Pengaruh Perbedaan Intensitas Cahaya terhadap Kelimpahan Chlorella sp. dan Dunaliella sp.

Abstract

Chlorella sp. dan Dunaliella sp. merupakan jenis fitoplankton dari kelas Chlorophyta yang menjadi pakan alami udang, terutama udang stadium pasca larva. Sebagai produsen primer di tambak, pertumbuhan fitoplankton dipengaruhi oleh intensitas cahaya. Penelitian bertujuan untuk menganalisis pengaruh besar intensitas cahaya yang berbeda terhadap kelimpahan Chlorella sp. dan Dunaliella sp. Kedua jenis fitoplankton ditumbuhkan pada intensitas cahaya 1000 lux, 3000 lux, dan 7000 lux. Sumber pencahayaan didapat dari lampu pendah putih (cool daylight TLD). Penghitungan kelimpahan dilakukan setiap hari selama 10 hari menggunakan haemocytometer. Analisis data dilakukan untuk mengetahui pertumbuhan sel, signifikansi pengaruh perbedaan intensitas cahaya terhadap kelimpahan sel, dan hubungan antara nutrien dengan kelimpahan sel. Hasil penelitian menunjukkan bahwa perbedaan intensitas cahaya memengaruhi kelimpahan Chlorella sp. dan Dunaliella sp. secara signifikan. Kelimpahan Chlorella sp. dan Dunaliella sp. tertinggi didapatkan pada intensitas cahaya 1000 lux, sedangkan kelimpahan terendah didapatkan pada intensitas cahaya 7000 lux.

Chlorella sp. and Dunaliella sp. are phytoplanktons from the class of Chlorophyceae which are natural foods for shrimp, mainly the postlarva. Being a primary producer in shrimp pond, phytoplankton growth is influenced by light intensity. The aim of this study is to examine the influence of different light intensities on the abundances of Chlorella sp. and Dunaliella sp. Both phytoplanktons were cultivated under 1000 lux, 3000 lux, and 7000 lux light intensities. The illuminance was from white fluorescent lamps (cool daylight TLD). Their abundances were counted every day within 10 days using haemocytometer. Data analyses were carried out to deduce the information about cell growth, significance of influence of different light intensities on the cell abundance, and relationship between nutrients and cell abundance. The result suggested that different light intensities significantly affected the abundances of Chlorella sp. and Dunaliella sp. The highest abundances of both phytoplanktons were obtained under 1000 lux, while the lowest abundances were obtained under 7000 lux.