superficial root triangular, large; deep root inconspicuous; slightly curved shaft and point, forming angle of approximately 75 °, point extending just past level of tip of superficial root, outer 28 (21 – 31; n = 8) long, inner 29 (27 – 31; n = 8) long, base 19 (16 – 31; n = 7) (Fig. 7). Ventral bar (Fig. 4) 35 (28 – 45; n = 10) long, 5 (3 – 7; n = 10 wide, broadly U-shaped with inflated ends, slightly curved in posterior direction. Dorsal bar (Fig. 5) 36 (28 – 45; n = 10) long, 4 (3 – 6; n = 10) wide, U-shaped with rounded ends, slightly curved; two submedial projections posteriorly directed. Hooks similar (Fig. 3), 13 (12 – 17; n = 10) long, with upright rounded thumb; slightly curved shaft, short; non-dilated shank; filamentous hooklet loop about shank length. Genital pore opening midventral, anterior to copulatory complex; muscular genital atrium. Testis post-germarial, dorsal to germarium, elongated 47 (31 – 69; n = 6) long, 33 (25 – 39; n = 6) wide. Vas deferens looping left of intestinal cecum; seminal vesicle a dilatation of vas deferens; long prostatic reservoir with medial constriction. Copulatory complex comprising MCO, accessory piece (Fig. 2). MCO, coiled sclerotized tube 236 (201 – 299; n = 7) long, with 2 ½ counterclockwise rings, with tapered distal region, base MCO, wide sclerotized margin. Accessory piece 36 (31 – 50; n = 6) long, non-articulated with MCO, comprising straight rod, distal end with elongate torch-shaped blade, guarding termination of MCO. Germarium 44 (31 – 69; n = 8) long, 23 (17 – 31; n = 8) wide, pyriform. Eggs, Mehlis’ gland, ootype and uterus not observed. Vagina slightly sclerotized, vaginal pore sinistral, marginal or submarginal, vaginal vestibule cup-shaped, long vaginal canal, sigmoid, slightly sclerotized; seminal receptacle oval. Vitelline follicles dense, coextensive with ceca. Comparative measurements. Table 3. Etymology. The specific name (a noun) is from Greek (phryctos = burning torch + phallos = penis) and refers to the unique shape of the accessory piece. Remarks. Cosmetocleithrum phryctophallus sp. nov. resembles Cosmetocleithrum akuanduba sp. nov. by sharing similar morphology of the haptoral structures. However, it can be easily distinguished from C. akuanduba sp. nov. due to the presence of a coiled MCO (J-shaped in C. akuanduba sp. nov.) and by having a lightly sclerotized vagina with a sigmoid vaginal canal (heavily sclerotized vagina with short, “ S ” - shaped vaginal canal in C. akuanduba sp. nov.). The new species also differs from C. akuanduba sp. nov. and all other congeneric species by possessing an accessory piece with an elongate torch-shaped blade.	en	Soares, Geusivam Barbosa, Neto, João Flor dos Santos, Domingues, Marcus Vinicius (2018): Dactylogyrids (Platyhelminthes: Monogenoidea) from the gills of Hassar gabiru and Hassar orestis (Siluriformes: Doradidae) from the Xingu Basin, Brazil. Zoologia (e 23917) 35: 1-19, DOI: 10.3897/zoologia.35.e23917, URL: http://dx.doi.org/10.3897/zoologia.35.e23917
03F14E3BFFF0FFB3FC7EFAFE5C73FE8A.taxon	description	Figs 8 – 14 Type host. Hassar gabiru Birindelli, Fayal & Wosiacki, 2011, Doradidae Site of infection. Gill filaments. Type locality. Bacajá River, municipality of Altamira, Pará (03 ° 33 ’ 47.1 ” S, 51 ° 36 ’ 50.3 ” W). Prevalence. 100 % of 15 hosts examined. Mean intensity. 20 parasites per infected host. Mean abundance. 20 parasites per host. Other records. Hassar gabiru (Prevalence: 100 % of 19 hosts; Mean intensity: 15; Mean abundance: 15), Ilha Grande, Xingu River, municipality of Altamira, Pará (03 ° 35 ’ 50.2 ” S, 52 ° 21 ’ 22.5 ” W); Hassar gabiru (Prevalence: 100 % of 2 hosts; Mean intensity: 2.5; Mean abundance: 2.5), Iriri River, municipality of Altamira, Pará (03 ° 49 ’ 06.4 ” S, 52 ° 41 ’ 25.8 ” W). Specimens deposited. Holotype, CHIOC 39053 a, and 8 paratypes, CHIOC 39053 b – f, INPA 773, MPEG 0137; 8 vouchers, CHIOC 39054 a – c, INPA 774, MPEG 0138 – 0140. Description (based on 10 type specimens, 6 mounted in Hoyer, 4 stained with Gomori’s trichrome): Body robust, fusiform, total length including haptor 712 (575 – 835; n = 8) long, 132 (102 – 157; n = 8) wide, at level of germarium. Tegument smooth (Fig. 8). Cephalic margin broad; cephalic lobes poorly differentiated; 4 or 5 bilateral pairs of head organs with rod-shaped secretion; cephalic glands unicellular, posterolateral to pharynx. Eyes, pigment granules (eye-spots), absent. Mouth subterminal; pharynx muscular, spherical, 39 (33 – 46; n = 7) long, 36 (30 – 42; n = 7) wide; esophagus short; two intestinal ceca, confluent posteriorly, lacking diverticula. Haptor subtriangular 89 (65 – 110; n = 8) wide. Anchors similar, base wide, superficial and deep root poorly developed. Ventral anchor, curved shaft and point, forming angle of approximately 85 °, point extending just past level of tip of superficial root, outer 40 (25 – 45; n = 10) long, inner 45 (28 – 52; n = 10) long, base 26 (16 – 30; n = 10) (Fig. 13). Dorsal anchor, slightly curved shaft and point, forming angle of approximately 110 °, point extending just past level of tip of superficial root, outer 35 (30 – 39; n = 10) long, inner 38 (36 – 42; n = 10) long, base 20 (15 – 23; n = 10) (Fig. 14). Ventral bar (Fig. 11) 44 (32 – 57; n = 9) long, 6 (4 – 9; n = 8) wide, straight with knobbed ends. Dorsal bar (Fig. 12) 49 (35 – 65; n = 10) long, 6 (3 – 8; n = 10) wide, straight with inflated or rounded ends; two submedial projections posteriorly directed. Hooks similar (Fig. 10), 14 (13 – 15; n = 8) long, with upright rounded thumb; slightly curved shaft, short; non-dilated shank; filamentous hooket about ½ shank length. Genital pore opening to left of body midline, anterior to copulatory complex; muscular genital atrium. Testis post-germarial, dorsal to germarium, ovoid, 43 (43 – 44; n = 2) long, 27 (24 – 30; n = 2) wide. Vas deferens looping left of intestinal cecum; seminal vesicle a dilatation of vas deferens; prostatic reservoir with medial constriction. Copulatory complex comprising MCO, accessory piece (Fig. 9). MCO, coiled sclerotized tube, 572 (550 – 637; n = 9) long, with 3 ½ counterclockwise rings, with tapered distal region, base of MCO sclerotized. Accessory piece 121 (110 – 130; n = 5) long, non-articulated with MCO, comprising sigmoid rod, with cup-shaped distal region. Germarium 85 (65 – 106; n = 5) long, 49 (39 – 62; n = 5) wide, pyriform. Eggs, Mehlis’ gland, ootype and uterus not observed. Vagina heavily sclerotized, vaginal pore sinistral, marginal or submarginal, vaginal canal long, convoluted, heavily sclerotized, proximal region looped, distal region sigmoid; seminal receptacle pyriform. Vitelline follicles dense, coextensive with ceca. Comparative measurements. Table 4. Etymology. The specific name is in honor of Dr Leandro Melo de Sousa, Universidade Federal do Pará, Brazil, in recognition of his valuable work on the fish diversity of Xingu River, and also because the specific name of the host species, “ gabiru ”, is the nickname of Dr de Souza (Birindelli et al. 2011). Now, Dr de Sousa has the host and parasite named after him. Remarks. Cosmetocleithrum leandroi sp. nov. resembles Cosmetocleithrum longivaginatum Suriano & Incorvaia, 1995 by the general morphology of the bars and by the presence of a long vaginal canal (see Suriano and Incorvaia 1995). However, the new species differs from C. longivaginatum, mainly by possessing a MCO comprising a coil of about with 3 ½ rings (6 rings in C. longivaginatum) and a sigmoid accessory piece with the distal portion cup-shaped (straight, non-expanded distal accessory piece in C. longivaginatum). Also, C. leandroi has hooks with similar size, whereas C. longivaginatum has 2 different sizes of hooks (pairs 2 to 5 are smaller than pairs 1, 6 and 7). Finally, these species differ in the shape of their anchors, i. e., C. longivaginatum has well-defined roots, whereas C. leandroi has poorly differentiated roots.	en	Soares, Geusivam Barbosa, Neto, João Flor dos Santos, Domingues, Marcus Vinicius (2018): Dactylogyrids (Platyhelminthes: Monogenoidea) from the gills of Hassar gabiru and Hassar orestis (Siluriformes: Doradidae) from the Xingu Basin, Brazil. Zoologia (e 23917) 35: 1-19, DOI: 10.3897/zoologia.35.e23917, URL: http://dx.doi.org/10.3897/zoologia.35.e23917
03F14E3BFFF3FFBDFF05FEF45CA8FB0A.taxon	description	Figs 15 – 22 Type host. Hassar gabiru Birindelli, Fayal & Wosiacki, 2011, Doradidae Site of infection. Gill filaments. Type locality. Ilha grande, Xingu River, municipality of Altamira, Pará (03 ° 35 ’ 50.2 ” S, 52 ° 21 ’ 22.5 ” W). Prevalence. 52 % of 19 hosts examined. Mean intensity. 3 parasites per infected host. Mean abundance. 1.6 parasites per host. Other records. Hassar gabiru (Prevalence: 100 % of 2 hosts; Mean intensity: 2.5; Mean abundance: 2.5) Iriri River, municipality of Altamira, Pará (03 ° 49 ’ 06.4 ” S, 52 ° 41 ’ 25.8 ” W); Hassar gabiru (Prevalence: 60 % of 15 hosts; Mean intensity: 3.8; Mean abundance: 2.3) Bacajá River, municipality of Altamira, Pará (03 ° 33 ’ 47.1 ” S, 51 ° 36 ’ 50.3 ” W); Hassar orestis (Prevalence: 62 % of 24 hosts; Mean intensity: 2.3; Mean abundance: 1.5), Xingu River, Belo Monte Community, municipality of Vitória do Xingu, Pará (03 ° 05 ’ 52.5 ” S, 51 ° 43 ’ 18.0 ” W; 02 ° 47 ’ 27.1 ” S, 51 ° 59 ’ 50.0 ” W). Specimens deposited. Holotype, CHIOC 39045 a, and 6 paratypes, CHIOC 39045 b-e, INPA 776, MPEG 0141; 8 vouchers, CHIOC 39046 a – b, 39047 a – c, INPA 777, MPEG 0142. Description (based on 7 type specimens, 1 mounted in Hoyer, 6 stained with Gomori’s trichrome): Body fusiform, total length including haptor 451 (360 – 517; n = 5) long, 110 (92 – 130; n = 5) wide at level of germarium. Tegument smooth (Fig. 15). Cephalic margin broad; cephalic lobes poorly differentiated; 4 bilateral pairs of head organs with rod-shaped secretion; cephalic glands unicellular, posterolateral to pharynx. Eyes, pigment granules (eye-spots), absent. Mouth subterminal; pharynx muscular, spherical, 32 (30 – 35; n = 5) long, 28 (25 – 30; n = 5) wide; esophagus short; two intestinal ceca, confluent posteriorly, lacking diverticula. Haptor globose 90 (75 – 117; n = 5) wide. Anchors similar. Ventral anchor, superficial root narrow subtriangular, well developed; deep root inconspicuous; slightly curved shaft and point, forming angle of approximately 75 °, point extending just past level of tip of superficial root, outer 27 (25 – 29; n = 7) long, inner 30 (25 – 41; n = 7) long, base 19 (17 – 20; n = 7) (Fig. 21). Dorsal anchor, superficial root subtriangular; deep root inconspicuous; slightly curved shaft and point forming angle of approximately 70 °, point extending just past level of tip of superficial root, outer 25 (22 – 29; n = 5) long, inner 30 (29 – 32; n = 5) long, base 19 (17 – 20; n = 5) (Fig. 22). Ventral bar, variable (Figs 18 – 19) 41 (30 – 57; n = 7) long, 6 (4 – 10; n = 7) wide, broadly U-shaped or straight with inflated or rounded ends. Dorsal bar (Fig. 20) 41 (31 – 56; n = 7) long, 5 (4 – 6; n = 7) wide, V-shaped with rounded ends, two submedial projections posteriorly directed. Hooks similar (Fig. 17), 13 (13 – 14; n = 7) long, with upright truncate thumb; slightly curved shaft, short; non-dilated shank; filamentous hook about shank length. Genital pore opening midventral, anterior to copulatory complex; muscular genital atrium. Testis post-germarial (observed on paratypes), dorsal to germarium, ovoid, 56 (51 – 64; n = 3) long, 40 (32 – 47; n = 3) wide. Vas deferens looping left of intestinal cecum; seminal vesicle a dilatation of vas deferens; long prostatic reservoir with medial constriction. Copulatory complex comprising MCO, accessory piece (Fig. 16). MCO with tubular coiled shaft of less than one counterclockwise ring, frequently appearing J shaped, 68 (54 – 76; n = 4) long, with tapered distal region; base sclerotized, bulbous. Accessory piece 23 (18 – 30; n = 5) long, non-articulated with MCO, comprising straight rod, with tapered distal region, distal portion with a small gutter guarding distal portion of shaft of MCO. Germarium 51 (47 – 55; n = 5) long, 42 (35 – 52; n = 5) wide, oval. Uterus delicate, ventral. Eggs, Mehlis’ gland and ootype not observed. Vagina heavily sclerotized, vaginal pore sinistral, marginal or submarginal, vaginal canal slightly sclerotized, proximal region “ S ” - shaped, distal region expanded; seminal receptacle, spherical. Vitelline follicles dense, coextensive with ceca. Comparative measurements. Table 5. Etymology. The name akuanduba refers to a divinity called “ Akuanduba ” of the Arara native people from the Xingu Basin in Pará. According Arara mythic narratives, Akuanduba played his flute to bring order to the world. One day, because of human disobedience, they were thrown into the water. The few survivors had to learn from scratch how to give continuity to life. Remarks. Cosmetocleithrum akuanduba sp. nov. resembles Cosmetocleithrum parvum Kritsky, Thatcher & Boeger, 1986 and Cosmetocleithrum sobrinus Kritsky, Thatcher & Boeger, 1986 by having a “ J ” - shaped MCO (see Kritsky et al. 1986). However, the new species differs from these two species by possessing an elongate accessory piece, with sharp distal region, distal tip with a small gutter (accessory piece with proximal arm, hollow bulbous portion distally in C. parvum, and accessory piece large, globose, and apparently hollow in C. sobrinus). Also C. akuanduba has a dorsal anchor with a broad subtriangular superficial root, undeveloped deep root, evenly curved shaft with angle of approximately 70 °; (narrow, subrectangular superficial root; developed deep root; evenly curved shaft with angle of approximately 70 ° and 80 ° in C. parvum and C. sobrinus, respectively). The morphological variations in the ventral bar of C. akuanduba (Figs 18 – 19) reported from different hosts and localities (i. e., H. orestis collected below the Volta Grande and H. gabiru collected above the Volta Grande rapids) were considered intraspecific variations.	en	Soares, Geusivam Barbosa, Neto, João Flor dos Santos, Domingues, Marcus Vinicius (2018): Dactylogyrids (Platyhelminthes: Monogenoidea) from the gills of Hassar gabiru and Hassar orestis (Siluriformes: Doradidae) from the Xingu Basin, Brazil. Zoologia (e 23917) 35: 1-19, DOI: 10.3897/zoologia.35.e23917, URL: http://dx.doi.org/10.3897/zoologia.35.e23917
03F14E3BFFFDFFBFFF52FB745F52FC8F.taxon	description	Figs 23 – 29	en	Soares, Geusivam Barbosa, Neto, João Flor dos Santos, Domingues, Marcus Vinicius (2018): Dactylogyrids (Platyhelminthes: Monogenoidea) from the gills of Hassar gabiru and Hassar orestis (Siluriformes: Doradidae) from the Xingu Basin, Brazil. Zoologia (e 23917) 35: 1-19, DOI: 10.3897/zoologia.35.e23917, URL: http://dx.doi.org/10.3897/zoologia.35.e23917
03F14E3BFFFDFFBFFF52FB745F52FC8F.taxon	materials_examined	Type host. Hassar orestis (Steindachner, 1875), Doradidae. Type locality. Aquarium Momón River, Iquitos, Peru (03 ° 44 ’ 56 ” S, 73 ° 15 ’ 13 ” W). Site of infection. Gill filaments. Other records. Hassar orestis (Prevalence: 100 % of 16 hosts examined; Mean intensity: 9.35 parasites per infected host; Mean abundance: 9.35 parasites per host), Xingu River, Belo Monte Community, municipality of Vitória do Xingu, Pará (03 ° 05 ’ 52.5 ” S, 51 ° 43 ’ 18.0 ” W); Hassar orestis (Prevalence: 100 % of 8 hosts; Mean intensity: 12.6; Mean abundance: 12.6) Xingu River, municipality of Vitória do Xingu, Pará (02 ° 47 ’ 27.1 ” S, 51 ° 59 ’ 50.0 ” W); Hassar gabiru (Prevalence: 100 % of 2 hosts; Mean intensity: 1; Mean abundance: 1) Iriri River, municipality of Altamira, Pará (03 ° 49 ’ 06.4 ” S, 52 ° 41 ’ 25.8 ” W); Hassar gabiru (Prevalence: 84 % of 19 hosts; Mean intensity: 2.6; Mean abundance: 2.2), Ilha Grande, Xingu River, municipality of Altamira, Pará (03 ° 35 ’ 50.2 ” S, 52 ° 21 ’ 22.5 ” W); Hassar gabiru (Prevalence: 100 % of 15 hosts; Mean intensity: 2.6; Mean abundance: 2.6), Bacajá River, municipality of Altamira, Pará (03 ° 33 ’ 47.1 ” S, 51 ° 36 ’ 50.3 ” W). Specimens deposited. 17 vouchers, CHIOC 39048 a – b, 39049 a – c, 39050,39051 a – c, 39052 a – b, INPA 780 – 781, MPEG 0145 – 0148. Comparative measurements. Table 6. Remarks. A comparative analysis of Cosmetocleithrum bifurcum Mendoza-Franco, Mendoza-Palmero & Scholz, 2016 and specimens of Cosmetocleithrum from Xingu River and related tributaries indicated that they are conspecific, mainly because they both share the morphology of the copulatory complex, bars and anchors. The specimens studied here also are similar morphometrically to those specimens from the type host and locality. Mendoza-Franco et al. (2016) recognized differences between hook pair 7 and the other hook pairs (Mendoza-Franco et al. 2016: figs 6 G – H), where hook pair 7 has a shaft longer and shank more slender than the other hook pairs. The specimens studied here have hooks similar in shape with erect thumb (thumb directed posteriorly in Mendoza-Franco et al. ’ s specimens), and evenly curved shaft and point (long shaft, delicate point in Mendoza-Franco et al. ’ s specimens). Cosmetocleithrum bifurcum was primarily characterized by possessing a MCO with about 1 – 1.5 rings, whereas the specimens studied in the present paper have a sigmoid MCO. However, these variations do not seem to be sufficient enough evidence to propose a new species and we consider them as intraspecific variations.	en	Soares, Geusivam Barbosa, Neto, João Flor dos Santos, Domingues, Marcus Vinicius (2018): Dactylogyrids (Platyhelminthes: Monogenoidea) from the gills of Hassar gabiru and Hassar orestis (Siluriformes: Doradidae) from the Xingu Basin, Brazil. Zoologia (e 23917) 35: 1-19, DOI: 10.3897/zoologia.35.e23917, URL: http://dx.doi.org/10.3897/zoologia.35.e23917
03F14E3BFFFFFFB9FEC8FCF95E2BFBA4.taxon	description	Figs 30 – 36 Type host. Hassar orestis (Steindachner, 1875), Doradidae Site of infection. Gill filaments. Type locality. Xingu River, Belo Monte Community, municipality of Vitória of Xingu, Pará (03 ° 05 ’ 52.5 ” S, 51 ° 43 ’ 18.0 ” W; 02 ° 47 ’ 27.1 ” S, 51 ° 59 ’ 50.0 ” W). Prevalence. 50 % of 24 hosts examined Mean intensity. 2.3 parasites per infected host. Mean abundance. 1.6 parasites per host. Other records. Hassar gabiru (Prevalence: 30 % of 15 hosts; Mean intensity: 2; Mean abundance: 0.6), Bacajá River, municipality of Altamira, Pará (03 ° 33 ’ 47.1 ” S, 51 ° 36 ’ 50.3 ” W); Hassar gabiru (Prevalence: 16 % of 12 hosts; Mean intensity: 2; Mean abundance: 0.3), Ilha Grande, Xingu River, municipality of Altamira, Pará (03 ° 35 ’ 50.2 ” S, 52 ° 21 ’ 22.5 ” W). Specimens deposited. Holotype CHIOC 39058 a, and 9 paratypes, CHIOC 39058 b – h, INPA 778, MPEG 0143; 4 vouchers, CHIOC 39059 – 39060, INPA 779, MPEG 0144. Description (based on 10 type specimens, 3 mounted in Hoyer, 7 stained with Gomori’s trichrome): Body fusiform, total length including haptor 315 (215 – 517; n = 9) long, 89 (65 – 122; n = 9) wide, at level of germarium. Tegument smooth (Fig. 30). Cephalic margin rounded, cephalic lobes inconspicuous; 5 or 6 bilateral pairs of head organs with rod-shaped secretion; cephalic glands unicellular, posterolateral to pharynx. Eyes, pigment granules (eye-spots), absent. Mouth subterminal; pharynx muscular, spherical, 33 (25 – 36; n = 8) long, 17 (15 – 20; n = 8) wide; esophagus short; two intestinal ceca, confluent posteriorly, lacking diverticula. Haptor hexagonal 71 (52 – 90; n = 9) wide. Anchors similar. Ventral anchor, divergent roots; superficial root triangular, well developed, with conspicuous fold; deep root developed; slightly curved shaft and point, forming angle of approximately 65 °, point extending just past level of tip of superficial root, outer 24 (21 – 28; n = 6) long, inner 28 (27 – 32; n = 6) long, base 10 (8 – 12; n = 6) (Fig. 35). Dorsal anchor, divergent roots; superficial root subtriangular, with conspicuous fold; deep root developed; slightly curved shaft and point, forming angle of approximately 80 °, point extending just past level of tip of superficial root, outer 24 (18 – 27; n = 4) long, inner 29 (29 – 30; n = 4) long, base 10 (10 – 11; n = 4) (Fig. 36). Ventral bar (Fig. 33) 35 (27 – 45; n = 10) long, 4 (3 – 5; n = 10) wide, broadly U-shaped with inflated ends, posteromedial projection developed. Dorsal bar (Fig. 34) 29 (21 – 38; n = 10) long, 3 (2 – 3; n = 10) wide, V-shaped, with slightly inflated ends. Hooks similar (Fig. 32), 21 (20 – 25; n = 10) long, with upright slightly acute thumb; slightly curved shaft, short; dilated shank; filamentous hook about ½ shank length. Genital pore opening midventral, anterior to copulatory complex. Testis post-germarial, dorsal to germarium, ovoid 25 (20 – 30; n = 2) long, 19 (19 – 20; n = 2) wide. Vas deferens looping left of intestinal cecum; seminal vesicle a dilatation of vas deferens; transversally elongated prostatic reservoir. Copulatory complex comprising MCO, accessory piece (Fig. 31). MCO a coiled sclerotized tube, 96 (88 – 106; n = 6) long, with 2 ½ counterclockwise rings, with tapered distal region; base a cap with sclerotized margin. Accessory piece 16 (15 – 18; n = 5) long, elongated, non-articulated with MCO, with tapered proximal region, distal end with small gutter guarding termination of MCO. Germarium 45 (29 – 62; n = 2) long, 18 (16 – 20; n = 2) wide, elongate. Eggs, Mehlis’ gland, ootype and uterus not observed. Vagina slightly sclerotized, ventral, opening sinistrally; vaginal canal slightly sclerotized, distal region with a bulb serving the connection to the seminal receptacle; seminal receptacle, pyriform. Vitelline follicles dense, coextensive with ceca. Comparative measurements. Table 7. Etymology. The species is dedicated to Dr. Gregory J. Klassen in recognition for his work on systematics of monogenoids. Remarks. Vancleaveus klasseni sp. nov. differs from its congeners by (1) possessing anchors with divergent roots; superficial root triangular to subtriangular, well developed, with conspicuous fold; deep root developed; curved shaft and point; (2) MCO a coiled sclerotized tube with 2 ½ rings, base with sclerotized margin; and (3) accessory piece with small gutter in the distal.	en	Soares, Geusivam Barbosa, Neto, João Flor dos Santos, Domingues, Marcus Vinicius (2018): Dactylogyrids (Platyhelminthes: Monogenoidea) from the gills of Hassar gabiru and Hassar orestis (Siluriformes: Doradidae) from the Xingu Basin, Brazil. Zoologia (e 23917) 35: 1-19, DOI: 10.3897/zoologia.35.e23917, URL: http://dx.doi.org/10.3897/zoologia.35.e23917
