Anacanthorus ataidei, Santos Neto & Muriel-Cunha & Domingues, 2019

Santos Neto, João F., Muriel-Cunha, Janice & Domingues, Marcus V., 2019, New species of Anacanthorus (Dactylogyridae: Anacanthorinae) from the gills of Hoplerythrinus unitaeniatus and Erythrinus erythrinus (Characiformes: Erythrinidae) of the coastal drainage in the Eastern Amazon, Brazil, Zootaxa 4615 (2), pp. 303-320 : 305-306

Anacanthorus ataidei sp. n.

( Figs. 4–7 )

Type-host: Erythrinus erythrinus (Bloch & Schneider) , Erythrinidae .

Site of infection: Gills.

Type-locality: Igarapé Cururutuia—Caeté River, municipality of Bragança, State of Pará, Brazil (1°4’44.55”S 46°44’18.54”W).

Other localities: Erythrinus erythrinus (Prevalence: 20% of five hosts examined; Mean intensity: five parasites per host infected), Pratinha Community—Caeté River, municipality of Bragança, Pará State (1°5’2.49”S 46°49’44.67”W); E. erythrinus (Prevalence: 25% of the four hosts examined; Mean intensity: six parasites per host infected), Igarapé Maratininga—Moju River, municipality of Tailândia, Pará State (02º27’55.7”S 048º53’27.6”W).

Prevalence: 50% of two hosts examined.

Mean intensity: 10, 5 parasites per host infected.

Specimens deposited: Holotype: CHIOC no. 40026 a. 19 paratypes: CHIOC nos. 40026 b–k; INPA no. 801; MPEG nos. 151–155. 8 vouchers: CHIOC nos. 40027 a–c; INPA nos. 802–803; MPEG no. 156.

ZooBank registration: The Life Science Identifier (LSID) urn:lsid:zoobank.org:act:57058C57-7341-4762-B5E7-E6EEA4033EDB .

Etymology: The specific epithet of the species is named after a local legend from the Northeast Pará, Brazil. Ataíde is a man-like being who inhabits the floodplains and mangroves of Pará State and is known for having a prominent genital organ.

Comparative measurements: Table 1 .

Description: (Based on twenty specimens, nine mounted in Gomori trichrome, eight mounted in Grey & Wess, and three mounted in Hoyer’s). Body fusiform 301 (213–424; n=17) long, excluding the haptor, 81 (37–122; n=18) wide at the height of germarium ( Fig. 7 ). Four cephalic lobes poorly developed; three groups of head organs; cephalic glands not observed ( Fig. 7 ). Two pairs of ocelli, similar in size; accessory granules present, oval-shaped, little scattered in the cephalic area ( Fig. 7 ). Pharynx spheric 20 (16–29; n=14) long, 20 (15–26; n=15) wide; oesophagus elongated ( Fig. 7 ). Two intestinal caeca, confluent, posterior to the gonads ( Fig. 7 ). Genital pore not observed. MCO 179 (112–239; n=11) long, sclerotized, tubular, elongated, extending proximally from the esophagus to close the peduncle region, comprising approximately 60% of the body length, with ribbon-like ornaments around the MCO ( Fig. 4 ); accessory piece absent ( Fig. 4 ). Seminal vesicle long, ascendant branch of the vas deferens looping the right intestinal caecum and posteriorly with a descendant branch, forming the seminal vesicle dorsal to germarium ( Fig. 4 ). Gonads not overlapping; germarium pyriform 45 (33–62; n=12) long, 27 (19–35; n=12) wide; testis oval 26 (17–31; n=4) long, 22 (19–25; n=4) wide, posterior to germarium ( Fig. 7 ). Uterus, muscular and with thick walls. Prostatic reservoir elongated, located near to the germarium with descendant duct directed to the of the MCO ( Fig. 7 ). Peduncle short ( Fig. 7 ). Haptor sub-hexagonal 34 (18–47; n=15) long, 34 (18–47; n=14) wide ( Fig. 7 ). Similar 4A hooks 10 (9–11; n=7) long ( Fig. 6 ). Seven pairs of similar hooks 16 (14–17; n=6) long; blade relatively elongated and slightly curved, point short and curved, delicate shank without proximal dilatation, thumb erect and slightly depressed ( Fig. 5 ). Hook filament delicate, extending more than the half of the shank ( Fig. 5 ).

Remarks: Anacanthorus ataidei sp. n. is similar to Anacanthorus franciscanus Monteiro, Kritsky & Brasil- Sato, 2010 parasite of Brycon orthotaenia Günther ( Characiformes : Bryconidae ) for having an elongated and tubular MCO. The new species differs from A. franciscanus by an elongated MCO, comprising approximately 60% of the body length with ornaments in the form of twisted slides around the MCO (in A. franciscanus , the MCO has no ornaments). Besides, A. franciscanus is characterized by the presence of the shank of hooks with proximal portion dilated in the form of a bulb with two translucent spots (in Anacanthorus ataidei sp. n., the hook has uniform shank).

Figures

FIGURES 1–7. Anacanthorus scyphophallus sp. n. 1. Holotype whole-mount (ventral); 2. Male copulatory organ (MCO); 3. Hook. Anacanthorus ataidei sp. n. 4. MCO; 5. Hook; 6. 4A hooks; 7. Holotype whole-mount (ventral). Fig. 1 scale of 50µm; Figs. 2–3 scale of 25µm; Fig. 4 scale of 25µm; Figs. 5–6 scale of 10µm; Fig. 7 scale of 50µm.