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 float

Keeping Afloat

To help prevent that sinking feeling

Whether we indulge in hang-gliding (not that I would ever have done that let alone attempt to do that) or relish the feeling of near weightlessness during a dive (which I did have experience with), nobody can really escape gravity on Earth. Staying afloat (in many ways) is staying alive. This holds true even for the smallest forms of plankton: without certain specializations to stay afloat they would all gradually sink to the bottom of the sea. Dead fish only float at the surface as long as their swim bladder is still intact – once ruptured they, too, sink. —>—>

biology zoology blog benno meyer rochow cave troglobites

Troglobites with Eyes?

Mr. Liddle solved that riddle

Our ancestors were troglodytes. They wore clothes of fur and lived in caves. To most people, however, the idea of living in a cave does not really strike them as terribly enticing: no sun, no flowers, no green plants, no breeze, no wide open spaces and always damp and cool. However, it is precisely the predictability of these conditions, their constancy, which are the characteristics of the cave habitat that work to the advantage of certain animals and make them actively search for caves to live in or even to embrace subterranean life on a permanent basis. —>—>