Of the approximately 4000 living species of foraminifera the life cycle
s of only 20 or so are known. There are a great variety of reproductive, growth and feeding strategies. Foraminifera may reproduce asexually by binary fission or may also reproduce sexually, producing many hundreds of offspring. The growth rate of the calcareous shells of foraminifera is light-dependent (Rottger, 1983). Larger forams alternate generations between a haploid, uninucleate gamont (sexual generation which produces gametes) and a diploid, multinucleate agamont (asexual generation producing daughter individuals through fission). An asexually produced haploid generation commonly form a large proloculus (first chamber) and are therefore termed megalospheric. Sexually produced diploid generations tend to produce a smaller proloculus and are termed microspheric. Many foraminiferal tests are either partially dissolved or disintegrated during the reproductive process as is evidenced in the fossil record.