Hamatopeduncularia cangatae, Domingues, Marcus V., Soares, Geusivam B. & Watanabe, Alana, 2016

Domingues, Marcus V., Soares, Geusivam B. & Watanabe, Alana, 2016, Monogenoidea (Polyonchoinea: Dactylogyridae) parasitizing the gills of marine catfish (Siluriformes: Ariidae) inhabiting the Atlantic Amazon Coast of Brazil, Zootaxa 4127 (2), pp. 301-326 : 315-317

Hamatopeduncularia cangatae n. sp.

( Figs. 30–36 )

Type-host: Aspistor quadriscutis (Valenciennes)

Site of infection: Secondary lamellae of the gills.

Type locality: Fish market, Municipality of Bragança, State of Pará, Brazil.

Other records: Aspistor quadriscutis, Fishing village of Ajuruteua, Municipality of Bragança, State of Pará, Brazil (0°49’31”N, 46°36'29"W); Notarius grandicassis (Valenciennes) , Bombom Village, Municipality of Viseu, State of Pará, Brazil (01°11’48”N, 46°08’24”W); N. grandicassis, Fishing village of Ajuruteua, Municipality of Bragança, State of Pará, Brazil; N. grandicassis, Fish market, Municipality of Bragança, State of Pará, Brazil.

Prevalence of infection: 30 of 52 Aspistor quadriscutis (57%); 12 of 13 Notarius grandicassis (92%).

Specimens deposited: Holotype, CHIOC 38264; 5 paratypes, CHIOC 38265a–b, 38266, INPA 670–671; 22 vouchers, CHIOC 38267–38272, INPA 672–677, MPEG 063–067.

Etymology: The specific name is derived from the local name of the type host, bagre-cangatá or cangatã.

Comparative measurements: Table 5 .

Description: Based on 12 adult specimens; 3 mounted in Gomori’s trichrome, 9 mounted in Hoyer’ medium. Body fusiform ( Fig. 30 ), total length excluding haptor 682 (600–740; n = 5) long, 105 (90–140; n=6) wide at level of germarium. Tegument smooth. Cephalic margin tapered with moderately developed terminal lobes containing three bilateral pairs of head organs with rod-shaped secretion. Cephalic glands unicellular, posterolateral to pharynx. Eyes present (two pairs), with posterior pair closer together than anterior pair; accessory granules absent or few in cephalic area, spherical. Mouth subterminal, midventral; pharynx ovate to subspherical, 50 (40–62; n=3) long, 35 (27–45; n=3) wide; oesophagus short; intestinal ceca, nonconfluent, lacking diverticula. Genital pore opening midventral, anterior to copulatory complex, genital atrium muscular. Testis post-germarial, dorsal to germarium. Testis pyriform, 160 (n=1) long, 140 (127–152; n=2) wide. Vas deferens apparently looping left intestinal cecum; seminal vesicle a dilatation of vas deferens; seminal vesicle with extensive loops flanking left margin; proximal loop, ascendant, extend close to cephalic glands; medial loop, descendant, extend to anterior portion of testis and looping anteriorly originating distal loop that extend to the base of male copulatory organ. One prostatic reservoir, pyriform, lying dorsal anterior to copulatory complex. Copulatory complex comprising male copulatory organ, accessory piece; male copulatory organ sclerotized, arcuate 64(54–69; n=10) long, proximal portion bent, directed anteriorly; distal aperture subterminal; base with sclerotized margin. Accessory piece sclerotized, non-articulated with male copulatory organ, comprising a variable sheath ( Fig. 32 ). Germarium 55 long (n = 1), 50 (n = 1) wide, oval. Vagina comprises a vaginal aperture with dextroventral opening, submarginal; vaginal vestibule with soft tissue, vaginal canal elongated, muscular. Seminal receptacle spherical. Unidentified tube, heavily sclerotized, running dorsally at midline of body and extends close to cephalic glands. Ootype not observed. Vitellaria coextensive with caeca. Eggs not observed. Peduncle elongate. Haptor digitate, 140(n=1) long, 90(n=1) wide. Anchors are similar, members of ventral pair larger than those of dorsal pair; each with moderately long depressed superficial root with short to nonexistent deep root, evenly curved shaft, point. Ventral anchor ( Fig. 35 ) 46 (42–50; n=4) long, base 22 (12–27; n=4) long, superficial root 30 (25–32; n=8) long. Dorsal anchor ( Fig. 36 ) 57 (50–65; n=5) long, base 26 (17–32; n=5) long, superficial root 42 (38–44; n=8) long. Ventral bar ( Fig. 33 ) broadly U-shaped with longitudinal groove at both terminations, 15 (10–20; n=3) long, 60 (n=1) wide. Dorsal bar ( Fig. 34 ) 8 (7–10; n=3) long, 65 (62–67; n=3) wide, elongate, with delicate tapered ends; longitudinal groove at both terminations. Hooks similar in shape ( Fig. 31 ), 15 (14–16; n = 9) long, shank without inflation, depressed thumb, lightly curved long shaft, delicate point; filamentous hook loop not observed.

Remarks: Hamatopeduncularia cangatae n. sp. seems to be closely related to H. isosimplex Lim, 1996 , H. malayanus Lim, 1996 , and H. simplex Bychowsky & Nagibina, 1969 because they share ventral pair of anchors larger than those of dorsal pair, each with depressed moderately long superficial root and short to nonexistent deep root. These species also share a subterminal opening in the distal portion of the male copulatory organ. The new species can be easily distinguished from these species and other congeners by the combination of the following characters: (1) male copulatory organ arcuate “J”-shape; (2) hooks without shank inflation; (3) vas deferens long and convoluted; and (4) an unidentified sclerotized tube running dorsally at midline of the body, extending close to cephalic glands.

Figures

FIGURES 30 – 36. Hamatopeduncularia cangatae n. sp. 30. Holotype, whole-mount (ventral). 31. Hook. 32. Copulatory complex. 33. Ventral bar. 34. Dorsal bar. 35. Ventral anchor. 36. Dorsal anchor. Fig. 30 scale of 100 µm; Fig. 31 scale of 10 µm; Figs. 32 – 36 scale of 25 µm.

Tables

TABLE 5. Comparative measurements (in µm) of specimens of Hamatopeduncularia cangatae n. sp. from Aspistor quadriscutis and Notarius grandicassis. MCO = male copulatory organ.

A. quadriscutis	N	N. grandicassis	N
Body
Length 682 (600–740)	5	900	1
Width 105 (90–140)	6	145 (140–150)	2
Haptor
Length 140	1	133 (100–150)	3
Width 90	1	85 (80–90)	2
Pharynx
Length 50 (40–62)	3	55 (52–58)	5
Width 35 (27–45)	3	41 (35–47)	5
MCO length 65 (62–67)	3	64 (54–69)	10
MCO ring 21 (20–23)	4	19 (15–22)	10
Ventral Bar
Length 15 (10–20)	3	6 (5–7)	12
Width 60	1	66 (49–74)	11
Dorsal Bar
Length 8 (7–10)	3	5 (5–6)	13
Width 65 (62–67)	3	63 (56–76)	11
Ventral Anchor
Inner 30 (25–32)	8	33 (29–35)	12
Outer 46 (42–50)	4	46 (43–49)	12
Base 22 (12–27)	4	14 (11–16)	12
Dorsal Anchor
Inner 42 (38–44)	8	45 (41–48)	12
Outer 57 (50–65)	5	63 (59–67)	12
Base 26 (17–32)	5	16 (14–17)	12
Hooks 15 (14–16)	9	12 (10–16)	11
Germarium
Length 55	1	84	1
Width 50	1	43	1
Testis
Length 160	1	162 (124–195)	6
Width 140 (127–152)	2	74 (56–84)	6