Muschelseide – Goldene Gewänder aus dem Meer

Zu den tierischen Rohstoffen, die der Mensch vor Erfindung der synthetischen Fasern nutzte, gehört eine besonders feine und seltene Faser zur Herstellung von Kleidungsstücken, die Byssus- oder Muschelseide. Hierbei handelt es sich um die Haftfäden der Edlen Steckmuschel Pinna nobilis Linnaeus, 1758 aus dem Mittelmeer, die bei erwachsenen Exemplaren bis 20 cm lang werden können. Schon in der Antike wurden aus diesen Fasern kostbare goldglänzende Gewänder in feinster mühevoller Handarbeit gefertigt. Nach einer Blütezeit während des Römischen Reichs wurde sie in den folgenden Jahrhunderten bis in das 20. Jh. zu Kleingegenständen, wie Handschuhe, Strümpfe oder Stickereien, verarbeitet. Die Zentren der Muschelseidenverarbeitung lagen im Golf von Tarent und auf Sardinien. Aufgrund von Überfischung kamen die Bestände fast zum Erlöschen und 1992 wurde die Art unter Schutz gestellt. Heute wird die Verarbeitung der Muschelseide nur noch zur Bewahrung eines alten Kunsthandwerks betrieben. In der Zoologischen Sammlung Rostock werden zwei Paar Handschuhe aus Muschelseide aus der 2. Hälfte des 18. Jh. aufbewahrt. Shell silk – golden robes from the sea Abstract: A particularly fine and rare fiber belongs to the animal raw materials that man used to make clothes, before the invention of synthetic fibers. It is byssus- or shell silk. This is the adhesive threads of the noble pen shell Pinna nobilis Linnaeus, 1758 from the Mediterranean Sea, which can grow up to 20 cm long in adult specimens. Even in ancient times, these fibers were used to make precious shiny gold garments with the finest of painstaking craftsmanship. After a heyday during the Roman Empire, it was processed in the following centuries until the 20th century to small items such as gloves, stockings or embroidery. The centers of shell silk processing were in the Gulf of Taranto and in Sardinia. Due to overfishing, the stocks almost became extinct and were placed under protection in 1992. Today, the processing of mussel silk is only carried out to preserve an old craft. Two pairs of gloves made of mussel silk from the 2nd half of the 18th century are kept in the Rostock Zoological Collection.

Synthesis and Physicochemical Characteristics of Chitosan Extracted from Pinna deltoides

Chitosan, a naturally produced polysaccharide that has a wide range of uses in biological, pharmacological, industrial, and commercial settings. The pen shell Pinna deltoides is a common species found along the coast of Thondi, and it is often collected as by-catch by fishermen. These species contain a high amount of chitin, which may be converted into chitosan. The goal of this research is to extract chitosan from P. deltoides and characterize it utilizing techniques like Fourier Transform Infrared Spectroscopy (FTIR), Micro Raman Spectroscopy, X-ray Powder Diffractometry (XRD), Thermogravimetric Analysis (TGA), and Scanning Electron Microscopy (SEM). The existence of C-O-C glycosidic connection (1156 cm-1), NHCO group (1216 cm-1), aliphatic compound, -CH2 bend (1418 cm-1), and asymmetric CH2 stretching were verified by FTIR analysis (1204 cm-1). Chitosan extract exhibited a greater degree of deacetylation of 55.17%, which is consistent with prior studies. The highest peaks in the Micro Raman Spectra were 2937 cm-1, 1106 cm-1, and 1376 cm-1. The crystallinity of the chitosan at 2θ was anticipated using X-ray Powder Diffractometry (XRD) data at about 20°-25°. SEM micrograms verified the crystalline nature of the chitosan by revealing its soft and crystal-like arrangement of the chitosan. TGA was used to assess the sample's thermal constancy, and the chitosan's stability was found to be consistent with that of prior research.

Phylogeography and Taxonomic Revision of the Pen Shell Atrina pectinata Species Complex in the South China Sea

Phylogeographic studies contribute to addressing questions regarding the geographic patterns and evolutionary scenarios within and among species and also shed light on the taxonomic status of widely distributed species complexes. The pen shell Atrina pectinata species complex is a widely distributed and economically important bivalve in the northwestern Pacific. Previous phylogeographic studies have identified four genetically distinct cryptic species within the A. pectinata species complex along the coast of China, of which three cryptic species were distributed in the South China Sea. However, less attention has been given to their identification and delimitation. Herein, we report the phylogeography and taxonomic revision of the A. pectinata species complex in the South China Sea using DNA sequence data from mitochondrial cytochrome oxidase I (COI) and 16S ribosomal RNA (16S rRNA), and nuclear 28S ribosomal RNA (28S rRNA) gene markers. Using a combination of phylogenetic and DNA-based species delimitation analysis methods, we found strong support for four genetically valid species in the A. pectinata species complex and defined them as A. japonica, A. lischkeana, Atrina sp., and A. pectinata based on our results as well as on previous morphological and genetic studies. A demographic historical analysis showed that all three species in the South China Sea had populations that were relatively stable over time and then subjected to sudden expansion during the late Pleistocene (60,000–90,000 years ago). These results provide new insights into the systematics and evolution of the A. pectinata species complex and have important conservation and management implications.

Noble Pen Shell (Pinna nobilis) Mortalities along the Eastern Adriatic Coast with a Study of the Spreading Velocity

Noble pen shells (Pinna nobilis) along the Eastern Adriatic coast were affected by mass mortalities similarly to the populations across the Mediterranean basin. Samples of live animals and organs originating from sites on Mljet Island on the south and the Istrian peninsula on the north of the Croatian Adriatic coast were analyzed using histology and molecular techniques to detect the presence of the previously described Haplosporidium pinnae and Mycobacterium spp. as possible causes of these mortalities. To obtain more information on the pattern of the spread of the mortalities, a study was undertaken in Mljet National Park, an area with a dense population of noble pen shells. The results of the diagnostic analysis and the velocity of the spread of the mortalities showed a significant correlation between increases in water temperature and the onset of mortality. Moderate to heavy lesions of the digestive glands were observed in specimens infected with H. pinnae. A phylogenetic analysis of the detected Haplosporidium pinnae showed an identity of 99.7 to 99.8% with isolates from other Mediterranean areas, while isolated Mycobacterium spp. showed a higher heterogeneity among isolates across the Mediterranean. The presence of Mycobacterium spp. in clinically healthy animals a few months before the onset of mortality imposes the need for further clarification of its role in mortality events.

Citizens’ Eyes on Mnemiopsis: How to Multiply Sightings with a Click!

Monitoring the spreading of marine invasive species represents one of the most relevant challenges for marine scientists in order to understand their impact on the environment. In recent years, citizen science is becoming more and more involved in research programs, especially taking advantage of new digital technologies. Here, we present the results obtained in the first 20 months (from 12 July 2019 to 8 March 2021) since launching avvistAPP. This new app was conceived to track the spreading of the invasive ctenophore Mnemiopsis leidyi in the Adriatic Sea; it was also designed to collect sightings of 18 additional marine taxa (ctenophores, jellyfish, sea turtles, dolphins, salps and noble pen shell). A total of 1224 sightings were recorded, of which 530 referred to Mnemiopsis, followed by the scyphozoan jellyfish Rhizostoma pulmo (22%), Cotylorhiza tuberculata (11%) and Aurelia spp. (8%). avvistAPP produced data confirming the presence of Mnemiopsis (often in abundances > 20 individuals m−2) along almost the entire Italian coast in the summer of 2019 and 2020.

Marine by-products tested as feed for almaco jack Seriola rivoliana and their effect on fatty acids and sterols in different tissues.

Marine by-products can compose up to 70% of the total weight of produce from fisheries; most of these by-products are discarded. However, these by-products are rich in highly unsaturated fatty acids that are not synthetized by most marine animals that are produced by aquaculture. Here, we used three marine by-products (shrimp head, Catarina scallop viscera, and Pen shell viscera) to produce meals without the step used to separate lipids as is traditionally done; this separation can promote hydrolysis of lipids and ultimately, oxidation of fatty acids and sterols. Lipid-rich meals were used to partially substitute commercial fishmeal on feeds that were used to grow almaco jack (Seriola rivoliana) juveniles for 10 weeks. The content of 20:5n-3 and 22:6n-3 in tissues of fish fed shrimp and Pen shell presented values similar to controls, but the former had had a better effect on growth, lipid, and phytosterols levels. However, Catarina meal had lower concentration of 20:4n-6 and 22:6n-3 but higher proportion of 20:4n-6 in muscle and 22:6n-3 in liver, indicating a selective conservation in relation to other fatty acids. Catarina meal contained traces of 18:5n-3 (0.02 g/kg) indicating that these scallops, albeit their healthy aspect, were in contact with toxins (okadaic acid) produced by dinoflagellates, a setback that needs to be addressed previous to meal manufacturing. In conclusion, marine by-products processed to maintain lipid composition can be used to reduce the use of fishmeal in the diet, and their use improve the lipid content and growth compared to control diet with fishmeal.