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Gomphonema pseudosphaerophorum

H.Kobayasi 1988      Category: Asymmetrical biraphid

Gomphonema nathorstii


Gomphonema pusillum

LM scalebar = 10 µm = 80 pixels.


Contributor: Meredith Tyree | Melissa Vaccarino - December 2016
Length Range: 42-50 µm
Width Range: 8.1-9.4 µm
Striae in 10 µm: 9-14


Valves are clavate and narrow, with a distinct, capitate headpole. The footpole is narrow and weakly subcapitate. The axial area is linear and narrow. The raphe is lateral and slightly sinuous. A single stigmoid is positioned in the small central area near a shortened striae on the primary sides of the valve and opposite a shortened stria on the secondary side. Striae are indistinctly punctate and radiate throughout the valve.

Original Description

Author: S.Ueyama and H.Kobayasi 1988
Length Range: 35-44 µm
Width Range: 8-10 µm
Striae in 10 µm: 8-12

Original Description

Gomphonema pseudosphaerophorum H. Kob. in Ueyama & Kobayasi sp. nov.

Valvae clavaeformes, polo apicali capitato et constricto, polo basali attenuato vel leviter capitato, 35-44 um longae, 8-10 um latae. Raphe directa, filiformis. Area acialis anguste linearis et area centralis rhoboide rotundata. Puncto segregato in uno latere noduli centralis. Striae transapicales robustae et subradiatae, 8-12 in 10 um, indistincte punctatae, punctis circiter 28 in 10 um.

Valves clavate with capitate and constricted apical pole and attenuate or slightly capitate basal pole, 35-44 um long, 8-10 um broad. Raphe straight, thread-like. Axial area narrow, linear. Central area rhomboidally rounded. Isolated punctum on one side of the central nodule. Transapical stiae robust and slightly radiate throughout the valve, 8-12 in 10 um, indistinctly punctate, about 28 in 10 um.

This species is closely related to Gomphonema sphaeroporum var. asiatica Skv. (1929; 1930) and G. sphaerophoroides Hust. in valve shape (1965). However, the isolated punctum is lacking in the variety asiatica and the striae of G. sphaerophoroides are composed of double rows of puncta.

Holotype: H.K. T-85. in coll. H. Kobayasi, will be housed in the Nat. Sci. Mus. Tokyo (Figs 11, 12). Type material: K-6089, epiphytic on Phragmites, coll. by T. Nagumo on 18, Nov, 1973. Type locality: Kawaguchi-ko (Kawaguchi Lake), Yamanashi Pref. central Japan.

Original Images

Cite This Page:
Tyree, M., and Vaccarino, M. (2016). Gomphonema pseudosphaerophorum. In Diatoms of the United States. Retrieved May 23, 2018, from

Species: Gomphonema pseudosphaerophorum

Contributor: Meredith Tyree | Melissa Vaccarino

Reviewer: Ingrid Jüttner


Amutha, M. and Muralidharan, M. (2017). Diatom community structure along physicochemical gradients in upland river segments of Tamiraparani river system, South India. International Journal of Aquatic Biology 5(1): 12-21.

Ohtsuka, T. (2002). Checklist and illustration of diatoms in the Hii River. Diatom 18: 23-56.

Ueyama, S. and Kobayasi, H. (1988). Two Gomphonema species with strongly capitate apices: G. sphaerophorum Ehr. and G. pseudosphaerophorum sp. nov. F.E. Round, ed., Proceedings of the Ninth International Diatom Symposium, 1986. Biopress Ltd., Bristol, and Koeltz Scientific Books, Koenigstein. pp. 449-458.

Wang, Q., Zhi, C., Hamilton, P. and Kang, F. (2009). Diatom distributions and species optima for phosphorus and current velocity in rivers from ZhuJiang Watershed within a Karst region of south-central China. Fundamental and Applied Limnology Archiv fur Hydrobiologie 175(2): 125-141.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Gomphonema pseudosphaerophorum CAS

North American Diatom Ecological Database (NADED)


Autecology Discussion

This taxon was found in low abundance in Hawaiian streams.

The type locality for G. pseudospharophorum is Kawaguchi-ko (Kawaguchi Lake), Yamanashi Prefecture, central Japan. It has also been reported from the Hii River in Central Japan (Ohtsuka, 2002), South Central China (Wang et al., 2009), and South India (Amutha and Muralidharan, 2017).