Here are my answers, as sources I used :
Schulte: Piranhas in the aquarium,
and your website.
I decided to answer in english, that all members can read and (i hope so ) understand my answers.
here I go :
1) some parts I remember : lens, retina, cornea
2) Linne, made systema nature, was the first who has published about P's in scientific-way
3)T, the lense can be moved in direction of the retina, via muscles; Contract ? if you are meant the iris :no
4) I think F : cause many P's live in white and black water with very low seight, and as I know : they don't have any degeneration of the eyes.
5) Hornhaut, horny skin: cornea
6) I think, that fishes, that cannot use their eyelight uses more then one other sense on the hunt:
lateral line, hearing with inner ear( Weberian's apparatur)
and smell ( with olfactic organ).
maybe that some fishes uses produced sounds like echo.
7) some fish uses more then just gills; eels, for example can breath throug skin, and there are more fishes like betta who uses theire labyrith for breething
8) didn't got the question, can you please explain in other words ?
9)If i got it right you mean the "supraneurals",
but my other idera was the otoliths, but If I got the question right, it is my first answer
10) The areation is caused by muscular compression in the heart in a single circle ( not 2 bloodcircles like in human ).
so here is the way:
bulbus arterius with valves to
muscular chamber ( ventricle) with contraction to
aorto ( thoracalis ?) to
2 branches into the left and right gill
with o2 to arteria carotis to head and
with o2 to aorta (abdominalis ???) to inner organs
and with branches to other parts of the body
( do I have to name here every vessel ?), like the skin , or muscles
and back to the bulbus via a system of veins
so Frank, I hope you anderstand my answers in some points.
it was a nice test and I had have a sleepless night,
but now I want to know the right answers.
If you don't want to post them this time , please answer via e-mail or PM.
Gute nacht und Prost