by Ranell Martin M. Dedicatoria, KMU-SEARCA
22-January-2009 SEARCA News Release
Sailfin catfish or janitor fish (Pterygoplichthys pardalis and P. disjunctivus), as it is more popularly known, has proliferated Laguna de Bay. This has seriously threatened the livelihood of many fishermen in many ways.
Janitor fish (Pterygoplichthys disjunctivus) is an exotic invasive species in Laguna de Bay. (Photo: nas.er.usgs.gov)
As an algae-eater, the janitor fish competes for food supply with other more marketable fish leading to the displacement of native species. Its breeding behavior contributes to water turbidity since it creates deep burrows in lake and riverbeds. The janitor fish’s bone structure can also damage gill nets used by fishermen.
The janitor fish is not normally considered as human food; although, there are undocumented cases where such fish is eaten. Originally introduced in the Philippines in the early 1990s as an aquarium fish to clean algae, it has become an invasive species and until recently, presented no economic benefit.
With the problem on its proliferation becoming more pronounced, the Laguna Lake Development Authority (LLDA) initiated a project funded by World Bank that would create an economic demand for the janitor fish. The project aims to control the species’ invasiveness and at the same time, provide additional income to the fisher folk. The premise is to use the janitor fish as an ingredient of feeds for pig and poultry.
Nutrient-wise, laboratory analyses showed that the processed janitor fish meal can be an alternative source of protein.
Field experiments evaluating the effects of feeding janitor fish meal to chickens and pigs showed that its inclusion in both animals’ diet improved their growth.
Toward this end, there are new livelihood opportunities that can be explored in the years to come. However, it is necessary that further studies on the janitor fish be conducted in order to effectively address their invasiveness.
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Reference:
Benefiting from the Dreaded Janitor Fish. Paper presented by Mr. Jose K. Cariño III, Division Chief for Community Development, LLDA during the Agriculture and Development Seminar Series (ADSS), 13 January 2009.
