Throughout the years, DNA barcoding has gained in importance in forensic entomology as it leads to fast and reliable species determination. High‐quality results, however, can only be achieved with a ...comprehensive DNA barcode reference database at hand. In collaboration with the Bavarian State Criminal Police Office, we have initiated at the Bavarian State Collection of Zoology the establishment of a reference library containing arthropods of potential forensic relevance to be used for DNA barcoding applications. CO1‐5P’ DNA barcode sequences of hundreds of arthropods were obtained via DNA extraction, PCR and Sanger Sequencing, leading to the establishment of a database containing 502 high‐quality sequences which provide coverage for 88 arthropod species. Furthermore, we demonstrate an application example of this library using it as a backbone to a high throughput sequencing analysis of arthropod bulk samples collected from human corpses, which enabled the identification of 31 different arthropod Barcode Index Numbers.
Rapid and reliable methods for fish authentication are required to protect consumers against food fraud. Matrix-assisted laser desorption ionization time of-flight mass spectrometry (MALDI-TOF MS) is ...known as a fast and accurate method for microorganisms. In this study, the effect of five preparation protocols for fish samples on the quality and reproducibility of spectra using the MALDI Biotyper platform were evaluated. The suitability of the protocols for the identification of high-fat Atlantic mackerel (
Scomber scombrus
) and low-fat rainbow trout (
Oncorhynchus mykiss
) was examined in dependence on different storage temperatures and levels of food processing (fresh, refrigerated, frozen, cooked and smoked). The results of the present study showed that acquisition of reproducible and high quality main spectra projections for high-fat and low-fat fishes in fresh and frozen states was only possible by sample preparation with 25% formic acid followed by chloroform–methanol defatting. MALDI-TOF MS based identification was also possible after treating samples at 99 °C for 5 min but not for smoked fish. Furthermore, log score values for identification of frozen fish remained stable even after 14 months of storage at −20 °C.
The creeping larva of the kamptozoan (entoproct) Loxosomella murmanica was investigated using transmission electron microscopy. The late larva exhibits a prominent apical organ connected to the ...‘cerebral’ commissure of large cerebral ganglia, which supply the paired frontal organ. From the cerebral ganglia two paired nerve cords project backwards, closely resembling the tetraneuralian pattern of basal molluscs. In addition, a neural ring supplying the prototroch is present. The epidermis is composed of myoepithelial cells. Dorsally its cuticle is covered by granules of unknown composition. The prototroch consists of two ciliary rings; a downstream collecting system is not present. Although there is a one‐way gut with a lumen throughout, the larva obviously does not feed. A single pair of protonephridia is present. The foot sole shares distinct similarities with basic molluscs, particularly with those of the aplacophoran Solenogastres: The anterior part shows a huge, subepidermal pedal gland and several bundles of cirri consisting of compound cilia. The posterior part is ciliated with intraepithelial mucous cells interspersed. The dorsoventral muscle fibres show the mollusc‐like ventral intercrossing. The present results and previous findings, in particular the chitinous, non‐moulted cuticle, the sinus circulatory system, and a number of neural features shared by Kamptozoa and Mollusca, provide substantial evidence for a direct sister‐group relationship between these phyla. In addition, the basal position of the Solenogastres (Neomeniomorpha) within the Mollusca is corroborated.
Adaptive radiation of an animal group is the evolutionary variation of morphology, physiology, and behavior opening up new habitats and resources. An impressive example of the reciprocal ...interdependency of form and function is found in the anatomy of cephalopod visual and central nervous systems. Interspecific differences of sensory organs and signal processing structures reflect the eco-functional context, e.g., the species-specific demands emanating from habitat and foraging behavior. To substantiate this, we investigated the eyes and brain neuropils of early post-hatching stages of six coleoid cephalopod species (Sepia officinalis, Rossia macrosoma, Sepietta obscura, Idiosepius notoides, Loligo vulgaris, and Octopus vulgaris), showing different size and inhabiting different ethoecological niches. Comprehensive 3D structure data sets were produced in light microscopic resolution, i.e., semithin section series of the head region (histology presented for I. notoides, R. macrosoma, and S. obscura for the first time) and 3D surface renderings of the neuropils, enabling the display of all components in arbitrary perspectives and combinations, and comparative volumetic anaylsis of homologous lobe neuropils. Differing in absolute size considerably, the visual and central nervous systems of the six species follow the same bauplan in adult-like configuration. The visual sense obviously is of paramount importance already after hatching, but also, equilibrioception and olfaction are well developed. The species-specific shapes of various components show that some plasticity and distinct differences in volumetric ratios are found, subject to their functional relevance and to different demands of the lifestyle on the brachial and swimming motor function, on camouflage, as well as on sensoric and cognitive abilities.
Abstract
So-called ‘dorsal vessels’ are poorly described network-like structures associated with the renopericardial system and located dorsally beneath the epidermis in different groups of ...heterobranch gastropods. So far, homology assumptions among the different ‘dorsal vessel systems’ have been hampered by a lack of comparative histological and ultrastructural data. In the present study, we provide the first detailed 3D-reconstruction of a sacoglossan ‘dorsal vessel system’, based on histological semithin sections combined with ultrastructural data. The renopericardial system of Elysia viridis comprises a monotocardial heart, surrounded by a sac-like pericardium that is connected with a ventrally situated kidney. Our histological data show that the ‘dorsal vessels’ connect to the atrium, rather than the pericardium as previously reported. The ‘dorsal vessels’ investigated herein entirely lack an endothelium and are thus more correctly termed ‘dorsal haemolymph sinuses’. With some exceptions, there is a conspicuous correlation between the ability of Sacoglossa to retain plastids from their algal prey and the presence of dorsal haemolymph sinuses. Thus, the latter might enhance circulation and form an internal recycling system that transports oxygen from the site of photosynthesis to the organs and carbon dioxide in the opposite direction. There are considerable structural and histological differences in the ‘dorsal vessels’ of Sacoglossa, Acochlidimorpha and likely Nudibranchia, probably reflecting independent developments to cope with different environmental stress factors and thus to adapt to various ecological niches. Further comparative microanatomical and ultrastructural (re)investigation of missing lineages are required for a better understanding of the variability of the renopericardial complex in heterobranch gastropods and of modifications of the circulatory system.
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