Changes in precipitation may alter food preference in an ecosystem engineer, the black land crab,Gecarcinus ruricola

Abstract

Gecarcinid land crabs are ecosystem engineers playing an important role in nutrient recycling and seedling propagation in coastal forests. Given a predicted future decline in precipitation for the Caribbean, the effects of dehydration on feeding preferences of the black land crab Gecarcinus ruricola were investigated. G. ruricola were offered novel food items of lettuce, apple, or herring to test for food choice based on water and nutritional (energetic) content in single and multiple choice experimental designs. The effect of dehydration was incorporated by depriving crabs of water for 0, 4, or 8 days, leading to an average body water loss of 0%, 9%, and 17%, respectively, (crabs survived a body water loss of 23% + 2% and 14–16 days without access to water). The results were consistent between the single and multiple choice experiments: crabs consumed relatively more apple and fish and only small amounts of lettuce. Overall, no selective preferences were observed as a function of dehydration, but crabs did consume less dry food when deprived of water and an overall lower food intake with increasing dehydration levels occurred. The decrease in feeding was likely due to loss of water from the gut resulting in the inability to produce ample digestive juices. Future climatic predictions suggest a 25–50% decline in rainfall in the Caribbean, which may lead to a lower food intake by the crabs, resulting in compromised growth. The subsequent reduction in nutrient recycling highlights possible long-term effects on coastal ecosystems and highlights the importance of future work on climate relative behavioral interactions that influence ecosystem function.

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

“…For example, crabs in plot 3 were smaller and lived under the shade of woody liana thicket, among complex root systems, in a low-elevation area along the Ponuga river shore. Small crabs in this habitat may have access to softer substratum and shallow ground water, which is critical (Nobbs, 2003;Ngo-Massou et al 2014;McGaw et al 2019). In contrast, larger crabs, including mature females, were found in plot 1, where the ground is higher.…”

The biometry of Cardisoma crassum (Brachyura: Gecarcinidae) from two folkloric festivals in Veraguas, Panama

“…The Blue Crab, Cardisoma crassum, is an integral fishery resource and a prevalent resident of the mangrove ecosystems in the Panamanian Pacific (Lombardo & Rojas, 2022;Vega et al 2018). Blue crabs are ecosystem engineers (McGaw et al 2019) that play an essential role in the intricate balance of mangrove ecosystems, through activities such as turning over organic material (Lindquist et al 2009;Robertson, 1986), and influencing soil chemistry through biological activity (Green, 2004b;Lindquist et al 2009;Perger et al 2013;Smith et al 1991). This species is captured mainly for subsistence in coastal communities (Hendrickx, 1995) through manual methods and artisanal fishing gear (Vázquez-López & Ramírez-Pérez, 2015;Vega et al 2018).…”

A morphological, phylogenetic and phylogeographic reappraisal of the land crabs Gecarcinus quadratus De Saussure, 1853, and G. lateralis Fréminville in Guérin, 1832 (Decapoda: Gecarcinidae). Are they different species?

“…The family Gecarcinidae H. Milne-Edwards 1837, is composed of semi-terrestrial crabs distributed in the tropical coastal plains of the Americas and in the southwestern Pacific region (Guinot et al 2018). They inhabit mangrove forests, as well as inland areas adjacent to salt marshes, estuaries and coastal lagoons, where they play a significant role in the structuring and functioning of the coastal ecosystem, processing organic litter, recycling nutrients and aerating the soil (Jones et al 1994;Sherman 2003;Griffiths et al 2007;McGaw et al 2019).…”