Names above the rank of genus; the radical approach.

The International Code of Nomenclature of Prokaryotes currently caters for the names of ranks from class to subspecies. The form of names and their typification is dealt with under Rules 7-22. The nature of names at different ranks has a direct influence on the structure of the Code. However, with minor changes it is possible to simplify the structure and the links between names and their nomenclatural types, even if the proposed solution may cause some changes that create a degree of upheaval in the short term.

The evolutionary reality of species and higher taxa in plants: a survey of post-modern opinion and evidence.

Species are normally considered to be the fundamental unit for understanding the evolution of biodiversity. Yet, in a survey of botanists in 1940, twice as many felt that plant genera were more natural units than plant species. Revisiting the survey, we found more people now regarded species as a more evolutionarily real unit, but a sizeable number still felt that genera were more evolutionarily real than species. Definitions of 'evolutionarily real' split into those based on shared evolutionary history and those based on shared evolutionary fate via ongoing evolutionary processes. We discuss recent work testing for shared evolutionary fate at the species and higher levels and present preliminary evidence for evolutionarily significant higher taxa in plants.

Higher classification of the Monostilifera (Nemertea: Hoplonemertea).

The nemertean order Monostilifera consists of 594 species in 127 genera and is distributed worldwide. Within the Monostilifera, two suborders have been recognized, Cratenemertea and Eumonostilifera. Within the latter, two, unranked clade names, Oerstediina and Amphiporina, were recently proposed without formal taxonomic definition. In this article, I give morphological circumscriptions and clade definitions for Cratenemertea, Eumonostilifera, Oerstediina, Plectonemertidae, Oerstediidae, and Amphiporina. Oerstediina and Amphiporina are placed on the Linnaean rank of infraorder. Constituent genera and species for each higher taxon are tabulated. The genus Amphiporella Friedrich, 1939 is herein replaced with Germanemertes nom. nov. to avoid homonymy with the Carboniferous fossil bryozoan genus Amphiporella Girty, 1910. Loxorrhochmidae Diesing, 1862 is declared a nomen oblitum relative to Tetrastemmatidae Hubrecht, 1897, a nomen protectum under Article 23.9 of the International Code of Zoological Nomenclature. There remain 308 species of eumonostiliferans whose infraorder affiliation is uncertain due to the lack of information on vascular morphology and molecular sequence data. The suborder affiliation of the two species Cinclidonemertes mooreae Crandall, 2010 and Verrillianemertes schultzei Senz, 2001 is left uncertain.

The Relationship between Genus/Species Richness and Morphological Diversity among Subfamilies of Jewel Beetles.

A positive correlation between the species richness and morphological diversity of some organisms has been found in almost all studies at the local community scale. However, this documented relationship has not always been consistent because of diverse niches and the status of an organism in an ecosystem. Global taxon sampling, new morphological approaches, and consideration of more taxonomic categories other than species level are possible methods to further investigate this contradiction. In this study, we proposed a new paradigm for higher taxa biodiversity analysis based on a cosmopolitan dataset. A total of 1106 species from around the world representing all subfamilies and 33% genera of Buprestidae (jewel beetles) were selected to test the correlation between morphological diversity (MD) and genus/species richness (GR/SR) among subfamilies. The MD was quantified by the contours of the pronotum and elytron in dorsal view based on a geometric morphometric approach. The positive correlation between MD and GR was found in all test combinations, but was irrelevant in the species-level test. Interestingly, the correlation between MD and GR was higher than MD and SR in both pronotum and elytron measurements. Additionally, the MD of the pronotum is obviously higher than the MD of the elytron. Our results demonstrate that the geometric morphometric approach could quite accurately reveal diversity patterns of the family Buprestidae. Future studies on different groups, using more characters, more analyses and detailed biological interpretations, are required to fully understand the relationship between MD and SR.

An approach based on the total-species accumulation curve and higher taxon richness to estimate realistic upper limits in regional species richness.

Most of accumulation curves tend to underestimate species richness, as they do not consider spatial heterogeneity in species distribution, or are structured to provide lower bound estimates and limited extrapolations. The total-species (T-S) curve allows extrapolations over large areas while taking into account spatial heterogeneity, making this estimator more prone to attempt upper bound estimates of regional species richness. However, the T-S curve may overestimate species richness due to (1) the mismatch among the spatial units used in the accumulation model and the actual units of variation in ß-diversity across the region, (2) small-scale patchiness, and/or (3) patterns of rarity of species. We propose a new framework allowing the T-S curve to limit overestimation and give an application to a large dataset of marine mollusks spanning over 11 km2 of subtidal bottom (W Mediterranean). As accumulation patterns are closely related across the taxonomic hierarchy up to family level, improvements of the T-S curve leading to more realistic estimates of family richness, that is, not exceeding the maximum number of known families potentially present in the area, can be considered as conducive to more realistic estimates of species richness. Results on real data showed that improvements of the T-S curve to accounts for true variations in ß-diversity within the sampled areas, small-scale patchiness, and rarity of families led to the most plausible richness when all aspects were considered in the model. Data on simulated communities indicated that in the presence of high heterogeneity, and when the proportion of rare species was not excessive (>2/3), the procedure led to almost unbiased estimates. Our findings highlighted the central role of variations in ß-diversity within the region when attempting to estimate species richness, providing a general framework exploiting the properties of the T-S curve and known family richness to estimate plausible upper bounds in γ-diversity.

Shortcuts in biodiversity research: What determines the performance of higher taxa as surrogates for species?

Biodiversity research is often impeded by the time and resources required to identify species. One possible solution is to use higher taxa to predict species richness and community composition. However, previous studies have shown that the performance of higher taxa as surrogates for species is highly variable, making it difficult to predict whether the method will be reliable for a particular objective. Using 8 independent datasets, I tested whether higher taxa accurately characterize the responses of beetle and ant communities to environmental drivers. For each dataset, ordinations were carried out using species and higher taxa, and the two compared using the Procrustes m² statistic (a scale-independent variant of Procrustes sum of squares). I then modelled the relationship between five hypothesised explanatory variables and 1) Procrustes m², and 2) the coefficient of determination (R²) for the correlation between richness of species and higher taxa. The species to higher taxon ratio, community structure, beta diversity, completeness of sampling, and taxon (beetles or ants) were all significant predictors of m², together explaining 88% of the variance. The only significant predictor of R² was the species to higher taxon ratio, which explained 45% of the variance. When using higher taxa to predict community composition, better performance is expected when the ratio of species to higher taxa is low, in communities with high evenness and high species turnover, and when there is niche conservation within higher taxa. When using higher taxa to predict species richness, effective surrogacy can be expected when the species to higher taxon ratio is very low. When it is not, surrogacy performance may be strongly influenced by stochastic factors, making predictions of performance difficult.

Changes of arthropod diversity across an altitudinal ecoregional zonation in Northwestern Argentina.

This study examined arthropod community patterns over an altitudinal ecoregional zonation that extended through three ecoregions (Yungas, Monte de Sierras y Bolsones, and Puna) and two ecotones (Yungas-Monte and Prepuna) of Northwestern Argentina (altitudinal range of 2,500 m), and evaluated the abiotic and biotic factors and the geographical distance that could influence them. Pitfall trap and suction samples were taken seasonally in 15 sampling sites (1,500-4,000 m a.s.l) during one year. In addition to climatic variables, several soil and vegetation variables were measured in the field. Values obtained for species richness between ecoregions and ecotones and by sampling sites were compared statistically and by interpolation-extrapolation analysis based on individuals at the same sample coverage level. Effects of predictor variables and the similarity of arthropods were shown using non-metric multidimensional scaling, and the resulting groups were evaluated using a multi-response permutation procedure. Polynomial regression was used to evaluate the relationship between altitude with total species richness and those of hyperdiverse/abundant higher taxa and the latter taxa with each predictor variable. The species richness pattern displayed a decrease in species diversity as the elevation increased at the bottom wet part (Yungas) of our altitudinal zonation until the Monte, and a unimodal pattern of diversity in the top dry part (Monte, Puna). Each ecoregion and ecotonal zone evidenced a particular species richness and assemblage of arthropods, but the latter ones displayed a high percentage of species shared with the adjacent ecoregions. The arthropod elevational pattern and the changes of the assemblages were explained by the environmental gradient (especially the climate) in addition to a geographic gradient (the distance of decay of similarity), demonstrating that the species turnover is important to explain the beta diversity along the elevational gradient. This suggests that patterns of diversity and distribution of arthropods are regulated by the dissimilarity of ecoregional environments that establish a wide range of geographic and environmental barriers, coupled with a limitation of species dispersal. Therefore, the arthropods of higher taxa respond differently to the altitudinal ecoregional zonation.

Insectos acuáticos asociados a los lagos interdunarios de la región central del Estado de Veracruz, México / Aquatic insects in dune lakes of the central region of the Gulf of Mexico

El objetivo de este trabajo fue registrar la presencia de insectos acuáticos durante la estación de lluvias y durante las secas en 15 lagos interdunarios localizados en la zona costera del Golfo de México. Estos sistemas albergan una riqueza de 62 familias en general, registrándose en época de lluvias un total de 60 familias y en secas 46. En ambas épocas Coleoptera es el orden con mayor número de familias seguido de Diptera. A pesar que la primera es la más diversa no es la más abundante, ya que la familia Chironomidae (Diptera) engloba un 40 por ciento de la abundancia total de individuos capturados. La utilización de taxa de alto rango para cuantificar la biodiversidad se basa en el principio de que un número elevado de géneros y/o familias se supone que alberga un mayor número de especies. No se encontraron diferencias significativas en la riqueza de familias entre la época de secas y la de lluvias para cada lago. La estructura trófica encontrada está dominada por familias de detritófagos (57 por ciento), seguido de los depredadores (38 por ciento) y el resto son herbívoros. Ello es un indicador de que estos cuerpos de agua presentan gran cantidad de materia orgánica. Con los resultados que se obtuvieron nuestra hipótesis de trabajo se rechazó, ya que no se encontraron diferencias en la riqueza, diversidad y estructura trófica de los lagos entre las épocas de secas y las de lluvias.

The aim of this study is to register the presence of aquatic insects during the rainy and dry seasons, in 15 dune lakes of the Gulf of Mexico's coastal zone. These ecosystems lodge a wealth of 62 families, 60 of them present during the rainy season and 46 during the dry period. At both times Coleoptera is the order with a greater number of families, followed by Diptera. The first one is the most diverse, but Chironomidae (Diptera) is the most abundant, representing 40 percent of the total number of individuals. We used high rank taxa to quantify the biodiversity based on the principle that a high number of families or genus is supposed to include a greater number of species. There were not significant differences in the alpha diversity within the same lake during the two climatic seasons. The trophic structure is dominated by the detritivorous groups (57 percent of scrapers, collectors, gatherers, shredders), followed by predators (38 percent) and herbivores (5 percent). These numbers indicate that dune lakes have a great amount of organic matter. The results obtained contradict our working hypothesis, thus it was rejected, in summary, because there were no important differences in family composition, abundance of individuals and trophic structure of the lakes between the rainy and dry seasons.