Metabolic responses of adult lion’s paw scallops Nodipecten subnodosus exposed to acute hyperthermia in relation to seasonal reproductive effort

Abstract

and balance, the response observed in adult scallops suggested that N. subnodosus presents a high capability to respond to acute temperature stress in the range of its thermal window tolerance. Our study examined the capability of scallops to respond to an acute challenge of 24 h, these results lead to additional unknowns regarding the metabolic and energetic capability of the response and homeostasis under repeated exposure to acute hyperthermia scenarios and regarding the increasing variability in seawater temperature as another possible large event in future global warming scenarios.

Energy metabolism of juvenile scallops Nodipecten subnodosus under acute increased temperature and low oxygen availability

“…In adductor muscle of N. subnodosus juveniles, the slight decrease in AEC and ATP levels concomitant with the increase in AMP would indicate some disruption of the energy balance in cells under acute hyperthermia (T), especially concomitant with moderate hypoxia (TH). This increased use of ATP was partially buffered by a decrease of ArgP, as previously observed in N. subnodosus adults exposed to a similar hyperthermia challenge (Salgado-García et al, 2020). Indeed, the decrease in ATP in the adductor muscle of N. subnodosus between treatments C and T was around 1.0 µmol g -1 , while ArgP decreased to up to ≥14 µmol g -1 , indicating that energy supply from phosphagen compensated by more than ten-fold the absolute decrease in ATP, as also observed in other scallop species (Bailey et al, 2003).…”

“…Therefore, under acute hyperthermia (T), the energy supply was probably efficient enough for the adductor muscle of juveniles, as ArgP content was not depleted. Indeed, this is confirmed by the negligible decrease in AEC (3 %, from 0.95 to 0.92) observed for N. subnodosus adults (refer to Salgado-García et al, 2020). However, AEC has some limitations as an indicator of the cellular energy status; for example, due to spontaneous natural oscillations in AEC representing a homeorhetic rather than a homeostatic regulation (De la Fuente et al, 2014).…”

“…Activities of the metabolic enzymes hexokinase (HK), pyruvate kinase (PK), cytochrome c oxidase (CCO), citrate synthase (CS), lactate dehydrogenase (LDH), octopine dehydrogenase (ODH), and arginine kinase (AK) were quantified in fifty milligrams of frozen powder of adductor muscle and mantle samples. Tissues were homogenized with specific buffers (1:10, v/v) for each enzyme using a Polytron device (PT 6100D, Kinematica AG, Switzerland) at 180 g for 30 s at 4 °C (refer to Salgado-García et al, 2020). All homogenates were immediately sonicated (Q125-110, Qsonica Sonicators, Newtown, CT) for 30 s and a 30 % output at 4 °C.…”

“…Conditions for the analysis of adductor muscle and mantle samples are described by Salgado-García et al (2020). Only for CCO and CS activities in the mantle, phosphate and Tris-HCl buffers were changed to 200 mM Imidazole, 5mM ethylenediaminetetraacetic acid (EDTA), 5 mM (ethylene glycol tetraacetic acid (EGTA), 0.1M sodium fluoride (NaF), 0.1 % Triton X100, and 0.2 mM Phenylmethylsulfonyl fluoride (PMSF), pH 7.2.…”

Effect of Dietary Supplementation with Lactiplantibacillus plantarum I On Queen Scallop Aequipecten opercularis Under Simulated Climate Change Conditions

“…In the third tank, the scallops were exposed to LAB culture (∼10 2 CFU/ mL of the tank) in parallel running under climate change conditions (ΔpHΔT + LAB). The climate change conditions were simulated according to the predictions by Salgado-García et al (2020). Temperature, pH, and dissolved oxygen were measured daily with the Hanna HI98193 multiparameter probe.…”