Ucides cordatus
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Ucides cordatus with Rhizophora leaf. Estuary of the Rio Caeté , Bragança , Pará , Northern Brazil |
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| Ucides cordatus | ||||||||||||
| L. |
Ucides is a crab art from the family Ucididae . It lives in the mangrove forests of Central and South America .
Description and system
Fully grown U. cordatus reach a carapace width of> 8 cm. The carapace is whitish or bluish, the legs and the tips of the scissors are dark reddish or purple. Males differ from females in that they have more powerful claws and the evenly tapered (rounded-wide in females) abdomen folded under the body .
The existence of 2 subspecies is discussed:
- Ucides cordatus cordatus with distribution on the Atlantic coasts from Florida / USA to Uruguay
- Ucides cordatus occidentalis with distribution along the Pacific coast from Baja California / Mexico to Peru .
ecology
U. cordatus feeds mainly on the fallen leaves of the mangrove trees ; Leaves from trees of the genus Rhizophora are preferred. In the event of danger or flooding and during the molting phase, the crab retreats into a self-dug tunnel in the mangrove mud. The corridors can reach a depth of> 1 m. Natural enemies of U. cordatus are birds, mammals (for example crab raccoons , Procyon cancrivorus ) and some fish. Mangrove crabs grow slowly and only reach sexual maturity after several years.
The breeding period of U. cordatus is tied to certain seasons . Mating behavior and spawning are determined by the cycle of the moon within the breeding season. During the search for a partner, the otherwise shy and rather sluggish mangrove crabs are very active. Spawning takes place at high tide in the flooded mangrove. The early larval stages are pelagic ; they drift into the coastal waters and only return to the mangrove after several moults when they reach the last larval stage ( megalope ).
Human use, exposure and protection
Ucides cordatus is valued as a delicacy in some areas. They are collected by hand or caught in net traps. Due to habitat destruction, disease and possibly overfishing , mangrove crabs have become rare in some regions. In order to protect the species, for example, there are legal regulations in Brazil that stipulate a minimum catch size, prohibit catching females and prohibit collecting during the breeding season.
literature
- K. Diele: Life history and populations structure of the exploited mangrove crab Ucides cordatus (L.) (Decapoda: Brachyura) in the Caeté estuary, North Brazil . ZMT Contributions 9, Center for Tropical Marine Ecology, Bremen 2000. ISSN 0944-0143 .
- K. Diele, DJB Simith: Salinity tolerance of northern Brazilian mangrove crab larvae, Ucides cordatus (Ocypodidae): Necessity for larval export? Estuarine, Coastal and Shelf Science. 2006 in press. ISSN 0272-7714 .
- M. Glaser, K. Diele: Asymmetric outcomes: assessing central aspects of the biological, economic and social sustainability of a mangrove crab fishery, Ucides cordatus (Ocypodidae), in North Brazil . Ecological Economics 49, 2004, pp. 361-373. ISSN 0921-8009 .
- I. Nordhaus, M. Wolff, K. Diele: Litter processing and population food intake of the mangrove crab Ucides cordatus in a high intertidal forest in northern Brazil . Estuarine, Coastal and Shelf Science 67 (1-2), 2006, pp. 239-250. ISSN 0272-7714 .
