Interference competition as a key determinant for spatial distribution of mangrove crabs

BMC Ecology

Marco Fusi¹  Sara Fratini²  Filippo Cimó²  Farid Dahdouh-Guebas³  Stefano Cannicci⁴ 

[1] Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST);Department of Biology, University of Florence;Laboratory of Systems Ecology and Resource Management, Université Libre de Bruxelles-ULB;The Swire Institute of Marine Science and the School of Biological Sciences, The University of Hong Kong;

关键词: Sesarmid crabs;    Aggressive behaviour;    Distribution patterns;    Indo-Pacific mangroves;    Environmental factors;   

DOI  :  10.1186/s12898-018-0164-1

来源: DOAJ

【 摘 要 】

Abstract Background The spatial distribution of mangrove crabs has been commonly associated with tree zonation and abiotic factors such as ground temperature and soil granulometry. Conversely, no studies were designed to investigate the role of competition for resources and predation in shaping crab distribution in mangroves, despite these biotic factors are recognised as key determinants for spatial patterns observed in the communities colonising rocky and sandy intertidal habitats.We studied floral and faunal assemblages in two zones of a Sri Lankan mangrove, a man-made upper intertidal level and a natural eulittoral, mid-shore one. Leaf choice experiments were designed to study both feeding rate and intra and inter-specific interactions for food of sesarmid crabs in the two habitats in order to better understand crab spatial distribution. Results The two intertidal belts differed in terms of floral composition and crab species abundance. The eulittoral zone was strongly dominated by Neosarmatium smithi, while within the elevated littoral fringe four sesarmids (N. smithi, N. asiaticum, N. malabaricum and Muradium tetragonum) were more evenly distributed. At both levels, all sesarmids showed to collect significantly more Bruguiera spp. and Rhizophora apiculata leaves than Excoecaria agallocha ones. There was no temporal segregation in feeding activity among the four species, resulting in a high interference competition for leaves. Regardless of the habitat, N. smithi was always successful in winning inter-specific fights. Conclusions Our results showed that the elevated littoral fringe was more crowded with crabs, but was less favourable in terms of food availability and environmental conditions. The dominance of N. smithi in gathering mangrove leaves suggests that this species may segregate the other sesarmids into less favourable habitats. The present data strongly suggest for the first time that interference competition for food can contribute to shape mangrove crab spatial distribution.

【 授权许可】

Unknown