Question

Почему круглых червей называют также первичнополостными

Answer 1

Т.к. у них полость тела первичная(собственных стенок не имеет),заполненная жидкостью

Answer 2

Why are roundworms also called nematodes?

Roundworms are also called nematodes because they belong to the phylum Nematoda, which is a group of elongated, cylindrical worms. The term "nematode" is derived from the Greek words "nema," meaning "thread," and "odes," meaning "like." This name reflects the characteristic thread-like appearance of these worms.

The phylum Nematoda includes a diverse range of species, many of which are parasitic, and they are found in various environments, including marine, freshwater, and soil habitats.

Nematodes are known for their unsegmented bodies and their abundance in various ecosystems. They play crucial roles in nutrient cycling and food webs, and some species are economically important as parasites of plants, animals, and humans.

In summary, the term "nematode" is used to describe roundworms due to their characteristic thread-like appearance and their classification within the phylum Nematoda