A review of the omicrine genera Omicrogiton,Mircogioton and Peratogonus of China (Coleoptera,Hydrophilidae, Sphaeridiinae)

The Chinese species of the genera Omicrogiton Orchymont, 1919, Peratogonus Sharp, 1884 and Mircogioton Orchymont, 1937 are reviewed, diagnosed and keyed. Mircogioton and Omicrogiton are reported for the first time from China, Peratogonus for the first time for mainland China. Five species are recognized: Omicrogiton coomani Balfour-Browne, 1939 (Guangdong, Hongkong), Omicrogiton hainanensis sp. n. (Hainan), Omicrogiton roberti sp. n. (Hainan), Mircogioton coomani Orchymont, 1937 (Yunnan), and Peratogonus reversus Sharp, 1884 (Guangdong, Jiangxi, Taiwan). Lectotype of Omicrogiton coomani is designated. Mircogioton cognitus (Malcolm, 1981), syn. n. is considered a junior subjective synonym of Mircogioton coomani Orchymont, 1939. Species of Mircogioton and Omicrogiton inhabit decaying banana trunks, whereas Peratogonus reversus was always collected from moist forest leaf litter.     

Morphology and biology of the flower‐visiting water scavenger beetle genus Rygmodus (Coleoptera: Hydrophilidae)

Hydrophilidae (water scavenger beetles) is well known as an aquatic beetle family; however, it contains ca. 1,000 secondarily terrestrial species derived from aquatic ancestors. The New Zealand endemic genus Rygmodus White is a member of the hydrophilid subfamily Cylominae, which is the early‐diverging taxon of the largest terrestrial lineage (Cylominae + Sphaeridiinae) within the Hydrophilidae. In this paper we report that Rygmodus beetles are pollen‐feeding flower visitors as adults, but aquatic predators as larvae. Based on analyses of gut contents and a summary of collecting records reported on museum specimen labels, adult Rygmodus beetles are generalists feeding on pollen of at least 13 plant families. Rygmodus adult mouthparts differ from those of other (saprophagous) hydrophilid beetles in having the simple scoop‐like apex and mola with roughly denticulate surface, resembling the morphology found in pollen‐feeding staphylinid beetles. Larvae were found along the sides of streams, under stones and in algal mats and water‐soaked moss; one collected larval specimen was identified using DNA barcoding of two molecular markers, mitochondrial cytochrome oxidase 1 (cox1) and nuclear histone 3 (H3). Larvae of two species, Rygmodus modestus and Rygmodus sp., are described in detail and illustrated; they closely resemble ambush‐type predatory larvae of the hydrophilid tribe Hydrophilini in the head morphology. Rygmodus is the only known hydrophilid beetle with adults and larvae inhabiting different environments.     

The morphological evolution of the Adephaga (Coleoptera)

The evolution of the coleopteran suborder Adephaga is discussed based on a robust phylogenetic background. Analyses of morphological characters yield results nearly identical to recent molecular phylogenies, with the highly specialized Gyrinidae placed as sister to the remaining families, which form two large, reciprocally monophyletic subunits, the aquatic Haliplidae + Dytiscoidea (Meruidae, Noteridae, Aspidytidae, Amphizoidae, Hygrobiidae, Dytiscidae) on one hand, and the terrestrial Geadephaga (Trachypachidae + Carabidae) on the other. The ancestral habitat of Adephaga, either terrestrial or aquatic, remains ambiguous. The former option would imply two or three independent invasions of aquatic habitats, with very different structural adaptations in larvae of Gyrinidae, Haliplidae and Dytiscoidea.     

Modern hydrophilid clades present and widespread in the Late Jurassic and Early Cretaceous (Coleoptera: Hydrophiloidea: Hydrophilidae)

We present a summary of the fossil evidence documenting the worldwide occurrence of the family Hydrophilidae (Insecta: Coleoptera: Polyphaga: Hydrophiloidea) in the Late Jurassic and Early Cretaceous. We present the first known fossils of the family from the Mesozoic, being c. 100 Myr older than the fossil record available until now. Two Late Jurassic fossils are documented: P rotochares brevipalpis gen. nov., sp. nov. from the Talbragar Fish Bed (New South Wales, Australia) and ‘Mesosperchus’ schultzi Ponomarenko, 1985 from Solnhofen (Bavaria, Germany). The occurrence of the Hydrophilidae in the Early Cretaceous is documented by six species, all of which may be already assigned to modern subfamilies/tribes: B aissalarva hydrobioides gen. nov., sp. nov. from the Baissa outcrops (Buryat Republic, Russia) and C retoxenus australis gen. nov., sp. nov. from Koonwarra outcrops (Victoria, Australia) are both assigned to the tribe Hydrobiusini (Hydrophilinae); A legorius yixianus gen. nov., sp. nov. and Alegorius sp. from the Yixian Formation (Liaoning, China) may represent the Acidocerinae or Enochrinae, H ydroyixia elongata gen. nov., sp. nov. and H . latissima sp. nov. from the same locality are assigned to the Acidocerinae. The phylogenetic position of Baissalarva hydrobioides is also tested by a phylogenetic analysis. The presence of extant clades (Hydrophilinae: Hydrobiusini, Acidocerinae) in the Early Cretaceous and the wide distribution of the Hydrobiusini in both Gondwana and Laurasia at the same time suggests that the principal extant clades of the Hydrophilidae are at least of Early–Middle Jurassic origin. © 2014 The Linnean Society of London     

Hypoglycemia and the Origin of Hypoxia-Induced Reduction in Human Fetal Growth

Background

The most well known reproductive consequence of residence at high altitude (HA >2700 m) is reduction in fetal growth. Reduced fetoplacental oxygenation is an underlying cause of pregnancy pathologies, including intrauterine growth restriction and preeclampsia, which are more common at HA. Therefore, altitude is a natural experimental model to study the etiology of pregnancy pathophysiologies. We have shown that the proximate cause of decreased fetal growth is not reduced oxygen availability, delivery, or consumption. We therefore asked whether glucose, the primary substrate for fetal growth, might be decreased and/or whether altered fetoplacental glucose metabolism might account for reduced fetal growth at HA.

Methods

Doppler and ultrasound were used to measure maternal uterine and fetal umbilical blood flows in 69 and 58 residents of 400 vs 3600 m. Arterial and venous blood samples from mother and fetus were collected at elective cesarean delivery and analyzed for glucose, lactate and insulin. Maternal delivery and fetal uptakes for oxygen and glucose were calculated.

Principal Findings

The maternal arterial – venous glucose concentration difference was greater at HA. However, umbilical venous and arterial glucose concentrations were markedly decreased, resulting in lower glucose delivery at 3600 m. Fetal glucose consumption was reduced by >28%, but strongly correlated with glucose delivery, highlighting the relevance of glucose concentration to fetal uptake. At altitude, fetal lactate levels were increased, insulin concentrations decreased, and the expression of GLUT1 glucose transporter protein in the placental basal membrane was reduced.

Conclusion/Significance

Our results support that preferential anaerobic consumption of glucose by the placenta at high altitude spares oxygen for fetal use, but limits glucose availability for fetal growth. Thus reduced fetal growth at high altitude is associated with fetal hypoglycemia, hypoinsulinemia and a trend towards lactacidemia. Our data support that placentally-mediated reduction in glucose transport is an initiating factor for reduced fetal growth under conditions of chronic hypoxemia.     

Contributions to the taxonomy of the genera Pachysternum and Cyrtonion (Coleoptera, Hydrophilidae, Sphaeridiinae)

Pachysternum loxodonta sp. n. from the Republic of the Congo and Pachysternum sulawesicum sp.n. from Sulawesi Island, Indonesia are described. The generic status of Pachysternum sculpticolle (Régimbart, 1907) is revised, the species is transferred to the genus Cyrtonion and its differences from C. ghanense Hansen, 1989 are discussed. Taxonomy of Pachysternum is discussed, dividing the genus prelusively into three species groups, one comprising all known Oriental and Eastern Palearctic species, and two comprising the Afrotropical species. Species with unclear positions within the genus Pachysternum or with questionable generic status are left as “Species incertae sedis”.     

A long-living species of the hydrophiloid beetles: Helophorus sibiricus from the early Miocene deposits of Kartashevo (Siberia, Russia)

The recent hydrophiloid species Helophorus (Gephelophorus) sibiricus (Motschulsky, 1860) is recorded from the early Miocene deposits of Kartashevo assigned to the Ombinsk Formation. A detailed comparison with recent specimens allowed a confident identification of the fossil specimen, which is therefore the oldest record of a recent species for the Hydrophiloidea. The paleodistribution as well as recent distribution of the species is summarized, and the relevance of the fossil is discussed. In addition, the complex geological settings of the Kartashevo area are briefly summarized.     

A review of the genus Berosus Leach of Cuba (Coleoptera,Hydrophilidae)

The Cuban fauna of the genus Berosus Leach, 1817 is reviewed based on newly collected material as well as historical and type specimens. Nine species are recognized, including three recorded from Cuba for the first time: Berosus infuscatus LeConte, 1855, Berosus interstitialis Knisch, 1924 (= Berosus stribalus Orchymont, 1946 syn. n.) and Berosus metalliceps Sharp, 1882. Only one of the nine Cuban species, Berosus chevrolati, remains endemic to Cuba, as two other species previously considered as endemic to Cuba are recorded from elsewhere: Berosus quadridens from Mexico and Central America and Berosus trilobus from the Dominican Republic. Notes on biology and Cuban distribution are provided for all nine species. Berosus quadridens Chevrolat, 1863, stat. restit. is removed from synonym with Berosus truncatipennis and considered a valid species.