Aegagropila Linnaei Research Articles

Anti-inflammatory and analgesic effect of an ointment containing carotenoids of the hexane extract of Cladophora aegagropila

Anti-inflammatory and analgesic effect of an ointment containing carotenoids of the hexane extract of Cladophora aegagropila

Microwave hydrolysis, as a sustainable approach in the processing of seaweed for protein and nanocellulose management

The nature of marine biomass is very complex for a material scientist due to the large seasonal variation in the chemical composition that makes it difficult to prepare standardized products. A systematic investigation of the interaction of microwave irradiation with seaweed from Norway and Caribbean region was performed, covering a broad temperature range (130 → 170 °C) and without and with addition of ℽ-valerolactone (GVL) in ratios of 1:4 and 1:2. The temperatures above 150 °C and without addition of GVL led to the closure of mass balances up to 90 % that includes polysaccharides, “pseudo-lignin” fraction, fatty acids, and proteins. Fucoidan and mannose represented >50 % of all detected polysaccharides in ascophyllum nodosum (AN), while aegagropila linnaei (AL) contained mostly glucose. The presence of arabinose and rhamnose in the upper surface of the cell wall hinders the glucose release during microwave treatment. The differences in the polysaccharide composition among both algae samples hindered the definition of a parameters set that can be used in microwave treatment of various seaweed species. A large fraction of protein (> 95 %) remained in the seaweed solid residue. Higher amount of protein was determined in AL, which was dominated by leucine and lysine. Another potential barrier to the application of seaweed in industry is the limited knowledge on the chemical composition of “pseudo-lignin” and extractives. The total amino acid analysis was identified as the most accurate to characterize the protein yield and composition. The results showed that microwave treatment of seaweed is indeed a viable method for producing bioactives in the temperature range 120–150 °C, and proteins and nanocellulose at temperatures above 170 °C without using GVL. The microwave temperature and seaweed type played a dominating role in the mass closure balances leading to >95 % identified compound.

Ideal water temperature environment for giant Marimo (Aegagropila linnaei) in Lake Akan, Japan

Aegagropila linnaei is a filamentous green algal species that often forms beautiful spherical shapes called "lake balls" or "Marimo". A. linnaei were once globally distributed around the world, but the population has been declining for several decades. Lake Akan, in Japan, is now the only lake in the world with a colony of giant Marimo (over 20 cm in diameter). Here we show the net growth rate of Marino resulting from photosynthesis and decomposition based on laboratory experiments, MRI analysis, and quantitative element analysis, which show the decomposition rate, the maximum annual Marimo diametric growth rate, and the carbon-to-nitrogen ratio, respectively. We found an explicit dependence of the decomposition rate of Marimo on the cumulative water temperature, with a threshold of 7 °C. MRI analysis showed a high correlation among a Marimo's diameter, surface thickness, and annual diametric growth rate. Moreover, the C/N ratio was high in the exterior side of the surface thickness, indicating that this layer is the main growth area for photosynthesis. These results suggest that the central cavity and the surface thickness represent the change in the growth environment such as water temperature and light intensity. Between the 1980s and the present, Between the 1980s and the present, the cumulative water temperature has increased from about 1250 to about 1600 °C-days. Therefore, the maximum surface thickness has decreased by approximately 1 cm, as estimated by water temperature records and annual diametric growth rates10. As a measure to preserve preferable conditions for colonies of giant Marimo in the face of global warming, the flow of low-temperature river water into Marimo colonies should be protected.

Enhanced sampling refines the biogeography of the freshwater green alga Aegagropila linnaei (Cladophoraceae)

ABSTRACT A phylogeographic approach is the only way to study the dispersal history of most algae, which are rarely preserved as fossils. However, the only freshwater alga for which this approach has been applied on a Eurasian scale is the endangered green alga Aegagropila linnaei, which is thought to be a poor disperser. Previous phylogeographic results were explained by stepwise dispersal across the Holarctic from an ancestral area in Japan, with further survival in European ice-dammed glacial lakes and extinction in continental Siberia, which lacks such refugia. To clarify the biogeography of A. linnaei in Eurasia we supplemented the published data on its ribotype (internal transcribed spacer of ribosomal DNA) distribution with data from previously unexplored East Europe, Mongolia and the Russian Far East. We have found two new ribotypes, one scattered across temperate Europe and another confined to one locality in the north-eastern Russian Far East. We also expanded the distribution of a ribotype previously reported from Scotland and continental West Europe to include East Europe, Iceland and Central Mongolia. Phylogeogeographic approach based on enhanced sampling allowed us to refine the biogeography of A. linnaei. We discuss reasons for underestimation of A. linnaei dispersal potential. A focused inventory of A. linnaei will likely reveal new localities of the species enabling a further improvement in biogeographical reconstructions. Area-wide studies of other freshwater algae in Eurasia need to be performed to test the generality of the revealed biogeographical patterns.

Effects of High Irradiance and Low Water Temperature on Photoinhibition and Repair of Photosystems in Marimo (Aegagropila linnaei) in Lake Akan, Japan.

The green alga Aegagropila linnaei often forms spherical aggregates called "marimo" in Lake Akan in Japan. In winter, marimo are exposed to low water temperatures at 1-4 °C but protected from strong sunlight by ice coverage, which may disappear due to global warming. In this study, photoinhibition in marimo was examined at 2 °C using chlorophyll fluorescence and 830 nm absorption. Filamentous cells of A. linnaei dissected from marimo were exposed to strong light at 2 °C. Photosystem II (PSII) was markedly photoinhibited, while photosystem I was unaffected. When the cells with PSII damaged by the 4 h treatment were subsequently illuminated with moderate repair light at 2 °C, the maximal efficiency of PSII was recovered to the level before photoinhibition. However, after the longer photoinhibitory treatments, PSII efficiency did not recover by the repair light. When the cells were exposed to simulated diurnal light for 12 h per day, which was more ecological, the cells died within a few days. Our results showed new findings of the PSII repair at 2 °C and serious damage at the cellular level from prolonged high-light treatments. Further, we provided a clue to what may happen to marimo in Lake Akan in the near future.

Development of a novel biochar/iron oxide composite from green algae for bisphenol-A removal: Adsorption and Fenton-like reaction

In this study, algae of Aegagropila linnaei (AL) was selected as low-cost raw material to synthesize biochar/iron oxide composites for the removal of bisphenol-A (BPA). Pristine biochar (BC) with olive-shaped pores and KOH-activated acid washed biochar (ABC) with novel interconnected structure were successfully prepared and further functionalized with ferrous sulfate for effective soldering of Fe 3 O 4 nanoparticles onto the surface of acid biochar through hydrothermal method. The iron modified acid biochar composite (FABC) was found to be with the optimal physicochemical property such as smaller crystalline size (100–150 nm), larger surface area (144.62 m 2 /g), larger pore volume (0.259 cm 3 /g), lower capacitance decrease (2.3%), and lower resistance (0.73 Ω ) as compared to other modified biochar. The removal rates of BPA by BC, ABC, and FABC were 43.2 ± 0.5%, 52.6 ± 0.3%, and 69.8 ± 2.3%, respectively, when the concentration of BPA was 10 mg/L (pH 3.0, 303k). Under acidic conditions (at pH 3.0), the reaction activity and the adsorption of hydrogen ions onto Fe 3 O 4 nanoparticles in FABC was prompted, and further increasing the removal rate of BPA. The result suggests that adsorption played main role, while active species ( ⋅ OH and ⋅ O 2 − ) produced by the nano-iron oxide on the surface of the composites played some effect in the removal of BPA. • Aegagropila linnaei algae was used to prepare iron modified acid biochar composite. • Biochar/iron oxide composite can be successfully produced by hydrothermal process. • Biochar/iron oxide composite could increase the removal of BPA under low pH condition. • ROS generated by the composite is responsible for oxidation removal of BPA.

Aegagropila linnaei Kütz. (Chlorophyta), Paludicola keratophyta (Bory) M.L.Vis et Necchi (Rhodophyta) та Lychnothamnus barbatus (Meyen) Leonhardi (Charophyta) – кандидати на включення до Червоної книги України

The results of the analysis of the diversity of rare algae of Ukraine are presented. The discussion is the basis for inclusion in the fourth edition of the Red Data Book of Ukraine the species Aegagropila linnaei Kütz. (Cladophorales, Chlorophyta), Paludicola keratophyta (Bory) M.L.Vis et Necchi (Batrachospermales, Rhodophyta) and Lychnothamnus barbatus (Meyen) Leonhardi (Charales, Charophyta). Their descriptions, nomenclature history, ecological features and typological timing are given. Summarized information on the distribution of known species proposed for protection at the state level in Ukraine and the world. The publication is illustrated with original photos and drawings. The information is supplemented by maps with the indicated localities of growth.

Comparison of the Antioxidant Properties of Green Macroalgae from Diverse European Water Habitats by Use of Several Semi-Quantitative Assays.

Nowadays, algae are becoming more and more popular as a food group rich in nutrients, cosmetic raw materials full of antioxidants or valuable dietary supplements. They are of interest for the industry because they are found almost all over the world, in all climatic zones, both in fresh and salt waters. The aim of this study was to take a broad look at green algae (Chlorophyta) and to show how large the variability of the content of active compounds may depend on the species and the place and time of sample collection. Particular attention was paid to compounds with antioxidant activity, whose simplified profiles were created on the basis of complementary, semi-quantitative methods. Additionally, time-yield extraction optimizations were performed. Three different specimens of Ulva lactuca were compared: from the coastal zone of the Baltic Sea, from the open Baltic Sea area around Bornholm and Ulva spiralis (Ulva lactuca polymorph) from the Atlantic Ocean. The studied algae of the Cladophora genera were three different species of freshwater algae from various habitats: a lake (Cladophora glomerata), a river (Cladophora rivularis) and aquarium farming (Cladophora aegagropila, syn. Aegagropila linnaei). The content of antioxidants and the extraction efficiency varied significantly depending on the species.

The structure and formation of giant Marimo (Aegagropila linnaei) in Lake Akan, Japan

Aegagropila linnaei is a freshwater green alga, which at one time was distributed widely in the northern hemisphere. The aggregate often forms beautiful spherical shapes known as “lake balls” or “Marimo”. The population of Marimo has been rapidly decreasing worldwide, and today the large Marimo, with a diameter of more than 12 cm, exit only in Lake Akan in Japan. However, how Marimo grow and maintain their unique spherical shape in natural habitats remains unsolved. Here we show that Marimo are “polished” into spheres by the rotation induced by wind waves. Such a process enhances the water exchange between the interior and exterior of the Marimo, thereby recycling nutrients for growth. Our results provide an intriguing model of a physical environment interacting with biological processes in a self-sustaining ecosystem. We also demonstrate that Marimo have a spherical annual ring structure, and their growth rate is associated with ice cover. The balance between the ecology of Marimo and the water environment in Lake Akan is highly vulnerable and at risk of irreversible degradation. We must endeavor to rescue Marimo from the fate of a "canary in the coal mine" of global climate change.

Hitchhiking Exotic Clam: Dreissena polymorpha (Pallas, 1771) Transported via the Ornamental Plant Trade

Ornamental aquaculture is one of the main sources of non-native species worldwide. Unintentionally transported “hitchhiking” organisms have been previously recorded; although most of these species are transported from tropical regions, here we report on the first accidental transport of the zebra mussel (Dreissena polymorpha) in a shipment of ornamental Aegagropila linnaei (Chlorophyta) from Russia to the Czech Republic. This invasive mussel is listed on the national blacklist of alien species in the Czech Republic and can be easily released in outdoor garden ponds together with A. linnaei. Since the Czech Republic is known to be a gateway for aquatic ornamental species from a European perspective, re-export to other European countries is also possible. Thus, the spread of D. polymorpha via this pathway cannot be excluded. This finding should be of importance to conservationists, traders, decision-makers and other stakeholders.

Influence of ultraviolet radiation on aquatic plants in conditions of low lighting

The effect of ultraviolet radiation (UV-r) on aquatic vegetation in conditions of general insufficient illumination was studied in laboratory conditions. In the studies such species of aquatic vegetation were used – submerged hornwort (Ceratophyllum demersum), thai fern (Microsorium pteropus), and globular cladophore (Aegagropila linnaei). The studies were carried out simultaneously in 3 aquariums, 3 liters each, with five iterations. For each of the experiments, the containers with water were covered with black paper on all sides, and 3 plants of each species were placed. Low-power LEDs were installed above the water surface of each aquarium. 2 white LEDs of the FYL-3014SRC brand (each with a power of 0.06 W at a luminous intensity of 600 mcd) were used for control experiments. In other versions of experiments with irradiation, we used – 2 white and 2 UV-diodes (similar power), and 2 white diodes together with 6 UV-diodes. Every week during the experiment, the morphometric parameters (weight, leaf area, length) and color of vegetation were measured during a 30-day continuous exposure from the sources described above. At the end of the experiment, it was found that with a general low power of white illumination, the presence of additional UV-r can have a multidirectional effect on vegetation that lives at different levels of the water system. Thus, UV irradiation negatively affects rootless plants of the upper layers of aquatic systems (Ceratophyllum demersum), probably due to known disturbances in the their photosynthetic apparatus. UV-r led to a decrease in the mass and leaf area of such plants (by 80–90 %), a change in their color, disruption of their vital activity, the development of tissue decay processes and even death by the end of the experiment. On root plants (Microsorium pteropus) with arrow-shaped leaves pointing upwards, additional UV-r can support the light balance and to some extent compensate (by 10–15 %) the overall decline in the level of their development (by 60–75 %). Bottom vegetation (Aegagropila sauterii), living at a depth of up to 5 m, is able to fully compensate for the lack of natural illumination by UV irradiation. UV-r penetrates the water column and after re-radiation on elements of aqueous solution penentrates to a considerable depth in the form of longer waves, and then used of plants with a general increase in the measured parameters by 5–20 %. This article concludes that the final effect on aquatic plants is formed by the depth of their habitat and the total intensity of light falling on the surface of the aquatic system. At the same time, under conditions of a lack of light, UV-r can act negatively on plants that are located close to the surface of the water, and at the same time positively as an additional source of energy – on benthic plants.

Internal microbial zonation during the massive growth of marimo, a lake ball of Aegagropila linnaei in Lake Akan

SummaryMarimo (lake ball) is an uncommon ball-like aggregation of the green alga, Aegagropila linnaei. Although A. linnaei is distributed in fresh and brackish waters in the northern hemisphere, marimo colonies are found only in particular habitats. Here, we report the bacterial communities inside various sizes and aggregating structures of natural marimo collected from Lake Akan, Japan. We observed multi-layers composed of sediment particles only in the sizable radial-type marimo with >20 cm diameter and not in the tangled-type marimo. The deeper layers were enriched by Nitrospira, potential sulfur-oxidizing bacteria, and sulfate-reducing bacteria. Microorganisms of the multi-layers would form biofilms incorporating nearby sediment, which would function as microbial “seals” within large radial-type marimo. These findings provide clues to deciphering the growth of endangered marimo.

Sulfoquinovosylglyceryl ether, a new group of ether lipids from lake ball-forming green alga Aegagropilopsis moravica (family Pithophoraceae).

Ether lipids are a minor group of glycerolipids but widespread in nature, playing a vital function as membrane lipids, signalling molecules, or buoyant material. We have discovered sulfoquinovosylchimyl alcohol (1), a sulfonate-substituted glyceroglycolipid, from a lake ball-forming green alga Aegagropilopsis moravica (family Pithophoraceae), with the guidance of antimicrobial activity. The structure of 1, including absolute configurations of all sterogenic centers, was established by extensive NMR analysis, chemical degradation studies, and finally by total synthesis. Lipid 1 is an ether variant of a lyso-form of sulfoquinovosyldiacylglycerol, a chloroplast-specific membrane lipid, and thus represents a new lipid class, sulfoquinovosylglyceryl ether. A high occurrence of mobile life form in the family Pithophoraceae and a unique behaviour of chloroplasts reported in closely related Aegagropila linnaei, the famous lake-ball alga, implies a possible role of lipid 1 or its acyl derivatives in ecological adaptation to dysphotic niches.

Reproductive behavior and role in maintaining an aggregative form of the freshwater green alga Marimo, Aegagropila linnaei, in Lake Akan, Hokkaido, Japan

Abstract Aegagropila linnaei is a unique freshwater green alga that develops into spherical aggregations known as “lake balls”, “Cladophora balls” or “Marimo”. Loss of this species is progressing globally, and there is concern over threats and its conservation. As part of the study which aims to conserve this endangered species, zoosporogenesis of A. linnaei in Lake Akan, designated as a Special Natural Monument of Japan, was investigated. Materials encompassing three growth forms of A. linnaei: aggregative, free-floating, and epilithic, were collected at five sites around the lake at regular intervals from spring to autumn of 2017 and 2018. Quadriflagellate zoospores were observed at three sites (one aggregative and two epilithic) in mid-August and early September with a reproducibility, but not at two sites (one aggregative and one free-floating). Percentages of zoospore-producing filaments were extremely low (maximum 1.3 %), and the result of statistical analysis by generalized linear model showed no significant difference among the study sites and periods in both years. These results indicated that the zoosporogenesis of A. linnaei, which has been thought to be an extremely rare event in the past, occurs regularly even though being low percentage. Such rare zoosporogenesis appears to provide a few initials for the ensuing generations and to contribute to maintaining the aggregative form through the continuation of vegetative growth.

Phytochemical analysis and anti-inflammatory activity of Cladophora aegagropila extract

Introduction: The aim of this research is centered on phytochemical analysis and anti-inflammatory activity of Cladophora aegagropila extract. Methods: Total flavonoid content in the appropriate ethanol extract of C. aegagropila was determined using the spectrometric method. Anti-inflammatory activity was evaluated by the models of carrageenan-induced and allyl isothiocyanate-induced (AITC-induced) inflammation of hind limb in rats. Experimental animals were divided into 3 groups, 5 animals each: 1st group – control; the animals without therapy of induced inflammation, 2nd group – animals were treated with application of 5% ointment containing C. aegagropila; 3rd group – animals were treated with application of 5% ibuprofen. Evaluation of anti-inflammatory activity was performed by determination of dynamic change of thickness and volume of affected animal limb for carrageenan-induced inflammation for 8 days (with daily registration of records), and for AITC induced inflammation for 24 h (with registration of records after 30 min, 1 h, 2 h, 3 h, 6 h and 24 h since phlogogen was introduced). Results: Flavonoids content in C. aegagropila extract varied depending on ethanol concentration: usage of 40% ethanol led to 18.2 mg of flavonoid recovery on 1.0 g of dry raw material; 70% ethanol – 39.5 mg and 96% ethanol – 35.5 mg. Therapy of 5% ointment based on C. aegagropila extract decreased inflammatory response caused by the subplantar introduction of the corresponding phlogogen. Conclusion: The ointment from C. aegagropila extract shows anti-inflammatory activity by inhibiting inflammation caused by AITC and carrageenan.

Marimo machines: oscillators, biosensors and actuators

BackgroundThe green algae balls (Aegagropila linnaei), known as Marimo, are large spherical colonies of live photosynthetic filaments, formed by rolling water currents in freshwater lakes. Photosynthesis therein produces gas bubbles that can attach to the Marimo, consequently changing its buoyancy. This property allows them to float in the presence of light and sink in its absence.ResultsWe demonstrate that this ability can be harnessed to make actuators, biosensors and bioprocessors (oscillator, logic gates). Factors affecting Marimo movement have been studied to enable the design, construction and testing of working prototypes.ConclusionsA novel actuator design is reported, incorporating an enhanced bubble retention system and the design and optimisation of a bio-oscillator is demonstrated. A range of logic gates (or, and, nor, nand, xor) implementable with Marimo have been proposed.

PROSPECTS OF WATER OBJECTS TREATMENT FROM CHLORPHENOL COMPOUNDS USING SEAWEED

Background The article is devoted to protection of natural waters located close to cities and industrial enterprises. Biotechnological methods of natural waters purification, which have high efficiency, low cost, ease of implementation of the process, as well as being environmentally safe, are of increasing interest. Aims and Objectives Investigation of the accumulation and subsequent biotransformation of toxic organic compounds, in particular chlorophenols, by lower aquatic plants from the cladophoric family ( Cladophoraceae ) - Linnea Ehagropila ( Aegagropila linnaei ). Methods Experimental studies using the chromatographic method. Results There presented the results of the study of the process of accumulation and subsequent biotransformation of chlorophenolic compounds (2-chlorophenol C6H5ClO, 2,4-dichlorophenol C6H4Cl2O, 2,4,6-trichlorophenol C6H3Cl3O, 2,3,4,6-tetrachlorophenol C6H2Cl4O, pentachlorophenol С6Н2Cl5O; lower cladophor family aquatic plants ( Cladophoraceae ). The intensity of these processes was determined by the chromatographic method on the residual content of organochlorine compounds in the purified water and plant tissues. The results indicate that algae provide high water purification from chlorophenolic compounds - the water purification efficiency for certain types of chlorophenols (2-chlorophenol С6Н5ClO) was more than 99 % in 24 hours. It was also found that the efficiency of the accumulation process depends on the size and properties of molecules and decreases in the series: monochlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol, pentachlorophenol. Studies on the biotransformation of chlorophenols in the phytomass of green plants were performed using 2,4-dichlorophenol as a pollutant. The study found that complete biotransformation of chlorophenolic compounds occurs in 24 hours. This, apparently, is explained by the fact that algae possess a definite set of enzyme systems that ensure the processes of destruction and splitting of organochlorine compounds. After the dechlorination process, the compounds are biodegradated to form paraffins with different contents of carbon atoms. Thus, Aegagropila linnaei algae are an effective accumulator and destructor of chlorophenolic compounds. And biotechnology, based on the use of phytomass of green plants, is quite promising in the treatment of natural waters polluted with toxic organochlorine compounds.

Perspective direction of small rivers water purification from ions of heavy metals

The article is devoted to the actual problem of purification of small rivers from ecotoxicants. In this paper we consider the biological method of cleaning small rivers with biofilters. The degree of bioaccumulation of heavy metals by water plants by Elodea canadensis and Cladophora aegagropila on the example of the river Shugurovka of the Republic of Bashkortostan is estimated.

Production of cellulose from Aegagropila Linnaei macro-algae: Chemical modification, characterization and application for the bio-sorptionof cationic and anionic dyes from water

Marine algae wereprovedto begoodadsorbentsformany pollutants. In this work, Aegagropila Linnaei (Aegagropila L.) was treated with sodium hydroxideand sodium chlorite. The extracted cellulose content was 18.5%. It was functionalized with Dimethyl diallyl ammonium chloride and diallylamin co-polymer. The products were characterized using Fourier Transform Infra-Red (FT-IR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and thermogravimetric analyses (TGA). The samples were studied as adsorbents of methylene blue(MB) and acid blue 25(AB25) in a controlled batch system. The effect of salts concentration (KCl, NaCl, and CaCl2), adsorbent dosage, pH, contact time and initial dye concentration on the adsorption mechanism was discussed. At equilibrium, the adsorption of MB and AB25ontoextracted and functionalized cellulose reached 109 mg/g and 139 mg/g, respectively. Under the same conditions, the adsorption capacity of AB25 and MB onto unmodified Aegagropila L. was, only, 32 mg/g and 47 mg/g. The pseudo second-order kinetic equation exhibited the optimal fitting results. The mean free energy (E = 70.71 to 223.6 Kj/mol), calculated from Dubinin-Radushkevich isotherm, suggested a chemi-sorption mechanism. Overall, the results confirmed that the studied products could be considered as valuable bio-sorbents of dyes from contaminated waters.

The endemic Cladophorales (Ulvophyceae) of ancient Lake Baikal represent a monophyletic group of very closely related but morphologically diverse species.

Lake Baikal, the oldest lake in the world, is home to spectacular biodiversity and extraordinary levels of endemism. While many of the animal species flocks from Lake Baikal are famous examples of evolutionary radiations, the lake also includes a wide diversity of endemic algae that are not well investigated with regards to molecular-biological taxonomy and phylogeny. The endemic taxa of the green algal order Cladophorales show a range of divergent morphologies that led to their classification in four genera in two families. We sequenced partial large- and small-subunit rDNA as well as the internal transcribed spacer region of 14 of the 16 described endemic taxa to clarify their phylogenetic relationships. One endemic morphospecies, Cladophora kusnetzowii, was shown to be conspecific with the widespread Aegagropila linnaei. All other endemic morphospecies formed a monophyletic group nested within the genus Rhizoclonium (Cladophoraceae), a very surprising result, in stark contrast to their morphological affinities. The Baikal clade represents a species flock of closely related taxa with very low genetic differentiation. Some of the morphospecies were congruent with lineages recovered in the phylogenies, but due to the low phylogenetic signal in the rDNA sequences the relationships within the Baikal clade were not all well resolved. The Baikal clade appears to represent a recent radiation, based on the low molecular divergence within the group, and it is hypothesized that the large morphological variation results from diversification in sympatry from a common ancestor in Lake Baikal.