1.1 Introduction.
‘’Fish’’ and ‘’Fishes’’ are two terms that usually used in worldwide. However, both are referring to different meaning. When referring to individuals of more than one species, the term ‘’fishes’’ is properly to used. Besides, the term ‘’fish’’ is correctly used when referring to one or more individuals of one species. Hence, the term ‘’fish’’ is suitable to be refer to 100 Rainbow Trout, while two different trout such as Brook Trout and Brown Trout is correctly to be refer as ‘’fishes’’ (J.S.Nelson, 2006). Disclosure of what the first fishes may looked like is based on fossil finds in recent years. Based on this finds, the fossil records of the fishes is push back into the early Cambrian. The fossil ascidians (eg: Cheungkongella), cephalochordate-like yunnanozoans (eg: Haikouella and Yunnanozoon) and jawless craniates (eg: Myllokunmingia and its junior synonym Haikouichthys) …show more content…
However, the growth of the fishes is depends on the quality and quantity of food that they eaten (Shelby D. Gerking, 1994). By identifying the species of food in stomach content of the fishes, it will be described the food habit of the fishes. Some fishes feed directly on plants (eg: phytoplankton or pondweeds or both) and some fishes fed on other animals, where the word of ‘’predator’’ usually implies on them (Shelby D. Gerking, 1994). However, Shelby D. Gerking (1994) also state that some fishes prefer phytoplankton and zooplankton (eg: plankton predator) and benthic predator more prefer pondweed and invertebrates living on the bottom as their nourishment. These show that food habits of the fishes fall into three categories, which is herbivorous, carnivorous and omnivorous. Fishes in herbivorous categories feed on plants while carnivorous fishes feed on other animals and omnivorous fishes prefer both plants and animals as their