Paradoxical selective feeding on a low-nutrient diet: why do mangrove crabs eat leaves?

  title={Paradoxical selective feeding on a low-nutrient diet: why do mangrove crabs eat leaves?},
  author={Martin W Skov and Richard G. Hartnoll},
Abstract. Sesarmid crabs dominate Indo West-Pacific mangroves, and consume large amounts of mangrove litter. This is surprising, since mangrove leaves have high tannin contents and C/N ratios that far exceed 17, normally taken as the maximum for sustainable animal nutrition. This paradox has led to the hitherto untested hypothesis that crabs let leaves age in burrows before consumption, thereby reducing tannin content and C/N ratio. We excavated burrows of Neosarmatium meinerti within high… 
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Consumption experiments showed that the mangrove crab Neosarmatiurn smithi substantially reduce export of leaf litter by tidal transport and regenerate nutrients for other small invertebrates and the manGroves themselves, and is not a direct link in the ecosystem food chain.
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