Hydrosera whampoensis

(Schwarz) Deby 1891      Category: Centric
BASIONYM: Triceratium whampoense Schwarz 1874

REPORTED AS: Hydrosera triquetra (Fungladda 1982, pg. 46, Pl. 19, Fig 317, Pl. 20, Fig 323) | Hydrosera triquetra (Simonsen 1965, pg. 49, Figs 1-7) | Hydrosera triquetra (Li and Chiang 1977, pg 203, Figs 1-32) 

Humidophila undulata


Hygropetra balfouriana

LM scalebar = 10 µm = 20 pixels.


Contributor: David R.L. Burge | Mark Edlund - April 2017
Diameter: 35.0-72.5 µm
Rows of areolae in 10 µm:


The valve face is flat, with a deep mantle and broad cingulum. In valve view, the valve margin is in the shape of two superimposed triangles. Porefields, containing pseudocelli, are positioned at the three apices of one of the apparent triangles.the valve face is triangular with pseudocelli positioned between each apex. Pseudoseptae are present. The areolae are loculate, externally with,large irregularly spaced foramina. Internally, the areolae open in small pores arranged in radial rows. Short spines may be visible in LM distal to the pseudocelli. A single, large rimoportula is present.

Hydrosera whampoensis and H. triquetra have been confused with one another. In fact, their differences have been variously recognized (Skortzow 1930, Hustedt 1938, Voigt 1939, Frenguelli 1953, Qie et al. 1982). At this time, the taxa are each considered to be distinct species, based on size of the external foramina and undulate margins (Qi et al. 1982). Reports of H. triquetra appear, instead, to be aligned with H. whampoensis (Simonsen 1965, Li and Chiang 1977 and Fungladda 1982). Hydrosera whampensis is considered be widespread in higher conductivity waters of lower latitudes, while H. triquetra is restricted to tropical, saline waters (Qi et al. 1982).

Original Description

Basionym: Triceratium whampoense
Author: Schwarz 1874
Diameter: 89 µm
Rows of areolae in 10 µm:

Original Description

Triceratium whampoense n. sp. Valvis triangularibus, margine undulatis (lateribus indole concavis sed medio globoso inflatis) anguila rotundatis costa transversali ab area separatis, area et ima parte angulorum subtiliter areolato-granulatis; membrana connectiva angusta et transverse punctato-striata. Magn. 0,089mm. = 0,0035” engl. Sehr selten. Mit keiner anderen Form von Triceratum zu verwechslende schöne Art, nur einmal aufgefunden.

Original Images

Cite This Page:
Burge, D., and Edlund, M. (2017). Hydrosera whampoensis. In Diatoms of the United States. Retrieved April 25, 2018, from http://westerndiatoms.colorado.edu/taxa/species/hydrosera_whampoensis

Species: Hydrosera whampoensis

Contributor: David R.L. Burge | Mark Edlund

Reviewer: Sylvia Lee


Deby, J. (1891). Note sur le genre Hydrosera de Wallich. Journal de Micrographie 15: 209-212.

Fungladda, N. (1982). A contribution to the freshwater diatom flora of the Hawai͏ian Islands. Doctoral dissertation, Department of Botany and Range Science, Brigham Young University, 130pp.

Julius, M.L. (2007). Why sweat the small stuff: the importance of microalgae in Hawaiian stream ecosystems. In: Biology of Hawaiian Streams and Estuaries (N.L. Evenhuis and J.M. Fitzsimons, eds.), Bishop Museum Bulletin in Cultural and Environmental Studies 3: 183-193.

Li, C.W. and Chiang, Y.M. (1977). The fine structure of the frustule of a centric diatom Hydrosera triquetra Wallich. British Phycological Journal 12(3): 203-213.

Qi, Y.Z., Reimer, C.W. and Mahoney, R.K. (1984). Taxonomic studies of the genus Hydrosera. I. Comparative morphology of H. triquetra Wallich and H. whampoensis (Schwartz) Deby, with ecological remarks. Proceedings of the 7th Diatom Symposium, 213-224.

Schwarz, A.F. (1874). Grundproben aus den chinesischen Gewassern gesammelt von R. Rabenhorst. Hedwigia 13: 161-166.

Sherwood, A.R. and Kido, M.H. (2002). Watershed-scale comparisons of algal biodiversity in high-quality proximate Hawaiian stream ecosystems. Pacific Science 56(4): 431-440.

Simonsen, R. (1965). Ökologische Bemerkungen zu der tropischen Kieselalgen Hydrosera triquetra Wallich und zur Aerophilie der Diatomeen. Internationale Revue der gesamten Hydrobiologie und Hydrographie 50(1): 49-56.

Links & ID's

Index Nominum Algarum (INA)

Transfer INA
Original INA

California Academy of Sciences (CAS)

Hydrosera whampoensis CAS

NCBI Genbank Taxonomy

Hydrosera whampoensis NCBI

North American Diatom Ecological Database (NADED)

NADED ID: 41001

Autecology Discussion

Hydrocera whampoensis is found in more southern sites, usually in higher conductivity waters. For example, it has been reported from rivers in California, Georgia, Louisiana, Texas, South Carolina (Qi et al. 1982) and Hawaii (Sherwood and Kido 2002, Julius 2007). This taxon can be dominant, in terms of biomass, in Hawaiian streams (Sherwood and Kido 2002) and forms the largest filamentous colonies streams with infrequent flood events (Julius 2007). Cells are joined in large zig-zag colonies by mucilage secreted from the pseudocelli. This taxon has also been reported (as H. triquetra) from Brazil, growing epiphytically on the red alga Bostrychia (Simonsen1965, Figs 1-2).


Living cells of H. whampoensis, showing multiple, discoid chloroplasts

Credit/Source: Image and collection from Steve Main

Distribution of Hydrosera whampoensis in rivers of the continental U.S. based on the USGS National Water Quality Assessment program. Retrieved 26 July 2016.

Credit/Source: USGS BioData

Distribution of Hydrosera whampoensis in rivers of Hawaii based on the USGS National Water Quality Assessment program. Retrieved 26 July 2016.

Credit/Source: USGS BioData