Genome-wide analysis of the Chinese sturgeon sox gene family: identification,characterisation and expression profiles of different tissues

The sox family is assumed to be responsible for a number of developmental systems. Genome sequencing technology makes it possible to scan sox genes and conduct characteristic analyses of different species. In fish, full characterisation of sox genes at the genome-wide level has been reported for pufferfish Takifugu rubripes, medaka Oryzias latipes, tilapia Oreochromis niloticus and channel catfish Ictalurus punctatus. However, no systematic investigation of the sox family in sturgeons (Acipenseridae) has been reported to date. This study conducted genome-wide identification of the sox genes in the Chinese sturgeon Acipenser sinensis and profiled their tissue distribution between male and female individuals. In total, 19 sox genes were identified, including soxb1, b2, c, d, e, f and h, in the Chinese sturgeon. Genomic structure analysis indicated relatively conserved exon–intron structures in each sox group and phylogenetic analysis supported the previous classification of the sox family. Most of the sox genes showed a tissue-specific expression pattern, indicating the possible involvement of Chinese sturgeon sox genes at different developmental processes such as cardiac and gonadal development. This study provides a comprehensive resource of Chinese sturgeon sox genes and enables a better understanding of the evolution and function of the sox family.     

Characterization of Pallid Sturgeon (Scaphirhynchus albus) Spawning Habitat in the Lower Missouri River

Acipenseriformes (sturgeons and paddlefish) globally have declined throughout their range due to river fragmentation, habitat loss, overfishing, and degradation of water quality. In North America, pallid sturgeon (Scaphirhynchus albus) populations have experienced poor to no recruitment, or substantial levels of hybridization with the closely related shovelnose sturgeon (S. platorynchus). The Lower Missouri River is the only portion of the species’ range where successful reproduction and recruitment of genetically pure pallid sturgeon have been documented. This paper documents spawning habitat and behavior on the Lower Missouri River, which comprises over 1,300 km of unfragmented river habitat. The objective of this study was to determine spawning locations and describe habitat characteristics and environmental conditions (depth, water velocity, substrate, discharge, temperature, and turbidity) on the Lower Missouri River. We measured habitat characteristics for spawning events of ten telemetry-tagged female pallid sturgeon from 2008–2013 that occurred in discrete reaches distributed over hundreds of kilometers. These results show pallid sturgeon select deep and fast areas in or near the navigation channel along outside revetted banks for spawning. These habitats are deeper and faster than nearby river habitats within the surrounding river reach. Spawning patches have a mean depth of 6.6 m and a mean depth-averaged water-column velocity of 1.4 m per second. Substrates in spawning patches consist of coarse bank revetment, gravel, sand, and bedrock. Results indicate habitat used by pallid sturgeon for spawning is more common and widespread in the present-day channelized Lower Missouri River relative to the sparse and disperse coarse substrates available prior to channelization. Understanding the spawning habitats currently utilized on the Lower Missouri River and if they are functioning properly is important for improving habitat remediation measures aimed at increasing reproductive success. Recovery efforts for pallid sturgeon on the Missouri River, if successful, can provide guidance to sturgeon recovery on other river systems; particularly large, regulated, and channelized rivers.     

First observations of intersex development in paddlefish Polyodon spathula

This study reports the first cases of intersex (abnormal development of both male and female reproductive tissues in a gonad) paddlefish Polyodon spathula, an Acipenseriform species of large rivers in the central U.S. and in aquaculture worldwide. Despite a large, multi-decadal data set in Oklahoma, Montana, and North Dakota, intersex development was not observed until 2019, when two individuals were harvested from the Grand Lake/Neosho River stock in Oklahoma. This suggests that intersex development in mid-water, zooplanktivorous paddlefish is rarer than in bottom-dwelling sturgeons for which intersex development is regularly observed. Although contaminants are implicated in causing intersex development in other Acipenseriformes, more investigation is needed.     

A new weevil genus of the tribe Metrioxenini (Coleoptera: Belidae) in Eocene Baltic amber

A new genus, Succinometrioxena n. gen., and a new species, S. poinari n. sp. (Metrioxenini: Oxycoryninae), are described from Baltic amber. This new genus resembles the recent genus Wallacexena Legalov, 2009 but differs from it by the frons with horn-like tubercles on either side, the absence of a middle pronotal carina, teeth on the side of the pronotum, the anterior margin of the pronotum lacking teeth and two long carinae on the elytra. From the fossil genus Paltorhynchus Scudder, 1893 the present fossil differs by possessing a frons with horn-like tubercles on either side, the absence of a middle pronotal carina, teeth on the sides of the pronotum, two long carinae on the elytra and short temples. From the fossil genus Archimetrioxena Voss, 1953, the new genus differs by the frons with horn-like tubercles on either side, the absence of the two truncated elytral carinae, the sides of the pronotum with teeth, short temples and a larger body size.     

Revision of fossil Metretopodidae (Insecta: Ephemeroptera) in Baltic amber – Part 2: Description of a new species of Metretopus Eaton, 1901

In the second part of the revision of fossil Metretopodidae, a new species of the genus Metretopus Eaton, 1901 is described and illustrated based on a male imago. Metretopus dividussp. nov. is the second fossil species of the genus. Distinguishing characters for its separation from other fossil and recent representatives of Metretopus are discussed. http://www.zoobank.org/urn:lsid:zoobank.org:act:BCC5CB69-8014-4DA1-A0DA-DCF714969081     

Margaret Constance Helen Blackler (1902–81)

Cyanobacteria are effective producers of bioactive metabolites, including both acute toxins and potential pharmaceuticals. In the current work, the biological activity of 27 strains of Baltic cyanobacteria representing different taxonomic groups and chemotypes were tested in a wide variety of assays. The cyanobacteria showed strain-specific differences in the induced effects. The extracts from Nodularia spumigena CCNP1401 were active in the highest number of tests, including protease and phosphatase inhibition assays. Four strains from Nostocales and four from Oscillatoriales increased proliferation of mitogen-stimulated human T cells. In antimicrobial assays, Phormidium sp. CCNP1317 (Oscillatoriales) strongly inhibited the growth of six fouling Gammaproteobacteria. The growth of monocotyl Sorghum saccharatum was inhibited by both toxin-producing and ‘non-toxic’ strains. The Baltic cyanobacteria were also found to be a rich source of commercially important enzymes. Among the 19 enzymatic activities tested, alkaline phosphatase, acid phosphatase, esterase (C4 and C8), and naphthol-AS-BI-phosphohydrolase were particularly common. In the cyanobacterial extracts, different peptides which may have been responsible for the observed effects were identified using LC-MS/MS. Their structures were classified to microcystins, nodularins, anabaenopeptins, cyanopeptolins, aeruginosins, spumigins and nostocyclopeptides.     

Observations on Chrysophyceae from a Norwegian mountain lake

Chrysosphaerella coronasircumspina Wujek & Kristiansen and Spiniferomonas bilacunosa Takahashi have been shown by electron microscopy to be regular members of the phytoplankton society in an oligotrophic Norwegian mountain lake. This is the first published record of these species in Norway.     

Fractionation of metals in the Sa1/2 sediment core from Lake Sarbsko (northern Poland) and its palaeolimnological implications

Abstract

This article documents and interprets stratigraphical changes in fractionation of Fe, Mn, Mg, K, Pb, Cu and Zn in the Sa1/2 sediment core from a coastal freshwater lake, Lake Sarbsko (northern Poland). The elements were sequentially extracted from the samples to distinguish five geochemical fractions: exchangeable, acid-extractable, reducible, oxidisable and residual. The analyses revealed substantial variations in geochemical partitioning of the elements and showed no correlation between the fractionation patterns and lithology of the sediments. In the sediments of Lake Sarbsko, iron is mainly bound to sulfides. Potassium occurs in its residual form. Magnesium and zinc are associated with carbonates and aluminosilicates, while copper occurs in compounds with organic matter and sulfides. Lead is found in connection with aluminosilicates and, to a lesser extent, with sulfides and organic matter. Manganese is partitioned between the oxidisable, acid-extractable, and exchangeable fractions. Heavy metals and potassium display the overall tendency to reduce the contents of their residual forms towards the top of the depositional sequence. Fe, Mn, Mg and Zn were found to be the most susceptible to post-sedimentary mobilisation.