W. Smith 1853 Category: Nitzschioid
SYNONYM(S): Nitzschia tryblionella Hantzsch
Contributor: Jacob Lister - June 2016
Length Range: 79-117 µm
Width Range: 20-24 µm
Striae in 10 µm: 32-34
Valves are linear-lanceolate and gradually taper to apices that are cuneate to sometimes slightly rostrate. The raphe is keeled and eccentric, fibulae 6-8 in 10 µm. The raphe is slightly constricted at the central nodule. A longitudinal undulation is located along the apical axis of the valve. Costae at the apices are easily distinguishable (6-8 in 10 µm), while costae near the valve center may appear thinner and less pronounced (7-11 in 10 µm). Costae may appear slightly curved and non-parallel across the valve undulation. Striae are difficult to observe with light microscopy.
The original description of Tryblionella gracilis by W. Smith (1853) is valid and legitimate. The taxon was renamed Nitzschia tryblionella Hantzsch in Rabenhorst when it was transferred to Nitzschia by Hantzsch in Rabenhorst 1848-1860. The change in the specific epithet was necessary because the name N. gracilis was already occupied. When the genus Tryblionella was resurrected by Round et al. (1990), the original name Tryblionella gracilis W. Smith 1853 was again recognized as the valid and legitimate name of this taxon.
Author: W. Smith 1853
Length Range: 23-75 µm
Striae in 10 µm:
Hofmann, G., Werum, M. and Lange-Bertalot, H. (2011). Diatomeen im Süßwasser-Benthos von Mitteleuropa. Koeltz Scientific Books, Königstein, 908 pp.
Krammer, K. and Lange-Bertalot, H. (1988). Bacillariophyceae. 2. Teil: Bacillariaceae, Epithemiaceae, Surirellaceae. In: Ettl, H., J. Gerloff, H. Heynig and D. Mollenhauer (eds.) Susswasserflora von Mitteleuropa, Band 2/2. Gustav Fisher Verlag, Jena.
Rabenhorst, L. (1848). Die Algen Sachsens. Resp. Mittel-Europa’s Gesammelt und herausgegeben von Dr. L. Rabenhorst, Dec. 1-100. No. 1-1000. Dresden. [Exsiccata, issued at various dates]. Dec. 1-100. No. 1-1000. Dresden. [Exsiccata, issued at various dates].
Round, F.E., Crawford, R.M. and Mann, D.G. (1990). The Diatoms. Biology and Morphology of the Genera. Cambridge University Press, Cambridge, 747 pp.
Smith, W. (1853). Synopsis of British Diatomaceae. John Van Voorst, London 1853. 89 pp., pls 1-31.
Witkowski, A., Lange-Bertalot, H. and Metzeltin, D. (2000). Diatom Flora of Marine Coasts I. Iconographia Diatomologica 7: 1-925.
Tryblionella gracilis was found in an epiphytic sample taken in Beck’s Canal, Dickinson County, Iowa, a site with slightly basic water (pH 8.05). Additionally, T. gracilis specimens in the Reimer Herbarium were collected in a benthic sample from Lazy Lagoon, Dickinson County, Iowa. Tryblionella gracilis is found in a variety of habitats: coastal, brackish, and fresh water. (Hofmann et al. 2011).
Distribution of Tryblionella gracilis in rivers of the continental U.S. based on the National Water Quality Assessment program. Retrieved 10 June 2016.
Credit/Source: USGS BioData