Cosmetocleithrum bifurcum Mendoza-Franco, Mendoza-Palmero & Scholz, 2016

Soares, Geusivam Barbosa, Neto, João Flor dos Santos & Domingues, Marcus Vinicius, 2018, Dactylogyrids (Platyhelminthes: Monogenoidea) from the gills of Hassar gabiru and Hassar orestis (Siluriformes: Doradidae) from the Xingu Basin, Brazil, Zoologia (e 23917) 35, pp. 1-19 : 10-12

Cosmetocleithrum bifurcum Mendoza-Franco, Mendoza-Palmero & Scholz, 2016

Figs 23–29

Cosmetocleithrum bifurcum, Mendoza-Franco et al. (2016): 858 – 859, figs 6a–h, (descr).

Type host. Hassar orestis (Steindachner, 1875) , Doradidae .

Type locality. Aquarium Momón River , Iquitos, Peru (03°44’56” S, 73°15’13” W) .

Site of infection. Gill filaments.

Other records. Hassar orestis (Prevalence: 100% of 16 hosts examined; Mean intensity: 9.35 parasites per infected host; Mean abundance: 9.35 parasites per host), Xingu River , Belo Monte Community , municipality of Vitória do Xingu, Pará (03°05’52.5”S, 51°43’18.0”W) ; Hassar orestis (Prevalence: 100% of 8 hosts; Mean intensity: 12.6; Mean abundance: 12.6) Xingu River , municipality of Vitória do Xingu, Pará (02°47’27.1”S, 51°59’50.0”W) ; Hassar gabiru (Prevalence: 100% of 2 hosts; Mean intensity: 1; Mean abundance: 1) Iriri River , municipality of Altamira, Pará (03°49’06.4”S, 52°41’25.8”W) ; Hassar gabiru (Prevalence: 84% of 19 hosts; Mean intensity: 2.6; Mean abundance: 2.2), Ilha Grande , Xingu River , municipality of Altamira, Pará (03°35’50.2”S, 52°21’22.5”W) ; Hassar gabiru (Prevalence: 100% of 15 hosts; Mean intensity: 2.6; Mean abundance: 2.6), Bacajá River , municipality of Altamira, Pará (03°33’47.1”S, 51°36’50.3”W) .

Specimens deposited.17 vouchers, CHIOC 39048a–b, 39049 a–c, 39050,39051 a–c, 39052 a–b, INPA 780–781, MPEG 0145–0148.

Comparative measurements. Table 6.

Remarks. A comparative analysis of Cosmetocleithrum bifurcum Mendoza-Franco, Mendoza-Palmero & Scholz, 2016 and specimens of Cosmetocleithrum from Xingu River and related tributaries indicated that they are conspecific, mainly because they both share the morphology of the copulatory complex, bars and anchors. The specimens studied here also are similar morphometrically to those specimens from the type host and locality. Mendoza-Franco et al. (2016) recognized differences between hook pair 7 and the other hook pairs ( Mendoza-Franco et al. 2016: figs 6G–H), where hook pair 7 has a shaft longer and shank more slender than the other hook pairs. The specimens studied here have hooks similar in shape with erect thumb (thumb directed posteriorly in Mendoza-Franco et al.’s specimens), and evenly curved shaft and point (long shaft, delicate point in Mendoza-Franco et al.’s specimens). Cosmetocleithrum bifurcum was primarily characterized by possessing a MCO with about 1–1.5 rings, whereas the specimens studied in the present paper have a sigmoid MCO. However, these variations do not seem to be sufficient enough evidence to propose a new species and we consider them as intraspecific variations.