Proliferation of Janitor Fish in a river system Background of the Study: A lot of fishermen now a days are complaining because of low catch due to rapid growth of Janitor fish (Hypostomus plecostomus). This type of fish contributes to the severe erosion of river banks, a predator to some local fishes and a competitor of food for the local fishes. The researcher chose this topic to know which river system has a rapid growth of janitor fishes. Janitor fish or Suckermouth Catfish is a tropical fish that occur in the wild in fresh running waters and brackish waters of river mouths. The suckermouth catfish is named for its sucker-like mouth, which allows it to adhere to a surface, as well as to hold and rasp at food. These fish are sold when they are young and small but they can grow to be a maximum size of over a foot to around 50 cm or so. Main problem: This study aims to determine if there is a chance of survival in the selected rivers in Iligan City. Sub-problems: 1. Which of the selected river systems in Iligan City has the most rapid growth Janitor fishes? 2. How rapid is the growth of Janitor fishes in a said river ? 3. Which river has been occupied the longest by Janitor fishes? 4. What is in the selected river systems that can affect the growth of the Janitor fish? Hypotheses: 1. There is a chance of survival of Janitor fish in the selected river systems. 2. There is no chance of survival of Janitor fish in the selected river systems. Objectives of the study: This study aims to: 1. Know if there is a chance of survival of Janitor fish in the selected rivers in Iligan City. 2. Know how rapid the growth of Janitor fish is in the selected river systems. 3. Determine what is in the selected river that can affect the life span of Janitor fishes. 4. Determine what is in the selected river systems that can affect the growth of the Janitor fish. Significance of the study: The research paper aims to determine which among the river system in Iligan City is being resided by Janitor fishes. The fishermen of Iligan City can benefit from this research because they will know what river is not abundant with fishes due to rapid growth of Janitor fish. The researchers can also gain knowledge from this research more about Janitor fish and their habitat. Scope and Limitations: This study is limited only to the determination of if there is a chance of survival in the selected rivers in Iligan City. This study is also limited only to know which river in Iligan City has the most abundant and has the most rapid growing Janitor fish. It is limited only to know what is in the selected river system of Iligan City that can affect growth and life span of the Janitor fish. This study is performed at the selected river system of Iligan city. Definition of terms: 1. Proliferation-To grow or multiply at a rapid rate.