Do nematodes have a fixed cell number?

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In nematodes cell divisions case near the end of embryonic development so that the number of the cells of the adult is constant.

What to you mean by eutely?

When eutelic organisms mature, they have a fixed number of somatic cells; the precise amount varies little depending on the species. Cell constancy is another name for this phenomena. Cell expansion is the only method of growth after development has reached maturity. Autetic growth is the term for this growth. Members of the phylum Aschelminthes demonstrate this. Sometimes an organism as a whole lacks eutelic characteristics, but certain parts do.

Eutely occurs when the initial embryonic cells each come with a limit for total divisions. After this limit is reached, the organism can only become larger due to cell enlargement rather than cell division. Eutelic organisms have a fixed number of somatic cells when they reach maturity, the exact number being constant for any one species. Development proceeds by cell division until maturity; further growth occurs via cell enlargement only. In nematodes, the number of nuclei is also constant; there is growth in size of the body but this is due to the growth in the size of the cells (hypertrophy). Most eutelic organisms are microscopic. Examples include the rotifers, many species of nematodes, tardigrades, larvacea and dicyemida.