Australian Red Claw Crayfish Cherax Research Articles

The effect of temperature on feeding and growth of australian redclaw crayfish Cherax quadricarinatus (Decapoda, Parastacidae)

The effect of temperature on feed intake and growth of juvenile Australian redclaw crayfish Cherax quadicarinatus was studied by individual observations. Three temperatures were studied: 19–20°C, 23–24°C and 27–28°C. Tetra Wafer Mix compound was used as feed. The duration of the experiment was 60 days. The correlation of feed intake with temperature, weight of juveniles and molting was shown. At the beginning of the experiment, the feed consumption of crayfish with a weight of less than 0,5 g was 2,7% at a temperature 19–20°C; 4,8% for 23–24°C and 5,3% for 27–28°C of the individual’s weight per day. At the end of the experiment, in juveniles weighing more than 2,5 g, the feed consumption for variants 23–24°C and 27–28°C was 1,5% and 2,1%, respectively. The growth rate depended on temperature and at 19–20°C was 3–4 times lower than in the other two versions of the experiment. Based on the data obtained, it was concluded that the range of 23–28°C is within the temperature range optimal for cultivating juveniles. The temperature of 19–20°C does not ensure effective growth of juveniles, however, at this temperature the release of juveniles into ponds is possible.

Technological scheme and biotechnical indices of industrial cultivation of Australian redclaw crayfish juveniles in aquaculture

The aim of the work: forming technological scheme and biotechnical indices of industrial cultivation of Australian redclaw crayfish Cherax quadricarinatus juveniles under controlled conditions based on a generalization of available research investigations.Used methods: the study was carried out on the basis of the aquarium room of Invertebrate Aquaculture Department of VNIRO on Australian redclaw crayfish juveniles and adults in the period from 2010 till 2023. Standard methods were used to determine hydrochemical parameters and fish-cultural and biological indicators of individuals. Studies were carried out on the characteristics of the life cycle, early stages of development, physiology and nutrition. The data was processed using statistical methods.Novelty: A technological scheme and biotechnical indicators of industrial rearing under RAS conditions have been formulated for Australian redclaw crayfish juveniles.Results: A technological scheme and biotechnical indicators for cultivation of Australian redclaw crayfish juveniles have been developed for a modular basin complex. The technological scheme includes six stages: “Selection and housing of brood stock” (1); “Mating and obtaining gravid females” (2); “Maintenance of females with eggs and early juveniles” (3); “Ongrowing of juveniles to 0.2–0.8 g” (4); “Ongrowing of juveniles from 0.2–0.8 g to 2–5 g” (5); “Ongrowing of juveniles for broodstock remount” (6). The success of stages 1 and 2 depends on the spawners’ physiological state, which is determined by the housing conditions during the preparation of crayfish for mating. Stages 3–6 require the use of single-type basins, specialization of which is achieved through the installation of sedimentation tanks for holding females with eggs, shelters and volume-structuring substrates of different types.Practical significance: application of the proposed biotechnical methods and approaches to the production and cultivation of juvenile Australian redclaw crayfish will optimize the cultivation of the species, which will be beneficial for the development of its cultivation in fish farms.

Food Spectrum of the Australian Redclaw Crayfish Cherax quadricarinatus (Von Martens, 1868) (Decapoda, Parastacidae) in the Ponds of Astrakhan Oblast

Food Spectrum of the Australian Redclaw Crayfish Cherax quadricarinatus (Von Martens, 1868) (Decapoda, Parastacidae) in the Ponds of Astrakhan Oblast

Allergen Diversity and Abundance in Different Tissues of the Redclaw Crayfish (Cherax quadricarinatus).

Shellfish allergy affects ~2.5% of the global population and is a type I immune response resulting from exposure to crustacean and/or molluscan proteins. The Australian Redclaw crayfish (Cherax quadricarinatus) is a freshwater species endemic to and farmed in northern Australia and is becoming an aquaculture species of interest globally. Despite being consumed as food, allergenic proteins from redclaw have not been identified or characterised. In addition, as different body parts are often consumed, it is conceivable that redclaw tissues vary in allergenicity depending on tissue type and function. To better understand food-derived allergenicity, this study characterised allergenic proteins in various redclaw body tissues (the tail, claw, and cephalothorax) and how the stability of allergenic proteins was affected through cooking (raw vs. cooked tissues). The potential of redclaw allergens to cross-react and cause IgE-binding in patients allergic to other shellfish (i.e., shrimp) was also investigated. Raw and cooked extracts were prepared from each body part. SDS-PAGE followed by immunoblotting was performed to determine allergen-specific antibody reactivity to sarcoplasmic calcium-binding protein and hemocyanin, as well as to identify redclaw proteins binding to IgE antibodies from individual and pooled sera of shrimp-allergic patients. Liquid chromatography-mass spectrometry (LC/MS) was utilised to identify proteins and to determine the proportion within extracts. Known crustacean allergens were found in all tissues, with a variation in tissue distribution (e.g., higher levels of hemocyanin in the claw and cephalothorax than in the tail). The proportion of some allergens as a percentage of remaining heat-stable proteins increased in cooked tissues. Previously described heat-stable allergens (i.e., hemocyanin and sarcoplasmic calcium-binding protein) were found to be partially heat-labile. Immunoblotting indicated that shrimp-allergic patients cross-react to redclaw allergens. IgE-binding bands, analysed by LC/MS, identified up to 11 known shellfish allergens. The findings of this study provide fundamental knowledge into the diagnostic and therapeutic field of shellfish allergy.

Socioeconomic impacts of Australian redclaw crayfish Cherax quadricarinatus in Lake Kariba

The rapidly spreading Australian red claw crayfish Cherax quadricarinatus in the Zambezi Basin is a cause for concern considering its potential impacts. The assessment of the impacts of C. quadricarinatus is critical for the prioritisation of policy and management actions in Africa where literature on impacts of C. quadricarinatus is generally scant. We quantified the socioeconomic impacts conferred by C. quadricarinatus on artisanal gillnetting fishery in Lake Kariba to validate anecdotal fisher reports regarding crayfish damage to fish catch on static gillnets. From the catch assessments with registered fishers, fish catch composition, catch per unit effort (CPUE), crayfish entangled on gillnets CPUE, damaged fish CPUE, and damaged areas of the fish were recorded. Basin 2 had significantly higher CPUE with respect to fish catch and crayfish, as well as catch damage, compared to other basins. Damage by crayfish on fish was recorded in all the basins except in Basin 5. There was no correlation between number of crayfish bycatch and fish catch damage. The most frequently affected species was Oreochromis niloticus. On all fish species, eyes, guts and the tail were the frequently damaged parts. Due to C. quadricarinatus damage, fishers are losing 212 tonnes per year which translates to US$ 512 352.92 in Lake Kariba. Damage losses are particularly high when the total income per household in the region, which is mainly contributed by fishing, is considered. The lack of damage in Basin 5 is likely due to fishers developing adaptive new techniques which are less likely to be affected by crayfish. This study is the first in Africa to quantify the socio-economic losses due to crayfish in the field, and the first globally to derive observed costs for C. quadricarinatus. Data from this study have huge conservation and management implications, as crayfish threaten food security as well as incur personal losses to fishers via damage-related costs.

Growth and competitions of the Australian red-claw crayfish, Cherax quadricarinatus (von Martens, 1868) in Thailand: the experimental approaches

The Australian red-claw crayfish (RCC) Cherax quadricarinatus (von Martens 1868) (Crustacea: Decapoda: Parastacidae) has been introduced and promoted for freshwater aquaculture in many countries including Thailand. This study i) evaluates the growth performance of RCC in near-natural conditions relative to captive conditions and ii) investigates how successfully RCC can compete with a trophically and functionally analogous native species. Growth of RCC was compared among two aquaculture systems (concrete tank and earthen pond) and a treatment with simulated natural conditions. After 12 months of rearing, total length and weight were greatest in the earthen pond and poorest in the near-natural treatment, with significant differences in total length between the near-natural treatment and the two culture systems. Length-weight relationships showed that the RCC had positive allometry in the culture systems but negative allometry in the near-natural treatment. Competition was evaluated by means of a biotic resistance test and an additive–substitutive experiment between RCC and the native freshwater crab Esanthelphusa dugasti (Rathbun, 1902) (Crustacea: Decapoda: Gecarcinucidae). Specific growth rates after 90 days of the experiments suggest that the crab inhibited growth of RCC. This implies that the invasion of RCC in Thai waters could be limited by competition from resident freshwater crabs.

Методика подсчета общего числа гемоцитов австралийского красноклешневого рака

The optimal formula for calculating the total number of hemocytes (HTN) of the Australian red-claw crayfish (Cherax quadricarinatus) has been established, which allows optimizing the time of counting HTN without re-ducing accuracy. Methodical recommendations on preparing a hemolymph sample, HTN calculation and differentiated calculation of hemocytes are given. It was found out that the differences in HTN are minimal when using different formulas, which is con-firmed by the analysis of variance F = 0.011, p = 0.998, the average values of HTN range from 2 384 to 2 427 cell/µl. Conducting multiple comparisons also demonstrated that the differences between the formulas are minimal: the significance levels between the formulas were p = 0.99. The optimal formula for the Australian red-claw crayfish is: HTN in 1 µl = N • 10, where N is the total number of hemocytes in 25 large squares of Gorjaev’s chamber. The counting chamber should be clean, since when even small dust particles are found on the grid, hemocyte clusters can form and impede counting, or the result of the calculation will be incorrect, because the distribution 
 of hemocytes on the grid will not be uniform. After filling the chamber with hemolymph, it is recommended to wait 
 1-1.5 minutes so that the movement of the hemolymph stops and the hemocytes stop moving. It is recommended to use an anticoagulant, which prevents the rapid decay of cells and promotes their uniform distribution on the grid of the chamber without developing clots (clusters) that affect the accuracy of counting. Working with the whole hemolymph implies the speed and accuracy of the researcher's actions, since it quickly coagulates and forms clusters of hemocytes. In order to avoid confusion when counting cells located on the border between squares, Egorov’s rule is applied. The optimal increase for counting is a 400-fold increase.

Transcriptomic Changes Following Induced De-Masculinisation of Australian Red Claw Crayfish Cherax quadricarinatus.

The Australian red claw crayfish Cherax quadricarinatus, an emerging species within the freshwater aquaculture trade, is not only an ideal species for commercial production due to its high fecundity, fast growth, and physiological robustness but also notoriously invasive. Investigating the reproductive axis of this species has been of great interest to farmers, geneticists, and conservationists alike for many decades; however, aside from the characterisation of the key masculinising insulin-like androgenic gland hormone (IAG) produced by the male-specific androgenic gland (AG), little remains known about this system and the downstream signalling cascade involved. This investigation used RNA interference to silence IAG in adult intersex C. quadricarinatus (Cq-IAG), known to be functionally male but genotypically female, successfully inducing sexual redifferentiation in all individuals. To investigate the downstream effects of Cq-IAG knockdown, a comprehensive transcriptomic library was constructed, comprised of three tissues within the male reproductive axis. Several factors known to be involved in the IAG signal transduction pathway, including a receptor, binding factor, and additional insulin-like peptide, were found to not be differentially expressed in response to Cq-IAG silencing, suggesting that the phenotypic changes observed may have occurred through post-transcriptional modifications. Many downstream factors displayed differential expression on a transcriptomic level, most notably related to stress, cell repair, apoptosis, and cell proliferation. These results suggest that IAG is required for sperm maturation, with necrosis of arrested tissue occurring in its absence. These results and the construction of a transcriptomic library for this species will inform future research involving reproductive pathways as well as biotechnological developments in this commercially and ecologically significant species.

Hemocytes of the Australian Red Claw Crayfish (Cherax quadricarinatus): Morphology and Hemogram

Hemocytes of the Australian Red Claw Crayfish (Cherax quadricarinatus): Morphology and Hemogram

Efficiency assessment of the use of compound feeds with protein different levels for juveniles Australian red claw crayfish in RAS conditions

The aim of the work is to investigate the effect of compound feeds with different levels of protein on the growth of juveniles of the Australian red claw crayfish Cherax quadricarinatus. Used methods: To solve this problem, two experiments were carried out in the aquariums of aquaculture invertebrate department at VNIRO: the first was on juveniles weighing 0.017 ± 0.004 g and 0.87 ± 0.08 mm long; the second one was on juveniles weighing 0.31 ± 0.14 g and 23.7 ± 3.9 mm long. The duration of the experiments was 30 and 40 days, respectively. Feeding of juveniles was carried out with three variants of compound feed recipes with an estimated protein content of 25 %, 35 % and 45 %. The main part of the formulations consisted of components of plant origin. Tetra Wafer Mix food for fish and crustaceans (Germany) with a protein content of 45 % was used as a control. The duration of the experiments was 30 and 40 days, respectively. Feeding of juveniles was carried out with three variants of compound feed recipes with an estimated protein content of 25 %, 35 % and 45 %. The main part of the formulations consisted of components of plant origin. Tetra Wafer Mix food for fish and crustaceans (Germany) with a protein content of 45 % was used as a control. Newness: Development of a feed formulation for rearing juveniles of the Australian red claw crayfish in recirculating aquaculture systems (RAS). Results: These experiments showed that the growth rate of juvenile Australian red claw crayfish is directly dependent on the proportion of protein in the feed. It was established that the relative content of protein in the muscles of crayfish depends on its content in compound feed. An analysis of our own and published data indicates that feeds with protein content below 35 % cannot be recommended for growing of juveniles’ Australian red claw crayfish. Feeds with a protein content of 45 % are optimal for the growth of juveniles. It was established that the effectiveness of compound feeds depends not only on the protein content and energy value, but also on their taste attractiveness. Practical significance: The obtained results will be used in the development of mixed feed for juveniles Australian red claw crayfish.

Improving the technology of growing crustaceans the example of redclaw crayfish Cherax quadricarinatus

The urgency of research with crustaceans in aquaculture is due to the significant demand for the consumption of delicacies of aquatic organisms, including redclaw (Cherax quadricarinatus). Production of freshwater crustaceans provides high profits. Significant volumes of cultivation of these objects on an industrial scale will contribute to the development of aquaculture as a sector of the economy of Ukraine. The scientific novelty is that for the first time in the aquarium-pool complex of a higher education institution a study was conducted on the artificial cultivation and maintenance of australian redclaw crayfish (Cherax quadricarinatus) with the improvement of the technological scheme of cultivation. For the first time in the technological scheme of cultivation, a shelter for crustaceans was used, where the main elements are separator plates and polymer pipes. The proposed design for sheltering crustaceans reduces their death during cultivation, improves the overall functional state of the body after changing the chitinous cover (molting), prevents cannibalism and minimizes stress in intensive reproduction and cultivation technology, optimizes the maintenance of the artificial shelter. The experiment involved testing the technological process of growing crustaceans using structures for their shelter, studying the growth rate and monitoring the hydrochemical regime. The practical significance of the study will help to improve the technology of artificial cultivation of australian redclaw with the prevention of cannibalism.

Bioindicators of the constants of homeostasis of the internal environment of crustaceans, cultured in different environmental conditions for the purpose of obtaining commodity products

The study of the composition and properties of the internal environment (hemolymph) of crustaceans grown in various conditions has an important ecological and physiological aspect, since a number of characteristics of the physiological status of objects can be used to assess the state of the environment, thus, they can be included in the number of bioindicators. However, the nature of the observed differences between objects grown under different conditions, the features of homeostatic regulatory mechanisms and the limits of the reference values of individual homeostasis constants are often not known. To formulate recommendations regarding the technological process of growing objects of warm-water aquaculture, taking into account the assessment of environmental conditions in dynamics through the analysis of indicators of the state of individuals — bioindicators — it is necessary to compare the state of individuals kept in different conditions. The object of the study was the Australian red claw crayfish Cherax quadricarinatus (Von Martens, 1868), cultivated under various conditions of intensive and semi-intensive cultivation. The studies have revealed that throughout the entire period of cultivation, individuals grown in ponds retained a high level of total protein, cholesterol and β-lipoproteins, in contrast to crayfish cultivated in pools. The values of these indicators as bioindicators indicate a high degree of compliance of the growing conditions with the needs of the studied object. Comparative assessment of fluctuations in the ratio of hemolymph shaped elements in the hemocyte composition between cancers grown under different conditions did not reveal significant differences. It was found that significantly higher growth rates are characteristic of crayfish grown in ponds, in contrast to the group of individuals cultivated in pools. The comparative analysis of bioindicators in different growing conditions presented by the authors of the article supplements information that is of significant interest for monitoring the growing conditions of this representative of warm water aquaculture, which will be valuable for specialists engaged in crustacean breeding.

Distribution and establishment of the alien Australian redclaw crayfish, Cherax quadricarinatus, in the Zambezi Basin

Abstract Crayfish are invasive polytrophic keystone species, which are phylogenetically unique on the African continent. The Australian redclaw crayfish Cherax quadricarinatus is invasive in southern African freshwater systems including the Zambezi River Basin. Surveys conducted across the Zambezi Basin (Botswana, Zimbabwe, Namibia and Zambia) between 2017 and 2019 showed that C. quadricarinatus is broadly distributed across the Upper and Middle Zambezi and is rapidly spreading through natural and human‐mediated means across several ecoregions. The probability of capture (Pcapture), catch per unit effort (CPUE) and population characteristics of C. quadricarinatus from the recent Barotse floodplain invasion were compared with older invasions from Lake Kariba and Kafue River. The Pcapture and CPUE of C. quadricarinatus in the recently invaded region of the Barotse floodplain were similar to those of the older invasions. Mass and carapace length of C. quadricarinatus from the Barotse floodplain were significantly lower than those of C. quadricarinatus from the older invasions. Sex ratios differed significantly between the three invasive populations. The Barotse floodplain population had a disproportionate investment in females (65.3%) and intersex individuals (8.4%). No crayfish were detected in the Zambezian Headwaters or the Okavango Floodplains ecoregions, but current spread rates are 49 km yr−1 downstream and 12 km yr−1 upstream. Investment in population management and the prevention of spread will have high conservation value across the invaded regions in order to restrict crayfish ecological impacts via direct predation and competition. In areas where crayfish are in high abundance, existing fisheries are affected through damage to nets, leading to increased net abandonment and ghost gear pollution in invaded regions. The emphasis should be on developing cohesive transboundary biosecurity policies in southern Africa to limit further spread that will threaten the integrity of freshwater ecosystems. However, long‐term monitoring is needed to gauge invasion risk to sensitive areas such as the Okavango Floodplains ecoregion and determine field‐based ecological impacts.

Standardisation of alien invasive Australian redclaw crayfish Cherax quadricarinatus sampling gear in Africa

Freshwater crayfish are damaging invaders across southern Africa; however, monitoring techniques and efforts are disparate across the region as different sampling methods have been used. To develop a standard method for assessing redclaw crayfish Cherax quadricarinatus abundance, a survey was conducted to assess for differences in detection and catch per unit effort (CPUE) in Lake Kariba. Two sampling approaches were compared: opera traps baited with cooked maize meal historically used in crayfish surveys in Zimbabwe, and Promar collapsible traps baited with dry dog food, which have been used for assessments in South Africa and Swaziland. Baits were compared in the Barotse Floodplain in Zambia using the Promar trap. Detection probability (Pcapture) and CPUE were significantly lower for opera traps baited with cooked maize meal (Pcapture = 0.41; CPUE = 1.19 ± 0.24 ind.·trap-1·night-1) compared to the Promar traps baited with dry dog food (Pcapture = 0.67; CPUE = 4.53 ± 0.82 ind·trap-1·night-1). The Pcapture and CPUE for Promar traps baited with dog food (Pcapture = 0.89; CPUE = 4.29 ± 0.83 ind·trap-1·night-1) was significantly higher than for maize meal baited traps (Pcapture = 0.29; CPUE = 0.25 ± 0.17 ind·trap-1·night-1). Sex ratio and carapace length of crayfish sampled did not differ between sampling methods. Due to higher CPUE, the authors consider the Promar collapsible trap baited with dog food approach as the better method for determining crayfish population abundance and suggest that comparisons of abundance take this into consideration by applying conversion factors if different methods are applied.

Etiological characteristics of “tail blister disease” of Australian redclaw crayfish (Cherax quadricarinatus)

In November 2019, an acute disease outbreak in Australian redclaw crayfish (Cherax quadricarinatus) occurred in a farm in Hubei, China, with a cumulative mortality rate of over 80%. One of the characteristic symptoms of the disease was blisters on the tail. This symptom is also common in diseased Procambarus clarkii every year in this country, but the causative agent has not been determined. This study analyzed the etiological characteristics of this disease. Bacterial isolation and identification combined with high-throughput sequencing analysis were conducted to obtain the microbiota characteristics in the hemolymph, hepatopancreas, and intestines. Results showed that this outbreak was caused by infection from Aeromonas hydrophila and Aeromonas veronii. The underlying cause was stress imposed on crayfish during transferring from outdoor pond to indoor pond because of temperature drops. Aeromonas infection caused remarkable changes in the structure of the microbial composition in the hemolymph, hepatopancreas, and intestines of the crayfish. The abundance of Aeromonas in the hemolymph of the sick crayfish was as high as 99.33%. In particular, KEGG metabolic pathway analysis showed that some antibiotic synthesis, enterobactin biosynthesis, and myo-inositol degradation pathways were abundant in healthy crayfish hemolymphs, which may be the mechanism of maintaining crayfish health. Conversely, inhibition of these pathways led to the disorder of microbiota structure, finally leading to the occurrence of diseases. To the knowledge of the authors, this study was the first to use high-throughput amplicon sequencing targeting the 16S rRNA gene to find the causative bacteria in aquatic animals. This protocol can provide more comprehensive and reliable evidence for pathogen identification, even if the pathogenic bacteria are anaerobes or other hard-to-culture bacteria.

Mapping a super-invader in a biodiversity hotspot, an eDNA-based success story

The lesser Antilles archipelago in the Caribbean is known as a biodiversity hotspot, hosting many endemic species. However, recent introduction of a highly invasive species, the Australian redclaw crayfish (Cherax quadricarinatus), has led to significant threats to this fragile ecosystem. Here we developed, validated, and optimized a species-specific eDNA-based detection protocol targeting the 16S region of the mitochondrial gene of C. quadricarinatus. Our aim was to assess the crayfish distribution across Martinique Island. Our developed assay was species-specific and showed high sensitivity in laboratory, mesocosm and field conditions. A significant and positive correlation was found between species biomass, detection probability and efficiency through mesocosm experiments. Moreover, we found eDNA persisted up to 23 days in tropical freshwaters. We investigated a total of 83 locations, spread over 53 rivers and two closed water basins using our novel eDNA assay and traditional trapping, the latter, undertaken to confirm the reliability of the molecular-based detection method. Overall, we detected C. quadricarinatus at 47 locations using eDNA and 28 using traditional trapping, all positive trapping sites were positive for eDNA. We found that eDNA-based monitoring was less time-consuming and less influenced by the crayfishes often patchy distributions, proving a more reliable tool for future large-scale surveys. The clear threat and worrying distribution of this invasive species is particularly alarming as the archipelago belongs to one of the 25 identified biodiversity hotspots on Earth.

First record of the Australian redclaw crayfish Cherax quadricarinatus (von Martens, 1868) in Hong Kong, China

First record of the Australian redclaw crayfish Cherax quadricarinatus (von Martens, 1868) in Hong Kong, China

First wild record of Australian redclaw crayfish Cherax quadricarinatus (von Martens, 1868) in the East Coast of Peninsular Malaysia

First wild record of Australian redclaw crayfish Cherax quadricarinatus (von Martens, 1868) in the East Coast of Peninsular Malaysia

Records of the Australian redclaw crayfish Cherax quadricarinatus (von Martens, 1868) on the island of Puerto Rico

This project was funded in part by National Science Foundation grants DGE 0841146 and DEB 1139899.

Influence of salinity on survival, growth, hemolymph osmolality, gill sodium potassium ATPase activity, and sodium potassium chloride co‐transporter expression in the redclaw crayfish Cherax quadricarinatus

AbstractThe Australian redclaw crayfish Cherax quadricarinatus is a freshwater crustacean aquacultured in many countries. Redclaw crayfish are often exposed to saline waters in attempts to improve flavor, to relieve stress during transport, and to prevent or treat parasitic infestations. However, the effect of salinity on the crayfish osmoregulatory process is not well studied. In the present work, we assessed the effect of various salinities on survival, growth, and osmoregulation in redclaw crayfish. Adult crayfish were maintained at seven salinities (0, 2, 4, 6, 8, 10, and 12 ppt) for 4 weeks, and hemolymph osmolality, gill sodium potassium ATPase activity, and sodium potassium chloride cotransporter expression were assessed. In another experiment, juvenile crayfish were size sorted to similar weights and stocked at four salinities (0, 2, 4, and 6 ppt) for 8 weeks. The animals were group weighed every 2 weeks and individually weighed at the end of the eighth week. Hemolymph osmolality was constant as salinity increased from 0 to 10 ppt then a significant increase was observed at 12 ppt. Redclaw growth rate decreased with an increase in salinity from 0 to 6 ppt. Sodium potassium ATPase activity and sodium potassium chloride cotransporter expression increased with salinity increase. Although salinity might help treat ectoparasites, improve taste, and reduce transportation stress, long‐term exposure increases osmoregulatory metabolic costs and affects growth and energy consumption.