Ciliated protozoans are one-celled animal-like organisms characterized by the presence of hair-like structures called cilia. Just like any other organisms, the ciliated protozoans (e.g. Paramecium, Tetrahymena, Vorticella, Stentor) play a very significant link in the food chain as algal grazers and bacterial feeders, and in energy flow and elementary recycling in ecosystems.  Ciliates are popular model organisms for many microbial, cell and molecular biology studies, toxicity bioassays of pollutants, chemosensory responses, lysosomal studies and others (Jahn et al. 1979, Pauli 1997, Banno 1983, Madoni P. and Romeo M. 2006, Rao et al., 2012). As test organisms, ciliates have many advantages such as ubiquitous distribution, high reproductive rate, and cheap and ease of culturing in hay infusion. More than 50% of the population in organically polluted rivers and streams are ciliates, playing impressive role in the ecosystem as warning indicator of changes in the environment. They have been utilized as indicators of organic pollution and in monitoring the health of aquatic ecosystems (Lynn & Gilron 1992, Bick 1972, Mason 1996, Tushmalova et al. 2014 and  Radhakrishnan  & Jayaprakas 2015). Moreover, they are abundant in almost every environment with liquid water: ocean waters, marine sediments, lakes, ponds, and rivers, and even soils. Because individual ciliate species vary greatly in their tolerance to pollution, the ciliates found in a body of water can be used to gauge the degree of pollution quickly.  

There is no documented and published identification of ciliated protozoans in Lake Lanao, the heart of Lanao del Sur ARMM province, Mindanao island (Fig. 1). Though the work of Lewis (1985) on Lake Lanao mentioned ciliates as a group under protozoans but he did not segregate and identify a particular ciliate genus or species. Moreover, most lake studies in the country did not include ciliates. There are phytoplankton and zooplankton studies but no particular studies for ciliated protozoans. In the study of Aquino et al. (2008) on zooplankton in Paoay Lake, Luzon Island, ciliates were not included. Even in “An Illustrated Key to the Philippine Freshwater Zooplankton including some brackish water species from Laguna de Bay” (Petersen et al. 2014), only Paramecium, Vorticella (freshwater), and Tintinnidium (brackish) are described. This project therefore aims to conduct a preliminary inventory of ciliated protozoans in Lake Lanao. Specifically, it intends to identify and classify ciliates morphologically and molecularly by DNA barcoding; to take and compile photomicrographs and video clips of all ciliates found in the lake; to determine ciliate species composition, diversity, frequency, and abundance; to determine ciliates’ spatial and temporal variations in the lake; and to monitor the lake’s aquatic condition for two years utilizing ciliates as bio-indicators of pollution.  

Lake Lanao, the second largest lake in the Philippines with surface area of 354.60 km2, is famous for being one of the ancient lakes in the world and for its endemic cyprinids fish fishes. The Lake has played a vital role in the religious activities, cultural practices, transport system, and livelihood for the Maranaos, the “people of the lake”. There are six hydroelectric power plants along its single outlet, the Agus River, providing approximately 70% of the electric power needs of Mindanao. Bordering the lake's shores are 17 municipalities and a city, Marawi City. There were 475,401 people living along the shoreline of Lake Lanao that comprises 68,759 families.

(http://www.mysmartschools.ph/web/lakelanao/com munity-profile.html). NSO data revealed Lanao del Sur had a total population of 800,162 in 2000; it increased to 1,138,544 in 2007 and decreased to 933,260 persons in 2010 (http://web0.psa.gov.ph). Compared with the other lakes in the country, Lake Lanao is relatively free from industrial effluents. However, as early as 1966, there were reports that Lake Lanao had undergone environmental disaster because of the massive algae contamination and some decaying matters on waters (Villaluz, 1966). Presently, ocular inspection around the lakeshore reveals floating thrash and massive growth of water hyacinth and algae. The impact of the hydroelectric power plants, the confront of climate change, the increasing human population, the alarming reports of extinction of endemic lake fish species, the dominance of invasive exotic species, and many other anthropogenic factors, if left unchecked, the lake’s deterioration will surely affect the lives of thousands of Maranaos who are dependent on it for food and water. This project therefore hopes to generate data from utilization of ciliates as bio-indicators of pollution that will be submitted to the ARMM government of Lanao de Sur and will serve as one basis in assessing the condition of the Lake, formulating and implementing policies and strategies for effective management of Lake Lanao’s natural resource sustainability. Furthermore, the baseline data on ciliate species composition, diversity, frequency, and abundance, would be vital micro-faunal component of Lake’s biodiversity and taxonomic studies later. Ciliates are also cheaper alternative in toxicity bioassays and in environmental bio-indication studies since they can easily be cultured in hay infusion medium. They have shorter generation time hence studies using ciliates yield and indicate fast, reliable results.  The culture collection of ciliates the proponent plans to maintain will be useful for basic instruction and laboratory exercises, and for researchers, teachers and students. 

On the first year of the project, preliminary inventory will be conducted in eight municipalities bordering Lake Lanao as sampling stations. Randomly, sampling will be done in shallower (littoral) and deeper (pelagic) regions of the lake. Surface, subsurface, horizontal and vertical tow samplings will be done using Plankton nets and Niskin bottles. Morphological identification is mainly through microscopy and identification keys. Photomicrographs and video clips will be taken and compiled. Data generated will include ciliate composition, diversity, abundance and frequency as well as ciliates’ spatial variations between littoral and pelagic areas in the lake.  On the second year, the same data will be generated but the ciliates’ temporal (dry, rainy, mixing and non-mixing seasons) variations at two different sampling sites away from inlet and outlet will be evaluated. Quarterly monitoring of Lake’s water condition using ciliates as indicators will also commence on the 2nd year and will continue on the 3rd year at six ecological sites (inlets and outlet, domestic, agricultural, forested, and undisturbed sites).  Dominant key ciliate indicators will be classified according to saprobic system. Molecular identification of ciliate species will start on the 3rd year.