Anacanthorus bicuspidatus, Cohen, Simone Chinicz, Kohn, Anna & Boeger, Walter A., 2012

Cohen, Simone Chinicz, Kohn, Anna & Boeger, Walter A., 2012, Neotropical Monogenoidea. 57. Nine new species of Dactylogyridae (Monogenoidea) from the gill of Salminus brasiliensis (Characidae, Characiformes) from the Paraná River, State of Paraná, Brazil, Zootaxa 3149, pp. 57-68 : 58-59

Anacanthorus bicuspidatus sp. n.

( Figs.1–2 )

Type locality. Paraná River below and above of the reservoir of Itaipu Hydroelectric Power Station in the locality of Guaira (24º04’48’’S, 54º15’21’’W), State of Paraná, Brazil

Prevalence. 19.2% (5 out of 26 fishes examined)

Specimens studied. Holotype, CHIOC 37595; 12 paratypes, CHIOC 37587–37588, 37598a–b, 37600, 37604, 37612–37613, 37623, 37631, 37722, 37730.

Etymology. The specific name is from Latin (bi = two, cuspidis = point) and refers to the presence of two pointed branches of the accessory piece.

Description. (Based on 16 specimens). Body 711 (520–890; n=9) long, 214 (130–290; n=9) wide. Tegument smooth. Cephalic lobes well developed, usually 3, with up to 2 head organs each. Eyes 4, posterior pair larger than anterior pair; accessory granules scattered in cephalic region. Pharynx 54 (48–65; n=9) long, 43 (40–50; n=9) wide. Haptor 129 (98–158; n=9) wide, slightly bilobed, with 7 pairs of hooks, with anacanthorine distribution. Anchors, bars absent. Hooks 19 (17–22; n=18), with depressed thumb, curved shaft, short recurved point, shank proximally expanded; filamentous hook (FH) loop ¾ shank length. Dorsal, ventral pairs of 4A hooks, splinter like. MCO 105 (97–112; n=11) long, slightly sigmoid, with pointed projection at the distal opening; base with sclerotized borders, opening lateral to longitudinal axis of MCO. Accessory piece 67 (62–70; n=11) long, articulated to Male copulatory organ (MCO) by a proximal process, rod-like, bifurcated; one branch rod-shaped distally pointed; other branch hook-like, with flattened, subterminal thumb-like projection. Testis postgermarial, 68–85 long, 34–80 wide (n=2); seminal vesicle a dilation of vas deferens; two prostatic reservoirs lying beneath copulatory organ; vas deferens looping left intestinal cecum. Germarium 62 (50–80; n=4) long, round. Vitellaria in two bilateral fields of trunk from pharynx to the posterior region of testes, coextensive with intestinal ceca. Oviduct, ootype not observed. Metraterm with delicate wall, non-sclerotized. Eggs not observed.

Remarks. The new species has great similarity to Anacanthorus cuticulovaginus Kritsky & Thatcher, 1974 (a parasite of Salminus affinis from the Rio Cauca-Rio Magdalena Basin, Colombia) based on the general morphology of hooks, MCO and copulatory complex. The new species can be easily differentiated from A. cuticulovaginus by presenting one of the rami hook shaped and with a subterminal thumb-like expansion (both pointed in A cuticulovaginus ), MCO more delicate and slender, with distal point (MCO more robust and distally wide, funnel shaped in A. cuticulovaginus ).

Figures

FIGURES 1 – 10. Sclerotized parts of Anacanthorus spp. from the dourado, Salminus brasiliensis, from Paraná River, Brazil. Figs. 1 – 2. Anacanthorus bicuspidatus 1. Copulatory complex (dorsal view). 2. Hook. Figs. 3 – 4. Anacanthorus contortus sp. n 3. Copulatory complex (dorsal view). 4. Hook. Figs. 5 – 6. Anacanthorus daulometrus sp. n. 5. Copulatory complex (ventral view). 6. Hook. Figs. 7 – 8. Anacanthorus douradensis sp. n.. 7. Copulatory complex (dorsal view). 8. Hook. Figs. 9 – 10. Anacanthorus kruidenieri sp. n. 9. Copulatory complex (dorsal view). 10. Hook. Fig. 7 is presented to the 50 µm scale; Figs. 2, 4, 6, 8 and 10 to the 10 µm scale; Figs. 1, 3, 5 and 9 to the 30 µm scale.