Marine (also referred to as saltwater) fishes are the most delicate species kept in the aquarium hobby. They require good sources of marine protein and higher levels of unsaturated fatty acids. O.S.I Marine Pellets are specially formulated to incorporate high levels of marine plant proteins, animal proteins and appropriate fat levels. Natural color-enhancing pigments, spirulina and all vitamins necessary to meet the special needs and requirements of marine fishes are also included. O.S.I Marine Pellets are appropriate for large marine fishes. Because most saltwater tanks utilize "surface skimming" filters, O.S.I Marine Pellets are designed to sink slowly allowing fish time to feed, while minimizing food being sucked into the filter.