Type — Arthropoda.
Subtype — Crustacea.
Class — Malacostraca.
Order — Decapoda.
Superfamily — Astacoidea
Family — Cambaridae.
Genus Cambarellus.
— Cambarellus patzcuarensis sp. Orange (CPO) [Villalobos, 1943] — Mexican Orange Dwarf Crayfish, Mandarin Crayfish, Lake Pátzcuaro Dwarf Crayfish. “Mexican Orange Dwarf crayfish”, “Orange Dwarf crayfish”. Mexico, Lake Pátzcuaro. A typical crayfish form with an elongated body, moderately sized claws (sometimes larger in males), and relatively short antennae. Females grow up to 6 cm in length, males 4-4.5 cm.
Its wild color ranges from light brown to dark brown, but breeding programs have developed a reddish-orange form. Good selective breeding lines feature a dark orange coloration with stripes or spots. The dorsal area is darker. Females have short, narrow claws, while males have long, lanceolate ones. When encountering other crayfish, males threateningly extend their claws forward. Color morphs include: — C. patzcuarensis sp. Choco – brown; — C. patzcuarensis sp. Black – black; — C. patzcuarensis sp. Blue – blue; — C. patzcuarensis sp. Light Yellow – light yellow;
No other crayfish is as well-suited for a small or medium community aquarium, if only because of its striking coloration. However, more significant advantages are its small size, lack of gastronomic interest in live plants, and exceptional peacefulness toward conspecifics and neighboring fish. An aquarium of at least 50 cm in length is required, with 30 liters per pair, featuring stones and driftwood dividing the area into separate territories, each containing shelters and hiding spots for the crayfish. They love to hide under roots or between leaves.
As a substrate, it is best to use dark, fine gravel: it highlights the color of the orange crayfish very well. The substrate layer should be at least 4 cm thick. The aquarium should be well-planted (e.g., with Java fern, freshwater algae, and mosses). Also, do not forget about driftwood—a multitude of microorganisms settle on their surfaces, which are essential for feeding baby crayfish. Such a “pasture” is just as attractive to the juveniles as dense patches of Riccia or Monosolenium. They can be kept in unheated aquariums.
These crayfish are quite aggressive among themselves, especially the males, which are more territorial than females. It is not recommended to keep crayfish in large numbers: as known, crayfish are not colonial creatures, especially males. Older specimens hide for most of the day, being more active during dark hours. Therefore, the aquarium should be larger, keeping 1 male and several females. Fish should be small and peaceful. They may hunt small bottom-dwelling fish.
They are omnivores that feed on carrion in natural ecosystems, as well as plant matter and small remains of invertebrates and fish. Everything that fits into a crayfish’s small claws is eaten: mosquito larvae, snails, detritus, decaying leaves, dead fish, etc. However, healthy green plants are not part of the menu; only decaying parts are eaten. Optimum temperature is 20-24°C. They require hard water dH 12-18°, pH 7.0-8.5. Weekly 25% water changes are mandatory.
Sexual maturity occurs at the age of 3-4 months at a size of 1.5-2 cm. Since crayfish live for only one to two years, early maturity makes sense. Reproduction is straightforward if water parameters in the aquarium are good. During mating, the male overpowers the female, subduing her with his claw to transfer sperm. Females carry eggs for about three weeks. During this time, they seek shelter and defend it from everyone. When breeding, supplementing with dry beech, oak leaves, and alder cones is mandatory.
Fry emerge at about 4 mm in size, and they are very sensitive to temperature changes and water parameter fluctuations. Coexistence of juveniles with parents is possible in an aquarium with plenty of hiding places. Lifespan is about 18 months. Therefore, it is necessary to keep several crayfish for breeding and maintaining a healthy population. The related species C. shufeldtii (Shufeldt’s dwarf crayfish) is morphologically almost identical and has similar care requirements.
Identification: Mexican Orange Crayfish — Cambarellus patzcuarensis.
— Cambarellus puer [Hobbs, 1941] — Cajun Dwarf Crayfish. “Cajun dwarf crayfish”. North America, Mississippi River. In nature, females grow up to only 3-4 cm in length, and males barely reach 2-2.5 cm. Freshwater. Outwardly very similar to Cambarellus shufeldtii.
Both range from red and red-brown to gray and gray-brown, with paired dark, wavy stripes or a dotted line along the dorsal surface. The tail usually has a dark spot in the center. Their claws are narrow and long. Belongs to the more peaceful dwarf crayfish. Fighting is rare; usually, animals flee into shelters. It is best to keep 2 females per 1 male.
The aquarium volume should be at least 60 liters for five to six crayfish (with a predominance of females), with plenty of driftwood and stones, and hollow bricks to divide territories. A very peaceful creature that gets along wonderfully in the same aquarium with small, non-aggressive fish. Diffuse lighting is recommended. Substrate of sand or fine gravel. A layer of dried oak leaves should be placed over the main substrate layer.
Constant aeration and filtration are mandatory: these crayfish are extremely sensitive to dirty water. Aeration is especially necessary at night. Requires weekly 25% aquarium water changes. They love boiled shrimp, bloodworms, Artemia, rotifers, mealworms, marine fish meat, scraped beef, snails, and will gladly eat sinking pellet food. The pond snail Physa is a good treat for them.
Sexual maturity occurs at about 3 months. The female carries up to 50 eggs. The pregnant female secludes herself and reappears after the young reach 1-2 weeks of age. To raise young crayfish, oak leaves, almond tree leaves, and alder cones are necessary. They eagerly hide under roots or between fallen leaves. Regular water changes are very important for successful breeding. They live for about 2 years. pH 6.5-7.8; dH 4-15°; T 20-23°C.
— Cambarellus shufeldtii [Faxon, 1884] — Shufeldt’s Dwarf Crayfish. North America, Mississippi River. During the dry period, it spends time burrowed in the mud. 3 cm. These crayfish are reddish-brown to gray, with dark dots in irregular rows, or paired dark, wavy stripes along the dorsal surface. Females are larger, wider, more intensely colored, and have a greater number of dark spots. Females also have a slight blue tint in places. Very similar to Cambarellus puer, but usually has a dark central spot, and the claws are narrow and long.
This species is the most peaceful, yet lives quite secretively. Young crayfish are active and move both along the substrate and among plants. They almost never fight among themselves; the more timid one usually yields. Due to their size, they cannot pose a danger to fish, but rather the opposite. They can be kept in a group of several individuals even in a small aquarium.
The aquarium must have plenty of shelters and plants, as females eagerly hide there while carrying eggs and releasing the young. Shelters in driftwood or stones should have a maximum diameter of at least 15 mm and a depth of at least 4 cm, otherwise they are not perceived as shelters. The crayfish does not feed on healthy plants. Water ranging from soft to hard suits them.
Reproduction is simple with good care and sufficient space, happening “on its own”. The female carries 10-30 eggs for about 4 weeks. The incubation period strongly depends on water temperature, so it is recommended to strictly maintain the temperature regime without sudden fluctuations. They live up to 2 years. pH 6.0-7.5, T 20-25°C.
Cherax boesemani, Cherax cainii.
Cambarellus diminutus, montezumae, ninae. 
