The second phantom aquatic leaf beetle in Japan: Macroplea mutica rediscovery in the wetlands (Coleoptera: Chrysomelidae)

Wetland biodiversity is currently declining on a global scale. Wetland biodiversity understanding is critical for determining the wetlands' conservation value. In this study, Macroplea Samouelle, 1819 (Coleoptera: Chrysomelidae) was discovered in Aomori Prefecture, Honshu Island, Japan. Only two Macroplea species have been recorded in Japan, M. japana (Jacoby, 1885) and M. mutica (Fabricius, 1792). Macroplea japana had been unrecorded for 60 years before being rediscovered in Honshu Island in 2022, and a single adult M. mutica female was discovered in Hokkaido Prefecture in 2003. The discovered individuals were concluded to be M. mutica based on morphological and molecular analyses. Although morphological differences were observed with the Eurasian M. mutica individuals, the male genitalia was nearly identical to M. mutica. For the molecular phylogenetic analysis based on COI and 28S sequences, Macroplea individuals in Japan were clustered with M. mutica on the Eurasian Continent. This is the first record of this species on Honshu Island (and the second in Japan), as well as the first record of adult males. This species would require conservation policies and additional distributional surveys.     

Extinction risk of Chinese angiosperms varies between woody and herbaceous species

Aim

Understanding how species' traits and environmental contexts relate to extinction risk is a critical priority for ecology and conservation biology. This study aims to identify and explore factors related to extinction risk between herbaceous and woody angiosperms to facilitate more effective conservation and management strategies and understand the interactions between environmental threats and species' traits.

Location

China.

Taxon

Angiosperms.

Methods

We obtained a large dataset including five traits, six extrinsic variables, and 796,118 occurrence records for 14,888 Chinese angiosperms. We assessed the phylogenetic signal and used phylogenetic generalized least squares regressions to explore relationships between extinction risk, plant traits, and extrinsic variables in woody and herbaceous angiosperms. We also used phylogenetic path analysis to evaluate causal relationships among traits, climate variables, and extinction risk of different growth forms.

Results

The phylogenetic signal of extinction risk differed among woody and herbaceous species. Angiosperm extinction risk was mainly affected by growth form, altitude, mean annual temperature, normalized difference vegetation index, and precipitation change from 1901 to 2020. Woody species' extinction risk was strongly affected by height and precipitation, whereas extinction risk for herbaceous species was mainly affected by mean annual temperature rather than plant traits.

Main conclusions

Woody species were more likely to have higher extinction risks than herbaceous species under climate change and extinction threat levels varied with both plant traits and extrinsic variables. The relationships we uncovered may help identify and protect threatened plant species and the ecosystems that rely on them.     

DNA/DNA hybridization studies of carnivorous marsupials. III. Relationships among species ofDidelphis (Didelphidae)

We report three sets of DNA hybridization experiments conducted to determine relationships among species ofDidelphis (D. albiventris, D. marsupialis, D. virginiana). The 1989 and 1991 sets had fewer replicates per cell than the 1990 series (3.4 and 5.4 vs 9), but in 1991 we distinguished two populations ofD. marsupialis and utilized several individuals for each heterologous comparison. BothPhilander opossum andLutreolina crassicaudata were used as outgroups in 1989, but onlyLutreolina was included in subsequent sets. For each set, we calculated all four standard indices of thermal stability (T _mode,T _m,T ₅₀ H, and NPH) and constructed trees by least-squares (FITCH) and neighbor-joining methods, both before and after correction for asymmetric reciprocal cell values. Subsets of the 1989 data lacking eitherPhilander orLutreolina were analyzed similarly. To explore measurement imprecision, the corrected and uncorrected matrices for each of the four indices were bootstrapped 100 times for the 1989 set and subsets and 1000 times for the 1990 and 1991 sets. Again, for the 1990 and 1991 data, an additional 100 bootstrapped distances were fitted to user trees representing the three possible pairings ofDidelphis spp. to determine the significance of the FITCH branch lengths. The successive experimental sets generated increasingly consistent evidence for pairingD. marsupialis withD. albiventris. The 1989 experiments involved just 85 comparisons, and only T _mode's pairedD. marsupialis withD. albiventris (at bootstrap percentages of 70% or above), but did so whetherPhilander orLutreolina or both were included as the outgroup(s). FITCH and neighbor-joining trees had identical topologies for T _mode's but sometimes differed for the other measures. In contrast, all but one of the corresponding FITCH and neighborjoining trees matched for the 1990 and 1991 data, and three of the four distance measures (T _mode, T _m, and T ₅₀ H) unitedD. marsupialis withD. albiventris at bootstrap percentages averaging 81%; NPH gave a different result for 1990, associatingD. marsupialis withD. virginiana. Further, all but 2 of the 16 matrices for 1990 and 1991 gave mean bootstrapped branch lengths for a consensus pairing that were positive and at least one standard deviation from zero, despite the very short internodes recovered. These results illustrate that the potential of DNA hybridization for resolving very close relationships depends on both the index and the experimental design employed. We conclude that of the three species,D. albiventris andD. marsupialis shared a more recent common ancestor and estimate thatDidelphis spp. have diverged at about 0.39% in nucleotide sequence per myr.Deceased.     

A molecular perspective on the phylogeny of placental mammals based on mitochondrial 12S rDNA sequences,with special reference to the problem of the Paenungulata

Part of the 12S rDNA gene was amplified and sequenced for 11 placental mammals, 3 marsupials, and 2 monotremes. Multiple alignments for these sequences and nine additional placental sequences taken from GenBank were obtained using CLUSTAL. Phylogenetic analyses were performed using standard parsimony, transversion parsimony, and Lake's method of invariants. All of our analyses uniteLoxodontia withDugong. Procavia, in turn, is a sister group to these taxa, thus supporting the monophyly of the Paenungulata. Perissodactyls are a sister group to paenungulates when transitions and transversions are both included but not when transitions are omitted. Likewise, cetaceans are a sister group to artiodactyls on minimum length trees under standard parsimony but not under transversion parsimony. Rodent monophyly and bat monophyly also receive mixed support, as does a putative alliance between primates and lagomorphs. Interestingly, the percentage divergence between the echidna and the platypus is less than for the rat and mouse.     

Chloroplast DNA variation and phylogeny of theRanunculaceae

Restriction site mapping of chloroplast DNA from 31 species representing 26 genera of theRanunculaceae was performed using eleven restriction endonucleases. The chloroplast genome varies in length from approximately 152 to 160 kb. Length variants are frequent in theRanunculaceae and range from usually less than 300 bp to rarely 1.5 kb. The inverted repeat is extended into the large single copy (LSC) region by 4–4.5 kb inAnemone, Clematis, Clematopsis, Hepatica, Knowltonia, andPulsatilla. Several inversions are present in the LSC-region of the cpDNA in all these genera and inAdonis. The frequency of restriction site mutations varies within the chloroplast genome in theRanunculaceae between 4 and 32 mutations per kilobase, and is lowest in the inverted repeat and the regions containing the ATPase-genes and the genespsaA, psaB, psbA, rpoB, andrbcL. A total of 547 phylogenetically informative restriction sites was utilized in cladistic analyses of the family using Wagner, Dollo, and weighted parsimony. These three parsimony analyses result in different tree topologies. Four, six, and one equally most parsimonious trees were obtained with Wagner, Dollo, and weighted parsimony, respectively. The amount of support for the monophyletic groups was evaluated using bootstrapping and decay analysis. All three parsimony methods suggest thatHydrastis is the sister group to the remainder of theRanunculaceae, and that theAnemone-Clematis group, which shares several derived cpDNA rearrangements, is monophyletic. Only a few of the traditional groups in theRanunculaceae are supported by cpDNA restriction side data. Only Dollo parsimony provides support for the hypothesis thatThalictroideae andRanunculoideae are monophyletic.     

Ribosomal DNA variation and its phylogenetic implication in the genusBrachypodium (Poaceae)

The structure of ribosomal DNA ofBrachypodium and several other grass species was investigated using a heterologous rDNA probe from wheat. Several different rDNA families were present among perennial and annual species within the genus. In contrast to the annual species the perennial species exhibited a very low degree of repeat length variation. An extra Eco RI site and a Hin dIII site were observed in the IGS, which distinguishedBrachypodium from other grass genera. The restriction fragment length polymorphism and length variation of the repeat units have taxonomic value withinBrachypodium and are correlated with the classification ofBrachypodium derived from other data.     

Naegleria: A Research Partner For Cell and Developmental Biology1

ABSTRACT. Organisms in the genus Naegleria offer special opportunities for research in contemporary biology. the dramatic cell differentiation from amebae to flagellates is unique among eukaryotes in the rapidity, synchrony, reproducibility, homogeneity, and accessibility of a major phenotypic change. Environmental signals initiate a progressive signal transduction pathway in which genes are turned on, including those for several calcium-binding proteins, and newly synthesized proteins become localized in newly assembled organelles, including the centriole-like basal bodies, with the overall consequence that the cell changes its shape, motility, and behavior. This essay reviews research opportunities for which Naegleria excels, as well as interesting aspects of its biology that provide challenges for future investigations. Because these organisms alternate between two major eukaryotic motility forms, their phylogenetic position is also provocative. Although there are hints that Naegleria is capable of sexual reproduction in nature, mating has not yet been observed in the laboratory. In order to fully exploit the opportunities offered by this wonderful experimental system we are working to develop means to do genetic manipulation, in particular via DNA-mediated transformation.     

New branched Porolithon species (Corallinales,Rhodophyta) from the Great Barrier Reef,Coral Sea,and Lord Howe Island

Porolithon is one of the most ecologically important genera of tropical and subtropical crustose (non-geniculate) coralline algae growing abundantly along the shallow margins of coral reefs and functioning to cement reef frameworks. Thalli of branched, fruticose Porolithon specimens from the Indo-Pacific Ocean traditionally have been called P. gardineri, while massive, columnar forms have been called P. craspedium. Sequence comparisons of the rbcL gene both from type specimens of P. gardineri and P. craspedium and from field-collected specimens demonstrate that neither species is present in east Australia and instead resolve into four unique genetic lineages. Porolithon howensis sp. nov. forms columnar protuberances and loosely attached margins and occurs predominantly at Lord Howe Island; P. lobulatum sp. nov. has fruticose to clavate forms and free margins that are lobed and occurs in the Coral Sea and on the Great Barrier Reef (GBR); P. parvulum sp. nov. has short (<2 cm), unbranched protuberances and attached margins and is restricted to the central and southern GBR; and P. pinnaculum sp. nov. has a mountain-like, columnar morphology and occurs on oceanic Coral Sea reefs. A rbcL gene sequence of the isotype of P. castellum demonstrates it is a different species from other columnar species. In addition to the diagnostic rbcL and psbA marker sequences, the four new species may be distinguished by a combination of features including thallus growth form, margin shape (attached or unattached), and medullary system (coaxial or plumose). Porolithon species, because of their ecological importance and sensitivity to ocean acidification, need urgent documentation of their taxonomic diversity.     

Hidden diversity in high-latitude Southern Hemisphere environments: Reinstatement of the genus Rama and description of Vandenhoekia gen. nov. (Cladophoraceae,Ulvophyceae, Chlorophyta), two highly variable genera

The continental coasts and remote islands in the high-latitude Southern Hemisphere, including the subantarctic region, are characterized by many endemic species, high abundance of taxa, and intermediate levels of biodiversity. The macroalgal flora of these locations has received relatively little attention. Filamentous green algae are prolific in the intertidal of southern islands, but the taxonomy, distribution, and evolutionary history of these taxa are yet to be fully explored, mostly due to the difficulty of access to some of these locations. In this study, we examined specimens of the order Cladophorales from various locations in the high-latitude Southern Hemisphere including the subantarctic (the Auckland Islands, Bounty Islands, Campbell Island, Macquarie Island, and Kerguelen Islands), as well as mainland New Zealand, the Chatham Islands, Chile, and Tasmania. The analyses of the rDNA sequences of the samples revealed the existence of two new clades in a phylogeny of the Cladophoraceae. One of these clades is described as the novel genus Vandenhoekia gen. nov., which contains three species that are branched or unbranched. The amended genus Rama is reinstated to accommodate the other clade, and contains four species, including the Northern Hemisphere “Cladophora rupestris.” In Rama both branched and unbranched morphologies are found. It is remarkable that gross morphology is not a predictor for generic affiliations in these algae. This study illustrates that much can still be learned about diversity in the Cladophorales and highlights the importance of new collections, especially in novel locations.