Incongruent molecular and morphological variation in the crab spider Synema globosum (Araneae, Thomisidae) in Europe

Establishing species boundaries is one of the challenges taxonomists around the world have been tackling for centuries. The relation between intraspecific and interspecific variability is still under discussion and in many taxa it remains understudied. Here the hypothesis of single versus multiple species of the crab spider Synema globosum (Fabricius) is tested. The wide distribution range as well as its high morphological variability makes this species an interesting candidate for re-evaluation using an integrative approach. This study combines information from barcoding, phylogenetic reconstruction based on mitochondrial CO1 and ITS2 of more than 60 specimens collected over a wide range of European localities, and morphology. The findings show deep clades with up to 6% mean pairwise distance in the CO1 barcode without any biogeographical pattern. The nuclear ITS2 gene did not support the CO1 clades. Morphological assessment of somatic and genital characters in males and females and a morphometric analysis of the male palp uncovered high intraspecific variation that does not match the CO1 or ITS2 phylogenies or biogeography either. Screening for endosymbiotic Wolbachia bacteria was conducted and only a single infected specimen was found. Several scenarios might explain these inconsistent patterns. While the deep divergences in the barcoding marker might suggest cryptic or ongoing speciation or geographical isolation in the past, the lack of congruent variation in the nuclear ITS2 gene or the studied morphological character systems, especially the male palp, indicates that S. globosum might simply be highly polymorphic both in terms of its mtDNA and morphology. Therefore, more data on ecology and behaviour and full genome sequences are necessary to ultimately resolve this taxonomically intriguing case.

Deep sea without limits—four new closely related species of Emertonia Wilson, 1932 (Copepoda: Harpacticoida: Paramesochridae) show characters with a world-wide distribution

The large-scale dispersal of deep-sea harpacticoid copepods is an increasing focus for ecological studies. A fundamental prerequisite for monitoring and explaining their geographical distribution is precise descriptions of their morphology. Four new, closely related species of the family Paramesochridae (Copepoda, Harpacticoida) were found in the deep sea of the Pacific (San Diego Trough and off Chile), the Atlantic Ocean (Porcupine Abyssal Plain and Angola Basin), and the Atlantic and Indian Ocean sectors of the Southern Ocean (Weddell Sea and off Crozet Island). The discovery of Emertonia berndi sp. nov., E. hessleri sp. nov., E. ilse sp. nov., and E. serrata sp. nov. increases the number of known deep-sea species in this genus to ten. The new species are placed in Emertonia Wilson, 1932 because of their one-segmented endopods on the second and third swimming legs. The presence of a two-segmented endopod on the fourth swimming leg allocates them to the “andeep-group” within this genus. The four species can be distinguished from their congeners by the strongly serrated spines on the exopods of their swimming legs and an outwardly directed flexible seta on the exopod of the fifth leg. It is conveivable that these two specific characters evolved only once in the genus Emertonia. Their apparently cosmopolitan distribution covers thousands of kilometres and spans all major oceans. This biogeographical pattern may be explained by resuspension events followed by passive transport by benthic currents. Discrepancies in their dispersal ranges may be a result of changing geological and oceanographic boundaries.

DNA Barcoding approach reveals 17 exploited fish species, including an unrecognised species of the yellow-lined snapper complex

Management of wild fisheries resources requires accurate knowledge on which species are being routinely exploited, but it can be hard to identify fishes to species level, especially in speciose fish groups where colour patterns vary with age. Snappers of the genus Lutjanus represent one such group, where fishes can be hard to identify and as a result fisheries statistics fail to capture species-level taxonomic information. This study employs DNA barcoding approaches to identify adult and juvenile Lutjanus species harvested in Malaysian wild-capture fishery. We uncovered two divergent groups of bigeye snapper ('Lutjanus lutjanus') distributed on either side of the Malay Peninsula, displaying a biogeographical pattern similar to distributions observed for many co-occurring reef distributed fish groups. One of these bigeye snapper groups almost certainly represents an unrecognized species in need of taxonomic description. The study demonstrates the utility of DNA barcoding in identifying overlooked diversity and for assessing species catch composition in a complicated but economically important taxonomic group.

Five new clavate-stigma Waltheria species endemic to Brazilian Cerrado (Malvaceae s. l., Byttnerioideae, Hermannieae)

Five new species are described and illustrated: Waltheria hatschbachii, W. hoehnei, both endangered for extinction, W. coriacea, W. flavovirens and W. matogrossensis. All are endemic to Brazil, in Cerrado s. l. associated with the Brazilian Plateau in N, NE, CW, and SE Brazil. Their affinities and the distinctness from W. ferruginea s. l. are discussed, and they are associated and compared with W. ferruginea s. str., from cerrado, W. brachypetala, from caatinga, W. biribiriensis and W. terminans, both from campo rupestre. The geographic distribution of all nine species is illustrated, and a new identification key for these and for the two sections of Waltheria is provided. All nine species share a clavate stigma in pin (or thrum) flowers, that morphotype given earlier as distinguishing one of three main species groups of the genus, and a new character, the ferruginea type stipitate-stellate trichome, illustrated here. Subconduplicate petals are first reported in the tribe Hermannieae, often keyed by flat petals. Waltheria is first signaled here to present the same enigmatic biogeographical pattern noted before for Triraphis (Poaceae) between Chapada dos Veadeiros, Africa and Australia. Other new taxonomic characters for Waltheria are given.

A new species of Trachylepis (Squamata: Scincidae) from the Amhara Region, Ethiopia, and a key to the Ethiopian Trachylepis

Ethiopia is known for its highly endemic and rich herpetofaunal diversity shaped by its biogeographical patterns. Here, a new species of skink, Trachylepis boehmei sp. nov., is described from the Ethiopian Highlands. It differs from its congeners in having smooth uncarinated dorsal scales, 26–29 scale rows around midbody, a slender body of small size, a relatively short tail, a low eye–snout distance and a unique colour pattern with 6–8 darkish brown dorsal stripes. Based on morphological characteristics, its biogeographical pattern and comparisons with other similar congeners this new species is closely related to Trachylepis megalura. A published new record of Trachylepis wingati for the Kafa region is re-examined and identified as T. megalura. An updated comprehensive key to the Trachylepis found in Ethiopia is provided. In the context of ongoing phylogenetic and taxonomic revisions of Trachylepis and its species complexes the presence of further cryptic taxa can be expected also for the Ethiopian biodiversity hotspots. Consequently, the need of further herpetological investigations in this region of ecological importance is stressed.

Thermodynamic Control on Biogeography and Functioning of Rare-Biosphere Propionate Syntrophs in Paddy Field Soils

Background Global biogeochemical processes are not only gauged by dominant taxa of soil microbiome but also depend on the critical functions of “rare biosphere” members. Here we evaluated the biogeographical pattern of “rare biosphere” propionate-oxidizing syntrophs in 113 paddy soil samples collected across eastern China. Results The relative abundance, functioning capacity and growth potential of propionate-oxidizing syntrophs were analyzed to provide a panoramic view of syntroph biogeographical distribution at the continental scale. The relative abundances of four syntroph genera, Syntrophobacter, Pelotomaculum, Smithella and Syntrophomonas were significantly greater at the warm low latitudes than at the cool high latitudes. Correspondingly, the functioning potential of propionate degradation was greater in the low latitude soils compared with the high latitude soils. The slow rate of propionate degradation in high latitude soils resulted in a greater fold change in increase of the relative abundance, probably due to the growth rate-yield tradeoff relationship. The mean annual temperature (MAT) is the most important factor shaping the biogeographical pattern of propionate-oxidizing syntrophs, with the next factor to be the total S content (TS) in soil. Conclusions We suggest that the effect of MAT is related to the Gibbs free energy change, in which the endergonic tension of propionate oxidation is leveraged with the increase of MAT. The TS effect is likely due to that some propionate syntrophs can facultatively perform sulfate respiration.