SUBSTITUSI PENGGUNAAN NAUPLIUS ARTEMIA DENGAN PAKAN MIKRO DALAM PEMELIHARAAN LARVA KEPITING BAKAU, Scylla olivacea

Abstract

Adanya molting death sindrom yang umumnya terjadi pada stadia zoea-5 ke megalopa dan ke krablet-1 pada kepiting bakau, Scylla olivacea, diduga berkaitan dengan ketidakcukupan nutrien yang dikonsumsi larva, sehingga perlu dicobakan penggunaan pakan buatan (mikro) pada stadia tersebut. Penelitian ini bertujuan untuk mendapatkan dosis optimum penggunaan pakan mikro (micro diet, MD) untuk mensubstitusi penggunaan nauplius Artemia (Art) dalam pemeliharaan larva kepiting bakau. Hewan uji yang digunakan adalah larva kepiting bakau stadia zoea-4—5. Hewan uji tersebut dipelihara dalam wadah bak fibre berisi air laut 150 L dengan kepadatan 12 ind./L. Perlakuan yang dicobakan adalah pemberian pakan uji berupa: nauplius Artemia sebanyak 100% (100% Art), nauplius Artemia 75% + pakan mikro 25% (75% Art + 25% MD), nauplius Artemia 50% + pakan mikro 50% (50% Art + 50% MD), nauplius Artemia 25% + pakan mikro 75% (25% Art + 75% MD), dan pakan mikro 100% (100% MD). Pemberian pakan uji dilakukan pada pagi dan sore hari selama 15 hari pemeliharaan (hingga larva mencapai stadia krablet-1). Hasil penelitian menunjukkan bahwa pada penggunaan nauplius Artemia 50% + pakan mikro 50% didapatkan sintasan krabet-1 tertinggi (5,6%) dan berbeda nyata (<0,05) dengan sintasan krablet pada penggunaan 100% nauplius Artemia (sintasan 2,4%) dan 100% pakan mikro (sintasan 2,1%). Bobot badan, lebar karapaks krablet, dan aktivitas enzim pencernaan relatif sama di antara perlakuan. Penggunaan pakan mikro dapat menggantikan 50% penggunaan Artemia dalam pemeliharaan larva (zoea-5 hingga krablet-1) kepiting bakau.Cases of molting death syndrome generally occur on the transitional stage of zoea-5 to megalopa stage and to crablet-1 of mud crab, Scylla olivacea. It is suspected that the event could be related to nutrient insufficiency consumed by the larvae which can be supplemented using artificial diet (micro diet). This study aims to obtain an optimum dosage use of the micro diet (MD) to substitute the use of Artemia nauplii (Art) in the crab-larva rearing. Test animals used were mud crab larvae of zoea-4—5 stadia. The test animals were reared in the fiberglass containers, filled with seawater as much as 150 L, and stocked with a density of 12 ind./L. The treatments tested were feeding tests in the form of: Artemia nauplii as much as 100% (100% Art), Artemia nauplii 75% + micro diet 25% (75% Art + 25% MD), Artemia nauplii 50% + micro diet 50% (50% Art + 50% MD), Artemia nauplii 25% + 75% micro diet (25% Art + 75% MD), and micro diet 100% (100% MD). The larvae were fed daily in the morning and afternoon for 15 days until the larvae reach crablet stage. The results showed that the use of Artemia nauplii 50% + 50% micro diets obtained the highest survival rate (5.6%) of crablet-1 and significantly different (<0.05) with the survival rates of crablet fed with 100% of Artemia nauplii (survival rate of 2.4%) and crablet fed with 100% micro diet (survival rate of 2.1%). Body weight, carapace width of crablet, and digestive enzyme activities were relatively similar between the treatments. The use of micro diet could replace 50% of the utilization of Artemia nauplii in larvae (zoea-5 to crablet-1) rearing of mud crab.