Anacanthorus circumspatulatus Santos Neto & Muriel-Cunha & Domingues 2019, sp. n.
Creators: name: Santos Neto, João F.
name: Muriel-Cunha, Janice
name: Domingues, Marcus V.
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Platyhelminthes
Monogenea
Dactylogyridea
Dactylogyridae
Anacanthorus
Anacanthorus circumspatulatus

description: Anacanthorus circumspatulatus sp. n.
(Figs. 26–28)
Type-host: Erythrinus erythrinus (Bloch & Schneider), Erythrinidae.
Site of infection: Gills.
Type-locality: Igarapé Cururutuia—Caeté River, municipality of Bragança, Pará State, Brazil (1°4’44.55”S 46°44’18.54”W).
Prevalence: 100% of one host examined.
Mean intensity: 2 parasites per host infected.
Other localities: Erythrinus erythrinus (Prevalence: 14% of seven hosts examined; Mean intensity: two parasites per host infected), Igarapé Maratininga—Moju River, Tailândia, Pará State (02º27’55.7”S 048º53’27.6”W).
Specimens deposited: Holotype: CHIOC no. 40028 a. 1 paratype: CHIOC no. 40028 b. 2 vouchers: CHIOC nos. 40029 a–b.
ZooBank registration: The Life Science Identifier (LSID) urn: lsid:zoobank.org:act: 37327D29-D790-4145- 8086-35543E65EE71.
Etymology: The specific epithet derives from the Latin (circum = around + spatula = small blades), and refers to the ornament in the form of small blades distributed around the MCO.
Comparative measurements: Table 6.
Description: (Based on two specimens, mounted in Hoyer’s). Body fusiform 314 (283–346; n=2) long, excluding the haptor, 108 (100–116; n=2) wide at the height of germarium. Cephalic lobes developed; three groups of developed head organs; cephalic glands not observed. Two pairs of ocelli; anterior pair smaller than posterior pair; accessory granules ellipsoids, present or absent. Pharynx spherical 30 (28–32; n=2) long, 34 (32–36; n=2) wide. Esophagus not observed. Two intestinal caeca, confluent, posteriorly. Genital pore not observed. MCO 104 (101– 107; n=2) long, sclerotized, tubular, moderately long, with ornaments in the form of pointed and small interleaved blades distributed helically around the MCO, extending from the medial region to the distal region of the MCO (Fig. 26); accessory piece absent (Fig. 26). Seminal vesicle, prostatic reservoir, and gonads not observed. Peduncle short. Haptor sub-hexagonal 42 (30–54; n=2) long, 74 (56–93; n=2) wide. Similar 4A hooks 9 (n=1) long, with proximal portion dilated, comprising 1/3 of the hook length (Fig. 27). Seven pairs of similar hooks, blade slightly curved and robust 28 (n=1) long; shank with proximal dilatation comprising approximately ½ of its length; point short and curved; thumb slightly depressed and robust (Fig. 28). Hook filament delicate, extending proximally to the shank dilatation (Fig. 28).
Remarks: Based on the MCO morphology, Anacanthorus circumspatulatus sp. n. is similar to Anacanthorus ataidei sp. n., since both species share the presence of a tubular and elongated MCO, with ornaments around it. However, they differ from each other by the hook morphology. Anacanthorus circumspatulatus sp. n. has the shank of hooks with a proximal dilatation comprising approximately ½ of the total shank length, a characteristic that is not observed in Anacanthorus ataidei sp. n., which has the shank of the hook without a proximal dilatation.
description: Published as part of 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, pp. 303-320 in Zootaxa 4615 (2) on pages 315-317, DOI: 10.11646/zootaxa.4615.2.4, http://zenodo.org/record/3244704