Lepidodermella squamata ( Dujardin, 1841 )

Kånneby, Tobias, 2011, New species and new records of freshwater Chaetonotida (Gastrotricha) from Sweden, Zootaxa 3115, pp. 29-55 : 47-48

Lepidodermella squamata ( Dujardin, 1841)

( Figure 14 )

Localities. Pond, Storlien W, Jämtland (N 63º 19’ 06’’; E 12º 05’ 22’’); Pond, Storlien E, Jämtland (N 63º 18’ 42’’; E 12º 06’ 43’’); Lake Trösvattnet, Västmanland (N 59º 33’ 21’’; E 14º 29’ 23’’); Gravel pit, Åhus, Skåne (N 55º 55’ 45’’; E 14º 15’ 08’’); Small stream, Fiskebäckskil, Bohuslän (N 58º 14’ 51’’; E 11º 27’ 05’’); Freshwater Rockpool among Sphagnum spp., Hållö, Bohuslän (N 58º 20’ 00’’; E 11º 12’ 50’’) Artificial pond, Nybro, Småland (N 56º 44’ 56’’; E 15º 54’ 14’’); Ditch at Abisko Scientific Research Station, Abisko, Lapland (N 68º 21’ 11’’; E 18º 48’ 54’’); Meadow west of Abisko Scientific Research Station, Abisko, Lapland (N 68º 21’ 18’’; E 18º 48’ 40’’); Among Sphagnum spp., Mount Njulla, Lapland (N 68º 21’ 36’’; E 18º 43’ 02’’); Roadside ditch, Highway E10, Lapland (N 68º 25’ 45’’; E 18º 18’ 17’’); Sphagnum spp. Bog at Highway E10, Lapland (N 68º 26’ 04’’; E 18º 14’ 53’’).

Material. 14 specimens. TL, 155–179 µm; FL, 18–24 µm; AL, 12–15 µm; PhL, 46–52 µm; MD, 4–7 µm; DC, 7–9; DR, 28–30; VC, 5; VB, 20–24; TS, 6.5– 8 x 6.5–9 µm; VTS, 12–14 x 6–7 µm.

Small to mid sized species with weakly five-lobed head. Hypostomium with two hooks. Dorsal head and trunk surface covered by smooth scales with either rounded or squared posterior edge; in the neck region the scales are more rectangular. The species is easily separated from the other species of the genus by a longitudinal series of more than 20 transverse cuticular plates below the pharynx and part of the anterior intestine. Interciliary area of the trunk with five columns of smooth more or less rounded quadrangular scales, or rounded equally sized scales. If interciliary scales are of different sizes, those of the medial column are the largest while the scales of the other columns decrease in size towards the ciliary bands. A pair of large keeled terminal scales and several smaller round scales are present ventrally at the posterior end. Ventral ciliation in two separate longitudinal bands. Pharynx gradually widens towards the pharyngeal intestinal junction. The Swedish specimens fall within the ranges of previously reported literature data.

A very common species widely distributed in Europe (see e. g. Marcolongo 1910; Greuter 1917; Remane 1935 –36; Valkanov 1937; Rudescu 1967; Martin 1981; Schwank 1990; Kisielewski 1998) and also reported from India ( Naidu & Rao 2004), Japan ( Saito 1937; Sudzuki 1975), Korea ( Lee & Chang 2000), Israel ( Kisielewski 1999), East Africa ( Daday 1910), Canada ( Schwank 1990), United States (see e. g. Brunson 1950; Evans 1993) Brazil ( Kisielewski 1991), Uruguay ( Cordero 1918) and Argentina ( Grosso & Drahg 1984).

Figures

FIGURE 14. Lepidodermella squamata. A) Habitus. B) Ventral view of head and neck region showing the transverse scales of the interciliary area. C) Dorsal view of trunk showing shape and distribution of scales. Scale bars: A, 30 µm; B, 15 µm; C, 20 µm.