New answers tagged ichthyology
I'll address fish here. It's hard to tell which way is up with many sea-dwelling invertebrates, e.g. sea cucumbers. Sea urchins often are oriented "sideways" if you count their mouths as "down". All animals normally orient themselves in the most advantageous manner dependent on their situation. Probably the most important determiners are field of vision and ...
Top 50 recent answers are included