Tuesday, 3. February 2009, 0:03
Text: Monika Rademacher
Photography: Oliver Mengedoht
Translation: Ulrike Bauer
[attachment=8230]
more pics: http://www.panzerwelten.de/v/Uca/U_tangeri/
Scientific name: Uca tangeri
Trivial name: European Fiddler 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: Ocypodoidea, family: Ocipodidae (fiddler crabs), subfamily: Ocypodinae, genus: Uca, subgenus: Uca, species: Uca tangeri
Origin/range: Eastern Atlantic (Portugal, Southern Spain to Angola/Africa)
[attachment=8231]
Description: Dark carapace with purple areas (mandibles, gill areas) and white dots, very fine indentations under the long eyestalks, green eyes, legs purple to beige/orange, claws orange, male's dominant claw with white tip.
Sex differences: Typical for crabs, the males have a narrow, wedge-shaped abdominal apron, the females have a wide, rounded apron and more delicate claws; Ucas can however also be sexed on their claws: the males have one very large claw, which can (depending on the Uca species) constitue up to 75% of their entire body mass.
[attachment=8232]
Males (l.) have a pronouncedly dominant claw, …
[attachment=8233]
…females only their two paddle-shaped claws they dig in the sediments with - and besides that a wide apron covering the entire abdomen.
Size: carapace width up to 6 cm
Life span: a few years
Temperature: 18 to 32 °C substrate temperature (below 18 °C the crabs retreat to their burrows and stay there until the temperatures rise again)
Tank size/stock: Colonial animals, keeping several pairs is highly recommendable; up to four pairs in a 1-meter tank.
[attachment=8234]
Fiddler crabs are social animals and should always be kept in groups, never alone!
Tank set-up: (Shallow) aquarium with sand and a maximum of 3 to 4 cm high water (fiddler crabs can actually drown!). Swamp plants, cork, stones and so on are possible on the land part, brackish water!
Food: Microorganisms, algae and detritus, fishbones
• Calcium: cuttlebone, smashed eggshells or powdered calcium in self-made food
[attachment=8235]
Behavior: Not especially aggressive towards con-specifics, these crabs sometimes sit still in concealment or in their caves for hours or even days, like to burrow. Dirunal.
Reproduction: They release their larvae into the sea, where they need several weeks during which they go through several larval stages, from zoean over megalopan stages to small crabs, then they return to the land.
[attachment=8236]
Socialization: It ought to be possible to keep several Uca species together in a sufficiently large tank with substrate that allows them to burrow. It is still unknown so far if large species like U. tangeri can successfully be socialized with small species like e.g. U. focipata, though.
[attachment=8237]
Additional information:
• Males are territorial and sometimes mark their patches with the mudballs they discard as indigestive from their food sorting area. Notably the males sometimes fight - especially about burrows or females - however, these fights seldomly result in lesions and have almost never a deadly outcome, they could rather be described as show fights.
• According to literature, they live on sandy ground in nature, bordering on salty water, as well as on salt meadows; they are rarely found on the open sea coast.
• Their burrows are up to 30 cm deep, when the tide is high they plug up their hole with a lid of chewed substrate up to 10 cm thick. The individuals' burrows can be interconnected with those of others. During low tide, the crabs leave their burrows in order to eat. The males spend up to 1.5 hours per low tide by marking their territory with the help of little mudballs.
[attachment=8238]
Links:
• http://www.fiddlercrab.info/u_tangeri.html
[attachment=8239]
Members after a molt often have a light yellow tint instead of a dark purple one.
[attachment=8240]
Ucas not only like to dig, they also live in those burrows.
![[Bild: 26d566d60eb54a9f937e0785ed8ff94d]](http://vg01.met.vgwort.de/na/26d566d60eb54a9f937e0785ed8ff94d)
Photography: Oliver Mengedoht
Translation: Ulrike Bauer
[attachment=8230]
more pics: http://www.panzerwelten.de/v/Uca/U_tangeri/
Scientific name: Uca tangeri
Trivial name: European Fiddler 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: Ocypodoidea, family: Ocipodidae (fiddler crabs), subfamily: Ocypodinae, genus: Uca, subgenus: Uca, species: Uca tangeri
Origin/range: Eastern Atlantic (Portugal, Southern Spain to Angola/Africa)
[attachment=8231]
Description: Dark carapace with purple areas (mandibles, gill areas) and white dots, very fine indentations under the long eyestalks, green eyes, legs purple to beige/orange, claws orange, male's dominant claw with white tip.
Sex differences: Typical for crabs, the males have a narrow, wedge-shaped abdominal apron, the females have a wide, rounded apron and more delicate claws; Ucas can however also be sexed on their claws: the males have one very large claw, which can (depending on the Uca species) constitue up to 75% of their entire body mass.
[attachment=8232]
Males (l.) have a pronouncedly dominant claw, …
[attachment=8233]
…females only their two paddle-shaped claws they dig in the sediments with - and besides that a wide apron covering the entire abdomen.
Size: carapace width up to 6 cm
Life span: a few years
Temperature: 18 to 32 °C substrate temperature (below 18 °C the crabs retreat to their burrows and stay there until the temperatures rise again)
Tank size/stock: Colonial animals, keeping several pairs is highly recommendable; up to four pairs in a 1-meter tank.
[attachment=8234]
Fiddler crabs are social animals and should always be kept in groups, never alone!
Tank set-up: (Shallow) aquarium with sand and a maximum of 3 to 4 cm high water (fiddler crabs can actually drown!). Swamp plants, cork, stones and so on are possible on the land part, brackish water!
Food: Microorganisms, algae and detritus, fishbones
• Calcium: cuttlebone, smashed eggshells or powdered calcium in self-made food
[attachment=8235]
Behavior: Not especially aggressive towards con-specifics, these crabs sometimes sit still in concealment or in their caves for hours or even days, like to burrow. Dirunal.
Reproduction: They release their larvae into the sea, where they need several weeks during which they go through several larval stages, from zoean over megalopan stages to small crabs, then they return to the land.
[attachment=8236]
Socialization: It ought to be possible to keep several Uca species together in a sufficiently large tank with substrate that allows them to burrow. It is still unknown so far if large species like U. tangeri can successfully be socialized with small species like e.g. U. focipata, though.
[attachment=8237]
Additional information:
• Males are territorial and sometimes mark their patches with the mudballs they discard as indigestive from their food sorting area. Notably the males sometimes fight - especially about burrows or females - however, these fights seldomly result in lesions and have almost never a deadly outcome, they could rather be described as show fights.
• According to literature, they live on sandy ground in nature, bordering on salty water, as well as on salt meadows; they are rarely found on the open sea coast.
• Their burrows are up to 30 cm deep, when the tide is high they plug up their hole with a lid of chewed substrate up to 10 cm thick. The individuals' burrows can be interconnected with those of others. During low tide, the crabs leave their burrows in order to eat. The males spend up to 1.5 hours per low tide by marking their territory with the help of little mudballs.
[attachment=8238]
Links:
• http://www.fiddlercrab.info/u_tangeri.html
[attachment=8239]
Members after a molt often have a light yellow tint instead of a dark purple one.
[attachment=8240]
Ucas not only like to dig, they also live in those burrows.