Green Hydra Tenticle
I believe this tentacle belongs to the hydra known as Hydra viridissima or the green Hydra. The green colour is from the green algae Chlorella which live symbiotically in the gastrodermis, or inner layer of cells.
The body of the hydra is topologically a hollow spheroid, i.e., it is like a glove blown up with air. The cells walls of the body and tentacles are really only 2 cells thick. The inner cells, i.e., the green ones here, make up the gastrodermis which is responsible for digestion. The ectodermis is the lighter colored structure on the outside. There is a structureless lamellar layer in-between. This layer is evident in this micrograph.
The ectoderm's is covered with the nematocysts which fire a tethered harpoon into the prey. Roughly at the center top and bottom of this micrograph are two nematocists and the associated cavity for the "harpoon". The spines on the tentacle are sensors which trigger the nematocists. In-between the namatocists are the epitheliomuscular cells which are responsible for the muscular action. Finally there are smaller interstitial cells which are a form of stem cell. The web page sites.google.com/site/drjerrodhunter/home/cnidarians/hydra provides a very nice description.
Specimen from a spring next to the dam on the Dowagiac River.
Phase contrast immage at 400X original magnification from a Nikon MS inverted microscope. Photographed with Sony NEX 5N using a Leica MIKAS 1/3X adapter.
Green Hydra Tenticle
I believe this tentacle belongs to the hydra known as Hydra viridissima or the green Hydra. The green colour is from the green algae Chlorella which live symbiotically in the gastrodermis, or inner layer of cells.
The body of the hydra is topologically a hollow spheroid, i.e., it is like a glove blown up with air. The cells walls of the body and tentacles are really only 2 cells thick. The inner cells, i.e., the green ones here, make up the gastrodermis which is responsible for digestion. The ectodermis is the lighter colored structure on the outside. There is a structureless lamellar layer in-between. This layer is evident in this micrograph.
The ectoderm's is covered with the nematocysts which fire a tethered harpoon into the prey. Roughly at the center top and bottom of this micrograph are two nematocists and the associated cavity for the "harpoon". The spines on the tentacle are sensors which trigger the nematocists. In-between the namatocists are the epitheliomuscular cells which are responsible for the muscular action. Finally there are smaller interstitial cells which are a form of stem cell. The web page sites.google.com/site/drjerrodhunter/home/cnidarians/hydra provides a very nice description.
Specimen from a spring next to the dam on the Dowagiac River.
Phase contrast immage at 400X original magnification from a Nikon MS inverted microscope. Photographed with Sony NEX 5N using a Leica MIKAS 1/3X adapter.