A review of fiddler crabs (genus Uca Leach, 1814) in South Africa

Abstract

Fiddler crabs occur globally across tropical and subtropical coastal habitats including mangrove swamps, which are in decline worldwide. The genus has been well-studied in the Americas, Australia and Asia, whereas information on African species is scarce. This review summarises the existing literature on fiddler crabs and highlights gaps in research for species at their southernmost distribution ranges in South Africa. Biological and ecological aspects including life cycle and reproduction, feeding ecology, biotic interactions and tolerance to environmental fluctuations and pollution are discussed. The systematics and distribution of the five fiddler crab species that occur in South Africa is provided. The St Lucia estuarine lake is presented as a case study for the effects of environmental change on Uca populations. Future research should focus on less-studied Uca populations, such as those found in the Indo-Pacific region. The effects of climate change and habitat modification on Uca populations should also be more widely investigated.

Keywords: connectivity, distribution limits, larval development, life cycle, mangrove ecology