PENGARUH INSEKTISIDA SEVIN 85 S TERHADAP
PERKEMBANGAN EMBRIO DAN LARVA KODOK (Bufo melanostictus)
A B S T R A K Telah dilakukan penelitian mengenai kelainan perkembangan embrio dan larva kodok (Bufo melanostictus) akibat perlakuan dengan Sevin 8 5 S. Pendedahan dilakukan pada sta-
dium zigot sampai menetas, gastrula sampai menetas, neurula sampai menetas, kuncup ekor/insang sampai menetas, gastrula awal sampai gastrula akhir, kuncup ekor/insang sampai in -
sang tumbuh sempurna, menetas sampai kaki dayung dan tunas kaki sampai kaki dayung. Embrio didedaukan dalam -suspensi Sevin 85 S konsentrasi 10, 1 5 , 20.-dan 3 0 ppm. Pengamatan pada stadium menetas menunjukkan total cacat bermakna (F.9) pada konsentrasi 10 ppm dan sangat bermakna (F.99) pada kon sentrasi 1 5 , 20 dan 3 0 ppm. Cacat ekor bermakna pada konsentrasi 10 dan 1 5 ppm aan sangat bermakna pada konsentrasi 20 dan 3 0 ppm. Pengamatan sesudah pendedahan sampai stadium insang tertutup sempurna menunjukkan total cacat masih sangat bermakna pada konsentrasi 15, 20 dan 30 ppm, sedang cacat ekor tidak bermakna lagi. Uji statistik metoda Duncan me nunjukkan bahwa perbedaan yang besar dalam persentase cacat terdapat antara kontrol dengan pendeaahan
-stadium neurula
sampai menetas atau stadium kuncup ekor/insang sampai mane tas. Kelainan yang timbul adalah eksensefali, kerdil, edema dan mata siklops. Ukuran panjang larva menunjukkan perbedaan yang nyata antara kontrol dengan perlakuan pada konsentrasi 15, 20 dan 3 0 ppm, tetapi tidak berbeda nyata antar
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erlpakuan. Pengamatan struktur histologi larva eksensefali menunjukkan bahwa jaringan otak depan terdedah dan -ke pala asimetri. Meskipun larva didedahkan --dalam suspensi
Sevin
8 5 S dalam
stadium perkembangan kaki, namon tidak
terjadi kelainan perkembangan kaki. Hasil analisa residu
Sevin dengan GLC pada pendedahan neurula _sampai menetas besarnya 2 5 , 6 ppm (85,3 %) dan 0,8 ppm (2,6 %) pada larva sesudah pendedahan, padastadium insang tertutup sempurna Disimpulkan, bahwa Sevin 85 S dapat menimbulkan cacat perkembangan dan menghambat pertumbuhan. embrio dan _larva kodok .
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A B S T R A C T Effect of insecticide Sevin 85 S on develoument of toad embryos and larvae ( Bufo melanostictus). Studies on the developmental abnormalities were carried out on toad embryos _and.- , larvae- ' ( Bufo melanostictus) treated with Sevin 85 S. The exposure were done at the zy gote stage to hatching, gastrula stage to hatching, neurula stage to hatching, tail/gill.bud_stage to hatching, early gastrula to late gastrula, limb bud stage to pedal shaped limb, tail/gill bud stage to completes ;gill_ growth and hatching to pedal shaped limb. Embryos were exposed with 10, 1 5 , 20 and 30 ppm Sevin 85 S. Observations on the
hatching stage revealed that total percentage of abnormalities were significant (F.95) in the 10 ppm and highly significant (F.99) in the 15, 20 and 30 ppm. The ,percentage of abnormal tails were significant in the 10 and 15 ppm and highly significant in tree 20 and 30 ppm concentrations. Observation after the treatment to closed gill stage showed that the total percentage of abnormalities were still hignr ly significant in the 15, 20 and 30 ppm,:.concentration,while tail abnormalities were not significant. Statistical test using the Duncan's method proved that the greatest differ ence in the percentage of abnormalities was between control and the treatment during the neurula stage to hatching or
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the treatment of tail/gill bud stage to hatching. Induced abnormalities were exencephaly, stunted growth, edema and cyclopia. The length of the larvae -showed' significant differences between control and treated with 15, 20 and 30 ppm,_but they were not significant among the treatments. Histological structure of exencephalic larvae showed that the forebrain was exposed and head asymmetrical. Although the larvae were exposed in Sevin 8 5 S during the developing limb stage, no limb malformation were induced. GLC analysis of Sevin residue from the exposure of neurula.. stage_ to hatching were 2 5 , 6 p p m ( 8 7 , 3 % ) and. 0,8 ppm.. (2,6 % .).at the closed gill stage. It was concluded that Sevin 8 5 S caused various developmental abnormalities and' hampered growth of toad embryos and larvae.
