Philippine E-Journals

Potentials of Invasive Pterygoplichtys Disjunctivus (Janitor Fish) Rind as Fish Skin Leather

Eusseph Federico | Andrea Denisse Verendia | Ryan Joseph Vidal | Enrico C. Garcia

 

Abstract:

Janitor fish (Pterygoplichtys disjunctivus) is one of the most destructive invasive fish species in the Philippines. Without having a natural predator to reduce its population, the number of janitor species had rapidly increased throughout the years. Laguna de Bay had been documented to be one of the bodies of water in the Philippines that had an abnormal number of janitor fishes. Since Janitor fish had been identified as an invasive species that had no recorded natural predators and had no use in fishery and agriculture, the researchers aim to produce fish skin leather made from janitor fish rind by removing and harvesting the skin then curing the produced fish leather in order to limit the population of these invasive fishes and to make an alternative product that would possibly help in aquaculture and economy in the Philippines. The Janitor Fish rind was acquired by removing the skin of the fish and separating the scales and meat from it. It was then marinated for a day in a solution containing 100 ml vegetable oil, dishwashing liquid, and one egg yolk. The skin was then hanged in direct sunlight overnight. It was then softened with the use of hands and a rolling pin, then was hanged for another three days in a cool shaded area. The Janitor fish leather was tested using the feasibility test provided by South African Leather Research Institute (SALRI). The leather registered a stretch index of 30% which passed the ≥ 20% and ≤ 40% LSI (Leather Stretch Index) of SALRI and it was also tested to be waterproof. The Flex Resistance was also measure using Bally Flex Method. Recommendations for the study includes careful removal of the scales from the skin since the scales of Pterygoplichtys disjunctivus is hard and rugged and would easily damage the skin if not carefully removed. It is also recommended to extract skin from adult Janitor fish as it does contain more abundant amount of removable skin throughout its body.