Bruno Fumanti

Benthic algal mats of some lakes of Inexpressible Island (northern Victoria Land, Antarctica)

Benthic algal mats from four lakes located on Inexpressible Island (northern Victoria Land, Antarctica) were studied, analysing their structure and floristic composition. Thirty taxa of algae were identified: 11 Cyanophyta, 15 Bacillariophyta and 4 Chlorophyta. The lake mats contained from 15 (lake C) to 26 species (lake D). The number of diatom frustules in the mats varied from 771×103 (lake C) to 9428×103 frustules g-1 (lake B). In terms of floristic composition and macromorphology, these mats were observed to be very similar to moat mats described from Lake Gondwana (northern Victoria Land) and the Dry Valleys lakes of southern Victoria Land.

Floristic studies on freshwater algae of Lake Gondwana Northern Victoria Land (Antarctica)

Benthic algal mats and phytoplankton of Lake Gondwana (Northern Victoria Land, Antarctica) were investigated. Biomass, chlorophyll content and floristic analyses were carried out on algal mats. The mats are composed of two layers different in colour, floristic composition and chlorophyll content. The algal flora of the mats amount to 34 taxa (19 Cyanophyta, 7 Bacillariophyta, 8 Chlorophyta). The phytoplankton community is species-poor (only 5 taxa). Crytophyta account for about 98% of total algal density.

MORPHOLOGY, ECOLOGY AND DISTRIBUTION OF AN ENDEMIC ANTARCTIC LACUSTRINE DIATOM: CHAMAEPINNULARIA CYMATOPLEURA COMB. NOV.

Specimens belonging to the diatom species Pinnularia cymatopleura collected from benthic cyanobacterial mats of lakes and ponds in Continental Antarctica were examined. In addiction, slides from the West & West collection which contain isotypes of this taxon were also investigated. Light Microscope (LM) and Scanning Electron Microscope (SEM) studies of this diatom reveal that its valve structure possesses features typical of the recently established diatom genus Chamaepinnularia. The most important features that justify the allocation of this taxon to Chamaepinnularia are: — the presence of uniseriate striae composed of alveoli occluded by external hymenes; — the absence of multiseriate round poroids in the outer wall; — internally an apical series of apertures, located on the valve face separated from a second series on the valve mantle. The new combination Chamaepinnularia cymatopleura (West & G. S. West) Cavacini is proposed. This highly tolerant to salinity taxon is currently only known from a few zones of Continental Antarctica. The absence of records of this taxon in Maritime- and Sub-Antarctica, Australia and South America seem to justify the classification of this species as “endemic to Continental Antarctica”.

The algal microflora of the salt works of Tarquinia (Italy)

The microflora and benthic microbial mats of the salt works of Tarquinia (Italy) are described. From 144 samples, 111 species and varieties of microalgae were identified. Diatoms prevailed up to 110‰. S. They were substituted by Cyanophyta at higher salinities. The microbial mats consisted of Cyanophyta, Beggiatoa spp., purple sulphur bacteria, and diatoms. Information on hypertonic resistance in some euryhaline species is given.

Desmids from Guma Valley (Sierra Leone, West Africa)

Twenty-two taxa of desmids are reported from a pool near Guma Valley (Sierra Leone). Six are new to the country. A new variety of Staurastrum hystrix (S. hystrix var. granulatum) is described.

Brachytheca inopinata (Desmidiaceae, Zygnematophyceae ), a new desmid from New Zealand

Abstract A new desmid species, Brachytheca inopinata Fumanti & Alfinito, is described from Lake Monowai, New Zealand, and the diagnosis of the genus Brachytheca is emended. The new species has cylindrical cells, about as long as broad, apical angles that are slightly rounded and a straight apex. The cell wall is smooth, with transverse rows of apical and subapical pores and without longitudinal grooves.