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In an in situ experiment we evaluated the growth of the red algae Furcellaria lumbricalis and Coccotylus truncatus in the Archipelago Sea. The results showed that the growth rates of both species were similar but that growth decreased with increasing algal coverage. The effects were more pronounced for C. truncatus than for F. lumbricalis. Economic analyses aiming to establish sustainable harvesting limits for F. lumbricalis in the study area should take account of the density dependent growth of these red algae.
Recent results of field studies on the exposed coast of Lithuania were used to model the area occupied by the red alga Furcellaria lumbricalis using the Natural Neighbor interpolation technique, while linear regression was applied to estimate the species’ standing stock. The area covered by F. lumbricalis extended for 26 km along the coast between depths of 1 and 15 m. The maximum species cover in the study area ranged between 4 and 10 m depth, which is one of the widest in the Baltic Sea. The modelled area of F. lumbricalis covered 35 ± 11 km2 with a total biomass of 7554 ± 3813 t.
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Freshwater red algae Hildenbrandia rivularis has been noted for the first time in central Poland near the Lodz agglomeration. Until now, this alga was recorded only in mountain and Polish Lowland areas. The wide range of habitat conditions influencing the occurrence for this protected species has been determined in the spring niche. The possible threat to habitat where H. rivularis occurs, is connected with construction and exploitation of the A2 highway
A single origin of plastids and the monophyly of three “primary” plastid-containing groups – the Chloroplastida (or Viridiplantae; green algae+land plants), Rhodophyta, and Glaucophyta – are widely accepted, mainstream hypotheses that form the basis for many comparative evolutionary studies. This “Archaeplastida” hypothesis, however, thus far has not been unambiguously confirmed by phylogenetic studies based on nucleocytoplasmic markers. In view of this as well as other lines of evidence, we suggest the testing of an alternate hypothesis that plastids of the Chloroplastida are of secondary origin. The new hypothesis is in agreement with, or perhaps better explains, existing data, including both the plastidal and nucleocytoplasmic characteristics of the Chloroplastida in comparison to those of other groups.
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Are all red algal parasites cut from the same cloth?

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Parasitism is a common life strategy throughout the eukaryotic tree of life. Many devastating human pathogens, including the causative agents of malaria and toxoplasmosis, have evolved from a photosynthetic ancestor. However, how an organism transitions from a photosynthetic to a parasitic life history strategy remains mostly unknown. This is largely because few systems present the opportunity to make meaningful comparisons between a parasite and a close free-living relative. Parasites have independently evolved dozens of times throughout the Florideophyceae (Rhodophyta), and often infect close relatives. The accepted evolutionary paradigm proposes that red algal parasites arise by first infecting a close relative and over time diversify and infect more distantly related species. This provides a natural evolutionary gradient of relationships between hosts and parasites that share a photosynthetic common ancestor. Elegant microscopic work in the late 20th century provided detailed insight into the infection cycle of red algal parasites and the cellular interactions between parasites and their hosts. Those studies led to the use of molecular work to further investigate the origins of the parasite organelles and reveal the evolutionary relationships between hosts and their parasites. Here we synthesize the research detailing the infection methods and cellular interactions between red algal parasites and their hosts. We offer an alternative hypothesis to the current dogma of red algal parasite evolution and propose that red algae can adopt a parasitic life strategy through multiple evolutionary pathways, including direct infection of distant relatives. Furthermore, we highlight potential directions for future research to further evaluate parasite evolution in red algae.
The bioaccumulation ability of radionuclides 51Cr, 54Mn, 57Co, 60Co, 65Zn, 85Sr, 109Cd, 110mAg, 113Sn, 137Cs and 241Am in two red algae species from the southern Baltic Sea – Polysiphonia fucoides and Furcellaria lumbricalis – was determined under laboratory conditions. P. fucoides demonstrated better bioaccumulative properties towards most of the investigated radionuclides. As a result, P. fucoides can be recommended as a good bioindicator of radioactive environmental pollution. The bioaccumulation of radionuclides in F. lumbricalis was studied during an extended laboratory experiment. The initial extensive uptake of radioisotopes was followed by the rapid removal of cations; in general, concentrations tended to decrease with time. 137Cs displayed a different behaviour, its concentration in the algae increasing over time mainly due to its large ion radius; this is a factor that could be responsible for the stronger mechanical and chemical bonding of Cs+ and that could hamper the movement of ions in both directions.
The relationships of Hildenbrandia rivularis (Rhodophyta), the species composition of its surroundings detailed environmental variables (water chemistry and hydrological, morphological and bottom features) in a lowland river (Wełna river, Western Poland) was investigated. H. rivularis from 40 stands was tested together with 25 environmental variables and vegetation. Detrended correspondence analysis (DCA) and redundancy analysis (RDA) were used to describe the relations between the species composition and the selected variables. The uniqueness of this protected species is an ability of formation incrustation on rocks but also coexistence with two groups of species: other algae and vascular plants. In study twenty-two plant taxa were recorded in 40 vegetation plots, including 4 macroscopic algae, 2 mosses and 16 vascular plants. The most common H. rivularis co-occurred with Leptodictyum riparium, Fontinalis antipyretica and Nuphar lutea. Most of the studied plots with red algae were characterised by shallow water and strong water velocity. H. rivularis prefers alkaline water with high conductivity. The results of the RDA, after forward selection, demonstrated that pH gradient, optical features such as dissolved organic matter and water colour – control the variation in the floristic communities with H. rivularis.
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