Red Claw Crayfish - Cherax quadricarinatus : Complete Crayfish Profile & Care Guide
Table of contents
Introduction
The Red Claw Crayfish (Cherax quadricarinatus), with its striking colouration, adaptable diet, rapid growth, high reproductive capacity, and tolerance to various environmental stressors, stands out as an excellent choice for large freshwater aquariums that require low maintenance. Despite their significant size, adult Red Claw Crayfish generally exhibit gregarious and non-aggressive behaviour. While they may not be inherently social creatures, they do display a higher tolerance for elevated stocking densities compared to other crayfish species. It is important to note that this tolerance does not extend to juvenile Red Claw Crayfish, which tend to be quite aggressive, often engaging in resource competition. Reports indicate that cannibalism among juveniles is a prominent factor contributing to low survival rates in aquaculture settings during this developmental stage.
It is not advisable to cohabitate Red Claw Crayfish with aquatic frogs or snails, as these creatures are vulnerable to predation by the Crayfish. Additionally, passing fish, regardless of size, may fall prey to these Crayfish, and smaller crayfish species are not spared from their aggression. Ideally, Red Claw Crayfish are best suited for single-species tanks. These Crayfish have a propensity for uprooting and consuming plants, as well as consuming sunken wood.
Red Claw Crayfish are nocturnal in nature, exhibiting heightened activity during the late evening and nighttime hours, with a gradual reduction in activity leading up to sunrise. During daylight hours, they tend to seek shelter in their environment. Overall, the care of Red Claw Crayfish is relatively straightforward, as they are not demanding pets and readily adapt to captivity. Nevertheless, it is essential to meet their basic requirements to ensure their well-being. These Crayfish require a spacious habitat due to their growth potential, with a recommended minimum tank size of 120 litres for a single adult crayfish.
Although Red Claw Crayfish exhibit high tolerance to ammonia, nitrites, and nitrates, it is advisable not to push the limits of their tolerance. Crustaceans, in particular, are vulnerable to gill damage caused by elevated levels of nitrogenous wastes. Hence, proper tank setup and water cycling are crucial. Regular weekly water changes of 15% to 20% help maintain optimal water quality.
Replicating their natural environment is essential in their captive habitat, making stones and gravel suitable substrate choices. The substrate should provide comfort and hiding opportunities. Artificial shelters are indispensable, especially during the breeding season, as they offer protection during vulnerable phases like moulting, safeguard against predation, and reduce aggressive interactions. Stacks of PVC pipes, mesh bundles, and driftwood can serve as effective shelters, especially during the grow-out phase. Given their propensity for escape, secure tank lids are advisable, as Red Claw Crayfish can displace lightweight covers.
Typically, Red Claw Crayfish exhibit a dark blue body adorned with beige and red/brown spots, featuring four keels on their heads. Adult males are distinguished by a distinct red patch on the outer margins of their claws. However, in the aquarium trade, various colour variations, including greenish or grey hues, may be encountered. Juveniles tend to display a different colour pattern, ranging from light blue to light grey, often mottled in white with whitish leg joints.
Red Claw Crayfish Photos
Sexual Dimorphism
Sexual dimorphism is evident in Red Claw Crayfish, with several distinguishing characteristics facilitating gender identification. Males typically exhibit accelerated growth rates, resulting in a larger overall size in comparison to females. Notably, males possess a distinct opening on one of their 5th legs, while females feature a corresponding opening on the opposite 3rd leg.
Confirmation of sexual dimorphism is further established through a comparative assessment of the major chelae, where male Crayfish display larger, broader, and longer chelae when matched with females of equivalent carapace length. Additionally, males boast a discernible red patch adorning their claws, further aiding in their gender differentiation.
Quick Facts
| Scientific Name | Cherax quadricarinatus |
|---|---|
| Year Described | 1868 |
| Other Names | Australian Red Clawed Crayfish, Redclaw Crayfish, Red Clawed Yabby, Queensland Red Claw, Tropical Blue Crayfish, Freshwater Blueclaw Crayfish |
| Kingdom | Animalia |
| Classification | Malacostraca |
| Order | Decapoda |
| Family | Pachychilidae |
| Genus | Cherax |
| Origins | Australia , Papua New Guinea |
| Max Size | 35 cm |
| Temperament | Semi-Aggressive |
| Aquarium Level | Bottom - Middle |
| Difficulty | Beginner - Intermediate |
| Shoaling | No |
| Best kept as | NA |
| Diet & Feeding | Omnivore |
| Reproduction | Livebearer |
| Average Lifespan | Up to 6 Years |
Water Parameters
| Water Type | Freshwater |
|---|---|
| pH | 7.0 - 8.5 |
| GH | 5 - 25 |
| KH | 3 - 18 |
| ℉ | 73 - 82 |
|---|---|
| ℃ | 23 - 28 |
Natural Habitat
The Red Claw Crayfish is a tropical freshwater species native to the Gulf of Carpentaria in northern Australia, as well as northeastern Queensland and Papua New Guinea. However, due to its adaptability and successful invasion tendencies, this species has become widely distributed beyond its original habitat, primarily as a result of its involvement in the global aquaculture and aquarium trade.
These tropical crustaceans exhibit remarkable resilience in the face of environmental fluctuations. They are typically found in aquatic environments characterized by high turbidity, including slow-moving rivers, lakes, lagoons, and static water bodies. Additionally, they have been observed in diverse settings such as freshwater irrigation channels, fast-flowing rivers and streams, as well as brackish-water lagoons.
In their preferred habitats, Red Claw Crayfish exhibit a preference for rocky terrain replete with ample caves, which serve a variety of purposes, including exploration, foraging, and providing shelter during the moulting process.
Breeding
Red Claw Crayfish attain sexual maturity typically between 6 to 12 months of age. In the courtship ritual, females predominantly take the initiative by approaching males. Subsequently, males assume a distinctive posture by arching their abdomen and rolling over onto their dorsal side, positioning themselves beneath the female. Copulation typically spans a few minutes, with both males and females maintaining this specific alignment throughout the process.
Fertilization of the eggs occurs within approximately 24 hours following spawning, contingent upon the water temperature remaining above 73°F (23°C). The reproductive capacity of female Red Claw Crayfish positively correlates with their size, with broods typically comprising anywhere from 300 to 1000 eggs per individual.
The female carries the eggs beneath her abdomen, utilizing her pleopods to ensure their cleanliness and adequate aeration. The incubation period for the eggs varies based on temperature, with hatching typically occurring within 6 to 8 weeks. During the embryonic development phase, the eggs undergo a colour transition from green to brown and eventually orange. Notably, Red Claw Crayfish do not have free-living larval stages; instead, their larvae develop within the confines of the eggs. Despite a relatively high hatching rate of around 85-90%, survival to the juvenile stage is markedly lower.
Newly hatched juveniles are wholly reliant on their mother for the initial 7-10 days of their existence. Subsequently, they begin to assert independence and typically depart from their mother's care within 1-3 days, emerging as miniature adults capable of self-sufficiency. It is noteworthy that instances of cannibalism among brooding females and their offspring are generally rare.
During the juvenile stage, these young Crayfish necessitate an ample supply of phytoplankton and zooplankton as essential dietary components. In the absence of a suitable diet, juveniles may resort to cannibalism, resulting in a limited number of survivors. Furthermore, during the early stages of juvenile development, they remain vulnerable to cannibalism from recently moulted individuals, and larger Crayfish may prey upon smaller counterparts. The frequent moulting observed among juveniles, coupled with competitive resource dynamics leading to size hierarchies, exacerbates the potential for cannibalistic behaviour.
Diet & Feeding
Red Claw Crayfish are renowned for their omnivorous nature and remarkable opportunistic feeding behaviour. This proclivity allows them to consume virtually any edible substance they encounter within their habitat.
Adult individuals of this species demonstrate adaptability to a relatively low-protein diet, which can include a substantial portion of cost-effective plant material. However, it is essential to exercise caution when applying such dietary preferences to hatchlings and juveniles. For these early life stages, a diet primarily composed of zooplankton is considered optimal.
In a captive setting, achieving the most favourable growth outcomes for Red Claw Crayfish necessitates a balanced and varied diet, encompassing both animal-based proteins and vegetation. This dietary regimen should be specially formulated to encompass the requisite protein content to support their nutritional needs.
