Green Hydra
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Green Hydra
Microscope: Zeiss Standard GFL
Objective: Zeiss 10/0.22 plan achro
Ocular: Olympus P15
Brightfield/blue filter
Camera: Canon Powershot S50
Sample from Warnham Millpond 08-Oct-2006
This first image shows as much of a small green hydra as I could get in one shot.
Microscope: Zeiss Standard GFL
Objective: Leitz 40/0.7 NPL Fluotar ICT
Ocular: Olympus P15
Substage: Leitz ICT
DIC
Camera: Canon Powershot S50
ISO200, F4.9, 1/8 sec
Sample from Warnham Millpond 08-Oct-2006
This second image is of the tip of a hydra tentacle. The ovoid structures with the teardrop centres are cnidoblasts. Each contains a nematocyst. The cnidoblast is touch sensitive and will discharge the nematocyst on contact. The nematocyst "dart" is poisonous and will paralyse prey. You can see some have been discharged by the hair-like features at right angles to the tentacle. The green colour is due to symbiotic algae. Some of these hydra had ingested small chyronomid midge larvae - you could see the heads and some body parts remaining within the hydra.
Graham
Though we lean upon the same balustrade, the colours of the mountain are different.
Though we lean upon the same balustrade, the colours of the mountain are different.