For a similar bowl see no. 139 in Brovarski, et al., Egypt's Golden Age: The Art of Living in the New Kingdom 1558-1085.
According to Lacovara (in Friedman, et al., Gifts of the Nile, Ancient Egyptian Faience, p. 211), the decoration "represents rebirth and resurrection. The closing and opening of the lotus during the diurnal cycle of night and day indicated the renewal of life. The tilapia, which guards its young in its mouth, might have seemed to have been a case of spontaneous regeneration, and as such was another powerful image signifying eternal life."