Aktivitas enzim pencernaan larva ikan kerapu macan (Epinephelus fuscogutattus Forsskal, 1775) terkait dengan perbedaan jenis pakan

MELIANAWATI, Regina, Dra. Rarastoeti Pratiwi, M.Sc., Ph.D

2008 | Tesis | S2 Biologi

Ikan kerapu macan (Epinephelus fuscoguttatus) merupakan jenis komoditas perikanan laut bemilai ekonomis tinggi yang hams dijaga kelestariannya, sehingga kegiatan budidaya terhadap ikan kerapu tersebut penting dilaksanakan. Namun dalam kegiatan budidaya masih dijumpai kendala tingginya mortalitas pada dua periode kritis larva berumur 1-20 hari. Faktor yang diduga menjadi penyebab mortalitas tersebut adalah masalah fisiologis larva yang berkaitan dengan enzim pencemaan karena pada kedua periode kritis tersebut larva mengalami dua kali pembahan sumber pakan, yaitu dari pakan endogen ke pakan eksogen yang bempa pakan alami dan dari pakan alami ke pakan buatan. Penelitian ini bertujuan untuk (1) mendeteksi waktu awal aktivitas enzim, (2) mengetahui pengaruh pemberian pakan alami dan pakan buatan terhadap aktivitas enzim dan (3) menemukan pola aktivitas enzim pada larva umur 1 hingga 20 hari, terkait dengan konsumsi p^an endogen dan pakan eksogen. Enzim yang dianalisis meliputi protease, amilase dan lipase. Penelitian terdiri dari 3 tahap sesuai dengan tingkat umur larva. (1) pada larva umur 1-3 hari, bertujuan mengetahui pengaruh pemberian pakan eksogen terhadap aktivitas enzim pencemaan, perlakuan yang diujikan (A) diberi pakan eksogen rotifer (Brachionus rotundiformis) dan (B) tidak diberi pakan eksogen, (2) pada larva umur 4-11 hari, bertujuan untuk mengetahui pengaruh umur terhadap aktivitas enzim pencemaan, (3) pada larva umur 12-20 han, bertujuan mengetahui pengaruh umur dan Jenis pakan terhadap aktivitas enzim pencemaan, perlakuan yang diujikan (A) diberi pakan eksogen bempa pakan alami dan (B) diberi pakan eksogen bempa pakan alami dan pakan buatan. Variabel yang diamati meliputi aktivitas enzim, ukuran pakan endogen, ukuran larva, Jumlah pakan alami yang dikonsumsi dan histologis larva. Data hasil pengukuran dianalisis secara deskriptif kuantitatif dan ditampilkan dalam bentuk grafik. Data yang berasal dari perbedaan perlakuan, dianalisis secara statistik dengan uji t. Hasil penelitian menunjukkan bahwa (1) aktivitas amilase dan lipase mulai terdeteksi pada larva umur 1 hari, sedangkan protease mulai terdeteksi pada larva umur 2 hari, (2) aktivitas protease, amilase dan lipase dipengaruhi oleh pakan alami rotifer dan pakan buatan dan (3) pada larva umur 1 hingga 20 hari pola aktivitas protease dan amilase meningkat mulai larva umur 1 hingga 11 hari, dan kemudian cenderung menurun, sedangkan pola aktivitas lipase menumn mulai dari larva umur 1 hingga 8 hari, kemudian cenderung meningkat. Aktivitas protease dan amilase yang tertinggi selama periode waktu tersebut teijadi pada larva umur 11 hari, sedangkan aktivitas lipase yang tertinggi teijadi pada larva umur 17 hari. Kata kunci: protease, amilase, lipase, pakan, larva

Tiger grouper is one of high economically seawater commodity. Aquaculture is very important for conserving them in the nature. However, aquaculture itself is still facing on high mortality on two critical periods at 1 -20 days old larvae. One factor that was suggested to be caused of the high mortality was larval physiologic that related to digestive enzyme. On those two critical periods larvae had changes its source of feed twice, i.e. from endogenous to exogenous live feed and from live feed to artificial feed. The objectives of this research were (1) to know the initial time of digestive enzyme activities of tiger grouper larvae can be detected, (2) to study the influence of live feed and artificial feed to digestive enzyme activities and (3) to find out the digestive enzyme pattern of 1-20 days old larvae, related to endogenous and exogenous feed. Enzymes those analyzed were protease, amylase and lipase. The research was including 3 stages as different ages of larvae. (1) at 1-3 days old larvae, was conducted to study the effect of exogenous live feed to enzyme activities, the treatment was (A) with exogenous live feed rotifer (Brachionus rotundiformis) and (B) without feed, (2) at 4-11 days old larvae, was conducted to study the influence of age to enzyme activity, (3) at 12-20 days old larvae, was conducted to study the influence of different kind of feed to enzyme activities, the treatment was (A) live feed only and (B) live feed and artificial feed. Investigated variables were enzyme activities, size of endogenous feed, size of larvae, number of live feed that was consumed by larvae and larval histological. Measured data were analyzed by descriptive quantitative and presented in the form of figures, while data from different treatments were analyzed statistically by t test. Results of the experiment showed that (1) amylase and lipase activities can be detected at 1 day old larvae, while protease activity was at 2 days old larvae, (2) enzyme activity was influenced by live feed rotifers and artificial feed and (3) protease and amylase activities pattern of 1-20 days old larvae was increased from 1 imtil 11 days old larvae and then tend to decrease, while lipase activity pattern was decrease from 1 until 8 days old larvae and then tend to increase. The highest protease and amylase activities were at 11 days old larvae, while the highest lipase activity was at 17 days old larvae. Key words: protease, amylase, lipase, feed, larva

Kata Kunci : Enzim,Lipase,Pakan,Larva