Paludiculture can support biodiversity conservation in rewetted fen peatlands.

Paludiculture, the productive use of wet or rewetted peatlands, offers an option for continued land use by farmers after rewetting formerly drained peatlands, while reducing the greenhouse gas emissions from peat soils. Biodiversity conservation may benefit, but research on how biodiversity responds to paludiculture is scarce. We conducted a multi-taxon study investigating vegetation, breeding bird and arthropod diversity at six rewetted fen sites dominated by Carex or Typha species. Sites were either unharvested, low- or high-intensity managed, and were located in Mecklenburg-Vorpommern in northeastern Germany. Biodiversity was estimated across the range of Hill numbers using the iNEXT package, and species were checked for Red List status. Here we show that paludiculture sites can provide biodiversity value even while not reflecting historic fen conditions; managed sites had high plant diversity, as well as Red Listed arthropods and breeding birds. Our study demonstrates that paludiculture has the potential to provide valuable habitat for species even while productive management of the land continues.

Copulatory behaviour and genital mechanics suggest sperm allocation by a non-intromittent sclerite in a pholcid spider.

The male genitalia of pholcid spiders, which is one of the most species-rich spider families, are characterized by a procursus, which is a morphologically diverse projection of the copulatory organ. It has been shown that the procursus interacts with the female genitalia during copulation. Here, we investigate the function of the procursus in Gertschiola neuquena, a species belonging to the early branched and understudied subfamily Ninetinae, using behavioural and morphological data. Although many aspects of the copulatory behaviour of G. neuquena follow the general pattern described for the family, males use only one pedipalp during each copulation. Based on our micro-CT analysis of cryofixed mating pairs using virgin females, we can show that the long and filiform procursus is inserted deeply into the unpaired convoluted female spermatheca, and the intromittent sclerite, the embolus, is rather short and stout only reaching the most distal part of the female sperm storage organ. Histological data revealed that sperm are present in the most proximal part of the spermatheca, suggesting that the procursus is used to allocate sperm deeply into the female sperm storage organ. This represents the first case of a replacement of the sperm allocation function of the intromittent sclerite in spiders.

Spermatozoa of an Old World Ricinulei (Ricinoides karschii, Ricinoidae) with notes about the relationships of Ricinulei within the Arachnida.

The ultrastructure of spermatozoa is a valuable tool for phylogenetic and systematic studies. Ricinulei are enigmatic and poorly studied arachnids. So far, spermatozoa are only known from New World ricinuleids. The goals were to study, by means of light and transmission electron microcopy, the spermatozoa of an Old World species with regard to their phylogenetic implications, e.g., does the sperm structure contribute to the debated sister-group relationship of Acari and Ricinulei. The spermatozoa are coiled-flagellate and characterized by a cap-like acrosomal vacuole covered by electron-dense material, an elongated nucleus covered by a manchette of microtubules during spermiogenesis, an axoneme with a 9+2 microtubular pattern, a nuclear tube and axonemal basis which both originate underneath the acrosomal vacuole and cleistospermia as transfer form equipped with three intracellular plates. The data of the present study did not support a close relationship of Ricinulei and Acari which have aflagellate sperm with various synapomorphies as e.g., lacking nuclear envelopes/membranes in Actinotrichida (very similar to Solifugae) or vacuolated spermatozoa in Anactinotrichida. Affinities of Ricinulei are discussed in the light of the ultrastructure of arachnid spermatozoa.

Spermatozoa and sperm packages of the European troglophylous scorpion Belisarius xambeui Simon, 1879 (Troglotayosicidae, Scorpiones).

Studies on the sperm morphology in scorpions are rare, but the existing investigations already revealed a remarkable interfamiliar diversity. The present study reports for the first time on the spermatozoa and sperm packages of a representative of the family Troglotayosicidae, the troglophylous species Belisarius xambeui. The spermatozoa are characterized by (1) a thread-like nucleus, which is slightly bent anteriorly; (2) an asymmetrical cap-like acrosomal vacuole, which encloses the anterior tip of the nucleus; an acrosomal filament is absent; (3) an axoneme with a 9+0 microtubular pattern; (4) a midpiece consisting of elongated mitochondria coiling around the axoneme; the number can vary between 3 and 6 (mostly 4). At the end of spermiogenesis, the spermatozoa aggregate in order to form oval-shaped sperm packages in which all sperm cells show the same orientation. A single package consists of approximately 150 sperms. A secretion sheath is always absent. The present results might provide new characters for further systematic studies and their phylogenetic implications are briefly discussed.

The male genital system of the New World Ricinulei (Arachnida): ultrastructure of spermatozoa and spermiogenesis with special emphasis on its phylogenetic implications.

This study is the first report on the male genital system and the sperm structure of the South American genus Cryptocellus and provides a second description for the Central American genus Pseudocellus. The spermatids of the Colombian species Cryptocellus narino are elongated and anteriorly lentoid-shaped due to two conspicuous intracellular electron-dense plates. Two cell protrusions are present, which contain in front of the lentoid part the acrosomal complex and parts of the axoneme and nucleus, and behind the lentoid part the continuing axoneme and nucleus. The acrosomal filament originates from a cap-like acrosomal vacuole, extends into the nuclear canal and ends behind the lentoid part. The nucleus runs parallel to the axoneme. The axoneme possesses a typical 9+2 microtubular pattern. At the end of spermiogenesis the acrosomal complex, nucleus and axoneme coil within the cell forming cleistospermia as transfer form. Our results of Pseudocellus pearsei confirm an earlier study on that genus which is considered to be not closely related to Cryptocellus. According to the present study the sperm structure of the observed Cryptocellus species is very similar to what is described for Pseudocellus.

Spermatozoa and spermiogenesis of Holocnemus pluchei (Scopoli, 1763) (Pholcidae, Araneae).

Until now, the knowledge on pholcid spermatozoa is based on two species, Pholcus phalangioides and, incompletely, Holocnemus pluchei. To complete this knowledge and to reveal more potential phylogenetic characters, we have investigated sperm ultrastructure and spermiogenesis of H. pluchei. We found that the sperm cells of this species are clearly different from those of P. phalangioides with respect to: (1) the lack of specialization in the cylindrical acrosomal vacuole; (2) a nuclear canal which is located in the periphery and not in the center of the nucleus; (3) a more prominent postcentriolar elongation of the nucleus; (4) the presence of "inner microtubules" in the implantation fossa in early and mid-spermatids; (5) the absence of a helical band of nuclear material; (6) the proximal centriole which is not prolonged; (7) the types of secretion in the seminal fluid (only two types in H. pluchei). Similarities in the spermatozoa of both species concern: (1) a large implantation fossa which contains large amounts of glycogen in mature spermatozoa; (2) absence of a centriolar adjunct; (3) an axonemal basis located in the posterior part of the implantation fossa; (4) the formation of the so-called cleistospermia in the vas deferens. Our results strongly support systematic relationships within Pholcidae placing these two species in different subgroups.

The ultrastructure of the peculiar synspermia of some Dysderidae (Araneae, Arachnida).

The present study reports on the ultrastructure features of spermatozoa and spermatogenesis of several species of Dysderidae (Dysdera crocata, Dysdera erythrina, Dysdera ninnii, Harpactea arguta, Harpactea piligera, Dasumia taeniifera). Dysderid spiders are known to possess a peculiar sperm transfer form known as synspermia, characterized by fused spermatozoa surrounded by a secreted sheath. Until now the exact mode of formation of the synspermia is unknown. The present study demonstrates that the spermatids are connected via narrow cell bridges during the entire spermiogenesis as is usual, although in Dysderidae they do not separate at end of the spermiogenesis. Instead, they fuse completely within the testes shortly after the spermatid has coiled to get a spherical shape. The number of fusing sperm cells is different in the different observed species. The species of the genus Harpactea thus have synspermia consisting of two fused spermatozoa; whereas in the species of the genus Dysdera four sperm cells are fused and in D. taeniifera at least three spermatozoa are fused. In contrast with other known families with this peculiar form transfer of sperm, the synspermia in Dysderidae are mainly characterized by a conspicuous vesicular area which extends through the entire synspermium surrounding the cell organelles. Thus, all main cell components (e.g., nucleus, acrosomal vacuole, and axoneme) are covered by the vesicular membrane. The vesicular area seems to be functional and probably it is important during sperm activation in female genital system. Simultaneously to the extension of the vesicular area, the synspermium accumulates large amounts of glycogen. The glycogen is mainly located around the centriolar adjunct and along the axoneme accompanying the postcentriolar elongation of the nucleus. A further peculiar feature is the extremely elongated acrosomal vacuole, which seems to be synapomorphic trait for sperm cells of dysderids. Interestingly, spermatogenesis, including the fusion, exclusively occurs within the testes (in contrast to the formation of coenospermia). In the vas deferens only synspermia were found. The secreted sheath surrounding the spermatozoa is finally synthesized in the parts of the vasa deferentia, which are close to the genital opening where numerous vacuoles and microvilli are seen in the epithelial cells.

On the occurrence of coenospermia in mesothelid spiders (Araneae: Heptathelidae).

Two species of the early derivative spider family Heptathelidae (Heptathela kimurai yanbaruensis and Ryuthela nishihirai nishihirai) have been investigated with respect to spermiogenesis, focussing on late events during which peculiar transfer forms are developed. It is shown, for the first time in detail, that these spiders produce coenospermia. The coenospermia of these species are large aggregates containing more than 20 individual encapsulated spermatozoa. The coenospermia possess a likely flexible envelope formed by a thick multilayered secretion, which protects the spermatozoa during transfer to the female genital system and storage in the receptacula. In addition, a short description of the main cell components of the individual spermatozoa is given as a complement to previous studies. With the observation presented here, the suggestion that coenospermia are an ancestral character in the Araneae is further confirmed, and plesiomorphic features of spider sperms are consolidated.

Ultrastructural observations of spermatozoa and spermiogenesis in Wandella orana Gray, 1994 (Araneae: Filistatidae) with notes on their phylogenetic implications.

Spermatozoa and spermiogenesis of the prithine filistatid spider Wandella orana are described. The spider produces coenospermia, i.e. sperm aggregations that include several single sperm cells commonly surrounded by a secretion sheath. One sectioned coenospermium in W. orana contains at least five spermatozoa. During copulation many coenospermia are transferred into the female. Coenospermia are regarded as a peculiar transfer form of sperm which occurs in early derivative spiders such as Liphistiomorphae and Mygalomorphae. The only exception which was found in Araneomorphae until now was the filistatine spider Filistata insidiatrix. Our observation is the second case and supports the view that Filistatidae represent an early derivative taxon. Furthermore, the individual sperm cells show characteristics which also may be regarded as being plesiomorphic. There is a cone-shaped acrosomal vacuole, a very long acrosomal filament, a rather stout nucleus and a small implantation fossa. The axoneme shows the 9x2+3 pattern of microtubules which is synapomorphic in Megoperculata (Uropygi, Amblypygi and Araneae). The finding of coenospermia in two distant taxa of Filistatidae may have consequences for phylogenetic and systematic considerations.

Identification and confirmation of arsenobetaine and arsenocholine in fish, lobster and shrimp by a combination of fast atom bombardment and tandem mass spectrometry.

Using fast atom bombardment (FAB) ionization combined with tandem mass spectrometry (MS/MS), the identity of arsenobetaine (AB) in extracts of sole, haddock, lobster and shrimp was unequivocally confirmed. Evidence was also presented for the presence of arsenocholine (AC) in the shrimp extract. Confirmation was obtained by comparing the collision-induced dissociation (CID) daughter ion and parent ion spectra of major ions in the FAB spectra from these extracts with those from the authentic standards.

Use of an electrostatic preconcentration system to identify interferences in atomic-absorption spectrometry.

Interference effects can be identified by deviations from ideality of the slopes of the concentration curves generated with an electrostatic trapping system. The technique is employed to detect spectral interferences in atomic-absorption measurements, due to the presence of sodium chloride, and caused by imperfect background correction. The electrostatic trap is found to be a particularly convenient means of obtaining the required concentration curves because the device gives a ready control of the concentration factor, reliable performance for a range of different solutions, and ease of use in dealing with the necessary number of samples.

Use of electrostatic preconcentration at high salt concentrations.

Apparatus is described for the electrostatic preconcentration of aerosol particles with a collector trough electrode from samples containing large amounts of matrix salts. A cooling and filtration cycle is used to precipitate and separate the matrix salts, and prevent saturation of the collector solution. The system has been applied to the preconcentration of sea-water species before analysis by flame atomic-absorption spectroscopy.

An instrumental method of solution preconcentration.

Aerosol concentration before atomic-absorption measurement is achieved by use of an electrostatic trapping technique. The effects of various experimental parameters are examined, including those of voltage, trap dimensions, gas flow-rate through the trap and trapping time. It is concluded that the technique offers an inherently clean method of solution preconcentration which is capable of enhancing the signal by an order of magnitude or more.

Aerosol preconcentration on a liquid electrode.

Electrostatic preconcentration of a dried aerosol is achieved with a water electrode. The system is found to show similar trapping characteristics to those given by wire electrodes, but the subsequent introduction of collected material into a flame atomizer is easier, merely requiring aspiration of the electrode solution after the trapping cycle is complete. The system has been tested for some 40 elements, 5 of which failed to show any response. The failures are attributed to a vapour-phase reaction of the solution aerosol during its passage through the desolvation system, leading to formation of water-insoluble species.