Echinoderms can have ambulacral parts that include ossicles, plates, spines, and suckers. For example, sea stars or "star fish" have an ambulacral groove on their oral side (underside). This ambulacral groove extends from the mouth to the end of each ray or arm. Each groove of each arm in turn has four rows of hollow tube feet that can be extended or withdrawn. Opposite the ambulacral groove is an ambulacral ridge on the aboral side of each ray.
aboral surface
Star fish don't have eye spots, or eyes, they depend on their skin to detect light.
If the water surface is frozen, fish continue to swim.
yer
Pelagic fish
how does upwelling bring fish and nutrients to the surface
Some fish are surface fish and others are not. Without you saying what kind of fish it is that is at the surface it is impossible to say if anything is wrong. BUT! if the fish are breaking the surface and gasping for air, then you have a major water problem and need to do some very large water changes immediately. Otherwise your fish will die.
the fish that live close to the surface are not unusual and the fish that live in the deep ocean are unusual. the unusual and surface fish both eat different thing's don't live the same way
Not necessarily.
i have seen native American artifacts of fish hooks carved from bone. the line end of the hook had a groove around the shank no doubt to retain a string or thread.
it insulates the fish
Gills
Before a storm, there is very little dissolved oxygen in the water, so fish rise to the surface for oxygen,which is more plentiful near the surface.