Anacanthorus parakruidenieri, 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 : 62

Anacanthorus parakruidenieri sp. n.

( Figs. 9–10 )

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 of 26 fishes examined)

Specimens studied. Holotype, CHIOC 37656; 10 paratypes, CHIOC 37603a–b, 37617, 37624, 37633a–b, 37639, 37661a–b, 37697.

Etymology. The species name alludes to its proximity to Anacanthorus kruidenieri Kritsky, Thatcher & Kayton, 1979 .

Description. (Based on 11 specimens). Body 600 (445–775; n=7) long, 140 (110–170; n=7) wide. Tegument smooth. Cephalic lobes well developed. Eyes 4, posterior pair larger than anterior pair. Pharynx 32–50 long, 30–36 wide (n=2). Haptor with 7 pairs of hooks with anacanthorine distribution. Anchors, bars absent. Hooks 43 (40–47; n=41), with truncate thumb, straight shaft, recurved point inconspicuous or absent, shank with expanded proximal bulbous portion with anterior subcircular foramen; bulbous portion of shank of variable length. FH loop 0.5 length of shank. Male copulatory organ 83 (75–87; n=7) long, a sclerotized tube, wide, slightly sinuous, base lacking sclerotized flange. Accessory piece 74 (70–80; n=7) long, articulated, rod-shaped, bifid near midlength, branches distally blunt. Testis post germarian; seminal vesicle a dilation of vas deferens; vas deferens looping left intestinal cecum. Germarium 40 long, 70 wide (n=1). Vitellaria in two bilateral fields of trunk, from pharynx to the posterior region of trunk, coextensive with intestinal ceca. Oviduct, ootype not observed. Metraterm delicate, non sclerotized. Eggs not observed.

Remarks. The shape of the marginal hooks, with an inconspicuous point, truncate thumb and a bulbous proximal shank bearing a foramen, and of the copulatory complex suggests the morphological and, likely, the phylogenetic proximity of the new species to Anacanthorus kruidenieri Kritsky, Thatcher & Kayton, 1979 , a parasite of Brycon melanopterus (Cope) from Amazon River Basin. These species are, however, easily distinguishable by the presence of a bifurcated accessory piece and a subcircular foramen in the shank bulb of A. parakruidnieri sp. n. The accessory piece of A. kruidenieri is single and the foramen of the hook shank elongate and ovate.

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.