Informatics Publishing Limited

M. Fakhri ¹, N. B. Arifin ¹, B. Budianto ¹, A. Yuniarti ¹, A. M. Hariati ²

Affiliations
1 Department of Aquaculture, Faculty of Fisheries and Marine Sciences, University of Brawijaya, Malang 65145, ID
2 Laboratory of Fish Nutrition, Faculty of Fisheries and Marine Sciences, University of Brawijaya, Malang 65145, ID

Abstract

In this present study, the effect of salinity and photoperiod on the growth of Nannochloropsis sp. and Tetraselmis sp. was examined to optimize microalgal growth. Different salinities (5, 10, 15 and 20‰) for Nannochloropsis sp. and (10, 15, 20 and 25‰) for Tetraselmis sp. were studied. Both microalgae were cultivated at two different photoperiod cycles (24:0 and 12:12 h light:dark). Maximum growth rates and cell concentrations for Nannochloropsis sp. and for Tetraselmis sp. were achieved at salinities of 10 and 15‰, respectively. In terms of photoperiod, the maximum growth rates and cell concentrations for both microalgae were obtained at photoperiod of 24:0 h light:dark. This study shows that the cell concentrations and growth rates of both microalgae are highly dependent on salinity and photoperiod.

Keywords

Microalgae, Salinity, Photoperiod Growth Rate, Cell Concentration.

Full Text

   

M. Fakhri ¹, B. Budianto ¹, A. Yuniarti ¹, A. M. Hariati ²

Affiliations
1 Department of Aquaculture, University of Brawijaya, Malang 65145, ID
2 Laboratory of Fish Nutrition, University of Brawijaya, Malang 65145, ID

Abstract

Measurement of nine water quality parameters were performed every two weeks in two shrimp farms for one production cycle, located in Tuban and Probolinggo, East Java Province, Indonesia. The average productivity for Farm 1 was 17,142.86 kg/ha, with an average size of 17.88 g; while the productivity for Farm 2 was 18,333.33 kg/ha, with an average size of 14.36 g. During the shrimp cultivating period, mean values for salinity, pH and dissolved oxygen (DO) in both the farms were significantly different, whereas temperature in both the farms was not different. TAN, nitrite and orthophosphate concentrations in both the farms were not different. But for nitrate and TSS, the levels are higher in Farm 2 than in Farm 1. The authors conclude that, compared with Farm 1 (water exchange and earthen pond), Farm 2 (zero-water exchange and lined pond) had significantly higher survival rate and higher environmental profits.

Keywords

Earthen and Lined Ponds, Shrimp Farm, Water Quality, Litopenaeus vannamei.

Full Text

   

M. Fakhri ¹, N. B. Arifin ¹, A. Yuniarti ¹, A. M. Hariati ²

Affiliations
1 Department of Aquaculture, University of Brawijaya, Malang 65145, ID
2 Laboratory of Fish Nutrition, University of Brawijaya, Malang 65145, ID

Abstract

In this study, the effect of salinity (5, 15, 25 and 35‰) on growth and total chlorophyll content of Nannochloropsis sp. BJ17 was evaluated. Moreover, chlorophyll content during logarithmic and stationary phases was investigated. The results showed that maximum cell growth and chlorophyll concentration of Nannochloropsis sp. BJ17 were achieved at the salinity of 15‰. The algae had the higher total chlorophyll concentration in stationary phase than in logarithmic phase. The authors conclude that, the optimum growth and chlorophyll content of Nannochloropsis sp. BJ17 were achieved in salinity of 15‰.

Keywords

Cell Growth, Chlorophyll, Nannochloropsis sp. BJ17 Salinity.

Full Text

   

A. M. Hariati ¹, Aulaniam ², E. Y. Herawati ³, D. G. R. Wiadnya ⁴

Affiliations
1 Laboratory of Fish Nutrition, University of Brawijaya (UB), Jl. Veteran 65145 Malang, ID
2 Laboratory of Biochemistry, University of Brawijaya, Malang, ID
3 Department of Aquatic Resources, FFMS, University of Brawijaya, Malang, ID
4 Department of Fisheries, FFMS, University of Brawijaya, Malang, ID

Abstract

In this study, immobilized bacteria (Nitrosomonas, Nitrobacter and Nitrospira) were added into three shrimp ponds in a concentration of 2x10⁶ cfu mL^-1 that equals to 20 kg beads ha^-1. The other three ponds were used as control treatment. All ponds were stocked with PL’s (Post Larvae) of Pacific white shrimp at a density of 100 PL’s m^-2. Shrimps were fed with a commercial diet containing 36% crude protein, 7% fat, 10% ash, and 2% crude fibre. Oxygen was kept near saturation through paddle-wheels. Secchi disc depth, pH and temperature were monitored daily. Total ammonia nitrogen (TAN), nitrite and nitrate were measured every 10 days together with sampling for shrimp body weight and feed adaptation. Average TAN concentration of ponds with nitrifying bacteria was 0.12±0.144 mg L^-1, one fourth of the control ponds (0.523±0.564 mg L^-1). Average nitrite concentration in control ponds (0.058±0.045 mg L^-1) was also significantly higher than the ponds added with immobilized bacteria (0.037±0.038 mg L^-1). However, the end product of nitrate was not significantly different (α = 0.607) among the ponds. Although not affecting shrimp growth, TAN suppression significantly increases the survival rate and finally resulted in higher (α = 0.043) biomass harvest, from 12.37 t ha^-1 (control ponds) to 18.87±2.91 t ha^-1 at treatment ponds. This study concluded the importance of transforming TAN concentration into nitrate, particularly in intensive culture system. To do this, the presence of immobile nitrifying bacteria is needed.

Keywords

Ammonia, Shrimp Production, Tambak System, Immobilized Bacteria.

Full Text