A new genus and species for the first recorded cave-dwelling Cavernicola (Platyhelminthes) from South America

Abstract

Species diversity of Brazilian cave fauna has been seriously underestimated. A karst area located in Felipe Guerra, northeastern Brazil, which is a hotspot of subterranean diversity in Brazil, has revealed more than 20 troglobitic species, most of them still undescribed. Based on recent samplings in this karst area, we document the occurrence of the suborder Cavernicola (Platyhelminthes) in South American hypogean environments for the first time and describe a new genus and species for this suborder. Hausera Leal-Zanchet & Souza, gen. n. has features concordant with those defined for the family Dimarcusidae. The new genus is characterized by two unique features, viz. an intestine extending dorsally to the brain and ovovitelline ducts located dorsally to the nerve cords, which is complemented by a combination of other characters. The type-specimens of Hausera hauseri Leal-Zanchet & Souza, sp. n. are typical stygobionts, unpigmented and eyeless, and they may constitute an oceanic relict as is the case of other stygobiotic invertebrates found in this karst area in northeastern Brazil.

A molecular analysis of the phylogenetic position of the suborder Cavernicola within the Tricladida (Platyhelminthes), with the description of a new species of stygobiont flatworm from Benin

“…16). With the addition of N. bursaelongata from West Africa and the recently described Hausera hauseri Leal‐Zanchet & Souza, from north‐eastern Brazil (Leal‐Zanchet et al ., ), this presumed track across Africa, still indicated by a broken line (cf. Sluys, : fig.…”

“…Since the first proposal of the suborder Cavernicola in 1990, the number of cavernicolans has increased recently by the addition of one more species, and thus the suborder currently comprises six species scattered over five genera, viz. Rhodax Marcus, 1946, Opisthobursa Benazzi, 1972, Balliania Gourbault, 1972, Novomitchellia Özdikmen, ; and Hausera Leal‐Zanchet & Souza, (Sluys, ; Sluys et al ., ; Özdikmen, ; Leal‐Zanchet, de Souza & Ferreira, ). Most of these species have only been collected from subterranean habitats, with the exception of Rhodax evelinae Marcus, 1946.…”

The first two hotspots of subterranean biodiversity in South America

“…Alternatively, other mechanisms of isolation (e.g. parapatric speciation, oceanic introgressions and regressions) might have led to the evolution of many lineages of subterranean fauna in Brazil (Ferreira et al 2010, Fišer et al 2013, Leal-Zanchet et al 2014. Moreover, most of the caves, particularly in tropical countries, have not been thoroughly explored (Deharveng and Bedos 2000, Lienhard and Ferreira 2015.…”

Two new species of freshwater flatworms (Platyhelminthes: Tricladida: Continenticola) from South American caves

“…Two triclad suborders have representatives in Brazilian freshwater environments, namely Continenticola and Cavernicola. Knowledge of triclad diversity in South American subterranean environments is limited to a few records in north and central Brazil, corresponding to the occurrence of a troglophilic and a troglobitic species of the suborder Continenticola (Kawakatsu & Froehlich 1992;Souza et al 2015), besides a troglobitic species of the suborder Cavernicola (Leal-Zanchet et al 2014).…”