Australian Redclaw Crayfish Cherax Quadricarinatus 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

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.

The invasive Australian redclaw crayfish Cherax quadricarinatus Von Martens, 1868: a new threat for biodiversity in the Sierra Gorda Biosphere Reserve, Central Mexican Plateau

The invasive Australian redclaw crayfish Cherax quadricarinatus Von Martens, 1868: a new threat for biodiversity in the Sierra Gorda Biosphere Reserve, Central Mexican Plateau

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.

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.

Predictor complexity and feature selection affect Maxent model transferability: Evidence from global freshwater invasive species

AbstractAimEcological niche models (ENMs) are widely used to address urgent real‐world problems such as climate change effects or invasive species; however, the generality of models when projected through space and/or time, that is transferability, remains a key challenge. Here, we explored the effects of complex predictors and feature selection on ENM transferability in a widely employed algorithm, Maxent, using five globally invasive freshwater species as case studies.LocationGlobal.MethodsWe modelled the global distributions of five notorious freshwater invasive species (African sharptooth catfish Clarias gariepinus, Mozambique tilapia Oreochromis mossambicus, American bullfrog Lithobates catesbeianus, red swamp crayfish Procambarus clarkii, and Australian redclaw crayfish Cherax quadricarinatus), using three predictor datasets of varying complexities derived from two commonly used climatic data sources (WorldClim and IPCC) and three methods of model tuning that differentially incorporated feature selection. Spatially explicit transferability assessments were then conducted using a suite of evaluation metrics previously used to quantify Maxent model performance.ResultsWe show that in the absence of detailed biological knowledge of focal species, simpler predictor datasets produce models that are more accurate than those calibrated using comprehensive “bioclimatic” datasets. Additionally, we find that tuning models for both optimal regularization parameters as well as feature‐class combinations led to the greatest increases in transferability and geographic niche conservatism. Results indicate a tenuous link between model transferability and Akaike's information criterion corrected for small sample sizes (AICc), suggesting that the indiscriminate use of AICc as an estimate of model parsimony may lead to erratic model performance.Main conclusionsOur findings demonstrate that methodological considerations can drastically affect the reliability of spatial and possibly temporal projections, which has severe implications when ENMs are used to infer species’ niches, and quantify ecological or evolutionary change across impacted landscapes.

The first occurrence of the Australian redclaw crayfish Cherax quadricarinatus (von Martens, 1868) in the contiguous United States

The first occurrence of the Australian redclaw crayfish Cherax quadricarinatus (von Martens, 1868) in the contiguous United States

Presence of the Australian redclaw crayfish Cherax quadricarinatus (von Martens, 1868) (Parastacidae, Astacoidea) in a freshwater system in the Caribbean drainage of Costa Rica

Presence of the Australian redclaw crayfish Cherax quadricarinatus (von Martens, 1868) (Parastacidae, Astacoidea) in a freshwater system in the Caribbean drainage of Costa Rica

Ornamental trade as a pathway for Australian ­redclaw crayfish introduction and establishment

AB Aquatic Biology Contact the journal Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AB 12:69-79 (2011) - DOI: https://doi.org/10.3354/ab00324 Ornamental trade as a pathway for Australian ­redclaw crayfish introduction and establishment Christina C. Belle1,2, Jason Q. H. Wong3, Darren C. J. Yeo1, S. H. Tan3, Heok H. Tan3, Esther Clews1, Peter A. Todd1,* 1Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore 2Tropical Marine Science Institute, National University of Singapore, 18 Kent Ridge Road, Singapore 119227, Singapore 3Raffles Museum of Biodiversity Research, Department of Biological Sciences, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore *Corresponding author. Email: dbspat@nus.edu.sg ABSTRACT: The ornamental trade is one of the major vectors of freshwater animal species translocation worldwide. The Australian redclaw crayfish Cherax quadricarinatus was brought into Singapore through the trade and culture of aquarium specimens during the late 1980s. From 2000 to the present, redclaw crayfish have been observed in at least 3 of Singapore’s 13 reservoirs, including 2 inland reservoirs in the Central Catchment Nature Reserve (CCNR). The current paper presents the first in situ population data of feral C. quadricarinatus populations originating from ornamental trade and includes updated distribution records in Singapore based on recent surveys and museum samples. We report a C. quadricarinatus range expansion in 2 additional reservoirs (1 coastal and 1 inland), and the presence of multiple size cohorts confirms the establishment of reproducing populations in 2 coastal reservoirs and 1 CCNR reservoir. This is alarming as the current distribution borders Singapore’s oldest and arguably most important nature reserve (Bukit Timah Nature Reserve: BTNR) and encircles the single remaining substantial freshwater swamp forest in the country (Nee Soon). The Nee Soon swamp forest and BTNR have extremely high conservation value as both areas together harbour the richest native freshwater fauna and flora of the island. Therefore, any range expansion of C. quadricarinatus in Singapore may have severe impacts on its native freshwater fauna and demands immediate attention. As C. quadricarinatus is one of the many invasive freshwater ­species occurring from the aquarium trade in Singapore, we argue that trade control might prevent ­further establishment of ornamentals. KEY WORDS: Cherax quadricarinatus · Invasive · Ornamental trade · Reproducing feral populations · Singapore reservoirs Full text in pdf format PreviousNextCite this article as: Belle CC, Wong JQH, Yeo DCJ, Tan SH, Tan HH, Clews E, Todd PA (2011) Ornamental trade as a pathway for Australian ­redclaw crayfish introduction and establishment. Aquat Biol 12:69-79. https://doi.org/10.3354/ab00324 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AB Vol. 12, No. 1. Online publication date: April 06, 2011 Print ISSN: 1864-7782; Online ISSN: 1864-7790 Copyright © 2011 Inter-Research.

Energy storage during the transition from endogenous to exogenous feeding in Australian redclaw crayfish Cherax quadricarinatus (Von Martens, 1898)

Summary The Australian redclaw crayfish Cherax quadricarinatus hatches at an advanced stage. Two post-hatching stages rely on yolk reserves before the organism becomes a juvenile. After a juvenile appears, the yolk is depleted and young crayfish might spend a few days among female pleopods before starting to feed independently. During this phase, the juvenile organism needs alternative energy sources. Offspring from three females were analyzed with histological and histochemical techniques, from hatching until reaching the 2-week juvenile stage, to trace digestive system development and internal organ lipid and glycogen accumulation. Neutral lipids are stored in specialized cells of the hepatopancreatic tissue until the juvenile stage is reached. An increasing rate of accumulation was found. Glycogen was stored in hepatopancreas and tail muscle cells until post-embryo II, and no increasing or decreasing rate was found in storage functions.

Sex determination in crayfish: are intersex Cherax quadricarinatus (Decapoda, Parastacidae) genetically females?

In the Australian red-claw crayfish Cherax quadricarinatus (von Martens) (Decapoda, Parastacidae), a gonochoristic species, seven different combinations of intersex individuals (with both male and female genital openings) have been described. However, to date, the genetic basis for this phenomenon has not been investigated. This study was designed to test a simple chromosome-based sex-determination model for C. quadricarinatus that assumes the male to be the homogametic (ZZ) sex. According to our model, intersex individuals that are functionally males are genetically females (WZ). Individual crosses were performed between intersex and female crayfish, with control crosses being performed between normal males and females. The control crosses yielded, in most cases, the expected 1:1 sex ratio in the F1 progeny. Crosses between intersex individuals and females yielded a 1:3 (male:female) sex ratio in most crosses. According to our hypothesis, one-third of the females produced in a cross of a female with an intersex animal should be WW females. The hypothesis was tested by crossing normal males with F1 females, which were progeny of intersex fathers. These crosses yielded almost 100% females, a finding that conforms to the above-suggested sex determination model for C. quadricarinatus and the female WZ genotype of intersex individuals.

Intensification of redclaw crayfish Cherax quadricarinatus culture : I. Hatchery and nursery system

Intensification of an indoor hatchery and nursery system for the Australian redclaw crayfish Cherax quadricarinatus (von Martens) (Decapoda: Parastacidae) was obtained by increasing the surface area available for the crayfish juveniles and by synchronizing the age of the hatchlings held in each tank. The former improvement was facilitated by distributing an artificial seaweed-like material throughout almost the entire volume of small (275 l) hatching tanks. As the number of egg-bearing females was increased from 3 to 8 per hatching tank, the number of juveniles per liter also increased to as many as 6.5 juveniles/l, without reaching an apparent upper limit. The hatchlings were kept in the tanks for 75 days from the day females were found to be gravid and then harvested and graded according to size. The average juvenile weight at harvest was 0.34±0.04 g. The weight distribution of the juvenile males was not significantly different from that of the juvenile females on the day of harvest, and in both the distribution was positively skewed.

Effects of Temperature and Salinity on Weight Gain, Oxygen Consumption Rate, and Growth Efficiency in Juvenile Red‐Claw Crayfish Cherax quadricarinatus

Abstract.— Weight gain and metabolic rates, as determined by oxygen consumption rates, were examined in juvenile Australian red‐claw crayfish Cherax quadricarinatus exposed to different temperatures (16–32 C in 2 C increments) or salinities (0–30 ppt in 5 ppt increments). Mean weight gain, molting frequency, and survival (%) were dependent on temperature and salinity. In freshwater (0 ppt), maximal weight gain and molting frequency were observed at 28 C with maximal survival observed over the temperature range of 24–30 C. Metabolic rates in freshwater were temperature dependent (mean Q10= 2.44). Maximal weight gain and molting frequency were observed at salinities of 0 and 5 ppt (28 C); however, survival was reduced at salinities ≥ 5 ppt. Metabolic rates were not salinity dependent and did not differ significantly over the salinity range from 0–20 ppt. Growth efficiencies, calculated by dividing weight gain by total metabolic energy expenditure (i.e., weight gain + metabolic rate), were highest at a temperature of 20 C (0 ppt) and at salinities of 0 and 5 ppt (28 C). These data suggest that, at higher culture temperatures, maximal weight gain of red‐claw juveniles may be reduced when food resources are limited. Maximal weight gain, at optimal temperatures (28 C) with unlimited food supply, does not appear to be effected by low salinity conditions. Because of the potential commercial value of red‐claw, culturists, should be aware of the relationship between environmental condition and metabolic energy requirements to ensure maximal weight gain and survival of juveniles.

Culture Of The Australian Red-Claw Crayfish (Cherax Quadricarinatus) In Israel Crayfish Incorporation Into Intensive Tilapia Production Units

This study tested the suitability of the Australian red-claw crayfish Cherax quadricarinatus for rear- ing in an intensive culture system as a supplement to Oreochromis niloticus. Fish were grown in twelve 5.5 m3 tanks at high density (33/m3) for 133 days, alone or with crayfish at two stocking den- sities (10/m2 and 20/m2) with added shelters or with crayfish at the lower density (10/m2) without shelters. Tilapia survival ranged 90.3-95.0% with no significant differences among treatments. The growth rate of the tilapia raised with crayfish (2.05 g/day) was significantly higher than that of tilapia grown alone (1.88 g/day) probably because the fish were feeding on part of the crayfish pellets. Among treatments, there were no significant differences in fish yield. Crayfish survival was extremely low in the ‘no shelter’ treatment (2.9±2.7%) but reasonable (approximately 60%) when raised with shelters. The growth rate of the crayfish raised with shelters was significantly higher at the lower density (0.21 g/day) than at the higher density (0.18 g/day). Further research is needed on rearing tilapia and crayfish to market size in intensive systems, to establish the economic prof- itability of this culture strategy.

Gonad maturation, morphological and physiological changes during the first reproductive cycle of the crayfishCherax quadricarinatusfemale

Summary Concurrent morphological, anatomical and physiological changes took place during the first reproductive cycle in the Australian red-claw crayfish Cherax quadricarinatus, which prepared the female for spawning and holding of the newly deposited eggs. The endopod became longer and wider than the exopod and developed a mixture of plumose and long thin simple (ovigerous) setae. Small oocytes (0.24±0.05 mm) were present in the immature ovary. The growing ovary contained two distinct oocyte populations: one consisted of small (0.55±0.07 mm), barely growing oocytes, while the other consisted of large oocytes, which increased in size continuously (0.73 to 2.55 mm) until egg laying took place. A gradual change in the relative abundance of ovarian polypeptides occurred until the late vitellogenic stage (large oocytes < 1.8 mm). Three predominant female-specific, SDS-PAGE separated, polypeptides were observed (103, 78 and 73 kDa) that may represent vitellin subunits. The most abundant carotenoid in the ovary...