They have evolved to fill a number of different ecological niches .
The feeding mechanism of the members of the family Daphniidae differs from that of Macrotrichidae in allowing the animals to engage in filter - feeding , rather than having to scrape food from a surface .
members have evolved to fill a number of different ecological niches .
The feeding mechanism of the members of the family Daphniidae differs from that of Macrotrichidae in allowing the animals to engage in filter - feeding , rather than having to scrape food from a surface .