Wednesday, October 1, 2014

[Invertebrate • 2014] Hausera hauseri • A New Genus and Species for the First Recorded Cave-dwelling Cavernicola (Platyhelminthes) from South America


Hausera hauseri Leal-Zanchet & Souza, sp. n.  photograph of live specimens in dorsal view, with intestine containing food and the pharynx visible

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.

Type-locality of Hausera hauseri Leal-Zanchet & Souza, sp. n.:
1–2 location in Rio Grande do Norte, Brazil, showing the range of limestone outcrops from the Apodi Group in detail (black) and the location of the Crotes cave (star) 3

Type-locality of Hausera hauseri Leal-Zanchet & Souza, sp. n.:
the location of the Crotes cave surroundings of the main cave entrance (3) and aerial view of the region (4) indicating the cave contours (red/yellow line), main entrance (white arrow) and secondary gallery (red arrow); 5 perennial stream representing the sampling site.

Systematic account

Order Tricladida Lang, 1884
Suborder Cavernicola Sluys, 1990
Family Dimarcusidae Mitchell & Kawakatsu, 1972

Genus Hausera Leal-Zanchet & Souza, gen. n.

Type-species: Hausera hauseri Leal-Zanchet & Souza, sp. n. Monotypic

Diagnosis: Dimarcusidae without eyes and without a copulatory bursa; female genital duct communicating with the intestine; ovovitelline ducts without caudal dichotomy, uniting to form a common ovovitelline duct; follicular testes; sperm ducts separately penetrating the penis bulb.

Distribution: Felipe Guerra (Crotes cave), Brazil

Etymology: The new genus is dedicated to the late Prof Dr Josef Hauser SJ as acknowledgement of his great enthusiasm for the study of freshwater flatworms. Gender: feminine.


Ana Leal-Zanchet, Stella Souza and Rodrigo Ferreira. 2014. A New Genus and Species for the first recorded Cave-dwelling Cavernicola (Platyhelminthes) from South America. ZooKeys. 442: 1-15. DOI:  10.3897/zookeys.442.8199

Brazilian zoologists discovered the first obligate cave- dwelling flatworm in South America

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