Hama macro is a parasitic organism that is larger than 2 cm contained cultivation location itself and has been in the form of large size / adults. Fish beronang (Siganus spp), is the biggest pests in the cultivation of seaweed. Beronang fish seed has clustered nature of the most serious pests of attack. These fish attack the entire thallus the outside, consequently seaweed left only the skeleton alone. Beronang fish is seasonal attacks especially in the seed, so that in every area of the attack time was different.
Beronang fish eat the ends thallus Gracilaria sp. Sign on fish inedible seaweed former beronang is contained small pieces at the end of the thallus, not all thallus inedible seaweed exhausted and do not decay. Beronang fish do not eat the whole thallus. Thallus are eaten only ramification of the youngest. Biota has become one of the bullies in seaweed cultivation because of the nature of the clustered eating and looking green plants.
Beronang fish have small mouths. Biota is also not eat seaweed as a main meal. So that the seaweed is eaten only thallus new branches grow or younger only. In contrast to thallus who eat turtle, turtle inedible end thallus that will easily grow again.
Figure 18. A group of fish that attack seaweed