Fractal analysis of Hippocampus spp. (seahorse) from Surigao City, Philippines

Abstract

Assessment of species can be promising for ecosystem and environment sustainability. The demand for trading and environmental impact becomes the culprit to decline in seahorse population. Hence, this paved way for the emergence of plausible non-destructive method and tools for monitoring to measure risks and vulnerability. The area near Surigao city, had been popular due to mining practices and also a famous route for seahorse trade in Mindanao. The aim of this study is to use fractal geometry to look into morphometric complexity patterns of different species of seahorses (Hippocampus spp.) in Surigao City. Irregular non-Euclidean objects are better described by fractal geometry and the measurable value is called the fractal dimension. Box-counting and lacunarity method were performed with FracLac v.2.5, and available as a plugin to ImageJ. The method was done to test whether significant differences in fractal dimension and lacunarity values can be speciesspecific and provide evidence of vulnerability. It is hypothesized that fractals are far from the equilibrium state and thus associated with chaos. Thus, high fractal dimensions have implications to vulnerability of species. High fractal dimension based on box-counting and lacunarity method was associated with H. comes. The results for fractal dimensions (DB) were in accordance with the coefficient of variation (CV) values. Information obtained aide in understanding the nature of species in Surigao city.

Keywords

• fractal analysis
• Hippocampus
• seahorse
• Surigao city
• box-counting method
• lacunarity