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Australian salt lakes contain a diverse range of endemic invertebrates. The brine shrimp Parartemia is among the most speciose and salt-tolerant of these invertebrates. The morphotaxonomy of Parartemia is well established but there has only been limited molecular assessment of the phylogenetic relationships and boundaries of the morphospecies. We used multiple genetic markers (nuclear 28S and mitochondrial 16S and COI) and tree-building methods (Bayesian inference and maximum likelihood) to investigate the phylogeny of Parartemia. We also used species delimitation methods to test the validity of morphological species designations. The data set included all but 2 of the 18 described Parartemia morphospecies, collected from a total of 93 sites from across southern Australia plus some sequences from GenBank. The results identified large amounts of molecular divergence (e.g. COI P- values of up to 25.23%), some groups of closely related species (which also usually shared some morphological similarities) and some distinctive species, although the relationships among divergent lineages were generally not well resolved. The most conservative set of results from the species delimitation analyses suggests that the morphotaxonomy is largely accurate, although many morphospecies comprised divergent genetic lineages separated by COI P- values of up to 17.02%. Two putative new morphospecies, three cryptic species and one synonymy were identified. Our findings improve the knowledge of Parartemia taxonomy and will facilitate the development of future studies and conservation of this taxon. The brine shrimp Parartemia is a diverse, salt-tolerant genus found in Australian salt lakes. Its current taxonomy is mainly based on morphological data. We used molecular data to investigate the number and relationships of Parartemia species and found two new morphospecies and three cryptic species. Although most species were valid, molecular divergence among and within some species was substantial. Our results confirm the species richness of the genus and our updated species list will aid in targeted conservation efforts. (Image credit: Md Aminul Islam.) [ABSTRACT FROM AUTHOR]

Introduced fishes into lowland rivers can result in invasive populations establishing and then dispersing, where knowledge of their life history traits contributes to understandings of their invasion ecology. Here, the age and growth rates of a translocated chub Squalius cephalus population were assessed in the River Frome, a lowland chalk-stream in Southern England, where chub was introduced approximately 15 years ago. The results were assessed in relation to 35 riverine indigenous chub populations in England. Across these populations, individual chub were present to lengths over 550 mm and aged to at least 19 years old. In samples collected from the River Frome, however, no fish were present over 300 mm and age 4+years. Growth rate analyses of both the annual length increment produced between age 1 and 2 years (juvenile growth rate) and length at the last annulus (adult growth rate) revealed that both of these were relatively high in the River Frome population, being among the fastest of all sampled populations. It is suggested these fast growth rates were the response of the fish to their new environment, facilitating their establishment and colonisation through, for example, enabling reproduction at relatively young ages.

The temporal effects of ethanol preservation on the δ13C and δ15N values of tissues excised from European eel Anguilla anguilla were assessed. Preservation significantly enriched 13C values of fin and mucus but not dorsal muscle. The 13C enrichment occurred in the initial 15 days of preservation and was independent of initial eel mass. Tissue preservation effects on δ15N values were negligible. These tissue‐specific isotopic shifts should be considered when ethanol‐preserved eel samples are used. [ABSTRACT FROM AUTHOR]

This study uses published and unpublished data to create a comprehensive and up-to-date synthesis of available information on a little-known group of invertebrates, namely, non-marine giant ostracods (cypridids ≥3 mm long). Approximately 8% of the ∼1000 living cypridid species are identified as 'giant'. They occur in a range of subfamilies, in all zoogeographic regions, except Antarctica, and mainly in small standing-water ecosystems. Only those in the subfamily Mytilocypridinae are reasonably well studied. This subfamily is endemic to Australia and comprises a diverse range of giant species (∼29 species in 6 genera), mainly in temporary habitats, mostly salt lakes, including in extreme conditions. We evaluate the current taxonomy of the Mytilocypridinae, analyse patterns in the field distributions and abiotic tolerances of species, and review the general biology of these ostracods. We also identify those species most in need of consideration in conservation planning, highlight critical gaps in knowledge and show how these ostracods could serve as useful models for testing ecological and evolutionary theories. The results of this study can be used to inform conservation planning for giant ostracods and direct further study of these unique invertebrates, which are an important component of the biodiversity of small standing-water ecosystems. It is important that conservation planning considers neglected taxa, supported by scientific studies. Accordingly, we critique the biology of giant ostracods, i.e. ostracods in the family Cyprididae that are ≥3 mm in length. These ostracods are common in small standing-water ecosystems, which are subject to a range of threats. We focus on the subfamily Mytilocypridinae, which consists of a diverse range of giant ostracods that are endemic to Australia and occur mainly in salt lakes, sometimes in extreme conditions. [ABSTRACT FROM AUTHOR]