Moina are are the smallest member of the daphnia family. Adult Moina (700-1,000 µm) are longer than newly-hatched brine shrimp (500 µm) and approximately two to three times the length of adult rotifers. Young Moina (less than 400 µm), however, are approximately the same size or only slightly larger than adult rotifers and smaller than newly-hatched brine shrimp.
Under optimum conditions, Moina reproduce at only 4-7 days of age, with a brood size of 4 – 22 per female. Broods are produced every 1.5 – 2.0 days, with most females producing 2 – 6 broods during their lifetime.
The nutritional content of Daphnia varies considerably depending on their age and the type of food they are receiving. Although variable, the protein content of Moina usually averages 50% of the dry weight. Adults normally have a higher fat content than juveniles. The total amount of fat per dry weight is 20 – 27% for adult females and 4 – 6% for juveniles. That said, Moina are generally believed to have a higher protein content, often as high as 70% protein.