Preliminary Study on Invasive Fish Species Diffusion in Selected Malaysian Freshwater Ecosystems

Area of Science:

• Ecology
• Freshwater Biology
• Invasive Species Research

Background:

• Malaysia faces significant invasive species intrusion in its river systems.
• Native fish species are threatened by the proliferation of alien species.

Purpose of the Study:

• To compare the composition and species richness of invasive and local fish.
• To estimate the growth patterns of both invasive and local fish species.

Main Methods:

• Fish sampling in pristine and disturbed freshwater ecosystems using cast nets and electric shock.
• Identification, measurement (length-weight), and photographic documentation of collected fish.
• Length-weight analysis to estimate growth patterns.

Main Results:

• 188 fish comprising 15 species (10 local, 5 alien) were identified.
• Tilapia nilotica was the dominant alien species; Sistomus binotatus was the dominant local species.
• Alien species show colonization potential, with Tilapia nilotica exhibiting isometric growth in both ecosystem types.

Conclusions:

• Alien species, particularly Tilapia nilotica, demonstrate colonization capability in stressed Malaysian freshwater ecosystems.
• Invasive species pose a threat to native fish through competition for resources and survival advantages.
• Effective management strategies are needed to mitigate the impact of invasive species on native biodiversity.