Effects of single and dual-stressor elevation of environmental temperature and PCO2 on metabolism and acid-base regulation in the Louisiana red swamp crayfish, Procambarus clarkii

Elevated dissolved carbon dioxide and associated acidification delays maturation and decreases calcification and survival in the freshwater crustacean Daphnia magna

“…This is not surprising since both processes are related to molting, a process that involves a net loss of calcium (Alstad et al 1999). Second, internal hypercapnia, resulting from CO 2 molecules entering body fluids, slows metabolic rates in marine invertebrates such as mollusks (Pörtner et al 2004; Michaelidis et al 2005) and freshwater decapod crustaceans (Quijada‐Rodriguez et al 2021; Tripp et al 2022). A prolonged state of such metabolic depression will affect energy demanding processes such as growth, reproduction and calcification (Fabry et al 2008; Quijada‐Rodriguez et al 2021) and might partly explain our observations.…”

“…Other potential mechanisms explaining the reduced calcium content we observed could involve energetic limitations resulting from acid-base disturbance and metabolic depression, solubilization of the carapace to buffer the hemolymph, or altered calcium transport processes (Quijada-Rodriguez et al 2021;Tripp et al 2022). More detailed experiments in which, for example, calcium uptake rates are quantified or the calcium metabolism is explored further under different pCO 2 and Ca 2+ levels will be required to determine the underlying mechanism of pCO 2 on calcification in planktonic freshwater crustaceans.…”

“…Effects of elevated pCO 2 include reduced calcification rates in the Chinese mitten crab (Quijada‐Rodriguez et al 2021) and a decrease in biomineralization regulators in a unionid mussel species (Jeffrey et al 2018). In a freshwater crayfish, no effect of pCO 2 on carapace Ca 2+ levels was found (Tripp et al 2022). It remains unknown to what extent calcification in planktonic freshwater crustaceans may also be impacted.…”

Branchial CO2 and ammonia excretion in crustaceans: Involvement of an apical Rhesus‐like glycoprotein

“…In the gills of crustaceans, two Rh proteins have been verified, Rh1 and Rh2. 33 Of these two, most studies assessing mRNA expression have focused on Rh1, where full-length open reading frames have been cloned. 32,[34][35][36] In the genome of Chinese mitten crab Eriocheir sinensis, three distinct Rh proteins (GenBank Accession No: XP_050735920.1, XP_050713622.1, XP_050714961.1) are present; however, expression of mRNA in the gills has not been confirmed.…”

“…Despite Rh proteins in the gills of aquatic organisms being first identified in decapod crustaceans nearly 20 years ago, 32 functional studies on the role of Rh proteins in the gills of crustaceans are lacking. In the gills of crustaceans, two Rh proteins have been verified, Rh1 and Rh2 33 . Of these two, most studies assessing mRNA expression have focused on Rh1, where full‐length open reading frames have been cloned 32,34–36 .…”