Microdalyellia armigera ( Schmidt, 1861 ) Gieysztor, 1938a

Steenkiste, Niels Van, Tessens, Bart, Krznaric, Kathleen & Artois, Tom, 2011, Dalytyphloplanida (Platyhelminthes: Rhabdocoela) from Andalusia, Spain, with the description of four new species, Zootaxa 2791, pp. 1-29 : 19-20

Microdalyellia armigera ( Schmidt, 1861) Gieysztor, 1938a

( Fig. 8 A)

syn. Vo rt e x a r m i ge r Schmidt, 1861

syn. Dalyellia armiger Graff, 1904 –1908 syn. Dalyellia armigera Hofsten, 1912

syn. Dalyellia armygera Valkanov, 1926 syn. Microdalyellia armiger Gieysztor, 1938a

New locality in Spain. Doñana National Park, Provincia de Huelva, Spain (36°58’50”N, 6°29’11”W). Laguna Dulce: swamp vegetation on the northern edge and floating algae and submersed vegetation on the border of the marsh and open water (19/03/2008; 06/04/2008).

Other localities in Spain. Central areas (Sierra de Guadarrama and river Tajo basin, see Gamo & Noreña- Janssen 1998); Corpa (Provincia de Madrid, Comunidad de Madrid), Fuentenovilla and Cogolludo (Provincia de Guadalajara, Castilla-La Mancha) ( Gamo 1987a, 1987b).

New localities outside Spain. Palearctic: Stekene, East Flanders, Belgium (51°14’26”N, 04°05’26”E; 51°14’25”N, 04°05’29”E; 51°14’32”N, 04°05’03”E). Stropers: aquatic vegetation in ditches and temporal ponds along the forest edge (13/07/2008).

Genk, Limburg, Belgium (50°55’30”N, 05°23’39”E; 50°57’21”N, 05°27’41”E). De Maten: submersed aquatic vegetation (grasses and Mentha aquatica ) from a pond and the Stiemerbeek (17/07/2008).

Kampenhout, Flemish Brabant, Belgium (50°55’40”N, 04°31’19”E). Hellebos: submersed grasses from a ditch (09/03/2009).

Opoeteren, Limburg, Belgium. Area of the Bosbeek: floating vegetation from a puddle with lots of pine needles and leaf litter (18/05/2009).

Seckauer Tauern, Niedere Tauern, Styria, Austria (47°20’39”N, 14°53’14”E, alt. 1315 m; 47°20’39”N, 14°53’22”E, alt. 1330 m). Valley north of Krautbath: aquatic vegetation in a small, shallow pond along the side of a track fed by a mountain stream; aquatic vegetation in marshy areas on the end of the track (23/06/2009).

Sölktäler Nature Park, Schladminger Tauern, Niedere Tauern, Styria, Austria (47°17’17”N, 13°52’01”E, alt. 1218 m). Schwarzensee near Kleinsölk: aquatic vegetation and mosses in a Sphagnum bog fed by a mountain stream southwest of the Schwarzensee (27/06/2009).

Gleinalpe, Lavanttal Alps, Styria, Austria (47°13’50”N, 14°58’57”E, alt. 1464 m). Glein Rachau: aquatic vegetation in mountain stream (29/06/2009).

Sumava National Park, South Bohemian Region, Czech Republic (48°58’13”N, 13°35’19”E, alt. 1216 m). Bogs and coniferous forests around Bučina: aquatic vegetation in forested Sphagnum bog (02/07/2009).

Palatinate Forest Nature Park, Rhineland-Palatinate, Germany (49°17’20”N, 07°49’14”E, alt. 536 m). Forests east of Leimen: moss and organic material in forest spring (04/08/2009).

Longskär, Raseborg, Uusimaa, Finland (59°49’09”N, 23°15’36”E). Submersed grasses in freshwater lake (07/ 08/2008).

Pojo, Raseborg, Uusimaa, Finland (60°05’30”N, 23°31’46”E). Mosses along small canal close to water edge (10/08/2008).

Known distribution. Widespread throughout the Palearctic: many localities in Europe, Western Russia, the Caucasus, Siberia and Japan (see Luther 1955 for localities and references), Western Europe ( UK: East Midlands, East of England, West Midlands and North Wales) ( Young 1970, 1973), Central Europe ( Germany: Schleswig-Holstein, Black Forest, Lake Constance, Thuringia, Franconia, Oberhessen, South Lower Saxony, Elbe estuary; Austria: Burgenland) ( Rixen 1961, 1965, 1968; Kraus 1965; Pörner 1966; Bauchhenss 1971; Schwank 1976, 1981, 1985; Heitkamp 1982; Müller & Faubel 1993), Eastern Europe ( Romania: freshwater sources of littoral lakes of the Black Sea, Bucegi Mountains, Retezat Mountains, Wallachian Plain; Poland: Greater Poland Province) ( Mack-Fira 1970b; Kolasa 1974), Western Russia (Northern Dvina River and upper Volga River) ( Korgina 1999, 2002) and the Middle East ( Israel) ( Noreña et al. 2008); Nearctic: localities in the USA uncertain according to Ruebush (1937).

Material. Studies on live animals from Spain of which two were whole mounted. Observations on live animals from the other new localities and several whole mounts (14 from Belgium, 7 from Austria, 2 from the Czech Republic, 1 from Germany, 1 from Finland).

Remarks. Animals from Andalusia are translucent, with a reddish colour frontally. Habitus and internal organization as described by Luther (1955). The characteristic stylet is about 165 µm long. The left distal axis consists of one spine in the whole mounts, but two spines were observed in a live specimen. The right distal axis bears eight spines, the most proximal one being the largest. The length range of the stylet of other palearctic populations usually varies between 82–125 µm (see Luther 1955; Rixen 1961; Bauchhenss 1971). Only the specimens from the Elbe estuary ( Müller & Faubel 1993) and Microdalyellia armigera var. vinculosa ( Szynal, 1933) Gieysztor, 1938a from Franconia ( Germany) ( Bauchhenss 1971) and the Western and Eastern Carpathians ( Szynal 1933; Gieysztor & Szynal 1939; Luther 1955), have considerably larger stylets (between 125–220 µm). As stated by Luther (1955) and other authors (see e.g. Bauchhenss 1971; Müller & Faubel 1993), the number of spines on the right distal axis (even within the same population) can range between three and nine. Also on the left distal axis, more than one spine can be present (up to four in Bauchhenss 1971). Its variable stylet morphology and widespread occurrence and abundance in many different types of freshwater habitats suggest a complex evolutionary history.

Figures

FIGURE 8. Microdalyellia armigera (Schmidt, 1861) Gieysztor, 1938 a (A) Stylet. Gieysztoria cuspidata (Schmidt, 1861) Ruebush & Hayes, 1939 (B) Stylet (arrows indicate digitiform protuberances). Gieysztoria macrovariata (Weise, 1942) Ruebush & Hayes, 1939 (C) Stylet. Gieysztoria beltrani (Gieysztor, 1931) Ruebush & Hayes, 1939 (D) Stylet.