Growth and development of the early juvenile Anodonta woodiana

Abstract:

The freshwater mussel Anodonta woodiana is a freshwater bivalve with important economic and ecological values, e.g., as a food source or for pearl cultivation, water purification, and aquatic biological monitoring. In order to understand the morphological change, organ development, and growth rate characteristics of A. woodiana during its early life stages, relevant studies were conducted on 1~30-day-old juveniles. From the 1 to 30-day stages, the leading and trailing edges of the hinge for the juveniles were raised upward. The umbo was contracted relatively inward. The anterior grew rapidly and extended outwards, but the posterior grew toward the ventral edge. The ventral edge grew toward the ventral edge. The most obvious feature in the one-day-old juveniles was the appearance of a mobile foot. The visceral mass was more obvious in 4-day-old juveniles. At 10 days old, the gills were clearly visible, and the anterior and posterior adductors were formed. The intestine and heart were obviously visible in 15-day-old juveniles. The incurrent and excurrent siphons had been formed in 20-day-old juveniles. For the 25-day-old juveniles, the organs were fully developed. The shell length, height, and age grew exponentially, and the shell length and height grew at a positive allometry. These results can provide theoretical guidance for the artificial breeding of A. woodiana, its germplasm resource protection and population restoration, and the effective development and utilization of this bivalve as a special indicator for aquatic pollution biomonitoring.