Anacanthorus lacinimentulatus, 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 : 311-312

Anacanthorus lacinimentulatus sp. n.

( Figs. 16–19 )

Type-host: Hoplerythrinus unitaeniatus (Spix & Agassiz) , Erythrinidae .

Site of infection. Gills.

Type-locality: Igarapé Arinandeua—Guamá River, municipality of São Miguel do Guamá, State of Pará, Brazil (1°37’42.50”S 47°29’45.06”W).

Other localities: Hoplerythrinus unitaeniatus (Prevalence: 16% of six hosts examined; Mean intensity: two parasites per host infected), Igarapé Maratininga—Moju River, municipality of Tailândia, Pará State (02º27’55.7”S 048º53’27.6”W).

Prevalence: 33% of three hosts examined.

Mean intensity: 1 parasite per host infected.

Specimens deposited: Holotype: CHIOC no. 40031 a. 2 paratypes: CHIOC nos. 40031 b–c. 2 vouchers: CH- IOC nos. 40031 a–b.

ZooBank registration: The Life Science Identifier (LSID) urn:lsid:zoobank.org:act:CEE15CB2-A8F7-44E8-8743-BC2FBC98CF65 .

Etymology: The specific epithet derives from the Latin (lacini = flap + mentul = penis), and refers to the flap morphology in the distal region of the MCO.

Comparative measurements: Table 4.

Description: (Based on three specimens, two mounted in Gomori trichrome and one mounted in Hoyer’s). Body fusiform 380 (337–410; n=3) long, excluding the haptor, 66 (52–85; n=3) wide at the height of germarium ( Fig. 16 ). Four cephalic lobes developed; three groups of head organs; cephalic glands not observed ( Fig. 16 ). Two pairs of ocelli, anterior pair smaller than the posterior pair; accessory granules absent ( Fig. 16 ). Pharynx oval or subspherical 29 (28–30; n=3) long, 24 (20–28; n=3) wide; oesophagus elongated ( Fig. 16 ). Two intestinal caeca confluent, posterior to the gonads ( Fig. 16 ). Genital pore not observed. MCO 32 (24–38; n=3) long, 8 (6–9; n=3) wide, sclerotized, simple and tubular, with extrovert flap skirting the distal region of the MCO ( Fig. 17 ); accessory piece absent ( Fig. 17 ). Seminal vesicle long, ascending from the vas deferens and looping the intestinal caecum near the testis ( Fig. 16 ). Gonads not overlapping; germarium 43 (36–49; n=2) long, 21 (15–26; n=2) wide; testis posterior to germarium, oval 45 (44–46; n=2) long, 24 (22–25; n=2) wide ( Fig. 16 ). Prostatic reservoir not observed. Peduncle elongated ( Fig 16 ). Haptor bilobed 34 (27–42; n=3) long, 52 (45–60; n=3) wide ( Fig. 16 ). Similar 4A hooks, with a proximal region, dilated, comprising ¼ of the hook length ( Fig. 18 ). Seven pairs of similar hooks 27 (n=1) long; blade slightly curved, point short and curved, shank with proximal dilatation 12 (n=1) long, comprising approximately ½ of the total shank length; thumb erect and short ( Fig. 19 ). Hook filament delicate, extending until near the shank dilatation ( Fig. 19 ).

Remarks: Anacanthorus lacinimentulatus sp. n. differs from the other Anacanthorus species for having MCO with extrovert flap skirting its distal region and the absence of accessory piece. The hooks have a shank with proximal dilatation comprising approximately ½ of the total shank length.

Figures

FIGURES 16–19. Anacanthorus lacinimentulatus sp. n. 16. Holotype whole-mount (ventral); 17. Male copulatory organ (MCO); 18. 4A hooks; 19. Hook. Fig. 16 scale of 50µm; Fig. 17 scale of 25µm; Figs. 18–19 scale of 10µm.