Three new species of genus Caridina are described from the northernmost part of Australia. Caridina darwin n. sp. resembles Caridina temasek Choy & Ng, 1991 from Singapore but differs in the armature of the rostrum, development of epipods on pereiopods and in lacking an appendix interna on male´s first pleopods. Caridina magnovis n. sp. resembles Caridina serratirostris de Man, 1892 but differs from this species in the armature of the ventral margin of the rostrum, a shorter stylocerite, a stouter carpus of first pereiopod, number and size of spiniform setae on third and fifth pereiopods, the shape of the preanal carina and in egg size. Caridina wilsoni n. sp. resembles Caridina gracilirostris de Man, 1892 but differs in egg size and some length to wide ratio of segments of the pereiopods. Detailed morphological descriptions of all three new species are given. A molecular phylogeny (mt DNA 16S) supports the morphospecies hypotheses and illustrates the phylogenetic relationship with morphologically similar species from outside Australia.

During a survey in 2015 an impressive assemblage of organisms were found in a hypersaline pond of the Messolonghi saltworks. The salinity ranged between 50 and 180 ppt and the organisms recorded fell in the categories of Cyanobacteria (17 species), Chlorophytes (4 species), Diatoms (23 species), Dinoflagellates (1 species), Protozoa (40 species), Rotifers (8 species), Copepods (1 species), Artemia sp., one nematode and Alternaria sp. (Fungi). Fabrea salina was the most prominent protist in all samples and salinities. This ciliate has the potential to be a live-food candidate for marine fish larvae. Asteromonas gracilis proved a sturdy microalga performing excellently in a broad spectrum of culture salinities ies. Most of the specimens were identified only to the genus level and, based on their morphology, as there are no relevant records in Greece, there is a possibility for some of them to be either new species or strikingly different strains of certain species recorded elsewhere.

Determining the DNA sequencing of a small element in the mitochondrial DNA (DNA barcoding) makes it possible to easily identify individuals of different larval stages of marine crustaceans without the need for laboratory rearing. It can also be used to construct taxonomic trees, although it is not yet clear to what extent this barcode-based taxonomy reflects more traditional morphological or molecular taxonomy. Collections of zooplankton were made using conventional plankton nets in Newport Bay and the Pacific Ocean near Newport Beach, California (Lat. 33.628342, Long. -117.927933) between May 2013 and January 2020, and individual crustacean specimens were documented by videomicroscopy. Adult crustaceans were collected from solid substrates in the same areas. Specimens were preserved in ethanol and sent to the Canadian Centre for DNA Barcoding at the University of Guelph, Ontario, Canada for sequencing of the COI DNA barcode. From 1042 specimens, 544 COI sequences were obtained falling into 199 Barcode Identification Numbers (BINs), of which 76 correspond to recognized species. The results show the utility of DNA barcoding for matching life-cycle stages as well as for documenting the diversity of this group of organisms.

A fundamental question in biology is whether phenotypes can be predicted by ecological or genomic rules. At least five cases of convergent evolution of the crab-like body plan (with a wide and flattened shape, and a bent abdomen) are known in decapod crustaceans, and have, for over 140 years, been known as ‘carcinization’. The repeated loss of this body plan has been identified as ‘decarcinization’. In reviewing the field, we offer phylogenetic strategies to include poorly known groups, and direct evidence from fossils, that will resolve the history of crab evolution and the degree of phenotypic variation within crabs. Proposed ecological advantages of the crab body are summarized into a hypothesis of phenotypic integration suggesting correlated evolution of the carapace shape and abdomen. Our premise provides fertile ground for future studies of the genomic and developmental basis, and the predictability, of the crab-like body form.

Crustacean hyaluronidases are 1 poorly understood both in terms of their enzymatic properties and in terms of their structural features. In this work, we have shown that the hepatopancreas homogenate of the red king crab has a hyaluronidase activity that is an order of magnitude higher than its commercial counterpart. Zymography revealed the hyaluronidase activity of the protein roughly from40 to 50 kDa relative to the molecular marker used in electrophoresis. Analysis of the hepatopancreas transcriptome revealed a hyaluronidase sequence with an expected molecular weight of 42.5 kDa. It turned out that the reaction of cleavage of hyaluronate in the presence of a homogenate proceeds by the mechanism of b-elimination, which is well known for bacterial hyaluronidases. Thus, a new hyaluronidase of higher eukaryotes was found and described, which is not integrated into the modern classification of hyaluronidases.