OK...back to the food issue, and rightly so.
Our lions are fed FW feeders for about 3 months out of the year, as here in the Tampa area, water temps drop to the low 60's in mid-winter (LOL! that's about 90 days, for you Yankees...eat your heart out!**grin**) and at that time all feeders move out into deeper water.
Once your lions have started feeding on cut food or silversides, feeding becomes much easier as ANY SW fish are acceptable, and strips cut from fish available at the local grocery store work very well.
A TIP: if you are feeding goldfish as occassional live feeders, the orange color of strips of salmon makes the transition easier...simply cut a strip off a filet in the appropriate size and voila...lunch! Most lions will attack salmon strips with gusto after goldfish and show very little hesitancy in doing so WITHOUT resorting to long term starvation to get them to do so.
Drop in one goldfish to get his attention, followed by a similar sized strip of salmon and his "feeding frenzy" will usually do the rest.
Dwarf lions can be harder, but that's because many feed primarily on ghost shrimp in the wild (yes, they are much more common in the sea than in freshwater), but here again, give him a live ghost shrimp, followed by a thawed frozen krill and you can usually make the switch with little effort and again, without resorting to starvation to do so.
On dwarf lions, my suggestion is to get FW ghost shrimp (available at most LFS) and put them in a 5 gal. bucket (aereated) with a sheet of marine algae, which they will attack ravenously, then when they are out into the marine tank they are "gut loaded" with nutritious food and much higher in nutrients.....an added advantage is that they will live in the marine water for up to several hours, and as the ones not immediately consumed upon introduction die off, it gets the lions used to eating non-living prey, then the switch to krill is half way made for you.
You can also acclimate many ghost shrimp over to saltwater, by gradual addition of same to the bucket, in which case you can end up with marine ghosties, the food of choice for dwarf lions.
And don't forget, mollies from the FW section of the LFS will often thrive in marine tanks if you want to keep some live food available for snacks......in my experience, a 6" sailfin green molly is also quite a pretty fish in its own right, and the greens are often found here in marine environments (they also grow much larger than you would suspect in a marine tank, sometimes double the size they will achieve in FW)