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Lee, Joe; Kwok, P. W.

doi:10.1023/a:1020175729972

Cited by 21 publications

(2 citation statements)

References 24 publications

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“…Although sesarmid crabs can rely on food sources other than leaf litter [22, 60–62], this is still the major component of their diet [see 21, 63–66]. Indeed, both shortage of litter and a diet based on litter of poor quality proved to have negative consequences on sesarmid crabs, as proved for Perisesarma messa [67] and for Parasesarma affine and Perisesarma bidens [68]. …”

Section: Discussionmentioning

confidence: 99%

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

et al. 2018

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BackgroundThe 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.ResultsThe 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.ConclusionsOur 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.

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Section: Discussionmentioning

confidence: 99%

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

et al. 2018

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“…In the K. obovata mangrove forest at Mai Po, the mean population density of P. affine was 1.39 individuals m -2 , with the mean carapace width (CW) and the mean dry weight at 18.3 mm and 1.5 g m -2 , respectively (Lee and Kwok, 2002). The N content of the crab tissues was about 6.5% of dry mass estimated according to the equation %N = 7.536 -0.059 CW established for the congener P. messa (Robertson, 2021).…”

Section: N Mass Balancementioning

confidence: 99%

Feeding Strategies of Mangrove Leaf-Eating Crabs for Meeting Their Nitrogen Needs on a Low-Nutrient Diet

Gao

Lee

2022

Front. Mar. Sci.

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Sesarmid crabs play an important role in mangrove biogeochemical processes due to their leaf-eating and burrowing activities. How leaf-eating mangrove crabs meet their nitrogen (N) needs remains a puzzle, as N-poor leaf litter (<1% dry weight) cannot support the growth of most macrofauna. Several strategies for overcoming this challenge have been proposed, but the actual mechanisms remain unknown. We identified two categories of leaf-eating crabs according to their feeding habits (1): species active outside their burrows during low tide - we hypothesize that they meet their N needs through consuming the microphytobenthos (MPB) (hypothesis H1); and (2) species spending most of their time inside burrows - we hypothesize that they meet their N needs through N-fixation by associated microbes (H2). To test H1, we conducted a series of feeding experiments on the sesarmid crab Parasesarma affine (model species for category 1) with 13C- and 15N-enriched MPB and mangrove leaves. P. affine relied mainly on mangrove leaves as their C source and MPB as their N source, supporting H1. Two feeding experiments on Neosarmatium smithi (model species for category 2) showed that N limitation could be ameliorated by selecting seasonally available higher-quality food items such as floral parts, or by supplements from the associated nitrogen-fixing bacteria, as identified by genomic analysis. The strategy by which leaf-eating crabs meet their N needs may make significant contribution both to the growth of crabs and to their ecosystem functions of regulating the cycling of significant nutrient elements. The stoichiometric regulations by leaf-eating crabs to meet their N needs, such as food selection, can enhance trophic efficiency and nutrient transfer rate at the community level and ultimately increase nutrient turnover rate at the ecosystem level.

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Populations and Communities

2021

Tropical Marine Ecology

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Untitled

Cited by 21 publications

References 24 publications

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

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

Feeding Strategies of Mangrove Leaf-Eating Crabs for Meeting Their Nitrogen Needs on a Low-Nutrient Diet

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