Do mandarins require any special feedings?
<< Very possibly... the common species need plenty of live food, supplied on an almost continuous basis... typically I suggest about four square feet of bottom space per specimen, of a well-aged, live rock and sand set-up... You'll be able to see yours getting thin if it's not eating enough... and most all of these fishes do die from starvation... They can/will take even live freshwater fish foods... so this is one avenue to try... otherwise, setting up a refugium in the tank or a sump (directions to these can be found on my site: www.wetwebmedia.com... which in turn will direct you elsewhere...)can provide some needed live food culture.
