Chauhanellus boegeri, Domingues, Marcus V. & Fehlauer, Karin H., 2006

Domingues, Marcus V. & Fehlauer, Karin H., 2006, New species of Chauhanellus (Monogenoidea, Platyhelminthes) from the gills of Southern Atlantic marine catfishes (Siluriformes, Ariidae) of the Neotropical region, Zootaxa 1365, pp. 61-68 : 65-68

Chauhanellus boegeri n. sp.

( Figs 8–14 )

Type-host: Genidens barbus (Lacepède, 1803) .

Site: Gills.

Type-locality: Baía de Guaratuba, Municipality of Guaratuba, State of Paraná, Brazil (01–XII–1998).

Other records: Genidens genidens (Cuvier, 1829) , Baía de Guaratuba, Municipality of Guaratuba, State of Paraná, Brazil (05–I–1994).

Specimens deposited: Holotype, MZUSP 6354; 19 paratypes, CHIOC 36821 a–e, MZUSP 6355 a–k, USNPC 98919; 8 vouchers, CHIOC 36822 a–b, MZUSP 6356 a–d; USNPC 98920.

Etymology: The specific name is in honor of Dr. Walter A. Boeger, Universidade Federal do Paraná, Brazil, in recognition of his valuable work on the Neotropical Monogenoidea.

Comparative measurements: Table 1 .

Description: (Based on 20 adult specimens) Body 1028 (940–1100; n=5) long, fusiform; greatest width 143 (125–163; n=8) usually at level of germarium. Tegument smooth. Cephalic lobes moderately developed; three pairs of head organs; cephalic glands unicellular, posterolateral to pharynx. Eyes 4; posterior pair closer than anterior pair; accessory granules absent or few in cephalic area. Mouth subterminal, midventral; pharynx spherical to subovate, 57 (48–65; n=7) in diameter; esophagus short; intestinal ceca two, nonconfluent, lacking diverticula. Haptor subspherical to hexagonal, 202 (173–234; n=4) long, 133 (144–168; n=4) wide. Anchors dissimilar; ventral anchor 71 (61–75; n=4) long, base 61 (59–64; n=4) wide, robust, with truncate superficial root, deep root expanded into wings, recurved shaft, short slightly recurved point. Dorsal anchor 85 (82–87; n= 4) long, base 35 (32–40; n=3) wide, robust, with inconspicuous superficial root, expanded deep root, evenly curved shaft and point; anchor spine blunt. Ventral bar 30 (28–31; n=3) long, 154 (139–166; n=3) wide, with protuberances at each end for articulation with ventral anchor; posterior protuberances foot-like. Dorsal bar 28 (25–33; n=3) long, 112 (103–120; n=2) wide, V-shaped, with spines on both ends, elongate posteromedial process bent ventrally. Hooks similar; each 16 (14–18; n=20) long, with depressed thumb, evenly curved, shaft, delicate point, shank without inflation, filamentous hook loop (FH loop) about half of shank length. Male copulatory organ sclerotised, a coiled tube of about 1 ¼ counterclockwise rings, 67 (61–75; n=15) long, base with sclerotised margin, flattened end; proximal ring diameter 22 (19–26; n=15). Accessory Genidens barbus N Genidens genidens N

Body

piece a variable sheath. Testis 206 (163–300; n=8) long, 82 (72–101; n=9) wide, pyriform; seminal vesicle sigmoid; prostatic reservoir ovate. Germarium 83 (72–96; n=8) long, 60 (50–72; n=8) wide, subspherical. Ootype not observed. Vaginal aperture dextral, vagina muscular. Seminal receptacle transversely ovate. Vitellaria coextensive with caeca. Eggs not observed.

Remarks: Chauhanellus boegeri n. sp. resembles C. neotropicalis based on the general morphology of haptoral structures. However, C. boegeri can be distinguished from C. neotropicalis by the morphology of the male copulatory organ. The distal tip of the male copulatory organ is flattened in C. boegeri and acute in the C. neotropicalis . Further, the morphology of the germarium (ovate in C. boegeri , pyriform in C. neotropicalis ) and the seminal receptacle (transversely pyriform in C. boegeri , sigmoid in C. neotropicalis ) can be used to distinguish both species.

Figures

FIGURES 8 – 14. Chauhanellus boegeri n. sp. 8. Holotype, ventral view. 9. Copulatory Complex. 10. Hook. 11. Ventral bar. 12. Dorsal bar. 13. Ventral anchor. 14. Ventral anchor. Fig. 8. scale 100 µm; Figs. 9 – 14 scale of 25 µm.

Tables

TABLE 1. Comparative measurements (in Μm) of specimens of Chauhanellus boegeri n. sp. from two species of Genidens from Brazil.

Length	1028 (940–1100)	5 730	1
Width	143 (125–163)	8 116 (113–120)	2
Pharynx
Diameter	57 (48–65)	7 49 (46–53)	2
Haptor
Length	202 (173–234)	4 144 (151–162)	2
Width	133 (144–168)	4 103 (101–106)	2
Copulatory organ
Length	67 (61–75)	15 68 (58–76)	7
Diameter	22 (19–26)	15 20 (15–25)	7
Ventral anchor
Length	71 (65–75)	4 62 (60–64)	2
Base width	61 (59–64)	4 45 (40–50)	3
Dorsal anchor
Length	85 (82–87)	4 67 (62–72)	2
Width	35 (32–40)	3 28 (25–30)	2
Ventral bar
Length	30 (28–31)	3 23 (22–24)	3
Width	154 (139–166)	3 104 (96–113)	2
Dorsal bar
Length	28 (25–33)	3 20	2
Width	112 (103–120)	2 103 (91–115)	2
Hook lengths
Pair 1	16 (14–16)	4 15	2
Pair 2	15 (15–16)	3 15	2
Pair 3	16	1 14	1
Pair 4	16 (14–17)	3 15	1
Pair 5	16 (15–17)	2 17	1
Pair 6	18	3 18 (17–18)	2
Pair 7	18 (17–18)	4 17	1
Testis
Length	206 (163–300)	8 136 (125–146)	2
Width	82 (72–101)	9 76 (70–82)	2
Germarium
Length	83 (72–96)	8 55	2
Width	60 (50–72)	8 48	2