Gomphonema acuminatum Ehrenberg; 1832; 88

Key references

Reichardt E. 1999. Zur Revision der Gattung Gomphonema. Die Arten um G. affine/insigne, G. angustatum/micropus, G. acuminatum sowie gomphonemoide Diatomeen aus dem Oberoligozän in Böhmen. Iconographia Diatomologica, Vol. 8, Koeltz Scientific Books, A.R.G. Gantner Verlag, Ruggell. 203 pp

Morphology

Shape
Valve margins triundulate, expanded and then narrowed to apiculate apex at head pole, lanceolate at centre, linear towards foot pole.

Symmetry
Heteropolar, bilaterally symmetrical; cuneate in girdle view.

Striae
Slightly radiate at centre, becoming more radiate near the foot pole, more parallel towards the head pole, with short inserted striae at margins, radiate around head pole; striae consist of c- or kidney-shaped areolae, striae can become biseriate towards the margins.

Axial area
Slightly widened, more or less parallel throughout, narrowing towards apices.

Central area
Small rounded, sometimes slightly extended transapically, bordered by 1-2 shorter striae; 1 small ‘stigma’ with round external
opening close to a shortened stria, internal opening short elongate (SEM).

Raphe
Undulate, proximal endings terminate just inside the central area, straight or very slightly deflected, internally terminating
in small hooks (SEM); distal raphe fissures curved and terminating on the mantle at the head pole (SEM).

Other features
A bilobed apical pore field, septa and pseudosepta present at foot pole.

Literature

References are given in chronological order.

Reference	Citation
Ehrenberg C.G. 1832. Über die Entwicklung und Lebensdauer der Infusionsthiere; nebst ferneren Beiträgen zu einer Vergleichung ihrer organischen Systeme. 1831. Abhandlungen der Königlichen Akademie der Wissenschaften zu Berlin. 1-154 pp; 4 pls	Description
Reichardt E. 1999. Zur Revision der Gattung Gomphonema. Die Arten um G. affine/insigne, G. angustatum/micropus, G. acuminatum sowie gomphonemoide Diatomeen aus dem Oberoligozän in Böhmen. Iconographia Diatomologica, Vol. 8, Koeltz Scientific Books, A.R.G. Gantner Verlag, Ruggell. 203 pp	Morphology; Taxonomy; Illustrations;
Thomas E.W., Kociolek J.P., Lowe R.L., Johansen J.R. 2009. Taxonomy, ultrastructure and distribution of Gomphonemoid diatoms (Bacillariophyceae) from Great Smoky Mountains National Park (U.S.A.). In: Kociolek, J.P., Theriot, E.C. & Stevenson, R.J. (eds), Diatom taxonomy, ultrastructure and ecology: modern methods and timeless questions. A tribute to Eugene F. Stoermer. Nova Hedwigia, Beiheft. 135: 201-237.	Morphology; Illustrations
Hofmann G., Werum M., Lange-Bertalot H. 2011. Diatomeen im Süßwasser-Benthos von Mitteleuropa. A.R.G. Gantner, Ruggell. 908 pp	Morphology; Ecology; Illustrations
Kulikovskiy M.S., Kociolek J.P., Solak C.N., Kuznetsova I. 2015. The diatom genus Gomphonema Ehrenberg in Lake Baikal. II. Revision of taxa from Gomphonema acuminatum and Gomphonema truncatum-capitatum complexes. Phytotaxa. 233(3): 251-272.	Morphology; Illustrations

Similar species not published on this website:

Gomphonema brebissonii Kützing; 1849; 66

This page should be cited as:

Cox E. J., Jones V., Jüttner I. Gomphonema acuminatum Ehrenberg; 1832; 88. In: Jüttner I., Carter C., Cox E.J., Ector L., Jones V., Kelly M.G., Kennedy B., Mann D.G., Turner J. A., Van de Vijver B., Wetzel C.E., Williams D.M.. Freshwater Diatom Flora of Britain and Ireland. Amgueddfa Cymru - National Museum Wales. Available online at https://naturalhistory.museumwales.ac.uk/diatoms/browsespecies.php?-recid=2558. [Accessed: ].

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