The Yeso scallop (Patinopecten yessoensis) is one of the most economically important marine bivalves that has been farmed on the north coast of China.
However, mass scallop mortality outbreaks have caused enormous economic losses for aquaculture producers. Many factors are suspected of causing mass mortality episodes, including fluctuations in environmental parameters, pathogens, and parasite infestation, among others.
Researchers from Qilu University of Technology and the Ocean University of China studied the movement of the Yeso scallop (Patinopecten yessoensis) shells, refining various parameters, including the frequency and speed of shell movement, to assess their correlation with the vitality and mortality of scallops.
Traditional indicators related to scallop health mainly comprise indices such as mortality rate and physiological indices (eg growth rate and food capture), as well as molecular biology indicators linked to enzyme activity and expression of functional genes. .
However, these indicators are measured using laborious and time-consuming methods, which often involve culling the scallops.
Behavior of bivalves
Bivalves are known to open and close their valves under natural conditions to maintain their basal metabolic state and respond to external stimuli to protect themselves.
In addition, the opening and closing of the leaflets is closely linked to vital activities, such as respiration, feeding, excretion, and escape behavior.
Shell movements were usually measured and used as a predominant indicator reflecting short-term changes in environmental conditions and water quality monitoring.
According to the study results, “variables related to maximum velocity of valve movement and scallop thickness dominated the estimate of scallop survival potential.”
“Scallops with greater shell width probably have better muscular physiological capacities, including muscle mass, strength and endurance, as well as energy cost advantages, which is beneficial for improving scallop survival performance,” they noted.
They conclude by highlighting that their findings highlight the roles of valve movements in relation to scallop vitality and provide relevant variables to predict individual survival potential without damaging scallops.
“Our results revealed that leaflet movement can be applied as a vital indicator associated with circadian rhythm and survival potential,” they conclude.
They also highlight that bivalves maintain their basal metabolic state and their response to external stimuli through the movements of their valves, which underlie aspects of scallop adaptation to variation in food availability and predation risk.
“Further analysis of bivalve valve behavior will help gain a deeper understanding of bivalve survival and provide a basis for exploring indicators important to the bivalve aquaculture industry,” they recommended.
The study was funded by the National Natural Science Foundation of China, the Pilot Innovation Project from Qilu University of Technology (Shandong Academy of Sciences), Key R&D Program of Shandong Province, China, Institute of Oceanographic Instrumentation, Shandong Academy of Sciences, and the Basic Research Project from Qilu University of Technology (Shandong Academy of Sciences).
Reference (free access)
Xun, X., Wang, J., Liu, F., Chen, L., Zou, Y., Liu, Y., … & Hu, X. Valve movements indicate rhythm and survival potential of scallop. Frontiers in Marine Science, 10, 432.