Document of bibliographic reference 369419

BibliographicReference record

Type

Bibliographic resource

Type of document

Journal article

BibLvlCode

AS

Title

Sexual and size dimorphism in two deep-water hermit crabs (Decapoda: Parapaguridae) from the Western Atlantic Ocean

Abstract

The Parapaguridae comprises hermit crabs that inhabit deep-water environments. In these environments, shell availability can be limited, mostly consisting of small and fragile-shelled gastropods. Thus, different strategies have evolved to mitigate this limited shell supply. Sympagurus dimorphus (Studer, 1883) lives in association with a zoanthid cnidarian that creates a pseudo-shell that grows with the hermit crab. In contrast, Oncopagurus gracilis (Henderson, 1888) inhabits small, calcified gastropod shells. Therefore, we selected these two species as models to test sexual dimorphism and shape patterns of their chelipeds and cephalothoracic shield, due to their different shelter acquisition methods. We photographed the animals and digitized the images to employ comparative geometric morphometric techniques. We tested the differences in shape between the sexes within each species, and also tested sexual size dimorphism based on centroid size. For O. gracilis, we found shape differences for the chelipeds and cephalothoracic shield, however, we only observed sexual size dimorphism for the chelipeds. For S. dimorphus, an inverse pattern was found, in which females presented more robust chelipeds, and sexual size dimorphism was present in which males were larger. These differences can be reasonably explained by their shelter acquisition methods, in which O. gracilis depends on small shells that limit growth, while S. dimorphus grows with its cnidarian pseudo-shell. The robustness found in the shape patterns may also be related to their behaviors, e.g., in addition to competition for shells, they also fight during mating. However, we emphasize that future studies with other populations of these species are needed for comparative purposes.

Bibliographic citation

Candiotto, A.; Schejter, L.; da Silva, A.R. (2023). Sexual and size dimorphism in two deep-water hermit crabs (Decapoda: Parapaguridae) from the Western Atlantic Ocean. Nauplius 31: e2023026. https://dx.doi.org/10.1590/2358-2936e2023026

Topic

Marine

Is peer reviewed

true

Access rights

open access

Is accessible for free

true