A revision of the East African Nebrioporus abyssinicus group (Coleoptera, Dytiscidae)

The four species of the Nebrioporus abyssinicus (Sharp, 1882) group, confined to East Africa, are revised and a key is given for their identification. Lectotypes are designated for the following nominal species: Deronectes abyssinicus Sharp, 1882, Hydroporus tellinii Régimbart, 1904, Hydroporus atratus Régimbart, 1908, Hydroporus flavidus Régimbart, 1908, Deronectes cooperi Omer-Cooper, 1931, and Deronectes scotti Omer-Cooper, 1931. Hydroporus septemvittatus Régimbart, 1883, is listed as a species dubium. The third-instar larva of the group is described for the first time

The genus- and family-group names of the Dytiscidae - additions and corrections (Coleoptera).

Eine frühere Revision der Gattungs- und Familiengruppennamen der Dytiscidae wird aktualisiert. Die Ergänzungen enthalten die in den vergangenen sechs Jahren beschriebenen Namen, und einige ältere, früher übersehene Namen, hauptsächlich von Gistel. Für Hydatoporus Gistel, Hyobius Gistel, Icmaleus Gistel, und Prosciastes Gistel werden Typusarten designiert. Actobaenidae Gistel wird als ein älteres subjektives Synonym von Hyphydrini Sharp erkannt. Die Konservierung von Hyphydrini wird empfohlen.Nomenklatorische HandlungenActobaenidae Gistel, 1856 (Dytiscidae), syn. n. of Hyphydrini SharpA previous review of genus- and family-group names of the water-beetle family Dytiscidae is updated. Additions include the names described within the last six years and some older, previously overlooked names, chiefly given by Gistel. Type species are designated for Hydatoporus Gistel, Hyobius Gistel, Icmaleus Gistel, and Prosciastes Gistel. Actobaenidae Gistel is considered a senior subjective synonym of Hyphydrini Sharp. Conservation of Hyphydrini is recommended. Nomenclatural ActsActobaenidae Gistel, 1856 (Dytiscidae), syn. n. of Hyphydrini Shar

The diving beetles of Kamchatka, with additional records from Sakhalin and the Kuril Islands (Coleoptera: Dytiscidae).

Die Dytiscidenfauna der nordostasiatischen Halbinsel Kamtschatka wird auf der Grundlage von Literaturnachweisen und neueren Aufsammlungen zusammengestellt. Die folgenden zehn Arten werden erstmals für Kamtschatka nachgewiesen: Hygrotus marklini (Gyllenhal), Hydroporus notabilis LeConte, H. submuticus Thomson, H. tristis (Paykull), H. uenoi Nakane, Oreodytes okulovi Lafer, Agabus balkei Fery & Nilsson, A. discolor Harris, Ilybius chishimanus Kôno, Rhantus suturellus (Harris), und Graphoderus perplexus Sharp. Insgesamt 38 Dytiscidenarten, davon 22 mit holarktischer Verbreitung, sind nun von Kamtschatka bekannt. Graphoderus perplexus wird erstmals aus der Paläarktis nachgewiesen. Weitere Nachweise werden für Sachalin und die Kurilen genannt. Die folgenden Arten sind Erstnachweise für Sachalin: Hydroporus nigellus Mannerheim, Agabus kholini Nilsson, Ilybius angustior (Gyllenhal), und Acilius canaliculatus (Nicolai). Zehn Arten werden erstmals für die Kurilen nachgewiesen: Hydroporus nigellus, H. notabilis, H. submuticus, H. tristis, Agabus clypealis (Thomson), A. confinis (Gyllenhal), A. costulatus (Motschulsky), A. discolor, Ilybius discedens Sharp, und Colymbetes dahuricus Aubé. Neun dieser Arten wurden auf den nördlichen, H. tristis dagegen auf den südlichen Kurilen gefunden. Damit sind jetzt von Sachalin 39 und von den Kurilen 36 Arten bekannt.The dytiscid fauna of the north-east Asian peninsula Kamchatka is reviewed based on literature records and more recent collections. The following ten species are here reported from Kamchatka for the first time: Hygrotus marklini (Gyllenhal), Hydroporus notabilis LeConte, H. submuticus Thomson, H. tristis (Paykull), H. uenoi Nakane, Oreodytes okulovi Lafer, Agabus balkei Fery & Nilsson, A. discolor Harris, Ilybius chishimanus Kôno, Rhantus suturellus (Harris), and Graphoderus perplexus Sharp. Altogether 38 species of Dytiscidae are now known from Kamchatka, and of these 22 have Holarctic distributions. Graphoderus perplexus is here reported for the Palearctic Region for the first time. Additional records are given for Sakhalin and the Kuril Islands. The following four species are here reported from Sakhalin for the first time: Hydroporus nigellus Mannerheim, Agabus kholini Nilsson, Ilybius angustior (Gyllenhal), and Acilius canaliculatus (Nicolai). The following ten species are here reported from the Kuril Islands for the first time: Hydroporus nigellus, H. notabilis, H. submuticus, H. tristis, Agabus clypealis (Thomson), A. confinis (Gyllenhal), A. costulatus (Motschulsky), A. discolor, Ilybius discedens Sharp, and Colymbetes dahuricus Aubé. Nine of the species were found in the North Kurils, whereas H. tristis was found in the South Kurils. With these additions, 39 species are now known from Sakhalin, and 36 from the Kuril Islands

The diving beetles of the Kuril Archipelago in the Far East of Russia (Coleoptera: Dytiscidae).

Nach Literaturangaben sowie Untersuchungen von Museumsmaterial und Ausbeuten der in den letzten Jahren durchgeführten Expeditionen sind die Schwimmkäfer (Dytiscidae) auf den Kurilen im Nordwest-Pazifik mit 24 Arten vertreten. Über die 357 adulten und 50 larvalen Dytisciden, die während der gemeinsamen amerikanisch-japanisch-russischen Expedition 1994 und 1995 auf den südlichen und mittleren Kurilen gesammelt wurden, wird detailliert berichtet. Die folgenden fünf Arten werden erstmals für die Kurilen nachgewiesen: Hydroporus uenoi Nakane, Platambus pictipennis (Sharp), Agabus japonicus Sharp, Ilybius nakanei Nilsson, und Graphoderus zonatus (Hoppe). Die Zahl der auf den einzelnen Inseln festgestellten Arten lag zwischen 1 und 11; den höchsten Artenreichtum zeigen die größten Inseln auf beiden Seiten des Großen Kurilen-Kamms. Auf den südlichen Kurilen dominieren die ussurisch-japanischen Arten, die auch von Sakhalin und Hokkaido bekannt sind, während sich die Fauna der nördlichen Kurilen durch einen hohen Anteil holarktischer und paläarktischer Arten auszeichnet, die auch in Kamtschatka vorkommen.The species of predaceous diving beetles (Coleoptera, Dytiscidae) ocurring in the Kuril Archipelago in the northwest Pacific are reviewed. Based on literature records, the study of museum collections, and material from recent expeditions 24 species are known from the archipelago. A detailed report is given on the 357 adult and 50 larval specimens collected in the South and Mid Kuril Islands by the joint American-Japanese-Russian expeditions in 1994 and 1995. The following five species are here recorded from the Kurils for the first time: Hydroporus uenoi Nakane, Platambus pictipennis (Sharp), Agabus japonicus Sharp, Ilybius nakanei Nilsson, and Graphoderus zonatus (Hoppe). The number of species recorded on individual islands ranged from 1 to 11, with the largest islands at either end of the Greater Kuril Ridge being the most diverse. The South Kurils are dominated by Ussurian-Japanese species known also from Sakhalin and Hokkaido, whereas the North Kuril fauna includes a high proportion of Holarctic or Palearctic species known also from Kamchatka

Multiple Origins of Elytral Reticulation Modifications in the West Palearctic Agabus bipustulatus Complex (Coleoptera, Dytiscidae)

The Agabus bipustulatus complex includes one of Europe's most widely distributed and common diving beetles. This complex, which is known for its large morphological variation, has a complex demographic and altitudinal variation in elytral reticulation. The various depth of the reticulation imprint, both in smaller and larger meshes, results in both mat and shiny individuals, as well as intermediate forms. The West Palearctic lowland is inhabited by a sexually dimorphic form, with shiny males and mat females. In mountain regions, shiny individuals of both sexes are found intermixed with mat individuals or in pure populations in central and southern areas, whereas pure populations of mat individuals are exclusively found in the northern region at high altitude. Sexual selection is proposed as a driving force in shaping this variation. However, the occurrence of different types of reticulation in both sexes and disjunct geographical distribution patterns suggest an additional function of the reticulation. Here we investigate the phylogeographical history, genetic structure and reticulation variation of several named forms within the Agabus bipustulatus complex including A. nevadensis. The molecular analyses recognised several well-supported clades within the complex. Several of the named forms had two or more independent origins. Few south European populations were uniform in reticulation patterns, and the males were found to display large variation. Reticulation diversity and population genetic variability were clearly correlated to altitude, but no genetic differences were detected among populations with mixed or homogenous forms. Observed reduction in secondary reticulation in female and increased variance in male at high altitude in South Europe may be explained by the occurrence of an additional selective force, beside sexual selection. The combined effect of these selective processes is here demonstrated in an extreme case to generate isolation barriers between populations at high altitudes. Here we discuss this selective force in relation to thermal selection

How and why acoustic detectability and catchability of herring change with individual motivation and physiological state in a variable environment: a multi-scale study on a local herring population in southwestern Norway

The understanding of distribution and aggregation in herring (Clupea harengus) can be enhanced by integrated multi-scale studies in small ecosystems. Hydro-acoustics, underwater cameras, herring and predator gillnet samples and oceanographical measurements were used to quantify herring schooling dynamics. During autumn (September) after an active feeding period, the herring was distributed in small and dense schools, mostly close to land and in relatively shallow water ( 40 m depth). All recorded herring schools were then vertically extended in the water column within the most variable temperature and oxygen profiles, presumably enabling individuals to adjust maturation rate to prevailing environmental conditions and synchronize spawning of individuals within the school. From late February prior to spawning, only one major pelagic school was observed, extraordinarily stationary at the only inlet to the inner basin. The pre-spawning herring aggregation was fairly easy to detect acoustically for more than one month. Just prior to spawning and during spawning, herring spread out and became extremely difficult to detect acoustically. Only underwater cameras and bottom set gillnets could then be used to identify herring and selected spawning areas. We argue that the dramatic seasonal changes in acoustic detectability and catchability we observe is best understood and predicted based on detailed knowledge of how herring react to a changing environment according to their physiological state and motivation. Such factors should also be taken more systematically into account when performing acoustic surveys in large marine ecosystems. We need to study in more detail the vital underlying processes behind the substantial variability observed in acoustic detectability and catchability of pelagic planktivorous fish species during their annual life cycle in order to better understand and quantify variability in acoustic surveys, and thereby improve our acoustic abundance estimation

Using force covariance to derive effective stochastic interactions in dissipative particle dynamics

There exist methods for determining effective conservative interactions in coarse grained particle based mesoscopic simulations. The resulting models can be used to capture thermal equilibrium behavior, but in the model system we study do not correctly represent transport properties. In this article we suggest the use of force covariance to determine the full functional form of dissipative and stochastic interactions. We show that a combination of the radial distribution function and a force covariance function can be used to determine all interactions in dissipative particle dynamics. Furthermore we use the method to test if the effective interactions in dissipative particle dynamics (DPD) can be adjusted to produce a force covariance consistent with a projection of a microscopic Lennard-Jones simulation. The results indicate that the DPD ansatz may not be consistent with the underlying microscopic dynamics. We discuss how this result relates to theoretical studies reported in the literature.Comment: 10 pages, 10 figure

PSB33 protein sustains photosystem II in plant chloroplasts under UV-A light

Plants can quickly and dynamically respond to spectral and intensity variations of the incident light. These responses include activation of developmental processes, morphological changes, and photosynthetic acclimation that ensure optimal energy conversion and minimal photoinhibition. Plant adaptation and acclimation to environmental changes have been extensively studied, but many details surrounding these processes remain elusive. The photosystem II (PSII)-associated protein PSB33 plays a fundamental role in sustaining PSII as well as in the regulation of the light antenna in fluctuating light. We investigated how PSB33 knock-out Arabidopsis plants perform under different light qualities. psb33 plants displayed a reduction of 88% of total fresh weight compared to wild type plants when cultivated at the boundary of UV-A and blue light. The sensitivity towards UV-A light was associated with a lower abundance of PSII proteins, which reduces psb33 plants\u27 capacity for photosynthesis. The UV-A phenotype was found to be linked to altered phytohormone status and changed thylakoid ultrastructure. Our results collectively show that PSB33 is involved in a UV-A light-mediated mechanism to maintain a functional PSII pool in the chloroplast

A lake as a microcosm: reflections on developments in aquatic ecology

In the present study, we aim at relating Forbes' remarkable paper on "The lake as a microcosm", published 125 years ago, to the present status of knowledge in our own research group. Hence, we relate the observations Forbes made to our own microcosm, Lake Krankesjon in southern Sweden, that has been intensively studied by several research groups for more than three decades. Specifically, we focus on the question: Have we made any significant progress or did Forbes and colleagues blaze the trail through the unknown wilderness and we are mainly paving that intellectual road? We conclude that lakes are more isolated than many other biomes, but have, indeed, many extensions, for example, input from the catchment, fishing and fish migration. We also conclude that irrespective of whether lakes should be viewed as microcosms or not, the paper by Forbes has been exceptionally influential and still is, especially since it touches upon almost all aspects of the lake ecosystem, from individual behaviour to food web interactions and environmental issues. Therefore, there is no doubt that even if 125 years have passed, Forbes' paper still is a source of inspiration and deserves to be read. Hence, although aquatic ecology has made considerable progress over the latest century, Forbes might be viewed as one of the major pioneers and visionary scientists of limnology