Lucectorea gen. nov., a new atypical genus of biraphid diatoms (Bacillariophyceae) with bent frustule

Authors

Tudesque L., Chrea S., Chea R., Wetzel C.E.

Reference

Nova Hedwigia, vol. 117, n° 1-4, pp. 25-44, 2023

Description

The freshwater diatom flora of Cambodia is poorly known but has received increased attention these last few years. The ongoing study of the benthic flora of the Sangker River in North-western Cambodia, revealed the presence of an unidentified small naviculoid taxon with atypical arched (bent) frustule. Detailed comparison with related genera, Eolimna, Mayamaea and Sella-phora, using light and scanning electron microscopy, results in an original set of taxonomical features, justifying the description of a new genus. The valve curvature in girdle view is the most prominent element that characterizes the proposed new genus, Lucectorea. The clearly lanceolate valve outline with narrow rounded apices, uniseriate striae running in multiple rows on the mantle, round to ovoid areolae externally occluded, the raphe system weakly silicified with central raphe fissures only extended on the external face are combined features that separate the proposed new genus to related small-celled naviculoid diatom genera. Additionally, the comparison with the closest species Eolimna comperei and Mayamaea cahabaensis, allows both the description of a new species and the transfer of E. comperei and M. cahabaensis to the newly described genus. Information on the ecology and distribution is also presented.

Link

doi:10.1127/nova_hedwigia/2023/0858