Today we are going to talk about the blue lobster. It is a crustacean that belongs to the Parastacidae family. Its scientific name is Cherax quadricarinatus (also known as redclaw or Australian freshwater lobster). It is one of the best-known species in aquariums and aquaculture. within the genre cheraxTherefore, we will dedicate the entire post to it.
Below you will find the characteristics, eating, reproduction, comportamiento, aquarium care, distribution and more information about the blue lobster, integrating practical and up-to-date data, and comparing with the characteristics of the red lobster.
Key features
The body of the blue lobster is divided into two parts. On one side, the abdomen (pleon) is the area where the tail is located and, on the other hand, the cephalothorax, where the thorax and head are located. It is covered by an exoskeleton or shell that protects and supports it. to the internal organs, which is periodically renewed through molting.
His face ends in a shape pointed (rostrum), with small lateral spines typical of the genus. Of the cabeza The compound eyes stand out, mounted on prominent peduncles. Sight is not its primary senseTherefore, it relies on long antennae and antennules to orient itself, explore its surroundings, and locate food.
As for the antennae, their tips are sharp and sensitive. It also has antennules chemoreceptors that it uses for touch and taste. Thanks to these sensory tools It is capable of detecting food, shelters and assessing water quality (temperature, pH and even changes in salinity in slightly brackish environments).
The lower part of the cephalothorax presents five pairs of legs (decapoda)The first pair forms the tweezers or flailswhich it uses to defend itself, capture food, and manipulate objects. The second and third pairs end in smaller pincers. with which it manipulates food. The last two pairs are walking legs that provide support and traction on the substrate.
The abdomen (pleon) is segmented and each segment has small fins (pleopods) on the ventral side, which aid both swimming and buoyancy egg incubation in femalesIt ends in a caudal fan whose central segment is called on the phoneessential for quick escape movements.
Description
They are usually of a big size, reaching the 25cm lengthAn average blue lobster can weigh around 500 gramsThis makes it one of the largest freshwater crayfish used in aquariums and aquaculture. Approximately 25% of body weight is in the tail, which is why it is the part of greatest culinary interest; its meat is prized and firm.
Unlike other species of lobster, Cherax quadricarinatus presents a body in shades of blue which can vary from light to dark blue, with brown, gray, yellow, or reddish undertones depending on age and physical condition. A [color/color] is usually seen all over the body fine whitish or yellowish dots characteristic of the genre.
The Males They have tweezers with two Red spots (redclaw) visible on the outer edge, and may show reddish markings on the pleon; the females They are distinguished by longer and "hairier" pleopods. The intensity of the color It depends on sex, age, health, genetics, water quality and molting frequency; Larger specimens tend to have darker colors.
Like other decapods, sheds the exoskeleton to grow. During that period it becomes softer and more vulnerable, therefore it requires hiding places and absence of stress; often reuses its exuvia as a source of minerals (calcium and magnesium) to harden the new shell.
Behavior of the blue lobster
The natural environment of this crustacean is the rivers and freshwater lakesIn drought-prone regions, some watercourses They greatly reduce their flow and even dry out in sections; to alleviate this situation, The blue lobster gathers in pools that conserve water and shelter.
If the river's dryness leaves it exposed and it doesn't reach pools, digs burrows in the mud to bury themselves and wait for new rains to restore the flow. Thanks to this strategy, they can survive long periods of drought in relative diapause within the substrate.
Prefer rocky or muddy bottoms of middle and lower reaches of rivers, as well as swamps and backwaters It has some depth, with logs, rocks, and hollows where it can hide. It is an organism benthic that roams the bottom in search of food and shelter.
It is one of the less aggressive crustaceans inside the large crayfish. It gets along well with fish of similar or larger size.although it can prey on very small or slow fish and snails. Presents primarily nighttime activityDuring the day it stays in its den; at dusk it goes out to forage.
Su Life expectancy In captivity it ranges around 2–3 years With good care. In the wild and depending on the conditions, there are records of variable longevities, associated with habitat quality and predator pressure.
Meals
Their natural diet is based on decomposing plant material (detritus) that it finds at the bottom of rivers and lakes. It also consumes fresh vegetables, seeds, invertebrates and small fish when opportunities arise.
By ingesting detritus, it incorporates bacteria and fungi associates that result very nutritious and rich in proteincomplementing its omnivorous profile. Its digestive system can digest meats and vegetablesand efficiently utilizes plant-based ingredients.
It accepts aquariums and cultivation commercial feed For shrimp/decapods. For balanced growth, the following are recommended: diets with 31% protein in juveniles and around 27% in adultsIdeally, food should be offered in the afternoon/evening to match their activity level.
- Vegetables: zucchini, spinach, shelled peas, blanched lettuce leaves.
- Proteins: shrimp feed, gammarus, mussel/fish pieces, freeze-dried Artemia.
- Mineral supplements: cuttlefish shell or calcium preparations to support hardening of the exoskeleton after the molt.
Avoid excesses so as not to compromise the water quality and remove any leftovers. A varied diet promotes intense colours and good development of the chelae.
Reproduction of the blue lobster
The blue lobster reproduces 1 to 4 times a yearwith marked seasonality depending on temperature and availability of shelters. rapid growth from birth and reaches sexual maturity Generally between 6 and 12 months, depending on conditions.
After the procession, the male deposits spermatophores near the sternal region of the female. She produces the ova, which fertilize with sperm and adhere to the pleopods through fine hairs that help to hold and ventilate them.
Each clutch can contain between 200 and 1000 eggsAccording to the size, age, and body condition of the female. incubation usually lasts 4–6 weeksDuring that period the female airs and cleans The eggs are laid using abdominal movements. Unlike lobsters, the offspring of cherax are born well developed and without a planktonic phase, remaining with the mother for a few days before becoming independent.
To encourage breeding in aquariums, it offers multiple sheltersGood quality water and a stable temperature within the warm range are recommended. After hatching, it is advisable to separate juveniles as adults and feed them micro-pellets and tender vegetables. Keep stable parameters It reduces the loss of eggs and fry.
Taxonomy and classification
- Reino: Animalia
- Phylum: Arthropoda
- ClassMalacostraca
- OrderDecapoda
- Infraorder: Astacidea
- Superfamily: Parastacoid
- Family: Parastacidae
- Gender: cherax
- Species: Cherax quadricarinatus
Its common names The most widespread are blue lobster, Australian freshwater lobster and redclawIn the literature, no current taxonomic synonyms are used for this species, and in aquariums, it is common to confusion with other species of cherax (e.g., C. cainii o C. destroyer) and with the lobsters (family Palinuridae), which do not have large pincers.
Distribution and biotope
It is originally from Northern Australia and the southern New Guinea. For her gastronomic value y ease of cultivation It has been widely introduced into other countries, establishing populations in favorable environments, including regions of South America with records in Uruguay y Argentina, among others.
It lives in its natural environment slow-moving riversbackwaters, Lagoons and channels with sandy, muddy, or gravelly bottoms, abundant in hiding places and marginal vegetation. In dry periods it may remain crowded into pools resistant to desiccation, and withstands moderate variations in parameters thanks to its ecological plasticity.
Aquarium parameters and maintenance
For your well-being, it is recommended to spacious aquariumWith one copy or a pair, a volume of 120–150 liters It's excellent; it can also be kept in smaller tanks (e.g., 40–60 liters per individual) if there is good filtration and shelters, understanding that the finished size and stability The system will improve with more water.
- Temperature: withstands 18–31 °C; typical optimum range 25–27 °C.
- pH: Of 7,0 to 8,5 (neutral to basic).
- Hardness: GH 15–25 dGH, KH 10–18 dKHThe hardness promotes good postmolt hardening.
- Oxygen: levels higher than 5 mg / Lgood aeration and surface movement.
decorate with logs, caves, rocks and ceramic/PVC pipes that provide shelter. substratum It can be fine sand or gravel that allows them remove and arrange the environment. The natural plants They are usually nibbled or pulled out; if you want vegetation, opt for java moss or fern anchored on elevated surfaces.
Avoid very small or sleepy companions, as well as other crustaceans that compete for hiding places. With medium/large fish of peaceful temperament Coexistence is usually good if there is space. Provides secure lidThey are able to climb and escape through cables or pipes.
Health, diseases and biosecurity
As a decapod of aquaculture interest, it is important disease prevention. and biosecurity in their management. Pathogens that can affect species of have been documented cherax and other crustaceans, so extra caution is advised:
- Virus: bacilliform and rheo-like complexes in cherax; they have also been reported WSSV (White Spot Syndrome) in susceptible crustaceans.
- Microsporidia: Thelohania (porcelain disease), Vairimorpha, Pleistophora.
- Bacteriagenres such as Aeromonas, Vibrio, Pseudomonas and other opportunists in conditions of stress or poor water quality.
- Mushrooms: Saprolegnia, Fusarium, among others, generally after injuries or problematic molting.
Good practices: quarantine of new specimens, efficient filtration, regular water changes, control of ammonium/nitrites at zero, good ventilation and avoid overcrowdingIn areas where the species is exotic, avoid any release into the natural environment and adjusts management to local recommendations for potentially invasive species.
Aquaculture and responsible management
Cherax quadricarinatus It is a species with complete crop biotechnologyraised in systems intensive and semi-intensiveIn ponds with refuges, moderate densities (e.g., on the order of 5–15 org/m² (depending on management) and formulated feeding, the following are achieved survival rates and interesting growth. The youth teams of 10-15 g They are common for planting and the cycle can be completed in months with good handling.
They work well in diets. plant-based feeds Soybeans, sunflower seeds, wheat, or corn with adequate protein content, since It has good digestibility. made with plant-based ingredients. Apply to any system. biosafety protocols (HACCP, quarantines, escape control) and comply with the regulations in force is essential.
Interesting facts and behavioral notes
Like other decapods, it can regenerate limbs Losses in subsequent molts, an advantage against injuries or attacks. Its escape movement consists of rapid tail contractions that propel it backwards to escape predators.
Although the production of sounds by stridulation is well known in lobsters, in cherax can be observed mechanical signals (tapping or snapping with the chelae) as part of the warning and courtship language. In aquariums, their Activity begins at sunsetwhich makes it especially entertaining at twilight hours.
Finally, remember that It does not form mass migrations like reef lobsters: their natural behavior is territorial and short radius In the background, there are local movements in search of food and shelter.
With all of the above, you now have a complete guide to recognizing the blue lobster and identifying its morphological features, understand your comportamiento, plan a balance diet, reproduce it with to maximise security and your enjoyment. and keep stable parameters in the aquarium, incorporating biosecurity practices and responsible management that ensure their well-being.
