Redescription of Houssayela sudobim (Woodland, 1935) (Cestoda: Proteocephalidea), a Parasite of Pseudoplatystoma Fasciatum (Pisces: Siluriformes) from the River Amazon

Abstract

The proteocephalidean cestode Houssayela sudobim (Woodland, 1935), the type and only species of Houssayela Rego, 1987, is redescribed on the basis of re-examination of its type-specimens and freshly collected material found in the intestine of the barred sudobim Pseudoplatystoma fasciatum (Siluriformes: Pimelodidae) from the River Amazon in Peru. The validity of the genus is confirmed, but its diagnosis is amended because suckers possess four pairs of cone-shaped (papilla-like) projections on their anterior margins (rather than 16, as reported in the original description), the actual number of testes is more than 400 in a proglottis (not 150 as given by Woodland, 1935) and the vitelline follicles form one dorsolateral medullary band and one lateral cortical band on both sides of proglottides. In addition, the distal (terminal) portion of the vagina has a double sphincter and the cirrus-sac has very thick walls; neither of these characteristics was mentioned in the original description. The specimen collected in Peru represents the first record of the species since its original description in 1935.

A new species of Pseudocrepidobothrium (Cestoda: Proteocephalidea) from Pseudoplatystoma reticulatum (Pisces: Siluriformes) in the Paraná River basin (Argentina)

“…On the other hand, the scolex can also be shared by genera belonging to different subfamilies, as for example Harriscolex and Houssayela with Euzetiella de Chambrier, Rego et Vaucher, 1999 of the Proteocephalinae, and these three with Regoella Arredondo, de Chambrier et Gil de Pertierra, 2013 of the Monticelliinae (de Chambrier et al 1999, de Chambrier and Scholz 2005, Gil de Pertierra and de Chambrier 2013, Arredondo et al 2013. Likewise, Macrobothriotaenia Freze, 1965 and Thaumasioscolex Cañeda-Guzmán, de Chambrier et Scholz, 2001 (both Proteocephaliinae) show a similar scolex morphology (formed by four lobes, with each lobe containing an unilocular, pincer-shaped sucker), but in fact they are not closely related species as demonstrated by Scholz et al (2013); the similarity in the morphology of both scoleces has been explained as an adaptation to the morphology of the hosts' intestine (Scholz et al 2013).…”

Luciaella ivanovae n. g., n. sp. (Eucestoda: Proteocephalidea: Peltidocotylinae), a parasite of Ageneiosus inermis (L.) (Siluriformes: Auchenipteridae) in Argentina

“…Freze, 1965;Rego, 1994;de Chambrier & Vaucher, 1999;Rego et al, 1999;de Chambrier et al, 2006a). Only Houssayela sudobim (Woodland, 1935) has paired cone-shaped (papilla-like) projections on the anterior margin of each unilocular sucker (de Chambrier & Scholz, 2005). The scolex of Harriscolex kaparari (Woodland, 1935) was described as having suckers with unguiculate protrusions (figures 13 and 14 of Rego, 1999), but these seem to be formed by an extension of the apical parenchyma and the musculature of the suckers (figure 62 of de Chambrier & Vaucher, 1999).…”

Annotated checklist of fish cestodes from South America

“… Pseudoplatystoma fasciatum ( Actinopterygii : Pimelodidae ); freshwater; intestine; adult; Amazon River basin; Brazil, Peru ( Woodland 1935a ; Rego 1987b , 2002 ; de Chambrier and Scholz 2005 ; de Chambrier et al 2006a , 2015a , b ).…”