Behavior and activity pattern of Minuca osa (Brachyura: Ocypodidae) from Ponuga, Veraguas, Panama Behavioral features of Minuca Osa crabs

Abstract

From November 2022 to February 2023, observations to describe the behavior and the activity pattern of Minuca osa were conducted in Ponuga, Veraguas, Panamanian Pacific. Quadrants (5m²) over four substrate types were also laid and the number and burrow diameter were recorded for density and relative fiddler crab associations to the substrate. Nine discrete behaviors were observed, with feeding and locomotion being the most frequent. There was a significant difference in elapsed time and frequency proportions among behaviors. Combat and waving were male-exclusive behaviors, and more time was spent waving than in combat. Behaviors were displayed non-randomly throughout the observation period with highest frequency between 10:30 a.m. and 12:30 p.m. The sex ratio was skewed towards males (2.4:1), while the carapace width of males and females averaged 23.40 mm and 18.42 mm, respectively. Quadrants covered with Hymenocallis littoralis had the most burrows (20.45 burrows/m²) with the smallest diameter, while the largest diameter burrows were found in mixed-cover quadrants. Maximum temperature and monthly accumulated rain significantly influenced the number of active crabs on the surface.