Aspidiophorus ophiodermus Balsamo, 1982

Kånneby, Tobias, 2011, New species and new records of freshwater Chaetonotida (Gastrotricha) from Sweden, Zootaxa 3115, pp. 29-55 : 34-35

Aspidiophorus ophiodermus Balsamo, 1982

( Figure 3 )

Localities. Artificial ponds, Fiskebäckskil, Bohuslän (N 58º 14’ 39’’; E 11º 27’ 16’’); Among Lemna sp., Lower Lake Rudan, Handen, Södermanland (N 59º 09’ 27’’; E 18º 07’ 31’’).

Material. 3 specimens. TL, 160–180 µm; FL, 18–20 µm; AL, 9–10 µm; PhL, 35–41 µm; MD, 5 µm; DC, 40– 45; DR, 49–51; VC, ~10; VTS, 8 x 4–5 µm; PL, 0.5 µm.

A rather slim and elongated species with rounded to weakly three-lobed head. Cephalion well developed. One pair of cephalic ciliary tufts with one cilium considerably longer than the others. Two pairs of dorsal sensory bristles. The dorsal scales are longitudinal elliptical and keeled. The posteriormost scales are keeled but not pedunculated and larger than the others. Ventral interciliary field with a pair of large suboval keeled terminal scales and approximately 10 columns of keeled scales; their borders could not be seen. Ventral ciliation in two longitudinal bands that are further divided on the head, but not merging. Pharynx widens towards the pharyngeal intestinal junction. The Swedish specimens, all in parthenogentic phase with large eggs, fall within the ranges of literature data but are in general larger than most previously recorded specimens. The anteriormost part of the intestine has a granulated appearance, also recorded in Polish specimens ( Kisielewski 1986).

Previously recorded from Great Britain ( Martin 1990), Italy ( Balsamo 1983), Poland ( Kisielewski 1998), Russia ( Tretjakova 1989) and Brazil ( Kisielewski 1991).

Figures

FIGURE 3. Aspidiophorus ophiodermus. A) Habitus. B) Dorsal view showing distribution of stalked scales. C) Dorsal view showing distribution and shape of scales of the furcal base. Scale bars: A, 50 µm; B, 20 µm; C, 10 µm.