Zooplankton Characteristics

I. Introduction

Inland bodies of waters of every form, composition, altitude and latitude are populated with organisms, both plants and animals. The quantity, distribution, and diversity of these organisms differ greatly in various waters and are primarily determined by its immediate environment and the factors that characterize it (Soo, et. al., 1997).

The animal components of these waters, particularly lakes, are represented mostly by zooplankton in extremely great numbers so that an evaluation of their population dynamics, and certain important environmental characteristics that influence these dynamics, is fundamental to formulations of the productivity of these aquatic bodies (Reazo, 2001).

Bukidnon is a province in Northern Mindanao with

Literature Review

Much of the fascination in the study of lakes lies in the structure and the dynamics of zooplankton populations in both space and time (Goldman and Horne, 1983). Normally, the zooplankton community in most lakes is composed of five to eight dominant species and several rarer forms, belonging to three major groups such as the Rotifera, Cladocera, and Copepoda. The rotifers and limentic copepods overwhelmingly constitute the dominants of zooplanktonic productivity (Wetzel, 1975). Rotifers, which can inhabit water of all kinds, possess a corona and specialized pharynx (mastrax) (Pettersen, 2011). Cladocerans are commonly known as water fleas due to their size and jerky swimming motion (Brian, 2010). They play a significant role in clearing lake water by their combined direct (efficient filtering) and indirect (suppression of ciliates and rotifers) impact on nutrient sedimentation from internal cycling (Karabini, et al., 2007). Planktonic copepods are important ecological link in the aquatic food chain linking microscopic algal cells to juvenile fish to whales. They also have the potential to act as control mechanisms for malaria by consuming mosquito larvae, and contrarily are intermediate hosts of many human and animal parasites (Walter & Boxshall,

They have been found to house a bacterium Vibro cholerae, which can cause cholera, by allowing the cholera vibrous to attach to their chitinous exoskeletons. This symbiotic relationship enhances the bacterium 's ability to survive in aquatic environment, as the exoskeleton provides the bacterium with carbon and nitrogen (Jude, 2005). Usually, the knowledge of zooplankton distribution, diversity, and abundance would be an indicator of the condition of freshwater ecosystem. If the diversity of the is low, the stability of the environment is also low, and would readily indicate unfavorable conditions such as perturbations and disturbances that are either man-made or natural. If the diversity is high, then the ecosystem is more stable, leading to longer trophic food chains and greater adaptations to possible environmental disturbances. Hence, diversity, abundance, and distribution are directly related to environmental stability (Mamaril,