Evaluation of Compartments Using in Floating Cage Culture On The Level of Stress and Growth of Spiny Lobsters Panulirus homarus.

Abstract

Still found weaknesses in survival rates and low productivity of spiny lobster, it is thought to be influenced by environmental factors such as stress levels arising from the cultivation of media used such as maintenance of the spiny lobster captured without the use of shelters, but shelter is useful as a shelter of cannibalism. So that the necessary development innovation of lobster container that can minimalized of stress levels and increase productivity such as making special compartment equipped with shelter. Compartments in this study is made of fiber-shaped cube that hung in floating net cages and lobster-sized used is ± 50gr/lobster derived from fishermen around the waters of Pelabuhan Ratu with the feed is trash fish with protein levels of 63.22%. Maintenance performed using a compartment in floating cages for 30 days.Test parameters were observed during the study consisted of the level of stress (kortisol and glucose levels in the hemolim), survival rates, weight gain, specific growth rate, behavior and quality of water. Experimental design applied in this study is completely randomized design. Treatments of this study consisted of (1) control treatment (K) that spiny lobsters were kept/cultivated in nets that did not use compartment and shelter with density of 20 lobster/m2, (2) KM1 treatment that spiny lobsters were cultivated used compartment with density of 25 lobsters/m2 and (3) KM2 treatment that spiny lobsters were cultivated used compartment and shelter with density 50 lobster /m2. Data of cortisol glucose and levels, survival and growth, were analyzed using ANOVA and with helped of software MINITAB 16. The results showed that the highest stress levels of spiny lobsters was found in control treatment, it was shown by the high levels of cortisol (1.59±0.28 nmol/l) and glucose (17.13±1.27 mg/dl), while the lowest stress levels was found in KM1 treatment with cortisol (1.17±0.14 nmol/l) and glucose level (8.34±0.5 mg/dl). The highest survival rate of spiny lobsters was found in KM2 treatment (95±0.03%) and the lowest survival rate was found in the control treatment (62.50 ±0.02%). The highest weight gain (26.29±1.69%) and highest specific growth rate (0.77±0.014%) were found in KM1 treatment, while the lowest weight gain (13.51±4.47%) and lowest specific growth rate (0.42±0.13%) was found in KM2 treatment. Spiny lobsters growths were cultivated using compartments and shelters was better than without using compartments and shelters. Spiny lobsters cultivated in floating nets without using compartments and shelters tend to be more stressful and caused decreasing of the growth and survival rates. Weight gain has a strong relationship with cortisol and glucose levels. Decreased levels of stress (cortisol and glucose levels) due to increase in growth Cortisol and glucose levels have a positive correlation, meaning that the increase cortisol levels followed by increased of glucose levels, which is in line with the opinion and Krogdahl Hemre (1996) and Falahatkar and Barton (2007) that cortisol can increase the levels of glucose in the haemolymph, disturbances in cortisol secretion may alter the response of glucose and increase glucose values can be attributed to differences in the mechanism of action of cortisol. Spiny lobsters cultivated using compartment showed normal behavior patterns such refuge in shelters in the morning until noon, huddled among others, took the feed even though the feed was given in the morning and during the day, mostly lobster there that bring the feed into the shelter, creeping to the upper compartment and moulting activities.