Taxa Of Higher Rank Research Articles

Summer phytoplankton species composition and abundance in the southern basin of Lake Baikal and Irkutsk Reservoir

Phytoplankton has higher species richness in summer, when water temperatures are higher than in other seasons in aquatic ecosystems. Here, we characterized phytoplankton communities using microscopy and environmental parameters (temperature, pH, transparency) in the southern basin of Lake Baikal and Irkutsk Reservoir, which is directly connected with the lake as it is the upper part of Angara River, the Lake Baikal outlet. Surface water temperature was 10.1-18.4 °С in the southern basin of Lake Baikal and 14.9-20.0 °С was in Irkutsk Reservoir, pH values were similar both in the lake and the reservoir (8.09-8.44 and 7.96-8.28, respectively), and Secchi disc water transparency was 4.5-9.0 m in the lake and 2.5-4.5 m in the reservoir. The phytoplankton community included 104 species from 7 high-rank taxa such as Chrysophyta (36), Chlorophyta (30), Bacillariophyta (22), Cyanobacteria (11), Cryptophyta (2), Dinophyta (2), and Haptophyta (1). Species composition of summer phytoplankton communities of the Irkutsk Reservoir and the southern basin of Lake Baikal were different, however the community composition in terms of high-level phylotypes was very similar. At the same time, a large number of small-cell cyanobacteria were identified in the lake. A high species richness of Chrysophyta, genus Dinobryon (11 species) and silica-scaled chrysophytes (22) was founded. The composition of dominant species of the southern basin of Lake Baikal and Irkutsk Reservoir became wider compared to data published earlier, and included Cyanodictyon planctonicum, Cyanodictyon sp., Microcystis sp., Dinobryon sociale, Dinobryon sociale var. americanum, Chlorella vulgaris and Mychonastes homosphaera.

Complexity and Local Specificity of the Virome Associated with Tospovirus-Transmitting Thrips Species.

SUMMARYFrankliniella occidentalis (western flower thrips [WFT]) and Thrips tabaci (onion thrips [OT]) are insect species that greatly impact horticultural crops through direct damage and their efficient vectoring of tomato spotted wilt virus and iris yellow spot virus. In this study, we collected thrips of these species from 12 field populations in various regions in Italy. We also included one field population of Neohydatothrips variabilis (soybean thrips [ST]) from the United States. Total RNA data from high-throughput sequencing (HTS) were used to assemble the virome, and then we assigned putative viral contigs to each thrips sample by real-time reverse transcription-quantitative PCR (qRT-PCR). Excluding plant and fungal viruses, we were able to identify 61 viral segments, corresponding to 41 viruses: 14 were assigned to WFT, 17 to OT, and 1 to ST; 9 viruses could not be assigned to any species based on our stringent criteria. All these viruses are putative representative of new species (with only the exception of a sobemo-like virus that is 100% identical to a virus recently characterized in ST) and some belong to new higher-ranking taxa. These additions to the viral phylogeny suggest previously undescribed evolutionary niches. Most of Baltimore’s classes of RNA viruses were present (positive- and minus-strand and double-stranded RNA viruses), but only one DNA virus was identified in our collection. Repeated sampling in a subset of locations in 2019 and 2020 and further virus characterization in a subset of four thrips populations maintained in the laboratory allowed us to provide evidence of a locally persistent thrips core virome that characterizes each population.IMPORTANCE Harnessing the insect microbiome can result in new approaches to contain their populations or the damage they cause vectoring viruses of medical, veterinary, or agricultural importance. Persistent insect viruses are a neglected component of their microbiota. In this study, for the first time, we characterize the virome associated with the two model systems for tospovirus-transmitting thrips species, of utmost importance for the direct and indirect damage they cause to a number of different crops. The thrips virome characterized includes several novel viruses, which in some cases reveal previously undescribed clades. More importantly, some of the viruses we describe are part of a core virome that is specific and consistently present in distinct geographical locations monitored over the years, hinting at a possible mutualistic symbiotic relationship with their host.

Taxonomy, Ontogenesis and Evolutionary Relationships of the Algae-Bearing Ciliate Bourlandella viridis () comb. nov., With Establishment of a New Genus and New Family (Protista, Ciliophora, Hypotrichia).

Hypotrichs are the most complex and highly differentiated ciliate lineages and have great potential for evolutionary novelties. Problems in hypotrich systematics are mainly due to discordance between the morphological and genetic data (mainly small subunit rRNA gene). Species with morphologies that are characteristic of two or more higher rank taxa are probably a major contributing factor to these conflicts. The present study describes a Chinese population of a poorly known organism with numerous endosymbiotic zoochlorellae, the morphology of which corresponds well with the type population of Limnoholosticha viridis (Kahl, 1932) Li et al., 2017. Newly obtained information shows this species has a zigzag midventral cirral pattern that is diagnostic of urostylids, whereas the dorsal ciliature shares features (presence of dorsomarginal kinety and dorsal kinety 3 fragmentation) that are typical of oxytrichids. Molecular phylogenetic analyses reveal a close relationship with oxytrichids. An integrative approach combining morphological, morphogenetic, phylogenetic and ecological analyses indicates that L. viridis represents a new genus and new family which might be an intermediate form between uorstylids and dorsomarginalians. Thus, Bourlandellidae fam. nov. and Bourlandella gen. nov. are here established. Lastly, we speculate that phenotypic convergence and mixtrophy might confer on the new combination, Bourlandella viridis (Kahl, 1932) comb. nov., the ability to adapt to a wide range of environmental conditions.

Devonian Radiolarian Ecozones of Northern Eurasia

This study provides a description of the Devonian radiolarian associations of northern Eurasia and discusses their role in the evolution of Earth’s biosphere. It contributes to evolutionary studies of the Earth and its organic world by reconstructing the diversity dynamics of the Devonian radiolarian biota and the chorology of its components, at the same time revealing the biostratigraphic and paleoecological potential of radiolarians. The taxonomic composition and characteristics of the dominant morphotypes in radiolarian communities are indicators of environmental conditions. Associations of radiolarians vary significantly between different, even neighboring, water areas, so they can be considered as ecozones. Data on the structure of associations of radiolarians at the level of taxa of higher rank (classes) are a kind of “certificate” or “passport” of ecozones of individual paleobasins. Radiolarian ecozones replace each other in time, which allows their use for biostratigraphy. The results of the new and revisional studies of the Devonian radiolarians from 15 regions of northern Eurasia enabled a refined and detailed radiolarian scale of the Devonian system and description of 39 Devonian radiolarian ecozones, 24 of which are described for the first time: 17 ecozones are recognized based on the literature data, while seven ecozones are based on analysis of new data. Of 39 ecozones, 33 are dated based on conodont data, and six are dated using the co-occurring foraminifers, ostracodes, and/or ammonoids. General patterns in the evolution of Devonian radiolarians of northern Eurasia are considered and discussed. Spherical porous Sphaerellaria distinctly dominated in the Devonian. A clear trend towards an eastward increase in the relative abundance of spongy and latticed morphotypes of Spumellaria is shown. Spiny Aculearia of the orders Fasciculata and Triangulata are found to have been widespread. The early evolution of the bilaterally symmetrical Albaillellata is recorded. It is shown that in the Famennian, radiolarians with a pylome, Popofskyellidae and Archocyrtiinae, were common, while the genus Caspiaza first appeared at that time. The habitats and the distribution of the discoidal and ellipsoidal radiolarian morphotypes are analyzed in space and time. The dominance of these morphotypes can be used as an indicator of shallow water settings and a marker of transgression and regression boundaries in the paleobasin. A model of cyclic deposition of Domanik-type rocks in an anoxic basin is proposed, and the ecology of radiolarians in the anoxic environments of the Middle Frasnian Domanik Paleosea is analyzed. The predominance of the spiny morphotypes over spherical radiolarians is proposed as a paleoclimatic coefficient indicating cooling of the seawater in a paleobasin. Devonian radiolarians are represented by indigenous species and migrant species: (1) the value of the settled index exceeds that of the migration index by 3–5 times, (2) radiolarians occupied new ecological niches by emigration of evolutionarily young species representing genera with one–two species in total. Four radiolarian migration episodes are established in the Famennian basins of Laurussia. The monograph is intended for widespread use in paleontology, biostratigraphy, paleoecology, paleobiogeography and for university courses.

The establishment of the fertile fish lineages derived from distant hybridization by overcoming the reproductive barriers.

Distant hybridization refers to the cross between two different species or higher-ranking taxa. It is very significant if the new lineages with genetic variation, fertile ability, and improved characteristics can be established through distant hybridization. However, reproductive barriers are key limitations that must be overcome to establish fertile lineages derived from distant hybridization. In the present review, we discussed how distant hybridization is an important way to form new species by overcoming reproductive barriers and summarized effective measures to overcome reproductive barriers in order to create fertile lineages of fish distant hybridization. In addition, we described the utilization of the fish lineages derived from distant hybridization. Finally, we discussed the relationship between distant hybridization and Mendel's laws, which generally apply to the inbred hybridization. We aim to provide a comprehensive reference for the establishment of fertile fish lineages by overcoming reproductive barriers and to emphasize the significance of fish distant hybridization in the fields of evolutionary biology, reproductive biology, and genetic breeding.

Diet composition of a Newly Recognized Canid Species, the African Golden Wolf (Canis anthus), in Northern Algeria

We analysed the diet composition of a recently recognized species, the African golden wolf (Canis anthus), in the Tlemcen Hunting Reserve in Algeria by means of scat analysis. A total of 246 scat samples were collected from the study area. Prey items found in the faeces were assigned to species or higher-ranked taxa using identification guides and our collection of hair samples from the reserve. We were able to identify 34 food items including wild and domestic animals, fruits, leaves, soil and organic waste. Animal remains represented 84.8% of the biomass consumed by the African golden wolf, while plant remains constituted 15.2%. Prey species richness was the highest in summer with 23 different food items and the lowest in autumn with 17 items. Wild boar was the most important prey in the species' food spectrum within the reserve. Our results show the opportunistic resource use by the African golden wolf, with seasonal variation and a propensity for large-sized prey, including considerable amounts of livestock carcasses (24% of the total biomass), which underlines the importance of an effective wildlife management.

The ranking of fungi: a tribute to David L. Hawksworth on his 70th birthday

The history of assigning ranks to fungi, as well as the relative importance of using divergence time estimates is reviewed. The paper pays tribute to the major mycological players, and especially to David Hawksworth on his 70th birthday and his contribution to fungal ranking in Systema Ascomycetum from 1982 to 1998. Following the conclusion of the latter series, the ranking continued with the Outlines of Ascomycota in 2007 and 2010 and more recently with specific classes in 'Towards an outline of Sordariomycetes' and 'Families of Dothideomycetes'. Earlier classifications based on phenotype were certainly more subjective; however, remarkably many of these old arrangements have stood the test of time. More recently, phylogenetic analyses have provided evidence towards a natural classification, resulting in significant changes in many lineages. The classification arrangements however, are still subjective and dependent on the taxa analysed, resulting in different taxonomic interpretations and schemes, particularly when it comes to ranking. Thus, what have been considered as genera by some, have been introduced as families by others. More recently, estimation of divergence times using molecular clock methods have been used as objective evidence for higher ranking of taxa. A divergence period (i.e. 200-300 MYA) can be used as a criterion to infer when a group of related taxa evolved and what rank they should be given. We compiled data on divergence times for various higher ranking taxa in the Kingdom Fungi. The kingdom evolved 1000-1600 MYA (Stenian-Calymmian), while the presently accepted phyla evolved between 358 and 541 MYA (Devonian-Cambrian). Divergence times for subphyla are generally between 358 and 485 MYA (Devonian-Ordovician), those of classes 145-358 MYA (Jurassic-Carboniferous), subclasses 66-358 MYA (Cretaceous-Carboniferous), orders 23-252 MYA (Paleogene-Triassic), families 2.8-145 MYA (Neogene-Cretaceous), and genera 2.8-66 MYA (Neogene-Paleogene). Thus, there are wide discrepancies in the times different taxa diverged. We provide an overview over Ascomycota, showing how application of temporal banding could affect the recognition of higher taxa at certain rank levels. We then use Sordariomycetes as an example where we use divergence times to provide additional evidence to stabilize ranking of taxa below class level. We propose a series of evolutionary periods that could be used as a guide to determine the various higher ranks of fungi: phyla[550 MYA, subphyla 400-550 MYA; classes 300-400 MYA; subclasses 250-300 MYA, orders 150-250 MYA, and families 50-150 MYA. It is proposed that classification schemes and ranking of taxa should, where possible, incorporate a polyphasic approach including phylogeny, phenotype, and estimate of divergence times.

Natural taxonomic categories of angiosperms obey Benford's law, but artificial ones do not

Benford's phenomenological law gives the expected frequencies of the first significant digit (i.e., the leftmost non-zero digit) of any given series of numbers. According to this law, the frequency of 1 is higher than that of 2; this in turn appears more often than 3, and so on decreasing until 9. Similarly, Benford's law can also be applied to the first two significant digits (i.e., from 10 to 99), and so on. We applied Benford's law to sets of taxonomic data sets consisting of the number of taxa included in taxa of higher rank. We chose the angiosperms (Magnoliophyta) as a model case, because they are very diverse, are monophyletic, and a consensus on taxonomy of orders and families has been achieved (classification APG III), and we used as sets of data the number of species, genera, families, and orders. Only the number of species per family and per order are Benford's sets, but the remaining data sets do not obey Benford. Furthermore, in the case of the analysis of the first two significant digits of species per genus, the deviation from Benford was very large, but they fit to a power law. Given that the conformity to Benford's law is fulfilled for ‘natural' taxonomic categories of angiosperms (i.e., species and family), but not for those with more artificiality (genus), we speculate, ‘the more natural, the more Benford'.

Gastropods of the Lower Jurassic Hierlatz Limestone Formation, part 2. Some new archaic type slit-bearing components from the fauna of the Hierlatz Alpe (Hallstatt, Austria) and the Bakony Mts (Hungary)

Th is paper presents the taxonomic classifi cation of gastropod specimens mainly from yet unpublished parts of collections of the Early Jurassic Hierlatz Limestone fauna. Th e discussed species most probably belong to such higher rank taxa that have been formerly thought to become extinct during the Late Triassic crisis and represent groups typical of Palaeozoic to Triassic times. Th e new taxa are: Wortheniopsis rakusi n. sp., Wortheniopsis bakonyensis n. sp., Foveolaria n. gen., Fo- veolaria bicarinata n. sp., Foveolaria conoidea n. sp., Foveolaria globosa n. sp., Foveolaria suemegensis n. sp., Foveolaria kocsisi n. sp. and Foveolaria sp. (?Pithodeidae), and Cyclostomaria praemonarii n. sp. (Gosseletinidae). With 40 fi gures.

Revision of Late Permian nonmarine bivalves of the genus Verneuilunio Starobogatov, 1987 and its type species Naiadites verneuili Amalitzky, 1892

The genus Verneuilunio Starobogatov, 1987 (with the type species Naiadites verneuili Amalitzky, 1892) was distinguished from the genus Palaeanodonta Amalitzky, 1895 based on the differences in the hinge line, which were recognized using published data. Both genera were included in the family Palaeanodontidae Modell, 1964, which the author regarded as a subjective synonym of the family Palaeomutelidae Lahusen, 1897 (=Palaeomutelidae Weir, 1969). Revision of the collection of V.P. Amalitzky performed by the authors has shown that the initial diagnosis of the genus contains certain inaccuracy complicating identification and assignment to higher-rank taxa. The present study improves the diagnosis of the genus Verneuilunio and provides a detailed description of its type species Naiadites verneuili Amalitzy, 1892. Based on the presence of the duplivincular, slightly amphidet ligament, the genus Verneuilunio is referred to the family Naiaditidae Scarlato et Starobogatov, 1979. This character sharply distinguishes this genus from other co-occurring Unio-like genera of Late Permian nonmarine bivalves, i.e., Palaeomutela Amalitzky, 1892, Palaeanodonta Amalitzky, 1895, Oligodontella Gusev, 1963, and Opokiella Plotnikov, 1949. Verneuilunio is most similar in appearance to atypical Anthraconaia Trueman et Weir, 1946, which is characterized by Unio-like outline and widespread in the Upper Carboniferous. Data processing of morphometric parameters of Verneuilunio verneuili Amalitzky, 1892 and A. pruvosti (Tschernyshew, 1931), which is most similar to it in external outline has revealed statistically significant distinctions in elongation of the posterior shell end. According to available data, the geographical range of Verneuilunio is restricted to the central part of the East European Platform and its stratigraphic range falls in the lower substage of the Severodvinian Stage (=Early Capitanian).

Morphological evidence on blattarian phylogeny: “phylogenetic histories and stories” (Insecta, Dictyoptera)

The hypotheses of Grandcolas and Klass on blattarian phylogeny are compared through a scrutiny of all stages of phylogenetic analysis: taxon sampling; morphological studies; establishment of topographic homologies; treatment and presentation of characters, states, and state distribution over taxa; cladistic analysis and support of clades. Grandcolas' hypothesis is difficult to test due to inadequate documentation in several stages. In the testable subsets, many mishomologizations between male genital (phallomere) components and many misscorings for phallomere and non-phallomere characters are demonstrated. Through the use of high-rank taxa as terminal taxa in the matrix, much support for alternative clades is neglected. With the exception of some that are uncontroversial, the clades established by Grandcolas lose their support when the necessary character revisions are performed; of the 52 clade autapomorphies indicated in the cladogram, 7 remain here untested, 7 are accepted, and 38 are refuted. The scenarios of dictyopteran evolution built by Grandcolas on his phylogenetic results cannot he upheld. Klass' hypothesis appears more strongly supported, being based on more detailed morphological observations and homology discussions and considering evidence from all character state distributions. It is thus another demonstration that extensive and detailed morphological investigations and structural comparisons between taxa are essential for morphology-based phylogenetic work, in particular if complex and diverse organs (such as the dictyopteran phallomeres) are used. Some further general issues of phylogeny reconstruction are also referred to, and the importance of the topographic homology level, which precedes the primary (s.s.) and secondary levels, is emphasized.

Ostracods (Crustacea): Some problems of systematics

The initially established ostracod classification was based mainly on soft part anatomy of extant taxa. In the fossil record, ostracods are usually represented by shells alone, complicating the elaboration of a unified taxonomic system. A brief review of ostracod development in the Phanerozoic is outlined. Long-lived groups, such as Myodocopida, Podocopida, and Platycopida (Ordovician-Recent), display stable uniformity of the shell and soft part structures. The Paleozoic ostracod groups possess sharply different shell structures. The ostracod shell type is undoubtedly an important taxonomic feature. It is noteworthy that the points of view on the systematic position of extraordinary ostracod groups which became extinct in the Paleozoic (leperditicopids, beyrichicopids, kloedenellocopids) vary widely. It is proposed to assign all the ostracodomorphs and ostracods (bradoriamorphs, palaeocopids sensu lato, platycopids, podocopids) to the same high-rank taxon.

Marked seasonality and high spatial variability of protist communities in shallow freshwater systems.

Small eukaryotes have key roles in aquatic ecosystems, influencing their local environment, global biogeochemical cycles and climate. Their impact depends on community structure, which varies along time. However, very few studies take into account temporal variation. This is especially true for small, shallow freshwater systems, which remain largely understudied despite their wide variety, global surface and intense microbial activity. We have monthly followed changes in the community structure of small microbial eukaryotes (0.2-5 μm cell diameter) for 2 years in four ponds and one brook located in North-Western France based on massive 18S rDNA amplicon 454 pyrosequencing. We detected a total of 3742 stringently defined operational taxonomic units (OTUs) encompassing all recognized eukaryotic supergroups and lineages of uncertain affiliation. Although geographically close, protist communities in the five ecosystems were contrasting, with very few shared OTUs, suggesting that environmental selection mainly drives community structure. The temporal dynamics of different high-rank taxa appeared complex and rapid at monthly scales. Despite this, a clear and reproducible seasonality was observed. As expected, low-abundance OTUs dominated the community. Although some of them appeared sporadically or remained at low frequencies during the survey, others occasionally reached relatively high abundances, sometimes recurrently. This shows that at least a fraction of low-abundance eukaryotes constitutes a seed bank. The annual proportion of primary producers, free-living heterotrophs and parasites appeared remarkably constant among the different ecosystems, suggesting underlying trends of ecosystem carrying capacity for these functional groups.

Phylogenetic diversity of bacteria in soda lake stratified sediments

Various previously developed techniques for DNA extraction from the samples with complex physicochemical structure (soils, silts, and sediments) and modifications of these techniques developed in the present work were tested. Their usability for DNA extraction from the sediments of the Kulunda Steppe hypersaline soda lakes was assessed, and the most efficient procedure for indirect (two-stage) DNA extraction was proposed. Almost complete separation of the cell fraction was shown, as well as the inefficiency of nested PCR for analysis of the clone libraries obtained from washed sediments by amplification of the 16S rRNA gene fragments. Analysis of the clone library obtained from the cell fractions of stratified sediments (upper, medium, and lower layers) revealed that in the sediments of Lake Gorchina-3 most eubacterial phylotypes belonged to the class Clostridia, phylum Firmicutes. They were probably specific for this habitatand formed a new, presently unknown high-rank taxon. The data obtained revealed no pronounced stratification of the spe- cies diversity of the eubacterial component of the microbial community inhabiting the sediments (0-20 cm) in the inshore zone of Lake Gorchina-3.

The dynamics of systematic structure floral complexes on the old fields during secondary succession

The national plan of actions concerning the natural environmental protection in Ukraine in 2011–2015 presupposes the average reduce of the arable lands by 5–10 % with the help of withdrawal from the intense farming, preserving of the degradation and inefficient agriculture lands, with a purpose of the natural carcass elements extension (forests, meadows, pastures) and the rationalization of the agro-landscapes structure. It is known that the fitocenoses play a deciding role in the system of environmental preservation actions, its upgrade and improvement. According to the data of the Department of State Land Cadastre of State Land Agency of Ukraine of 01.01.2013 277.2 thousands hectares of land were excluded from the category of arable land and transferred to the old field land class consisting 0,5 % of the general area of Ukraine that is transforming under the influence of natural and anthropogenic processes. These changes in the structure and dynamics of the main landscape parameters and the danger of losing a significant part of biodiversity determine the relevance of the investigating systematic structure of the old-field species-composition at different stages of secondary succession. The research was made in 2010–2013 with the help of route and stationary methods on the calculation ground: 2×2 m for the grassy vegetation, 10×10 m for the tree and bush vegetation. The plots were chosen on different stages of the secondary succession, which most fully reflect the representatives of the flora complexes and enclose the whole spectrum of the main abiotic factors of its forming: I – old-fields, which were not processed for 1–3 years, II – old-fields, which were not processed for 4–7 years, III – old-fields, which were not processed for 8–13 years, IV – old-fields, which were not processed for 14–22 years. Taxonomic composition is given according to the field studies and basing on the collected herbarium material. Systematic spectrum (leading, middle and final) was defined using an average index of saturation (H) of higher rank taxa with lower rank taxa. To the middle part there belonged the amount of lower rank taxa equal to the average index of saturation of higher rank taxa ± 50 % of its value: H ± 0.5 × H. To compare the degree of species composition similarity there was used the Jaccard similarity coefficient (Kj). The similarity degree of floral complexes according to the systematic structure was defined using modified Bravais-Pearson coefficient of correlation (r). Taxonomic composition of the old-field land floral complexes of Prydnistrovske Podillia showed that it numbered 413 species belonging to 238 genera and 64 families. The old field floral complexes of the studied territory are characterized by the dominance by the amount of species and genera of few families, the taxonomic spectrum of which comprises 264 species (63,9 %) and 150 genera (62,9 %). In the genera spectrum of floral complexes prevails monotype fraction – 204 genera (85,7 %) uniting 253 species (61,3 %). The role of absolute indices of the floristic abundance (amount of species, kinships and families) have a natural tendency to extension, which is a result of the change in soil and climatic as well as the cenotic conditions in the process of demutation of the flora cover in the old-fields. The analysis of the floral wealth, systematic diversity and taxonomic composition indicate the dynamic process of flora-genesis at the old field lands and the largest similarity of floras of the 3rd and the 4th degrees of secondary succession as a result of stabilization of ecological conditions. The least similar are the floral complexes of the 1st and the 4th degrees of syngenesis. Besides the general systematic structure of the flora complexes of the old-fields, the determination of the species abundance of the biotopic old-plough lands still remains urgent. Based on the principles of the heterogeneity and change of the vegetation depending on the dynamics indices of the environment, dimensionally (discretely), as well as timely (successively) on the territory of the research, we found out and described the species abundance of 10 biotypes. The analysis of biotopes species composition similarity shows that most of them are characterized by low degree similarity. Our further researches will be connected with the peculiarities of the ecological succession at old field lands. The ecological analysis of floral complexes was based on the study of O. L. Belgard about ecomorphs.

Research advances in animal distant hybridization.

Distant hybridization refers to crosses between two different species or higher-ranking taxa that enables interspecific genome transfer and leads to changes in phenotypes and genotypes of the resulting progeny. If progeny derived from distant hybridization are bisexual and fertile, they can form a hybrid lineage through self-mating, with major implications for evolutionary biology, genetics, and breeding. Here, we review and summarize the published literature, and present our results on fish distant hybridization. Relevant problems involving distant hybridization between orders, families, subfamilies, genera, and species of animals are introduced and discussed, with an additional focus on fish distant hybrid lineages, genetic variation, patterns, and applications. Our review serves as a useful reference for evolutionary biology research and animal genetic breeding.

Complex origins of the Lusitania biogeographic province and northeastern Atlantic fishes

The Lusitania Province encompasses the warm temperate marine waters between the southern end of the English Channel, in the North, and Cape Juby or Cape Blanco, in the South, including the Mediterranean and the archipelagoes of the Azores, Madeira and the Canary Islands. Briggs and Bowen (2012) proposed that the warm temperate provinces, although retaining their provincial status, should be grouped with the adjacent tropical ones. Thus, they included the Lusitania Province in a warm eastern Atlantic region. We argue that the time elapsed since the Miocene was sufficient to allow the evolution of endemic species, genera and some higher rank taxa, a finding that emphasizes the convenience to avoid the integration of the province in this larger region. The tropicality index for the Lusitania Province is 1.82, indicating a prevalence of warm water over cold water fish. However, this value is strongly biased by the large differences between the Macaronesian archipelagos (4.08) and the mainland coasts of the Lusitania Province (0.66).

Complex origins of the Lusitania biogeographic province and northeastern Atlantic fishes

The Lusitania Province encompasses the warm temperate marine waters between the southern end of the English Channel, in the North, and Cape Juby or Cape Blanco, in the South, including the Mediterranean and the archipelagoes of the Azores, Madeira and the Canary Is- lands. Briggs and Bowen (2012) proposed that the warm temperate provinces, although retain- ing their provincial status, should be grouped with the adjacent tropical ones. Thus, they in- cluded the Lusitania Province in a warm eastern Atlantic region. We argue that the time elapsed since the Miocene was sufficient to allow the evolution of endemic species, genera and some higher rank taxa, a finding that emphasizes the convenience to avoid the integration of the province in this larger region. The tropicality index for the Lusitania Provi nce is 1.82, indicat- ing a prevalence of warm water over cold water fish. However, this value is strongly biased by the large differences between the Ma caronesian archipelagos (4.08) and the mainland coasts of the Lusitania Province (0.66).

Dynamics of the middle-rank taxonomic diversity structure of brachiopods: a quantitative assessment of the Phanerozoic fossil record

Ruban, D.A., September 2012. Dynamics of the middle-rank taxonomic diversity structure of brachiopods: a quantitative assessment of the Phanerozoic fossil record. Alcheringa 36, 413–426. ISSN 0311-5518. Taxonomic diversity structure indicates how higher-rank taxa influence the diversity of lower-rank taxa. Brachiopods experienced significant changes in the superfamily–family, superfamily–genus and family–genus components of diversity structure during the Phanerozoic. The most intense changes occurred at the Cambrian–Ordovician, Devonian–Carboniferous and Permian–Triassic transitions, when new higher-rank taxa began to determine the diversity at lower taxonomic levels. In contrast, the similarity of successive brachiopod assemblages was relatively high during the Ordovician–Devonian, Carboniferous–Permian, Triassic–Cretaceous and Paleogene–Quaternary intervals indicating a form of evolutionary stagnation. High dissimilarity between older and younger assemblages was established at the Cambrian–Ordovician and Permian–Triassic transitions, which mark the distinctions between the Cambrian, Palaeozoic and Modern evolutionary faunas within the target fossil group, i.e., brachiopods. Changes in superfamily–family, superfamily–genus and family–genus components of diversity structure were similar. All ‘Big Five’ mass extinctions left a more or less significant imprint in the dynamics of the diversity structure of brachiopods, but the Late Devonian and end-Permian catastrophes were especially important. Results of the present study may be refined with future improvements to brachiopod suprageneric systematics.

Floral morphogenesis in choripetalous and sympetalous members of Ericaceae s.l. (Ericales)

Choripetaly of Rhododendron tomentosum is the result of secondary reduction. Our data support earlier observations of P. Leins [4] that a rudimentary corolla tube occurs during early stages of floral development. Choripetaly of Empetrum may be a plesiomorphic condition, because no vestiges of corolla tube were detected throughout all stages of flower development. However, a complete loss of corolla tube cannot be excluded. The type of congenital petal fusion varies within a group of closely related taxa of Ericaceae: Phyllodoce caerulea has late sympetaly while Loiseleuria procumbens has early sympetaly. In contrast, in euasterids, the type of sympetaly appears to characterize taxa of higher rank.