ИСТИНА

Nematodes were found in living agglutinated foraminifera Reophax curtus (shell length is about 1 mm) in silt sediment at depth about 30 m in the White Sea. Nematodes are detected in 201 out of 2337 exposed foraminifera, so the intensity of invasion is about 8.6%. Usually the nematodes are located in the youngest large chamber with residual live cytoplasm. A nematode population within one host foraminifera specimen includes often males, females and juveniles. The number of nematodes may vary from one to six or more individuals. Morphology of males agree with that of the family Camacolaimidae and probably with the genus Camacolaimus (comma-like amphid just anterior to the level of cephalic setae, often tooth-like rod in the stoma, elongate glandular posterior widening of the pharynx, two outstretched testes, spicules with knobs bent ventrally, etc.). While males are slim the females are corpulent and spindle-shaped. All the males look similar in appearance whereas females are presented by two distinct morphotypes. Morphotype 1 is characterized by having four cephalic setae, comma-like amphids and paired antidromously re ected ovaries. Morphotype 2 is distinguished by lacking evident anterior sensilla and peculiar paired ovaries, each as a spheric cluster of numerous and relatively small oocytes and a small hemispheric germinal zone. Intestine of both female morphotypes look as partly or entirely devoid of internal lumen and cell borders. Evidently, the nematodes spend considerable part of their life cycle within foram where they feed at the expense of the host. The study is supported by Russian Fund of Fundamental Researches, grant N 15- 04-02597 A