Whittingtonocotyle caetei, Santos Neto, João F., Rodrigues, Allan R. O. & Domingues, Marcus V., 2015

Santos Neto, João F., Rodrigues, Allan R. O. & Domingues, Marcus V., 2015, Proposal of Whittingtonocotyle n. gen. (Dactylogyroidea: Dactylogyridae), with the description of two new species from the gills of Hoplerythrinus unitaeniatus (Characiformes: Erythrinidae) in Brazil, Zootaxa 3937 (1), pp. 191-200 : 193-194

Whittingtonocotyle caetei n. sp.

( Figs. 1–9 )

Type host. Hoplerythrinus unitaeniatus

Site. Gills

Type locality. Caeté River, municipality of Augusto Corrêa, Pará State, Brazil (1°3’58.21” S 46°40’3.65”W) collected in October 2013.

Other records. Guamá River, municipality of Irituia, Pará State, Brazil (01°51’59.8” S, 47°24’17.2”W) collected in July 2014.

Prevalence. 66% of 3 hosts examined.

Mean intensity. 13 parasites per infected host.

Specimens deposited. Holotype, CHIOC 38012a; 5 paratypes, CHIOC 38012b–d, INPA 657, MPEG 00038; 12 vouchers, CHIOC 38013a–f, INPA 658, MPEG 00039–00041.

Etymology. The specific name is derived from the type locality.

Comparative measurements. Table 1 .

Description (based on 6 specimens; 4 mounted in Gomori’s trichrome, 2 mounted in Hoyer’ medium): Body fusiform. Cephalic margin tapered; cephalic lobes poorly developed, 2 pairs; 4–5 pairs of head organs with rodshaped secretion; cephalic glands not observed. Eyes 4, posterior pair slightly larger and farther apart than anterior pair; accessory granules distributed in cephalic and anterior trunk regions. Pharynx spherical to subovate. Male copulatory organ with approximately 29 rings ( Fig. 2 ). Accessory piece, a variable sheath, enclosing some distal rings of MCO. Testis spherical; vas deferens conspicuous; seminal vesicle fusiform; prostatic reservoir large, bacilliform separated into two zones with one terminal area densely stained. Germarium fusiform; oviduct, ootype, Mehlis’ glands, uterus not observed. Vagina comprising vaginal vestibule with soft tissue, vaginal canal heavily sclerotized, coiled, dilated in the distal portion before entering into the seminal receptacle. Seminal receptacle spherical. Peduncle short; pair of haptor glands starting at level of peduncle with long narrow ducts ending at level of the anchor/bar complexes ( Fig. 1 ). Haptor subhexagonal. Anchors dissimilar, with poorly developed roots. Ventral anchor ( Fig. 8 ) with superficial root short, tapered, deep root truncate, broad base, evenly curved shaft, point. Dorsal anchor ( Fig. 9 ) with superficial root depressed, deep root short, evenly curved shaft, point. Ventral bar, broadly V-shaped, ends enlarged. Dorsal bar ( Fig. 4 ), broadly V-shaped, with elongate anteromedial process, ½ dorsal bar length. Hooks similar ( Figs. 6–7 ); each with delicate point and shaft, slightly depressed thumb, elongate straight shank; FH loop ½ shank length; hook pair 1 smaller than hook pairs 2–7.

Remarks. Whittingtonocotyle caetei n. gen. n. sp. is the type species of the genus. The new species is characterized by having: (1) ventral anchor with deep root truncate; (2) prostatic reservoir separated into two zones with one terminal area densely stained; and (3) vaginal canal heavily sclerotized, coiled and dilate distally.

* Type locality; **Dorsal bar length measurement at level of anteromedial process.

Figures

FIGURES 1 – 9. Whittingtonocotyle caetei n. gen. n. sp. 1. Holotype, whole-mount (ventral). 2. Copulatory complex. 3. Egg. 4. Dorsal bar. 5. Ventral bar. 6. Hook pairs 2 – 7. 7. Hook pair 1. 8. Ventral anchor. 9. Dorsal anchor. Fig. 1 scale of 100 µm; Figs. 2, 4 – 5, 8 – 9 scale of 25 µm; Fig. 3 scale of 50 µm; Figs. 6 – 7 scale of 10 µm.

Tables

TABLE 1. Comparative measurements (in Μm) of specimens of Whittingtonocotyle caetei n. gen. n. sp. from two localities, respectively. MCO = male copulatory organ.

	*Caeté River	N Guamá River	N
Body
Length	605 (550–860)	5 978 (700–1280)	8
Width	241 (146–259)	5 244 (146–391)	12
Pharynx
Length	31 (25–38)	3 71 (52– 80)	7
Width	39 (31–55)	3 48 (48–58)	8
Haptor
Length	64 (58–69)	5 59 (50–65)	8
Width	108 (80–125)	5 103 (75–134)	10
Ventral Anchor
Outer	34 (33–35)	3 35 (32–37)	7
Inner	28 (27–30)	3 27 (26–28)	5
Base	12 (11–12)	3 14 (13–15)	7
Dorsal Anchor
Outer	31 (29–33)	3 33 (30–34)	6
Inner	21 (20–23)	3 22 (20–24)	6
Base	16 (16–17)	3 14 (12–15)	7
Ventral Bar
Length		3	4
Width	39 (35–42)	3 43 (42–50)	5
Dorsal Bar
**Length	15 (12–17)	3 14 (12–16)	4
Width	39 (35–45)	3 41 (39–46)	5
Hook pair 1	9	1 8	1
Hook pair 2–7	13 (12–14)	10 12 (11–13)	10
Testis
Length	–	– 34 (32–38)	2
Width	–	– 26 (22–30)
Germarium
Length	98 (70–120)	3 103 (100–107)	3
Width	52 (40–80)	2 49 (40–51)	7
MCO	117 (104–126)	5 110 (100–120)	10
Accessory piece	42 (39–45)	3 –	–
Egg
Length	–	55 (49–60)	2
Width	–	41 (38–43)	2