Chaetonotus (Hystricochaetonotus) luxus
Reference
Rataj Križanová F. & Vďačný P. (2022) A huge undescribed diversity of the subgenus Hystricochaetonotus (Gastrotricha, Chaetonotidae, Chaetonotus) in Central Europe. European Journal of Taxonomy 840: 1-93. https://doi.org/10.5852/ejt.2022.840.1941
Chaetonotus (Hystricochaetonotus) luxus, schematic drawings. (A, H) Dorsal and lateral overviews showing the scale and spine pattern. (B) Head scale. (C) Neck and upper-trunk scale. (D–E) Frontal and lateral views of a trunk spined scale. (F) Posterior trunk scale. (G) Dorsal furcal scale. Scale bars: 30 μm.
© 2022 Rataj Križanová F. & Vďačný P. This picture is licensed under a CC BY-NC-ND 4.0 license.
Chaetonotus (Hystricochaetonotus) luxus, schematic drawings. (A) Ventral overview showing the scale and ciliary pattern. (B) Ventrolateral scale. (C) Ventral furcal scale. (D) Internal morphology. (E) Detail of the ventral terminal body region. Scale bars: 10 μm (E), 20 μm (D), and 30 μm (A).
© 2022 Rataj Križanová F. & Vďačný P. This picture is licensed under a CC BY-NC-ND 4.0 license.
Secondary structure of the 18S rRNA molecule of Chaetonotus (Hystricochaetonotus) luxus. The reference 18S secondary structure map of Saccharomyces cerevisiae (inset) is from apollo.chemistry.gatech.edu/RibosomeGallery.
© 2022 Rataj Križanová F. & Vďačný P. This picture is licensed under a CC BY-NC-ND 4.0 license.
Secondary structure of the first two domains of the 28S rRNA molecule of Chaetonotus (Hystricochaetonotus) luxus. The reference 28S secondary structure map of Saccharomyces cerevisiae (inset) is from apollo.chemistry.gatech.edu/RibosomeGallery.
© 2022 Rataj Križanová F. & Vďačný P. This picture is licensed under a CC BY-NC-ND 4.0 license.
Morphological diagnosis
Body stocky and around 87–112 μm long. Head wider than neck, separated from trunk by a more or less distinct neck constriction. Cephalion, epipleurae, and hypopleurae clearly demarcated. Trunk widest at ca U55, gradually tapers towards furca base (U83). Mouth ventral, no cuticular teeth. Pharynx without dilatations. Intestine straight, with a marked anterior section. Scales spined, three-lobed, not overlapping, distributed in a minimum of 10 columns, 15 scales per column. Spines with a very short lateral denticle. Scales and spines increase gradually in size in a posterior direction. Dorsal surface covered with: (i) head and upper-neck scales with a small, narrowly rounded anterior lobe and elongated posterior lobes; (ii) lower-neck and anterior trunk scales with a slightly larger anterior lobe and elongated posterior lobes; (iii) posterior trunk scales with an elongated anterior lobe and posterior lobes about as long as anterior lobe; and (iv) posteriormost trunk scales with a tongue-shaped anterior lobe and short posterior lobes. Furca branches shorter than adhesive tubes, lateral margins more or less straight, furcal indentation U-shaped, adhesive tubes long and diverging posteriorly. Dorsal and lateral sides of furca branches covered with narrowly trapezoid, keeled scales with rounded edges and ventral side of furca base and branches covered with (i) a pair of oblong, keeled scales and (ii) three-lobed, spined scales, with an elongated anterior lobe and comparatively short, narrowly rounded posterior lobes, transition between anterior and posterior lobes continuous and indistinct.
Molecular diagnosis
ITS2: 36 T, 61 C, 71 T, 72 G, 126 T, 135 A, 164 C, 171 C, 175 A, 176 A, 177 A.
Cytochrome c oxidase subunit I: 69 (205‒207) CTG, 92 (274‒276) TTG, 109 (325‒327) GCG, 156 (466‒468) GCT, 168 (502‒504) CTA, 174 (520‒522) GCC, 176 (526‒528) TTA.
Type material
A DNA sample of the holotype specimen ZPvs 20 has been deposited in the Natural History Museum, Vajanského nábrežie 2, 810 06 Bratislava, Slovakia (ID Collection Code 01427593).
Type locality
Zlaté Piesky lake, municipal recreation area, Ružinov, Bratislava, Podunajská rovina plain, 48°11′17.1″ N, 17°11′24.3″ E.