Ultrastructure of spermatozoa of redclaw Cherax quadricarinatus and yabby Cherax destructor were described and compared. The acrosome complex and nucleus are located at the anterior and posterior region of the spermatozoon, respectively. The acrosome is a complex vesicle divided into two parts: the main body of the acrosome appears as a dense cup-shaped structure in longitudinal sagittal view, with the subacrosome zone occupying the central area of the vesicle. The acrosome is larger in C. quadricarinatus (width 2.37±0.27μm, length 1.31±0.23μm) than in C. destructor (width 1.80±0.27μm, length 1.01±0.15μm). There was no significant difference in L:W ratios of the studied species. The subacrosome zone in both species consists of two areas of different electron density. The nucleus is substantially decondensed and irregular in shape, with elaborate extended processes. The examined species exhibited a well-conserved structure of crayfish spermatozoon, similar to those of Cherax cainii and Cherax albidus. Small acrosome size, the absence of radial arms, and an extracellular capsule seem to be the morphological features that mostly distinguish Cherax from the Astacidae and Cambaridae.

• MeSH
• akrozom ultrastruktura   MeSH
• Decapoda (Crustacea) ultrastruktura   MeSH
• spermie ultrastruktura   MeSH
• transmisní elektronová mikroskopie MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Cherax (Astaconephrops) gherardii n. sp. is a moderate burrowing crayfish endemic to the Ajamaru Lakes of West Papua, Indonesia. This species is one of the crayfish species from this region that are exploited for ornamental purposes. Its commonly used commercial name in the pet trade is "Rainbow Crayfish" or "Blue Moon Crayfish", and its native name is "udang kuku biru". The new species is genetically and morphologically similar to Cherax boesemani, however, both species may be easily distinguished morphologically or by using sequence divergence, which is substantial for considering C. gherardii n. sp. to be a valid species.

• MeSH
• anatomické struktury zvířat anatomie a histologie   růst a vývoj   MeSH
• ekosystém MeSH
• rozšíření zvířat MeSH
• severní raci anatomie a histologie   klasifikace   genetika   růst a vývoj   MeSH
• velikost orgánu MeSH
• velikost těla MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Indonésie MeSH

Atrazine (ATR) is a triazine herbicide banned in the European Union. It remains one of the most widely used herbicides in other parts of the world. Considering the scarcity of data on its possible harm to the environment and to human health, we assessed sub-chronic effects of a 14-day exposure at the environmentally relevant concentration of 6.86 μg/L and at 10% of the 96hLC50 (1.21 mg/L) in crayfish Cherax destructor and their recovery in a 14-day period in ATR-free water. Indicators assessed were behavior; hemolymph biochemical profile; oxidative and antioxidant parameters in gill, hepatopancreas, and muscle; and histology of gill and hepatopancreas. Crayfish exposed to the environmental concentration showed significant differences (P < 0.01) from controls in biochemical parameters of hemolymph (lactate, alkaline phosphatase) and activity of superoxide dismutase, as well as in histology of gill tissue. The higher concentration led to low motor activity, differences in biochemical profile of hemolymph (lactate, alkaline phosphatase, ammonia, glucose), antioxidant biomarkers (superoxide dismutase, catalase, glutathione reductase, glutathione S-transferase, reduced glutathione), as well as gill and hepatopancreas histology. Some observed effects persisted after 14-days recovery in ATR-free water. The results provide evidence that environmental concentrations of ATR produce negative effects on freshwater crayfish.

• MeSH
• antioxidancia metabolismus   MeSH
• atrazin toxicita   MeSH
• biologické markery metabolismus   MeSH
• glutathiontransferasa metabolismus   MeSH
• hemolymfa účinky léků   metabolismus   MeSH
• hepatopankreas cytologie   účinky léků   MeSH
• oxidační stres účinky léků   MeSH
• severní raci cytologie   účinky léků   metabolismus   MeSH
• superoxiddismutasa metabolismus   MeSH
• testy chronické toxicity * MeSH
• vystavení vlivu životního prostředí * MeSH
• žábry cytologie   účinky léků   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Cherax acherontis n. sp., is a crayfish endemic to the submerged river Yumugima in Hagepma/Jugurama cave in the New Guinea Highlands, Jayawijaya Regency, Papua Province, Indonesia. This species is the first cave crayfish from the Southern Hemisphere. The new species is most similar to Cherax monticola. Both species can be easily distinguished by certain morphological characteristics, which easily demonstrate C. acherontis n. sp. is a valid species.

• MeSH
• jeskyně MeSH
• severní raci * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Indonésie MeSH
• Nová Guinea MeSH
• Papua Nová Guinea MeSH

Přehledné a především aktuální informace obsažené v praktické části publikace pomohou zájemcům o tyto atraktivní, poměrně nenáročné a cenově dostupné živočichy, aby se vyvarovali chyb, kterých by se mohli při chovu dopustit. Těžiště části speciální spočívá v přehledu raků dostupných na našem trhu, jejich popisu, způsobu života a podmínkách, jež požadují v akváriu.

The phylogenetic relationships among imported ornamental crayfish belonging to the genus Cherax were inferred from a combined dataset of 3 mitochondrial genes (COI, 16S and 12S) and by comparison with available GenBank sequences of 14 Cherax species. Furthermore, the concordance of previously described species obtained from a wholesaler (Cherax boesemani, C. holthuisi and C. peknyi) with available GenBank sequences was verified based on COI with special respect to comparison with sequences assigned as Cherax species. Recently described species C. gherardiae, C. pulcher and C. subterigneus belong to the northern group of Cherax species. Comparison and analysis with other GenBank COI sequences show previously unreported diversity of New Guinean species, suggesting 5 putative new species. Surprisingly, species assigned to the subgenus Astaconephrops do not form a monophyletic clade; this subgenus should be reappraised relative to the purported typical morphological characteristic of the uncalcified patch on male chelae. Increasing importation of crayfish underscores the importance of accurate species identification. Use of basic molecular methods is a necessary requisite for documenting occurrence, abundance and population trends of target species. Consequently, it helps to support eventual conservation decision-making by stakeholders.

• MeSH
• druhová specificita MeSH
• fylogeneze MeSH
• mitochondriální DNA genetika   MeSH
• respirační komplex IV genetika   MeSH
• RNA ribozomální 16S genetika   MeSH
• RNA ribozomální genetika   MeSH
• severní raci klasifikace   genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Nová Guinea MeSH

The spreading of new crayfish species poses a serious risk for freshwater ecosystems; because they are omnivores they influence more than one level in the trophic chain and they represent a significant part of the benthic biomass. Both the environmental change through global warming and the expansion of the pet trade increase the possibilities of their spreading. We investigated the potential of four "warm water" highly invasive crayfish species to overwinter in the temperate zone, so as to predict whether these species pose a risk for European freshwaters. We used 15 specimens of each of the following species: the red swamp crayfish (Procambarus clarkii), the marbled crayfish (Procambarus fallax f. virginalis), the yabby (Cherax destructor), and the redclaw (Cherax quadricarinatus). Specimens were acclimatized and kept for 6.5 months at temperatures simulating the winter temperature regime of European temperate zone lentic ecosystems. We conclude that the red swamp crayfish, marbled crayfish and yabby have the ability to withstand low winter temperatures relevant for lentic habitats in the European temperate zone, making them a serious invasive threat to freshwater ecosystems.

• MeSH
• analýza přežití MeSH
• ekosystém MeSH
• nízká teplota * MeSH
• severní raci fyziologie   MeSH
• vodní hospodářství MeSH
• zavlečené druhy * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Cercariae and metacercariae of three species of the Microphallidae Travassos, 1920 were found in snails and crustaceans from tributaries of the Brisbane River, Queensland, Australia. Specimens of Maritrema brevisacciferum Shimazu et Pearson, 1991 and Microphallus minutus Johnston, 1948, which have previously been reported in Queensland, were found as cercariae in the tateid gastropod Posticobia brazieri (Smith) and as metacercariae of M. brevisacciferum in the atyid shrimp Caridina indistincta Calman and of M. minutus in the parastacid crayfish Cherax dispar Reik. Combined analysis of morphological and molecular data, based on newly generated ITS2 and partial 28S rDNA data, linked cercariae and metacercariae for both species. This is the first report of the first intermediate hosts of M. brevisacciferum and M. minutus. Infections of another unidentified microphallid metacercariae, Microphallidae gen. sp., were found in P. brazieri and C. indistincta. The sequences of metacercarial isolates from both hosts were identical. The data on the Microphallidae from Australia and species that develop in freshwater invertebrates were examined in detail.

• MeSH
• cerkárie anatomie a histologie   MeSH
• diagnostické techniky molekulární MeSH
• DNA izolace a purifikace   MeSH
• fylogeneze MeSH
• hlemýždi parazitologie   MeSH
• hostitelská specificita MeSH
• korýši parazitologie   MeSH
• metacerkárie anatomie a histologie   MeSH
• řeky parazitologie   MeSH
• sekvenční seřazení MeSH
• sladká voda parazitologie   MeSH
• stadia vývoje MeSH
• Trematoda * anatomie a histologie   klasifikace   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Austrálie MeSH

Freshwater biodiversity is globally threatened by various factors while severe weather events like long-term droughts may be substantially devastating. In order to remain in contact with the water or stay in a sufficiently humid environment at drying localities, the ability to withstand desiccation by dwelling in the hyporheic zone, particularly through vertical burrowing is crucial. We assessed the ability of three European native and five non-native crayfish as models to survive and construct vertical burrows in a humid sandy-clayey substrate under a simulated one-week drought. Three native species (Astacus astacus, A. leptodactylus, and Austropotamobius torrentium) suffered extensive mortalities. Survival of non-native species was substantially higher while all specimens of Cherax destructor and Procambarus clarkii survived. The native species and Pacifastacus leniusculus exhibited no ability to construct vertical burrows. Procambarus fallax f. virginalis and P. clarkii constructed bigger and deeper burrows than C. destructor and Orconectes limosus. In the context of predicted weather fluctuations, the ability to withstand desiccation through constructing vertical burrows into the hyporheic zone under drought conditions might play a significant role in the success of particular crayfish species, as well as a wide range of further hyporheic-dwelling aquatic organisms in general.

• MeSH
• analýza přežití MeSH
• biodiverzita MeSH
• biologické modely MeSH
• období sucha * MeSH
• severní raci klasifikace   fyziologie   MeSH
• sladká voda MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH