A new species of Ovalona Van Damme & Dumont, 2008 (Cladocera: Anomopoda) related to the rare Australian species Ovalona archeri (Sars, 1888), is described from the Mekong Delta, South Vietnam. Ovalona garibiani sp. nov. differs from O. archeri in morphology of antenna, postabdomen, and proportions of setae on thoracic limbs II-III. Both species differ from other species of the genus Ovalona in the postabdomen with a narrow and sparsely spaced group of lateral setulae, the distance between the postanal groups being slightly greater than the width of the group. O. garibiani sp. nov. is a rare phytophilous species, known from a few localities in continental Malaysia, Southern Thailand and Vietnam.
In the interval 1994-1999, in Australia, Malaysia and Singapore, epizootic and epidemiological episodes of meningoencephalitis and severe acute respiratory syndromes were reported. Highly lethal in horses, swine and humans, the episodes were proved to be caused by the "new" viruses Hendra (HeV) and Nipah (NiV). At the same time three "new" viral agents have been isolated: Lyssavirus, Menanglevirus and Tupaia paramyxovirus. The intense contemporary circulation of people, animals and food products together with changes in human ecosystem favor new relations between humans and the "natural reservoirs" of biologic agents with a pathogenic potential for domestic and peridomestic animals and humans.
During recent years, many taxa of water fleas (Crustacea: Cladocera) with wide distribution ranges were revised and finally accepted as groups of cryptic species. Here we provide a redescription of Ilyocryptus raridentatus Smirnov, 1989 (Anomopoda: Ilyocryptidae). Our study clearly confirms that I. raridentatus belongs to the sarsi-group based on incomplete moulting, absence of dorsal keel, structure of antennule, thoracic limb I and postabdomen. The species is widely distributed in Australia and East Asia (Malaysia, Thailand, Vietnam, Central China, Japan, South Korea) and penetrates north to the Far East of Russia. A morphological variability among different populations of I. raridentatus does not exceed an intrapopulational level. I. raridentatus seems to be a relatively rare species with a benthic lifestyle similar to its congeners.
Cladoceran samples from Peninsular Malaysia were collected during four sampling trips: in October 2013, November-December 2014, January-February 2018, and September 2022. More than 50 localities were sampled on each trip, including ditches, canals, rivers, ponds, swamps, lakes, old mining pools, and reservoirs. In these samples, we revealed six species new to Malaysia: two of them are planktonic (Bosmina meridionalis and Bosmina fatalis) and four are substrate-associated (Simocephalus expinosus, Anthalona spinifera, Anthalona vandammei, Karualona serrulata). Both species of the genus Bosmina appear to be recent additions to the local fauna, as this genus was not recorded in Malaysia until the last decade. New records are obtained on three rare local species: Simocephalus mixtus, Streblocerus spinulatus, and Acroperus harpae. The morphology of two uncommon East Asian species, Coronatella acuticostata and Chydorus obscurirostris tasekberae was investigated in detail for the first time. With the new records, the list of valid cladoceran species of Malaysia now consists of 72 species as compared to 62 species reported by Idris (1983) in his monograph. However, more studies are needed to produce an exhaustive final species list of the Malaysian cladocerans.
In this work, we proposed a biosensor for trypsin proteolytic activity assay using immobilization of model peptides on screen-printed electrodes (SPE) modified with gold nanoparticles (AuNPs) prepared by electrosynthetic method. Sensing of proteolytic activity was based on electrochemical oxidation of tyrosine residues of peptides. We designed peptides containing N-terminal cysteine residue for immobilization on an SPE, modified with gold nanoparticles, trypsin-specific cleavage site and tyrosine residue as a redox label. The peptides were immobilized on SPE by formation of chemical bonds between mercapto groups of the N-terminal cysteine residues and AuNPs. After the incubation with trypsin, time-dependent cleavage of the immobilized peptides was observed by decline in tyrosine electrochemical oxidation signal. The kinetic parameters of trypsin, such as the catalytic constant (kcat), the Michaelis constant (KM) and the catalytic efficiency (kcat/KM), toward the CGGGRYR peptide were determined as 0.33 ± 0.01 min-1, 198 ± 24 nM and 0.0016 min-1 nM-1, respectively. Using the developed biosensor, we demonstrated the possibility of analysis of trypsin specificity toward the peptides with amino acid residues disrupting proteolysis. Further, we designed the peptides with proline or glutamic acid residues after the cleavage site (CGGRPYR and CGGREYR), and trypsin had reduced activity toward both of them according to the existing knowledge of the enzyme specificity. The developed biosensor system allows one to perform a comparative analysis of the protease steady-state kinetic parameters and specificity toward model peptides with different amino acid sequences.