Neohelice granulata burrow fidelity behaviour related to landscape heterogeneity

Abstract

Neohelice granulata provides an interesting animal model for studying behavioural process because it is widely distributed, ensuring variability related to different environmental conditions. The aim of this study was to analyse variation in site fidelity with relation to landscape heterogeneity. Field observations were carried out in three geographically distant marshes in Argentina (Mar Chiquita, San Antonio Oeste, and Riacho San José), which differ in their environmental characteristics and where crabs display different reproductive strategies. We analysed potential variation in burrow fidelity with relation to body size, sex and presence of vegetation (mudflat and saltmarsh) at all study sites. In addition, we analysed the influence of tidal flooding on fidelity in the Mar Chiquita saltmarsh. To achieve these goals, we used a mark-recapture method in which we tagged approximately 100 crabs during midsummer for each zone at each site (a total of 668 crabs) for geographical comparison and approximately 370 crabs to evaluate the influence of tidal flooding. We found more faithful individuals in Mar Chiquita than in San Antonio Oeste and Riacho San José. For the San Antonio Oeste and Riacho San José populations and for Mar Chiquita previous to flooding samples we also found differences in site fidelity related to crab body size. At San Antonio Oeste and Riacho San José the relationship between size and proportion of faithful crabs was negative (smaller crabs were more faithful than larger crabs). In Mar Chiquita, a higher proportion of fidelity previous to flooding and a size-dependent response to flooding were detected, suggesting that fidelity may be modulated by tides having different effects on crabs with different body sizes. Equal proportions of males and females displaying site fidelity were observed at all study zones and sites. Our study suggests that N. granulata burrow fidelity behaviour changes with latitude and landscape (mudflat or saltmarsh) and can be sensitive to variables such as body size and frequency of flooding.

Segregation by size in the mouthless crab Cardisoma crassum (Brachyura: Gecarcinidae) from Ponuga, Veraguas, Panama

“…Habitat complexity, conferred by vegetation cover in plots 2 and 3, may provide protection against predators due to reduced access (Almeida et al 2008). Benefits from the protective role of vegetation cover in plot 1 are less obvious, provided that the undergrowth is sparse and may not present the same challenge for potential predators as the vegetation in plots 2 or 3; however, burrow fidelity in this species (Lombardo & Rojas, 2022) might offset potential costs (Moraes-Costa & Schwamborn, 2018;Nuñez et al 2018).…”

Regenerative bioturbation by intertidal burrowing crabs modifies microphytobenthic composition and enhances primary production in SW Atlantic mudflats

“…However, crabs inhabiting mudflats change their trophic mode to deposit feeding (Botto et al 2005, Alberti et al 2011, and their burrowing activity is concentrated in patches that exhibit high variation both in areal extent and temporal stability (Botto & Iribarne 1999, Iribarne et al 2005. This is partially explained by the high mobility rate among patches in short periods (Luppi et al 2013) and also by the low site fidelity that this species shows (Nuñez et al 2018).…”