?'s about nudibranch

 

Seriously though, the original question was about Nudibranchs.  Most Nudi's are very specific about what they eat.  They usually eat only one thing.  There is one called a Lettuce Nudibranch that will eat hair algae and nothing else.  They are short lived with a life span of somewhere near a year in the wild.  They typically don't do really well in tanks because they tend to get blown around by the high water movement and because they like to crawl into power heads and pumps and get chewed up.  The other problem is that since they don't eat anything else when the hair algae is gone they starve to death.  Also I would not expect them to do anywhere near as much good as a Sea Hare.  They are much smaller and thus need much less to eat.

 

As far as being eaten by fish, most fish leave Nudi's alone because many are very toxic.  They concentrate the toxins from whatever they eat in their bodies as a protection.  Lettuce Nudi's are probably less toxic than others since they eat algae, but be assured that most brightly colored Nudi's are very toxic when eaten.

 

If I had an algae problem I would also turn to a Lawnmower Blenny.  Besides doing a good job eating algae, they also have great personalities and a lot of fun to watch.  Few fish are as photogenic as Lawnmower Blennys