Ciencias Marinas (2018), 44(3): 155–167 http://dx.doi.org/10.7773/cm.v44i3.2851 Burrowing activity of the Neohelice granulata crab (Brachyura, Varunidae) in southwest Atlantic intertidal areas Actividad cavadora del cangrejo Neohelice granulata (Brachyura, Varunidae) en sitios intermareales del atlántico sudoccidental Sabrina Angeletti1*, Patricia M Cervellini1, Leticia Lescano2,3 1 Instituto de Ciencias Biológicas y Biomédicas del Sur, Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad Nacional del Sur (CONICET-UNS), San Juan 670, 8000-Bahía Blanca, Argentina. 2 Departamento de Geología, Universidad Nacional del Sur, San Juan 670, 8000-Bahía Blanca, Argentina. 3 Comisión de Investigaciones Científicas de la Provincia de Buenos Aires, Calle 526 entre 10 y 11, 1900-La Plata, Argentina. * Corresponding author. E-mail:
[email protected] A. The burrowing and semiterrestrial crab Neohelice granulata actively and constantly builds its burrows in the intertidal zone of the Bahía Blanca Estuary during low tide. Differences in structural morphology of N. granulata burrows and burrowing activities in contrasting microhabitats (saltmarsh and mudflat) were analyzed and related to several conditions, such as tide level, substrate type, sediment properties, and population density. In the mudflat the higher density of total burrows in autumn (172 burrows·m–2) was associated with molt timing, and the higher density of active burrows in summer (144 burrows·m–2) was associated with reproductive migration. Sediments from biogenic mounds (removed by crabs) showed higher water content and penetrability than surface sediments (control), suggesting that bioturbation increases the values of these parameters. Grain size distribution profiles and mineralogical composition did not vary between microhabitats or between seasons.