Stylochaeta scirtetica Brunson, 1950

Kånneby, Tobias, 2011, New species and new records of freshwater Chaetonotida (Gastrotricha) from Sweden, Zootaxa 3115, pp. 29-55 : 51

Stylochaeta scirtetica Brunson, 1950

( Figure 18 )

Localities. Artificial pond, Nybro, Småland (N 56º 44’ 56’’; E 15º 54’ 14’’).

Material. 2 specimens. TL, 175 µm; CL, 5 µm; PhL, 33 µm; MD, 10 µm; SG1, 160 µm; SG2, 70–100 µm; SG3, 80–90 µm; SG4, 20 µm.

Large sized species with three-lobed head and a thin cephalion. At the posterior end two short styli are present each carrying three setae/bristles, of which one is much longer than the other two. Four pairs of spine groups are present, originating ventrally or ventrolaterally. The three anterior groups consist of spines with two denticles, while the spines of the posteriormost spine group have only one denticle with a small bifurcation at their ends. From anterior to posterior each group consists of 3, 3, 2 and 1 spine/s. The first group is situated in the neck region and has the longest spines. Spines of group 2 and 3 are of approximately equal length. The single spine of the last group is much shorter than those of the anterior groups. Locomotory ciliature consists of five ventral ciliary tufts and three pairs of semi-circular ciliary tufts on the head. Pharynx short but with strong posterior swelling.

Previously reported from Germany ( Schwank 1990), United States ( Brunson 1950; Schwank 1990) and Canada ( Schwank 1990).

Figures

FIGURE 18. Stylochaeta scirtetica. A) Habitus. B) Ventral view showing insertion of four of the five pairs of spine groups. Scale bars: A, 40 µm; B, 15 µm.