Eutheama forrestensis n. sp. (Acotylea, Polycladida, Plathelminthes) from Australia

Abstract

A new species, Eutheama forrestensis n. sp., Acotylea, Polycladida, is described from sandy beaches of the eastern coastline of the tropic region of Australia. The species lives both in surface layers and deeper in the sediment down to the coastal groundwater table.

Theama mediterranea sp. nov. (Platyhelminthes, Polycladida), the first interstitial polyclad from the Mediterranean

“…The new species is easily distinguished from the eastern Australian T. forrestensis (Bulnes & Faubel 2003), as the latter is a very minute species (the holotype, a fixed mature specimen, is 1 mm long), characterized by the presence of a common (male+female) genital pore. The species is described without any sclerotization of the inner lining of the ejaculatory duct, and the penis papilla, which is bulky and massively muscular, is indeed quite different from that of the other species of the genus, in which it is far more slender and elongate.…”

“…Exploitation by polyclads of the mesopsammic niche has been reported so far only for tropical habitats (see, for example, Sopott-Ehlers & Schmidt 1975). Members of the family Theamatidae Marcus, 1949 are among the most characteristic mesopsammic polyclads and show marked adaptations to an interstitial life (such as reduced size, very elongate body, lack of tentacles; Bulnes & Faubel 2003). The few species of the family are known from the Atlantic (Brazil) and the Pacific oceans (Galapagos; northern Australia; Marcus 1949;Sopott-Ehlers & Schmidt 1975;Bulnes & Faubel 2003).…”

“…Members of the family Theamatidae Marcus, 1949 are among the most characteristic mesopsammic polyclads and show marked adaptations to an interstitial life (such as reduced size, very elongate body, lack of tentacles; Bulnes & Faubel 2003). The few species of the family are known from the Atlantic (Brazil) and the Pacific oceans (Galapagos; northern Australia; Marcus 1949;Sopott-Ehlers & Schmidt 1975;Bulnes & Faubel 2003). Research in intertidal habitats of the Mediterranean has revealed the presence of an abundant and widespread representative of the Theamatidae, which is new to science.…”

“…The species is described without any sclerotization of the inner lining of the ejaculatory duct, and the penis papilla, which is bulky and massively muscular, is indeed quite different from that of the other species of the genus, in which it is far more slender and elongate. Furthermore, due to its minute size, the production of eggs is limited, and the uteri of all specimens studied contained at most one single egg (Bulnes & Faubel, 2003).…”

Reversible shifts between interstitial and epibenthic habitats in evolutionary history: Molecular phylogeny of the marine flatworm family Boniniidae (Platyhelminthes: Polycladida: Cotylea) with descriptions of two new species

“…23]). Most polyclads have a relatively large body size (�5 mm) and dwell on the surface of the marine bottom [24], whereas only a tiny fraction inhabit interstitial environments [25]; of the ~800-1,000 species of polyclads described worldwide to date, 12 (5 in 4 acotylean families and 7 in 3 cotylean families) are mesopsammic in the adult stage [25][26][27][28][29][30]. On the other hand, some surface dwellers can also be found from interstitial environments when they are juveniles or subadults (authors' personal observation).…”