Additions to the Mastogloia (Bacillariophyceae: Mastogloiales) of the Revillagigedo Archipelago, Mexico

Certain diatom species, mainly those that are conspicuous within an assemblage, may constitute useful references while addressing various ecological and biogeographical issues. This may well be the case with Mastogloia species which are frequently the most diverse diatom taxa in benthic marine assemblages from warm seas. Twenty three new records of Mastogloia taxa collected from several thalli of red and brown macroalgae are here added to the epiphytic diatom floristics of the Revillagigedo Archipelago, summing a total of 51 Mastogloia taxa. Most conspicuous forms were frequent, and several taxa seemed to dominate the assemblages, e.g., Mastogloia binotata, M. cocconeiformis, M. cuneata, M. fimbriata, M. inaequalis, M. ovum-paschale, and M. punctatissima, as well as others recorded earlier. Of the new records, M. asperuloides, M. graciloides, M. peragalloi, and M. mauritiana also appeared frequently. The list includes 8 new records for Mexican waters, although no new taxa for this genus were found. However, because of the few macroalgae thalli inspected, it is expected that further inspection of surfaces of other species of macroalgae, and other substrates, will increase the species richness of Mastogloia recorded for the archipelago.