PANZERWELTEN-FORUM

Text: Monika Rademacher
Photos: Oliver Mengedoht
Translation: Ulli Bauer

Scientific name: Oziotelphusa ceylonensis

Trivial name: Indian freshwater crab

Systematics: Domain: Eucaryota, kingdom: Animalia, subkingdom: Metazoa (multiple-celled animals), Eumetazoa (true tissue), grade: Bilateria, branch: Protostomia, infrakingdom: Ecdysozoa (molting animals), phylum: Arthropoda (jointed-leg invertebrates), subphylum: Crustacea, class: Malacostraca (higher crustaceans), superorder: Eucarida, order: Decapoda (ten-legged crayfish), suborder: Pleocyemata, infraorder: Reptantia, section: Brachyura (true crabs), superfamily: Gecarcinucoidea, family: Parathelphusidae (Sri Lankan freshwater crabs), genus: Oziotelphusa, species: Oziotelphusa ceylonensis

There are 15 species in the genus Oziothelphusa, differing only slightly respectively not at all by outward characteristics, that can only be exactly told apart by an examination of the gonopods (male sexual organs) or by a DNA analysis.

Origin/distribution: Sri Lanka and Southern India, often in rice fields, but also in tunnels on rivers, canals and water reservoirs; "near threatened" in the Red List of Endangered Species.



More pix: http://www.panzerwelten.de/v/Oziothelphusa/

Description: Orange-brown hues with dark spots on the back, abdomen noticeably lighter.

Sex differences: Typical for crabs, the males have a narrow abdominal apron and unequal claws, females have a wide apron and smaller claws.

Size: Carapace at least up to 6 cm wide.

Life span: ? (several years)

Water temperature: tropical (around 20 to 28 °C, more active from 24 °C upwards)

Tank size/stock: From 60 cm tank length for a pair, better are 80 cm for a small group which should always consist of more females than males.

Tank set-up: Aquarium with a small land part (if you plan to breed them) and/or wood, rocks and stable plants; well-structured with hideouts (wood, stones), fallen tree leaves (as hideaway and staple food).

Food: Typical for crabs, they are omnivores.
• Leaves (the main staple of many crabs in nature; mostly oak and beech are fed, however, all European broadleaved tree leaves are possible, also Indian almond leaves), muck, water plants
• Vegetables/fruit: nearly all vegetables and fruit are suitable (peas, lettuce, cucumber, apple, zucchini, pear, banana, grapes, tomato, Brussels sprouts, bell peppers) except for parsley and beans or other kinds that contain Prussic acid or copper; carrots (boiled); potato and rice (boiled) or noodles (uncooked? Don't leave these in the tank for too long a time though, they can be the cause of turbid water and finally lead to a bacteria bloom and oxygen depletion); no citrus fruit due to their high acid content
• Dry food: Catfish tabs, fish (flake) food, food pellets, rabbit, guinea pig and chinchilla food pellets (without copper!), Spirulina tabs, crayfish tabs, Gammarus
• Frozen food: Black, glass and blood worms, Cyclops, brine shrimp, clam meat
• Live food: Earthworms (it's best to cut them into pieces though, or else these worms might burrow in the substrate, possibly also under water, die and rot there unnoticed until it's too late)
• Meat (rarely): Chicken bones with meat rests (rinsed well to prevent too much fat from getting into the terrarium)
• Fish: deep-frozen smelts et.al., tuna fish, sardines, herring etc. fresh or from a can (in their own juice, not in oil)
• Calcium: cuttlebone, smashed eggshells or powdered calcium in self-made food sticks

Behavior: Relatively peaceful, like to sit at close quarters from time to time, live practically exclusively under water (except if they reproduce), however, they like to catch some air on a piece of wood or a sturdy plant; not very shy, shred many aquarium plants.

Reproduction: specialized reproduction in freshwater with fully developed juvenile crabs instead of larvae; the female burrows into the ground a few days after mating on the land part and only resurfaces after several weeks together with the young crabs.

Socialization: Shrimp, snails (smaller specimens might be eaten from time to time), guppies; not with neon tetras or ground-dwelling fish, angelfish and armoured catfish are said to be predated on, too.





Additional information:
• When two crabs of this species died on us, unfortunately we found roundworms they had obviously brought with them from the habitat. If these worms were the reason for their deaths or just surfaced due to their molts gone awry cannot be said for sure.

• We currently have five of these crabs (2 m, 3 f) in a 120 cm long tank. They live together relatively peacefully, are also active during the day and very gluttony. You can even lift them out of the water when they hang on to a pair of tweezers with food, they hardly ever let go. To catch some air, from time to time they like to sit on wood or sturdy plants that reach to the surface. They burrow under rocks and wood and also like a climb.

• Scientific revision: A revision of the genus Oziotelphusa Müller, 1887 with descriptions of eight new species


Female (very clear: the wide abdominal apron)

Greed Three males peacefully in one spot Mating