Chaetoceros laevisporus, Li & Boonprakob & Gaonkar & Kooistra & Lange & Hernández-Becerril & Chen & Moestrup & Lundholm, 2017

Li, Yang, Boonprakob, Atchaneey, Gaonkar, Chetan C., Kooistra, Wiebe H. C. F., Lange, Carina B., Hernández-Becerril, David, Chen, Zuoyi, Moestrup, Øjvind & Lundholm, Nina, 2017, Diversity in the Globally Distributed Diatom Genus Chaetoceros (Bacillariophyceae): Three New Species from Warm-Temperate Waters, PLoS ONE (e 0168887) 12 (1), pp. 1-38 : 34

Chaetoceros laevisporus

This is the only species in the C. lorenzianus complex with smooth resting spores without processes, and in the phylogenetic tree the strains form a separate branch. The smooth resting spore ( Fig 10A and 10B) differs markedly from the spores of C. lorenzianus , C. mitra and C. elegans with their dichotomously-branching extensions. Furthermore the apertures are oval-peanut shaped in C. laevisporus ( Figs 8A, 8B, 8D and 10A), thus differing from most other taxa in the complex. Seta poroid density is intermediate, 13.8± 1.9 in 10 μm as in C. mannaii ( Table 1), but different from all the other taxa. Poroid size on the setae was assessed to be c. 0.6 μm, slightly less than in C. mannaii , but the poroids were still visible in LM ( Fig 8C).