Subterranean Aquatic Planarians of Sardinia, with a Discussion on the Penial Flagellum and the Bursal Canal Sphincter in the Genus Dendrocoelum (Platyhelminthes, Tricladida, Dendrocoelidae)

Abstract

The paper provides the first detailed account on the taxonomic richness of the subterranean freshwater triclads from Sardinia, including the description of four new species for the genera Dendrocoelum and Phagocata. New records for Dugesia benazzii, Dugesia sp., Crenobia alpina, and Phagocata sp. are also reported. The three new species of Dendrocoelum are the first reported for the island of Sardinia. These species display a bursal canal sphincter and a large adenodactyl with a characteristic anatomy with a zone of fine circular muscle fibers running through the mesenchyme of its papilla. A detailed analysis of the structure of the penial flagellum in the genus Dendrocoelum highlighted six main conditions, some of which have not been previously reported, in regard to the histology of the tip of the penis papilla and the extent of its inversion. The new species of Phagocata represents the first species recorded from Italy and the first anophtalmous species reported from Europe.

A new species of freshwater flatworm (Platyhelminthes, Tricladida, Dendrocoelidae) inhabiting a chemoautotrophic groundwater ecosystem in Romania

“…mariae, D. nuraghum andD. vesiculosum from Sardinia (Stocchino et al 2013). The discovery of the Balkan type of adenodactyl in Romanian animals as well enlarges the geographic range of this character and corroborates the wide distribution of this character among Dendrocoelum species, as already hypothesised by Harrath et al (2012).…”

“…Dendrocoelum stenophallus is characterized by an "inflexible flagellum" sensu Stocchino et al (2013) (see also Sluys 2012), which is absent in D. obstinatum. The former species has also been described with an elongated muscular sphincter ("sphincter papilliforme") at the level of the atrial papilla.…”

“…Gourbault 1972Gourbault , 1986Dahm & Gourbault 1978;Kenk 1978;Bromley 1982;Dyganova 1988;Sluys & Benazzi 1992;Vila-Farrè et al 2011;Harrath et al 2012;Sluys 2012;Stocchino et al 2013).…”

“…Sluys 1989) their presence is not a universal character among these flatworms. For example, among dendrocoelids spermatophores are also absent in D. mariae Stocchino & Sluys, 2013, D. nuraghum Stocchino & Sluys, 2013and D. vesiculosum Stocchino & Sluys, 2013. Among invertebrates spermatophores usually occur in species that need to protect sperm during their transfer from males to females (cf.…”

Overview of life cycles in model species of the genusDugesia(Platyhelminthes: Tricladida)

“…Dugesia etrusca is restricted to Tuscany and Sardinia (Benazzi 1946;Pala et al 1980 Stocchino et al 2013) and from the Molara Islet (EM lab strain) in June 1979 respectively (Pala et al 1980). The life cycle of both species was monitored for more than 13 years.…”