Once the organic matter has been fabricated by the chemosynthetic bacteria, animals living around the hydrothermal springs have only to help themselves. The mechanism of the transmission between producers and consumers is sometimes surprising.
Riftia pachyptila
The giant worm, Riftia pachyptila, has no digestive tube. First, by means of its branchial plume (coloured purple in the photo), it absorbs the energetic molecules contained in the fluid emitted by the hydrothermal spring as well as oxygen and carbon dioxide present in sea water. These components are then transported, in the blood, as far as the bacteria which are found in the interior of certain cells of the animal. Nourished in this way, the bacteria multiply and supply the organic matter which the Riftia pachyptila needs to live. This symbiotic mechanism minimises losses. It is far more productive than the classic system of ingestion, digestion, excretion.
Modiole Bathymodiolus
The Bathymodiolus modiole, also called the deep water modiole, is a shellfish close to the mussel. It is very common around hot springs. This organism is capable of filtering sea water and feeding itself by digesting the suspended particles. The chemosynthetic bacteria which live symbiotically in the branches of the shellfish transform these particles into organic matter there also. As far as waste from the animal is concerned, it is a delicious treat for a scaled worm which lives between the modiole’s two valves. It is therefore clear that in the ocean deeps, just like everywhere else, nothing goes to waste … |