The effect of formaline, malachite green and methylen blue on the infestation degree of ectoparasites of Epinephelus suillus fry

English. A study on the effect of treatments on infestation degree of ectoparasites of Epinephelus suillus fry was conducted in the laboratory. These fry were infected by parasites of Trichodina, Broklynella and Diplectanum treated with 200 ppm technical formaline, 0.5 ppm malachite green, 0.1 ppm methylene blue, 100 percent fresh water and control (no treatment) with three replicates. The treatment were done by dipping the fry to those solutions for one hour and replicates three times for three days, respectively. Results of this experiment showed that there were no significant differences among the treatments on intensity of each parasite (p0.01), but there were very significant differences on prevalency of each parasite (p0.01). Although the treatment could minimized the intensity and prevalence of each parasite, they still could not eradicate the parasites

Indonesian. Penelitian tentang pengobatan infestasi beberapa ektoparasit pada Epinephelus suillus (ikan kerapu lumpur) dilakukan di laboratorium. Benih ikan telah terinfeksi parasit Trichodina, Broklynella dan Diplectanum diberi perlakuan dengan formalin teknis 200 ppm, hijau malakit 0,5 ppm, metilin biru 0,1 ppm, air tawar 100 persen dan kontrol (tanpa obat) dalam rancangan acak lengkap. Pengobatan dikerjakan dengan cara merendam benih ikan itu selama satu jam dalam larutan dengan tiga kali ulangan berturut-turut selama 3 hari. Hasil penelitian menunjukkan bahwa intensitas setiap jenis parasit tidak ada perbedaan nyata, tetapi perbedaan yang sangat nyata terlihat terhadap prevalensi setiap jenis parasit. Semua perlakuan pengobatan di dalam penelitian ini tidak mampu memberantas ketiga jenis parasit yang menginfestasi, tetapi hanya dapat mengurangi intensitas dan prevalensinya saja