Effects of Elevated pCO2 on the Survival and Growth of Portunus trituberculatus

Abstract

Identifying the response of Portunus trituberculatus to ocean acidification (OA) is critical to understanding the future development of this commercially important Chinese crab species. Recent studies have reported negative effects of OA on crustaceans. Here, we subjected swimming crabs to projected oceanic CO 2 levels (current: 380 µatm; 2100: 750 µatm; 2200: 1500 µatm) for 4 weeks and analyzed the effects on survival, growth, digestion, antioxidant capacity, immune function, tissue metabolites, and gut bacteria of the crabs and on seawater bacteria. We integrated these findings to construct a structural equation model to evaluate the contribution of these variables to the survival and growth of swimming crabs. Reduced crab growth shown under OA is significantly correlated with changes in gut, muscle, and hepatopancreas metabolites whereas enhanced crab survival is significantly associated with changes in the carbonate system, seawater and gut bacteria, and activities of antioxidative and digestive enzymes. In addition, seawater bacteria appear to play a central role in the digestion, stress response, immune response, and metabolism of swimming crabs and their gut bacteria. We predict that if anthropogenic CO 2 emissions continue to rise, future OA could lead to severe alterations in antioxidative, immune, and metabolic functions and gut bacterial community composition in the swimming crabs through direct oxidative stress and/or indirect seawater bacterial roles. These effects appear to mediate improved survival, but at the cost of growth of the swimming crabs.

Will ocean acidification affect the digestive physiology and gut microbiota of whelk Brunneifusus ternatanus?

“…In addition, a decrease in pH in the digestive glands can damage its tissue structure, involving not only excessive death of abnormal epithelial cells but also changing the integrity of the endoplasmic reticulum, resulting in the inactivation of digestive enzymes (Stumpp et al, 2013;Xu et al, 2020). This negative effect on the digestive capacity was consistent with a similar study that described the responses of the crab Poryunus trituberculatus to an elevated pCO2 condition (Lin et al, 2020). Although, earlier studies show that in mussels, oysters, and clams, digestive enzymes were moderately or not affected at an elevated pCO2 condition, (Götze et al, 2014).…”

Low water pH depressed growth and early development of giant freshwater prawn Macrobrachium rosenbergii larvae

“…The poor morphological development of M. rosenbergii larvae exposed to acidic pH observed in this study could also be attributed to the disturbance in the ionoregulation mechanism. Similar poor feeding efficiency and prolonged larvae period with low survival and growth were also reported in other crustacean species (Taylor et al, 2015;Lin et al, 2020). Furthermore, the higher 96-h LC50 of pH of M. rosenbergii compared to other crustacean species highlights the higher sensitivity of this species towards acidic pH (Chen and Chen, 2003).…”

“…In previous studies, low water pH depressed foraging sensitivity and feeding performances in PL and juveniles of M. rosenbergii (Kawamura et al, 2018). Similar impairment of feeding was also observed in other crustacean species (Kennedy and Picard, 2012) such as tiger prawn Penaeus monodon (Chen and Lin, 1992), Northern shrimp Pandalus borealis (Arnberg et al, 2013), red rock shrimp Lysmata californica (Taylor et al, 2015), Pacific white shrimp Litopenaeus vannamei (Yu et al, 2020), swimming crab Portunus trituberculatus (Lin et al, 2020), kuruma shrimp Marsupenaeus joponicus (Chen et al, 1996;Fukami et al, 2021), and teleost such as cobia Rachycentron canadum (Rodrigues et al, 2013), African catfish Clarias garienpinus and tilapia Oreochromis niloticus (Mota et al, 2015), turbot Psetta maxima (Mota et al, 2018) and hybrid grouper Epinephelus lanceolatus  Epinephelus fuscoguttatus (Thalib et al, 2021).…”

Tolerant Larvae and Sensitive Juveniles: Integrating Metabolomics and Whole-Organism Responses to Define Life-Stage Specific Sensitivity to Ocean Acidification in the American Lobster

“…In stage II larvae, the same metabolites (fatty acids and citrate cycle intermediates) accumulate under 3000 µatm, with no change in succinate or a clear trend in phospho-L-arginine, but with a trend of increasing lactate concentration, suggesting a transition to anaerobic metabolism. An increase in lactate has also been reported in juveniles of several crab species, suggesting the utilisation of anaerobic metabolism to support acid-base regulation under increased seawater p CO 2 [ 66 , 67 , 68 ]. However, in subadult females H. americanus (50–65 mm CL), elevated p CO 2 induced a depletion of L-lactate, which was considered to lead to a putative reduction in oxygen carrying capacity, as L-lactate is a known molecular modulator of hemocyanin’s oxygen affinity [ 69 ].…”