Diaphorocleidus affinis ( Mizelle, Kritsky & Crane, 1968 ) Jogunoori, Kritsky & Venkatanarasaiah, 2004

Silva, Marciara Lopes, Cohen, Simone Chinicz, Ottoni, Felipe Polivanov, Viana, Diego Carvalho, Meneses, Yuri Costa De & Justo, Marcia Cristina Nascimento, 2024, Two new species of Diaphorocleidus and new data on D. affinis (Monogenoidea: Dactylogyridae) parasitizing Bryconops cf. affinis (Characiformes: Iguanodectidae) from the Munim River basin, State of Maranhão, northeastern Brazil, Zootaxa 5403 (1), pp. 91-103 : 98-100

Diaphorocleidus affinis ( Mizelle, Kritsky & Crane, 1968) Jogunoori, Kritsky & Venkatanarasaiah, 2004 ( Figure 5 )

Type-host: Bryconops affinis [referred to as Creatochanes affinis (Günther) ]

Type-locality: Peixe Boi River, near Peixe Boi, State of Pará, Brazil

Site of infestation: Gills

Other host: Bryconops cf. affinis (present study)

Locality: Rural area of Chapadinha in the “Riacho Feio” (03º51’18.1’’S 043º17’14.0’’W) and the urban area of Anapurus in the “Riacho Estrela” (03°40’15.6”S 043°7’9.7”W), tributaries of the Munim River, Munim basin, Maranhão, Brazil .

Parasitological indexes: Total number of hosts: 64; number of infected hosts: 33; total number of parasites: 179; Range of intensity: 1–19

Specimens deposited: Voucher CHIOC 40271, 40272, 40273, 40274, 40275

New data from 34 specimens newly collected and mounted in Hoyer’s medium: Body fusiform, comprising cephalic region, trunk and haptor, 503 (272–665, n = 34) long by 172 (85–305, n = 34) wide at level of vagina. Tegument smooth. Anterior region with cephalic lobes moderately developed; three bilateral pairs of head organs; cephalic glands indistinct. Two pairs of eyes subequal, the anterior is smaller than the posterior pair; rare accessory granules in the cephalic region. Pharynx 37 (30–42, n = 3) in diameter. Oesophagus short, bifurcating into two intestinal caeca, confluent posteriorly to gonads, lacking diverticula. Gonads overlapping; testis elongate dorsoposterior to germarium; seminal vesicle a distal expansion of vas deferens. Vaginal aperture sinistral, sacshaped, opening ventrally near body mid-length, vaginal canal elongated, sclerotized. Oviduct, ooptype, and uterus not visualized. Vitelline follicles scattered throughout trunk but absent around the reproductive organs ( Fig. 5A ). Copulatory complex comprising unarticulated male copulatory organ ( MCO) and accessory piece. MCO sclerotized, tubular, coiled with 1 ½–2 counterclockwise rings, 120 (92–131, n = 25) of total length and 22 (18–26, n = 15) diameter of the first ring; base forming a small tube with two circular flanges at each end. Accessory piece robust, formed by two wide plates, with the basal portion in a single unit that extends to the middle portion of the piece, where they separate and form a pincer, which serves as a guide for the MCO, 36 (30–43, n = 15) long and 17 (12–21, n = 30) wide ( Fig. 5B ). Peduncle inconspicuous. Haptor subhexagonal, armed with 7 pairs of hooks, 71 (65–78, n = 12) long and 108 (71–141, n = 31) wide ( Fig. 5A ). Anchors dissimilar in shape and size; ventral anchor superficial root well-developed, elongate, straight edges; deep root well-developed, rounded distally; slightly curved shaft and short tip; anchor filament present, 33 (29–37, n = 16) long, base 22 (20–24, n = 16) wide ( Fig. 5D ); dorsal anchor wide, with superficial and deep roots exhibiting a sheath; slightly straight shaft stem and short, thick tip; anchor filament present, 12 (10–14, n = 16) long, base 14 (11–15, n = 16) wide ( Fig. 5C ). Ventral bar slightly open V-shaped with depression in the anteromedial region and small medial fracture with expanded ends 36 (30–41, n = 15) long ( Fig. 5F ). Dorsal bar V-shaped, 46 (37–65, n = 15) long ( Fig. 5G ). Hook pairs similar in size and shape, hooks with inconspicuous pointed thumb; and slightly curved point tip, shank composed of two subunits, distal subunit slightly expanded; pair 1, 16 (12–20, n = 24), pair 2, 17 (15–20, n = 22), pair 3, 18 (12–21, n = 26), pair 4, 17 (11–21, n = 24), pair 5, 16 (12–19, n = 26), pair 6, 17 (11–19, n = 23), pair 7, 16 (12–19, n = 21) long. FH loop 0.3 shank length ( Fig. 5E ). Egg 85 by 62.

Remarks: The morphology of the specimens studied herein is similar to the original description, differing only in the body size (specimens of the present study being much larger than the original description), with comparisons presented in Table 2 . Considering that Mizelle et al. (1968) examined only four specimens, the drawings shown are not clearly detailed, and Jogunoori et al. (2004) did not present morphological data, it is opportune to present new morphological data and new drawings for specimens of D. affinis found parasitizing the gills of Bryconops cf. affinis from the Rio Munim basin, which is now reported as a new geographical distribution for this species.

Figures

FIGURE 5. Diaphorocleidus affinis (Mizelle, Kritsky & Crane, 1968) Jogunoori, Kritsky & Venkatanarasaiah, 2004 from Bryconops cf. affinis (Characiformes, Iguanodectidae) from São José, municipality of Chapadinha and in Riacho Estrela, municipality of Anapurus, River Munim basin, Maranhão, Brazil: (a) total, ventral view; (b) copulatory complex, ventral view; (c) dorsal anchor; (d) ventral anchor; (e) hook; (f) ventral bar; (g) dorsal bar. Scale bars: (a) 100 μm; (b, c, d) 20 μm; (e, f, g) 10 μm.