Anacanthorus daulometrus, 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 : 60-61

Anacanthorus daulometrus sp. n.

( Figs. 5–6 , 11–12 )

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. 30.7% (8 of 26 fishes examined)

Specimens studied. Holotype, CHIOC 37681; 25 paratypes, CHIOC 37596, 37602, 37614, 37630, 37636, 37641, 37659, 37663, 37666a–c, 37668, 37671, 37683–37684, 37709a–b, 37711a–c, 37713a–b, 37717, 37726, 37728.

Etymology. The specific name is from Greek (daulo = thick and metra =womb) and refers to the presence of a metraterm with sclerotized walls.

Description. (Based on 26 specimens). Body 525 (460–600; n=8) long, 183 (105–220; n=8) wide. Tegument smooth. Cephalic lobes well developed. Eyes 4, posterior pair larger than anterior; accessory granules scattered in cephalic region. Pharynx 36 (30–45; n=3) long, 28–45 (34; n=3) wide. Haptor 52 (34–70; n=15) long, 127 (86– 175; n=15) wide, slightly bilobed, with 7 pairs of hooks with anacanthorine distribution. Anchors, bars absent. Hooks 23 (18–27; n=63) long, with depressed thumb, curved shaft, short recurved point, shank proximally expanded; FH loop about ½ shank length. MCO 88 (77–98; n=17) long, a thick sigmoid tube with expanded distal end; base with sclerotized borders, opening lateral to longitudinal axis of MCO. Accessory piece 70 (65–78; n=17) long, articulated to MCO, composed by two branches, one branch rod shaped, distally expanded; another branch slightly flattened near midlength, distally bifid. Testis 50 long, 66 wide (n=1), postgermarial; seminal vesicle a dilation of vas deferens; vas deferens looping left intestinal cecum. Germarium 40–54 (n=2) long, irregular. Vitellaria in two bilateral fields of trunk, from pharynx to the posterior region of testes. Oviduct, ootype not observed. Metraterm conspicuous with sclerotized walls. Eggs not observed.

Remarks. The new species is similar to Anacanthorus cuticulovaginus and A. biscuspidatus sp. n. considering that the accessory piece in all of these species is formed by two branches. Contrary to the other two species, however, one of the branches of the accessory piece of A. daulometrus sp. n. is bifid (not hook shaped as in A. bicuspidatus sp. n. nor simply pointed as in A. cuticulovaginus ). Further differentiation of the new species is possible by the presence of a conspicuous metraterm with heavily sclerotized walls.

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.

FIGURES 11 – 12. Anacanthorus daulometrus sp. n. Copulatory complex and metraterm. cc: copulatory complex; vd: vas deferens; mt: metraterm.