Anacanthorus adkruidenieri, Monteiro, Cassandra Moraes, Cohen, Simone Chinicz & Brasil-Sato, Marilia Carvalho, 2015

Monteiro, Cassandra Moraes, Cohen, Simone Chinicz & Brasil-Sato, Marilia Carvalho, 2015, New species and reports of dactylogyrids (Monogenoidea) from Salminus franciscanus (Actinopterygii: Bryconidae) from the upper São Francisco River, Brazil, Zootaxa 3941 (1), pp. 137-143 : 138-139

Anacanthorus adkruidenieri sp. n.

( Figs. 1–3 )

Type locality: São Francisco River, near Três Marias Reservoir (18º12’32”S; 45º15’41”W), State of Minas Gerais, Brazil.

Site. Gills.

Specimens studied. Holotype, CHIOC 38018a and 14 paratypes, CHIOC 38017a–b, 38018b–e, 38019a–d, 38020a–d.

Etymology. the specific epithet, “ adkruidenieri ”, refers to the similarity between the new species, A. kruidenieri , and A. parakruidenieri .

Description. (Based on 16 specimens “in toto”). Body 582 (499–671; n=5) long, 127 (86–168; n=5) wide. Tegument smooth. Cephalic lobes well developed. Eyes 4, posterior pair larger than anterior. Pharynx subspherical, 41 (33–56; n=5) long, 38 (34–48; n=5) wide. Haptor with 7 pairs of hooks and 2 pairs (1 dorsal, 1 ventral) of 4A’s. Anchors, bars absent. Hooks 37 (32–41; n=37), with truncate thumb, shaft straight, recurved point reduced, shank with expanded proximal bulbous portion with central, elliptical foramen. FH loop about 0.4 length of shank. Male copulatory organ 90 (76–104; n=15) long, a sclerotized tube, wide, slightly sinuous with expanded distal portion. Accessory piece 84 (76-101, n = 13) long, rod-shaped, articulated with base of MCO and coiled around it. Testis postgermarial 106 (86–127; n=3) long, 72 (66–79; n=4) wide; vas deferens looping around left intestinal cecum, seminal vesicle a dilation of vas deferens. Germarium 84 (53–91; n=4) long, 50 (36–66; n=5) wide. Vitellaria in two bilateral fields of trunk, extending from pharynx to posterior region of trunk, coextensive with intestinal ceca. Oviduct, ootype not observed. Metraterm delicate, non-sclerotized. Egg not observed.

Remarks. Anacanthorus adkruidenieri sp. n. belongs to a group formed by A. kruidenieri and A. parakruidenieri , with the following characteristics: 1) MCO a sclerotized tube, slightly sinuous; 2) accessory piece articulated with the base of the MCO and rod-shaped; 3) hooks with reduced, inconspicuous or absent recurved portion, shank with expanded proximal bulbous with central foramen. A. adkruidenieri sp. n. differs from A. parakruidenieri mainly by the morphology of the accessory piece: in both species this structure is rod-shaped, but in A. parakruidenieri it has a median bifurcation, while in the new species a bifurcation is not present.

Anacanthorus adkruidenieri sp. n. and A. kruidenieri are very similar in the male copulatory complex. In both species the MCO is a sclerotized, slightly sinuous tube and the accessory piece is an elongated rod, not bifurcated, articulated with the base of the copulatory complex. The species can be differentiated by the dimensions of the male copulatory organ ( A. kruidenieri = 162–190; A. adkruidenieri sp. n. = 76–104) and accessory piece ( A . kruidenieri = 148–174; A. adkruidenieri sp. n. = 76–101), which are larger in A. kruidenieri than in A. adkruidenieri sp. n. Unlike the structures of the male copulatory complex, the hooks of A. kruidenieri are larger than those of A. adkruidenieri sp.n. ( A. kruidenieri = 42–44; A. adkruidenieri sp. n = 32–41). There are also observed differences in the dilated portion of the shaft, which is hexagonal in A. kruidenieri and oval in A. adkruidenieri sp. n.

The type material of A. parakruidenieri was re-studied and the distal portion of the MCO presents a terminal expansion that was not mentioned in the original description.

Figures

FIGURES 1 – 6. Sclerotized structures of Anacanthorus spp. from Salminus franciscanus Lima & Britsky from São Francisco River, Brazil. Figs 1 – 3. Anacanthorus adkruidenieri sp. n. 1. Copulatory complex (dorsal view). 2. Hook. 3. 4 A; Figs 4 – 6. Anacanthorus paradouradensis sp. n. 4. Copulatory complex (dorsal view). 5. Hook. 6. 4 A.