SPECIALIZATION OF HELMINTHS - PROGRESS OR REGRESS

Helminths are regarded as a lateral branch of the evolution progressively adapting to peculiarities of the ecological niche. The transition to endoparasitism is a consequence of allomorphosis due to which free-living forms of organisms could develop a new, qualitatively distinct, habitat. The ability to membrane digestion, which is thus acquired by integumentary tissues of helminths, leads to a reduction of the alimentary canal through substitution of the function. Emerging from relatively primitive ancestral forms endoparasites have achieved notable progress in the adaptation to a parasitic mode of life both in biological and morphofunctional respect and combine a high degree of species-specificity during their adaptation to definite hosts with sufficient plasticity of the adaptive reaction during hostal irradiation.