Shrimp

I've read something about a shrimp. It lays its eggs in the ground. It doesn't live more than 90 years, but its eggs can stay in the water for 25 years. Shrimps in California are more than that in China. There are more shrimp in California than in China.  Shrimps feed on similar animals. Shrimps are categorized under as a living fossil. In California, Shrimps are pests because they move the sediment that doesn't allow keeps light from reaching seedlings

"Shrimps feed on similar animals" -- i don't totally understand what you are saying here because the word "similar" needs to compare to something that was referred to earlier or to compare to something in the same sentence.  Which animals are similar to what shrimp eat?