Andreas Martens

Pädagogische Hochschule Karlsruhe · Department of Biology

Small lotic waterbodies are abundant and species rich habitats, offering refuges and microhabitats to protected species of the European Union Habitats Directive. Highly impacted by water management actions, it is essential to reveal the current status and challenges of water management. The present study aims to identify relevant issues by conducti...

Der Kalikokrebs Faxonius immunis besitzt mehrere Eifarben. Dazu wurden seit 2017 gezielt Erfassungen durchgeführt. Hier vorgestellt werden systematische Untersuchungen an mehreren Gewässern auf dem Stadtgebiet von Rheinstetten südlich von Karlsruhe 2019 bis 2021. Es dominierten die Eigelegefarben Schwarz, Braun, Rot und Orange; selten waren Beige,...

A zebra mussel Dreissena polymorpha epizoic on a larvae of Anax imperator (Bivalvia: Dreissenidae; Odonata: Aeshnidae) – One Dreissena polymorpha was reported from an exuviae of a male A. imperator collected from a stake at the northern shore of Lake Starnberg near the efflux into the River Würm at Starnberg, Germany, on 20 July 2023.

Boyeria irene larvae of different stages sampled at several localities in the headwaters of the Gardon River, Southern France, frequently showed malformations and injuries in their anal pyramid. The majority of these were broken or imperfectly regenerated tips of the anal spines. To quantify this phenomenon in a standardized way, exuviae of B. iren...

At a summer-dry stream on the Aegean island of Lesvos, a population of Chalcolestes parvidens (Artobolevski, 1929) was studied during the reproductive period from late August to November 2018. Mediterranean intermittent streams display unique characteristics with a seasonal sequence of abiotic and biotic regulation and provide valuable habitats for...

The invasive crayfish Faxonius immunis is regarded as a threat to amphibians and macroinvertebrates in the Upper Rhine Valley, Germany, eradicating macrophytes and establishing high-density populations in stagnant waters. This study investigates the macroinvertebrate community structure of five conservation ponds south of Karlsruhe, Germany, to ide...

To better understand anthropogenically induced shifts of lake nutrient dynamics and subsequent consequences for fish and their zooplankton food sources, an increased spatial and temporal resolution of zooplankton monitoring data is needed. The Zooscan, an instrument mainly used in marine research, enables digitalization of zooplankton samples, and...

The bryozoan class Gymnolaemata is mostly found in the marine environment. There are few representatives in European freshwaters. By collecting biological samples during the inspection of the drained Iffezheim navigation lock on 08-10-2021 we found remnants of a bryozoan we had never seen before. A targeted investigation of embankment stones downst...

The invasive crayfish Faxonius immunis is regarded as a threat to amphibians and macroinvertebrates in the Upper Rhine Valley, Germany, eradicating macrophytes and establishing high-density populations in stagnant waters. This study investigates the macroinvertebrate community structure of five conservation ponds south of Karlsruhe, Germany, to ide...

Metal pollution poses a major threat to aquatic systems especially in anthropogenic influenced areas, in as much as metals are persistent in the environment. The freshwater snail Theodoxus fluviatilis has often been used as an indicator species for the ecological status in river monitoring. In the River Rhine, the native Northern-European form of T...

The introduction of non-indigenous organisms in new areas in the context of host-parasite interactions is still poorly understood. This study aimed at a parasitological and histopathological comparison of two phylogenetically distinct forms of the freshwater snail Theodoxus fluviatilis in the River Rhine system: the native Northern-European form, w...

Species introductions often coincide with loss of genetic diversity and natural enemies. Anthropogenic translocation of the North-American pumpkinseed Lepomis gibbosus (L., 1758) (Centrarchidae) and its further spread have resulted in recent species establishment in most European countries. This study determines genetic differentiation of non-nativ...

Aus dem für Libellen untypischen Lebenszyklus mit imaginaler Überwinterung resultiert für Sympecma fusca eine be-sonders lange Flugzeit, die sich vom Sommer eines Jahres bis zum Sommer des Folgejahres erstreckt und nach niedersächsischen Daten bis zu 13 Monate dauern kann. Somit können sich die Generationen überlappen, doch gibt es noch keine Beric...

Es ist bis heute strittig, ob Erythromma viridulum in Niedersachsen und Bremen früher allgemein übersehen wurde oder als gelegentlicher Vermehrungsgast auftrat. Spätes-tens seit Beginn der 1990er Jahre ist eindeutig klar, dass die Art in Niedersachsen fest etabliert ist. Die Sommerart fliegt über der Tauchblattzone eutropher Gewässer, aber auch übe...

Hansruedi Wildermuth: Some highlights of his Odonata studies - Hansruedi Wildermuth is one of the most creative odonatologist in the present time. This paper focuses on two aspects: (1) his special contribution on midges as odonate parasites and (2) the development of his fundamental monography on European Corduliidae.

Species portrait of occurence in Niedersachsen (Lower Saxony), Germany. History, distribution, biology.

Unusual habitats of Eubranchipus grubii in Karlsruhe and Rastatt, Germany.- In spring 2019, Eubranchipus grubii was recorded in temporary to ephemeral ponds in the SE of Karlsruhe. The habitat is a refilled gravel pit with re-establishing forest. This is a very rare record in a secondary habitat. In 2019, another population near Rastatt, introduce...

In November 2016, soil samples were taken at the Upper Rhine near Karlsruhe, Germany from dried up ephemeral ponds. Here, large branchiopods had previously been documented in June and July 2016 during flooding by the River Rhine. In addition, further sites were sampled, where large branchiopods were expected. Cysts were extracted from the soil, whi...

Radix balthica as a temporary epibiont of Ischnura elegans (Gastropoda; Odonata) - A female I. elegans was photographed in the evening of 24 June 2020 at a garden pond in Meißen, Germany, with two young snails of R. balthica attached, one on the thorax and one on the abdomen. In spite of the additional load the damselfly was able to fly a short dis...

Der Kalikokrebs Faxonius immunis verbreitet sich über Fließgewässer und Gräben und ist in der Lage, durch Wanderung über Land Kleingewässer zu besiedeln. Dort bildet die Art hohe Populationsdichten aus und verändert das Habitat drastisch. Um die konkreten Auswirkungen der Krebsinvasion auf die Wirbellosenfauna in Kleingewässern darzustellen, wurden...

The various uses of copper or copper compounds in industrial, biocidal or pesticidal products lead to inputs of the metal into aquatic environments. To assess effects of copper ions on non-target organisms, the freshwater snail Theodoxus fluviatilis was used as test organism for a three-week laboratory experiment. Snails were exposed to four copper...

Exposure to plastic litter in ecosystems is increasing globally. Marine and terrestrial ecosystems, as well as freshwater ecosystems, are affected. Despite this, the impact of increased exposure to plastics on the freshwater fauna is largely unexplored. The present work investigates the reactions of 42 Anax imperator larvae to plastics in their hab...

Biological invasions are a growing threat to global biodiversity due to negative impacts on native biota and ecosystem functioning. Research has expanded from investigating native and alien species interactions to examining relationships among alien species. Invasive crayfish may have similar life histories, niche preferences, and adaptation strate...

Die Donauform von Theodoxus fluviatilis wurde im Rheinhafen Karlsruhe erstmals 2012 gefunden, dort war sie auf einen bestimmten Hafenbereich beschränkt. Bis zum Herbst 2015 hatte sich die Art in alle Hafenbecken ausgebreitet und besiedelt heute Steinschüttungen sowohl in Fließ- als auch Stillwasserbereichen. The Danubian form of Theodoxus fluviati...

In June 2014, in a mire near Nadibani, Georgia, a female biting midge of Forcipo­ myia (Microhelea) fuliginosa was found parasitizing a female of Aeshna juncea just before its maiden flight. The midge was observed sucking at a soft area of the mesothorax. Forcipomyia fuliginosa is well known as an ectoparasite of caterpillars and sawfly larvae.

In June and July 2013, at two streams in the Middle Atlas Mountains, Morocco, ceratopogonid midges were photographed on and taken from the wings of six species of odonates. The specimens were identified as Forcipomyia paludis, a widespread European ceratopogonid midge new to Africa. The data increase the range of known hosts with the addition of Co...

Metazoan parasite communities of Lepomis gibbosus (Centrarchidae), one of the most successfully introduced fish species in Europe, were studied at two isolated ponds (Knielingen, Tropfen) along the Upper Rhine in Germany. Nine parasite taxa were observed, including North American species co-introduced to Europe (ancyrocephalid monogeneans, diplosto...

Sculpting representations of human organs out of modeling clay is an acknowledged method of teaching anatomical structures. Because of its potential to provide detailed spatial information, stereoscopic imagery can be understood to function as a suitable template for such sculpting tasks. Currently, it is unknown whether the advantages of stereosco...

Die Tabelle 3 lautet richtig (s. Umseite).

Am 15.09.2017 wurden zwei Exemplare von Paramysis lacustris in der Unteren Havel bei Berlin-Spandau gefangen. Bislang wurde die Art aus Deutschland nur vom Stettiner Haff an der Ostseeküste gemeldet. On, 15 September 2017, two specimens of Paramysis lacustris were recorded in the River Havel near Spandau, Berlin, Germany. So far, in Germany the sp...

Im Dezember 2017 wurden an vier Gewässern bei Karlsruhe insgesamt 524 Individuen des invasiven Kalikokrebses Faxonius immunis gefangen. Davon waren 148 Individuen durch den koloniebildenden Ciliaten Epistylis niagarae besiedelt. Die davon betroffenen Krebse wurden nach einem einheitlichen Protokoll fotografisch dokumentiert. Der Datensatz ermöglich...

Im Juli 2018 wurden uns aus der Rheinaue beiderseits der Mündung des Mains auf dem Stadtgebiet von Wies-baden bzw. Ginsheim-Gustafsburg Fotos von Flusskrebsen bzw. Krebsexuvien geschickt. Die Überprüfung und weitere Nachsuche erbrachte den eindeutigen Nachweis von Faxonius immunis an 4 verschiedenen Stellen zwischen Wiesbaden und Ginsheim, und dami...

Paul-André Robert (1901-1977), peintre et naturaliste suisse, a écrit et illustré plusieurs livres faisant autorité sur l’histoire naturelle. Il est bien connu en Europe pour son ouvrage « Les Libellules », paru en 1958. Sa monographie monumentale des larves des libellules d’Europe, commencée à l’âge de 16 ans, est cependant bien moins connue. Ce m...

The non-indigenous crayfish Faxonius immunis (Hagen) is the dominant crayfish species at the Upper Rhine River system since his detection in 1993. As an invasive alien species, it is one of the biggest threats to aquatic biodiversity in the area. By dispersing over land, the species has a high potential to colonize small ponds created for threatene...

The invasive crayfish species Faxonius immunis (formerly Orconectes immunis) grows high population densities in invaded conservation ponds at the Upper Rhine River. This case study compared macrobenthos diversity data from the years 2015 and 2017. In 2017, only 14 of formerly 36 species were found.

At a flooded maize field in the Upper Rhine River floodplain near Elchesheim­ Illingen south of Karlsruhe, Germany, the first emergence of adult Ischnura elegans and I. pumilio was recorded on 07­vii­2016, i.e., just 55 days after the beginning of the field being inundated by upward seepage flow caused by the elevated water levels of the River Rhin...

Records of the biting midge Forcipomyia paludis (Macfie, 1936) from Slovenia and Bosnia and Herzegovina are reported herewith as the first finds of F. paludis in both countries, together with new records from Croatia and Sweden. This biting midge is a temporary ectoparasite of dragonfly imagines and the only ceratopogonid species known in Europe to...

Gross anatomy is located in a three-dimensional space. Visualizing aspects of structures in gross anatomy education should aim to provide information that best resembles their original spatial proportions. Stereoscopic three-dimensional imagery might offer possibilities to implement this aim, though some research has revealed potential impairments...

We report cases of long-distance dispersal in Odonata, some of which were directly observed by identifying single individuals of riverine species in unsuitable habitat, mostly desert, far distant from reproduction habitats. The shortest possible linear distances of the observation points to reproduction habitats were measured. Furthermore, establis...

Bereits im August 2013 gelangen Nachweise von Dreissena rostriformis im Oder-Havel-Kanal bei Eberswalde. Bei Tauchgängen im Werbellinsee (östliches Deutschland, Brandenburg) konnten im Juli 2014 lebende Exem-plare in einer Wassertiefe bis zu 4 m nachgewiesen werden. Die systematische Suche im Sommer 2015 er-brachte den Nachweis einer initial aufwac...

Orconectes immunis stellt für das Makrozoobenthos in Kleingewässern am mittleren Oberrhein eine Bedrohung dar. Es konnte gezeigt werden, dass die Jungtiere innerhalb von 30 Tagen ihre Körpergröße verdoppeln und somit potentiell die Geschlechtsreife erreichen. Zudem zeigen die Wachstumsdaten, dass Jungkrebse von O.immunis einen großen Anteil an tier...

At a pond below the Von Bach Dam near Okahandja, Namibia, adults of the libellulid anisopteran dragonflies Crocothemis erythraea (Brullé) and Diplacodes lefebvrii (Rambur) were observed being trapped by flowering stands of Setaria verticilliata (Poaceae). The spiny seeds of this grass offer a means of seed dispersal by animals. As this species grow...

To realise the goals of Germany's National Biodiversity Strategy, the WIPs-De project aims to contribute to the conservation of 15 endangered plant species for which Germany has a special responsibility (Verantwortungsarten). Six partners, comprising five botanical gardens and one college of education, will participate in the WIPs-De network. Three...

Atlas of Odonata of Germany – For the first time, we present a complete overview about the distribution of all dragonfly species occurring in Germany. The atlas is based on a data collection compiled during 2007-2012, which was organized by the atlas-working-group of Gesellschaft deutschsprachiger Odonatologen. The database comprises more than 1.16...

While learning biological topics constructing depictive representations may be the first step to a deeper understanding. The referred to as visualization type as well as interaction type are supposed to have influence on learning with multimedia applications. Comparing 3D and 2D visualizations (both in combination with written text), there is littl...

Uncinocythere occidentalis (Ostracoda) und Xironogiton victorien-sis (Branchiobdellidae), zwei Aufsitzer des Signalkrebses Pacifastacus leniusculus, nun auch in Rheinland-Pfalz / Uncinocythere occidentalis (Ostracoda) and Xironogiton victoriensis (Branchiobdellidae), epibionts of the signal crayfish Pacifastacus leniusculus, recorded in Rineland-Pa...

Zygonyx torridus inhabits waterfalls, rapids and riffle sections. Males patrol over these sites. After copulation the partners perform an extensive search while flying in tandem over a wide range. Behavioural studies in Mauritius 1997 and 2014 showed that there is considerable plasticity in oviposition behaviour. Three main modes could be distingui...

The endangered freshwater snail Theodoxus fluviatilis is a widely distributed European member of the gastropod family Neritidae. This taxon was abundantly found in the River Rhine until the end of the 20th century, and was considered to be extinct there since the late 1990s. Since 2006, a new, but morphological different form of T. fluviatilis has...

German vernacular names for several species of Mediterranean dragonflies (Odonata) – German vernacular names are available for nearly all western Palaearctic odonate species. The meaning of these names, beginning from Schiemenz (1953), was mainly explained by Wildermuth & Martens (2014). The German translation of Dijkstra & Lewington (2014) expande...

Predation of Enallagma cyathigerum by an adult Cicindela hybrida (Odonata: Aeshnidae; Coleoptera: Carabidae) – On 26 July 2014 near Nuremberg, Germany, an adult Northern Dune Tiger Beetle Cicindela hybrida was observed capturing a mature male Enallagma cyathigerum and photographed devouring the prey. In contrast to Cicindela larvae adult beetles ha...

Photographs of odonates parasitised by Forcipomyia (Pterobosca) paludis taken 2007 and 2014 in the Parc Natural de s' Albufera de Mallorca, Spain, document the first records of this cera to pogonid for the Balearic Islands.

Water mites on the wings of Sympetrum meridionale: an analysis of the 2013 records in Germany (Acari: Hydrachnidia; Odonata: Libellulidae) – During an extensive survey of Sym­ petrum meridionale in Germany parasitism of this species by the water mite Arrenurus papillator was recorded on the basis of photographic documents. The localities of para-si...

Between 1991 and 2011, more than 1,000 adults of exotic odonate species were recorded from glasshouses of a wholesaler dealer of aquarium plants near Wels, Austria. Twenty-three species could be identified to species level. All species were accidentally introduced as eggs or larvae. The majority are widely distributed and common southeastern Asian...

Durch Ausbau des Rheins, Trockenlegungen der Flussaue und gezielte Beseitigung wurde die Wilde Weinrebe in den letzten 150 Jahren fast völlig ausgerottet. Untersuchungen an den letzten Pflanzen ergaben, dass diese Eigenschaften besitzen, welche wichtige Kulturrebsorten vor dem Falschen Mehltau schützen könnten.

The uploaded file is a low resolution version. The high resolution print version can be ordered via GdO (gdo@libellula.org) Abstract We present an illustrated key to the exuviae and final stadium larvae of the dragonflies of Namibia. We have also included some taxa from neighbouring areas, which have not been recorded in Namibia yet. The key is th...

This paper presents a checklist of the Odonata of Namibia and provides up-to-date dis- tribution maps of 130 species. Compared with the checklist from 2007, five species have been added to the list, four of them were new for science. Two species were omitted.

A small Aeshna larva (Odonata: Aeshnidae) as prey of the Southern Bladderwort Utricularia australis – A second stadium larva of Aeshna cf. cyanea was recorded in a bladder of U. australis sampled from a garden pond in Karlsruhe, Germany, on 16-v-2013. The larva was still alive, parts of the abdomen protruded from the bladder. Furthermore two larvae...

In invasion processes, both abiotic and biotic factors are considered essential, but the latter are usually disregarded when modeling the potential spread of exotic species. In the framework of set theory, interactions between biotic (B), abiotic (A), and movement-related (M) factors in the geographical space can be hypothesized with BAM diagrams a...