Algal endosymbionts in European Hydra strains reflect multiple origins of the zoochlorella symbiosis.

Symbiotic associations are of broad significance in evolution and biodiversity. Green Hydra is a classic example of endosymbiosis. In its gastrodermal myoepithelial cells it harbors endosymbiotic unicellular green algae, most commonly from the genus Chlorella.

Behavioral, morphological and histopathological effects of sublethal doses of quercetin on the species Polycelis felina (Dalyell).

The effect of quercetin was studied on the multi-eyed flatworm Polycelis felina (Daly.) in laboratory conditions. This is a very suitable test-organism available year-round in nature, easily maintained in the laboratory.

Isolation and cultivation of endosymbiotic algae from green hydra and phylogenetic analysis of 18S rDNA sequences.

Symbiotic associations are of wide significance in evolution and biodiversity. The green hydra is a typical example of endosymbiosis. In its gastrodermal myoepithelial cells it harbors the individuals of a unicellular green algae.

Aluminium deposition in hydras.

The aim of this research was to explore, compare and explain the appearance, purpose and possible distribution of aluminium depositions in symbiotic and aposymbiotic hydra species. Al deposition in treated hydras appeared pink as single and multiple aluminium depositions or as clusters in the shape of globular or spot-like structures inside the cytoplasm of the hydra cells. Areas ofaluminium deposits were also present.

Effects of norflurazon on green and brown hydra.

For the first time effects of norflurazon on green (Hydra viridissima Pallas, 1766) and brown hydra (Hydra oligactis Pallas, 1766) in high- and low-light conditions were investigated in order to establish the extent of damage that this substance inflicts, with special emphasis on the "bleaching effect" and the effect on hydra-algae symbiosis. Green hydra is a typical example of an endosymbiotic organism. The gastrodermal myoepithelial cells of green hydra contain endosymbiotic algae.