Compare

Gomphonema insularum is similar in length, breadth, and stria density but has a less linear, more lanceolate, even slightly clavate outline. Gomphonema insularum also has more uniformly short striae throughout the valve and round depressions on external valve surface.

Gomphonema incognitum is considerably more clavate. Gomphonema christenseni is both larger and lacks an isolated stigmoid.

Gomphonema freesei has a greater length and width.

LM scalebar = 10 µm
Gomphonema caperatum LM3 Gomphonema caperatum LM7 Gomphonema caperatum LM4 Gomphonema caperatum LM2 Gomphonema caperatum LM1 Gomphonema caperatum LM5 Gomphonema caperatum LM6
Length Range
22.4-31.9 µm
Width Range
4.4-5.2 µm
Striae in 10 µm
14-16

Gomphonema incognitum

E.Reichardt, J├╝ttner and E.J.Cox 2004

G Incog 15620A 10132015 12 Cl G Incog 15576A 08142015 20 Cl G Incog 15576A 08142015 37 Cl G Incog 15576A 08142015 21 Cl G Incog 15558A 08132015 42 Cl G Incog 15576A 08142015 29 Cl G Incognito Lm6
Length Range
17.8-29.5 µm
Width Range
5.0-5.8 µm
Striae in 10 µm
13-16 at mid-valve; up to 18 at the apices

Gomphonema insularum

Kociolek, Woodward and Graeff 2016

Gomphonema insularum LM1 Gomphonema insularum LM2 Gomphonema insularum LM3 Gomphonema insularum LM4 Gomphonema insularum LM5 Gomphonema insularum LM6 Gomphonema insularum LM7
Length Range
15.2-42 µm
Width Range
4.4-7 µm
Striae in 10 µm
13-16

Gomphonema christenseni

R.L.Lowe and Kociolek 1984

Gomphonema christenseni LM2 Gomphonema christenseni LM5 Gomphonema christenseni LM6 4 53920  Gchristenseni Holo 5 53920  Gchristenseni2 6 53920  Gchristenseni2 7 53920  Gchristenseni2
Length Range
32.8-57.4 µm
Width Range
6.1-7.8 µm
Striae in 10 µm
13-16

Gomphonema freesei

R.L.Lowe and Kociolek 1984

Gc53921  Gomphonema Freesei 1 Gc53921  Gomphonema Freesei 2 Gc53921  Gomphonema Freesei 3 Gc53921  Gomphonema Freesei 4 Holotype Gc53921  Gomphonema Freesei 4B Holotype Gc53921  Gomphonema Freesei 5
Length Range
35.0-53.9 µm
Width Range
6.5-7.5 µm
Striae in 10 µm
12.1-14.5 at valve center, 14.2-16.2 at headpole, 11.7-15.4 at footpole