Butterfly structure

A butterfly structure is a siliceous membrane extending internally from the valve margin to the stauros in the genus Tursiocola. The membrane creates a bridge between the stauros and the valve margin and connects with the pseudoseptum at each apex.

In valve view, the outline of the butterfly structure resembles butterfly wings around the stauros.

The butterfly structure has been referred to as a roof-like structure or bridge over the internal valve mantle and valve face (Denys 1997, Majewska 2020). It has also been referred to as a “butterfly-like structure” (Denys 1997) and as a “butterfly-like stauros” (Wetzel et al. 2012). The morphogenetic relationship of the butterfly structure to the apical pseudoseptae and stauros awaits further investigations (Majewska 2020).

The butterfly structure is visible in both LM and SEM.

Citations

Denys, L. (1997) Morphology and taxonomy of epizoic diatoms (Epiphalaina and Tursiocola) on a sperm whale (Physeter macrocephalus) stranded on the coast of Belgium. Diatom Research 12: 1–18.

Publication Link: 10.1080/0269249X.1997.9705398
Majewska, R. (2020) Tursiocola neliana sp. nov. (Bacillariophyceae) epizoic on South African leatherback sea turtles (Dermochelys coriacea) and new observations on the genus Tursiocola. Phytotaxa 453: 1-15.

Publication Link: 10.11646/phytotaxa.453.1.1
Wetzel, C.E., Van de Vijver, B., Cox, E.J., Bicudo, D.C. and Ector, L. (2012) Tursiocola podocnemicola sp. nov., a new epizoic freshwater diatom species from the Rio Negro in the Brazilian Amazon Basin Diatom Research 27: 1-8

butterfly-structure-tursiocola — Interior of central area of a valve of *Tursiocola ziemanii* (SEM). The butterfly structure connects the stauros with the valve margin. Scale bar = 1µm.