Effects of chlorella sp. and spirulina sp. on survival, growth and resistance of Penaeus monodon larvae against Vibrio harveyi

This study is focused on the effects of Chlorella sp. and Spirulina sp. on survival, growth and resistance of Penaeus monodon Fabricus larvae against Vibrio harveyi. Two set-ups with five treatments in three replicates were tested in a complete random design. Set-up A consists of Skeletonema: Chorella (Sk: Ch) treatment ratios; 1 SK:0Ch, 3SK:1Ch, 1SK:1Ch, 1SK:3Ch and 0SK:1Ch designated as T1A, T2A, T3A, T4A and T5A, respectively. Set-up B consists of Skeletonema: Spirulina (Sk:Sp) treatment ratios; 1SK:0SP, 3SK:ISP, 1SK:ISP, 1SK:3SP and OSK:1SP designated as T1B, T2B, T3B, T4B and T5B respectively. One hundred percent Skeletonema, Chlorella, and Spirulina treatments corresponded to a density of 10,000 cells/mL, 20,000 cells/mL, 1,000 cells/mL (1mg/L), respectively. Feeding was initiated at zoea one day(Z1) stage with 8 hours interval until the post larval five day (PL5) stage. Survival and growth were determined at mysis 1 day (M1) and post larval five day (PL5) stages. Growth was measured using absolute values of growth at M1 and total growth at PL5 using a micrometer ruler. Resistane of larvae was determined in terms of survival at PL5 after a challenge dose(1.5x10E2 cells/mL) of V. harveyi. Set-up A survival at M1 showed highest percentage in T4A (56.67%), followed by T3A (49.00%), T2A (44.67%), T1A (21.00%) and T5A (20.00%). Better survival after challenge of V. harveyi was shown at PL5 by larvae fed with chlorella with T3A having the highest(52.15%) followed by T4A(46.32%), T2A(45.6%), T5A and T1A(26.80%). All treatments with chlorella showed better growth at M1 with T3A (4.34) having the highest value. T3A obtained the highest total growth at PL5(5-80) followed by T2A(5.55) T4A (5.45) T1A(4.98) and T5A(4.90). Set-upB survival at M1 showed the highest percentage in T1B(52%) followedby T2B(36.67%), T3B and T4B (25.67%), and T5B (0%).T3B had the highest percentage survival at PL5 (55.99%), followed by T1B(42.31%), T2B(33.66%), and T4B(28.60%). T1B and T2B had the highest value of growth (3.55%), followed by T3B (2.90) and T4B (2.85). T3B had the highest growth at PL5(5.06) followed by T4B (4.72), T1B(4.40) and T2B (4.38). The results suggest that Chlorella sp. can enhance P. monodon survival from Z1 to M1, stage at a concentration ratio of 75% Chlorella: 25% Skeletonema, growth and resistance of the larvae against V. harveyi at a concentration ratio of 50% Chlorella: 50% Skeletonema and that it has the potential to replace Skelatonema as food for P. monodon in the earlier stages. Spirulina has no significant role in increasing the growth and survival of P. monodon from Z1 to M1, but play a role in resistance to V. harveyi and growth after M1 at 50% Spirulina; 50% Skeletonema sp.