Format:
203 p. = 4074 KB, text and images
Edition:
[Electronic ed.]
Content:
Ucides cordatus, mangrove crab, feeding ecology, behaviour, diet, gut evacuation, consumption rates, assimilation efficiency, microorganisms. - The objective of this thesis was to investigate the feeding ecology of the intensively exploited semi-terrestrial crab Ucides cordatus cordatus, and to contribute to the understanding of its influence on the flow of organic matter, nutrients, and energy in a mangrove ecosystem in northern Brazil. The mangrove crab U. cordatus is the most conspicuous species of the benthos, contributing to about 84% of its biomass. Stomach content analyses showed that the crabs ́diet is mainly composed of mangrove leaves, unidentified plant material, roots, and sediment. The gut evacuation rates were used in conjunction with the mean daily gastrointestinal contents to calculate the daily food intake of U. cordatus. The daily food intake was 1.0 g dw in small males (cw 3.0-3.5 cm), corresponding to 19.8 % of the crabs ́body dry weight. Large males (cw 7.0-7.5 cm) consumed 3.3 g dw daily, corresponding to 6.0 % of their body dry weight. The overall daily food intake of the U. cordatus population at an Rhizophora mangle dominated forest stand was estimated as 4.1 g dw m-2, corresponding to 81.3 % of the daily litter and propagule production. This indicates that litter processing by U. cordatus highly influences the flux of organic matter, leading to the retention of nutrients and energy inside the mangrove forest. High litter ...
Note:
Bremen, Univ., Diss., 2004
Language:
English
Keywords:
Hochschulschrift
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