biology zoology blog benno meyer rochow lamprey parasitism

Something Terribly Fishy

But unquestionably true

Speak with a non-zoologist about “parasitic fishes” and the conversation will inevitably come to “murderous” piranhas. Yet, in spite of their reputation these South American freshwater fish are not parasitic, but represent predators with razor sharp teeth and a healthy appetite, which can indeed kill, but aren’t murderous. Predators, by definition, finish off their prey; yes, but parasites are animals that obtain nourishment from another living animal without killing it, like for instance blood-sucking hagfishes and lampreys. —>—>

biology zoology blog benno meyer rochow chemotrophy cave movile

A Chemotrophic Ecosystem

The wonders of Romania’s “Movile Cave”

Most people would have been taught that life on Earth depended entirely on the sun and the green plants. The latter with their ability in the presence of chlorophyll and light to turn the inorganic molecules CO2 and water into organic carbohydrate (known as photosynthesis), are said to be the basis of the food chain for all animals A few people, however, may also have been taught that there is an alternative to photosynthesis, namely chemosynthesis and that this gave rise to a food chain, for example near hydrothermal vents, not based on green plants and sunlight, but on thermophilic bacteria that use hydrogen and sulphides to build organic material and release methane. But deep sea hydrothermal vents are not the only places where chemosynthetic activity leads to a food chain. The so-called “black layer” a few centimeters below the surface of intertidal mudflats is also a place of chemosynthesis, but the most amazing place is “Movile”. —>—>