PERKEMBANGAN JUMLAH EKTOPARASIT Pseudorhabdosynochus spp. PADA INSANG KERAPU HIBRIDA CANTIK (Epinephelus fuscoguttatus x E. polyphekadion) MELALUI METODE KOHABITASI

Genus Pseudorhabdosynocus merupakan Monogenea yang sering menginfeksi ikan kerapu. Pengaruh perbedaan jarak antara ikan sakit dengan ikan sehat terhadap perkembangan jumlah Pseudorhabdosynochus spp. pada ikan kerapu hibrida “cantik” dipelajari dalam penelitian ini melalui metode kohabitasi. Kohabitasi dilakukan dengan dua metode yaitu (a) menempatkan lima ekor ikan sakit ke dalam keranjang dengan jarak 25 cm dari dasar bak, dan (b) menempatkan lima ekor ikan sakit ke dalam keranjang dengan jarak 10 cm dari dasar bak. Kedua keranjang tersebut diapungkan ke dalam bak plastik berbeda dengan volume 100 L air laut (33 ppt) yang masing-masing telah berisi 30 ekor ikan kerapu hibrida “cantik” sehat. Masing-masing lima ekor ikan dari kedua metode kohabitasi diambil pada hari ke-2, 4, 6, 8, 10, dan 15 pemeliharaan. Hasil penelitian menunjukkan bahwa infeksi buatan menggunakan metode kohabitasi (b) lebih cepat menyebarkan Pseudorhabdosynochus spp. dari ikan sakit ke ikan sehat dibandingkan dengan metode kohabitasi (a). Perkembangan populasi Pseudorhabdosynochus spp. dan telurnya pada metode kohabitasi (b) lebih tinggi yaitu 1.495 ± 206,3 ekor/ikan dan 18,6 ± 3,8 telur/ikan dibandingkan dengan metode kohabitasi (a) yaitu 163,2 ± 16,3 ekor/ikan dan 3,8 ± 0,7 telur/ikan pasca 15 hari kohabitasi. Secara histopatologi, lamela insang yang terinfeksi Pseudorhabdosynochus spp. menunjukkan adanya hyperplasia epitel sel filamen insang yang menimbulkan fusi filamen. Kerusakan filamen di hampir semua lamela insang menyebabkan terganggunya sistem pernapasan ikan kerapu. Hasil tersebut dapat disimpulkan bahwa penyebaran Pseudorhabdosynochus spp. semakin cepat dengan semakin dekat jarak kontak antara ikan sakit dengan ikan sehat.Pseudorhabdosynocus is a genus of Monogenea that frequently infect grouper fish. This study aimed to observe the changes of density patterns of Pseudorhabdosynochus spp. in hybrid grouper gill through cohabitation. Two cohabitation methods were applied to understand the effects of distance between sick and healthy fish in terms of parasite infection. The cohabitation methos were arranged as follows: (a) five fish infected with Pseudorhabdosynochus spp. were placed into a basket at a distance of 25 cm from the bottom of the tank, and (b) five fish infected with Pseudorhabdosynochus spp. were placed into a basket at a distance of 10 cm from the bottom of the tank. The two baskets were floated into different plastic tanks of 100 L of seawater (33 ppt), each of which contained 30 healthy hybrid groupers. Each of the five fish from the two cohabitation methods was sampled on day 2, 4, 6, 8, 10, and 15 after cohabitation. The results showed that the spread of Pseudorhabdosynochus spp. from sick fish to healthy fish with the cohabitation method b was faster than the cohabitation method a. The development number of Pseudorhabdosynochus spp. and its eggs in the cohabitation method b were higher, reaching 1,495 ± 206.3 parasite/fish and 18.6 ± 3.8 eggs/fish than the cohabitation method a, 163.2 ± 16.3 parasite/fish and 3.8 ± 0.7 eggs/fish after 15 days of cohabitation. Histopathologically, gill lamella infected with Pseudorhabdosynochus spp. showed the presence of epithelial hyperplasia of gill filament cells causing fusion. Damage of the gill filament in all of gill lamella has caused disruption of the grouper breathing system. From these findings, it can be concluded that the spread of Pseudorhabdosynochus spp. was faster if the distance of direct contact between sick and healthy fish was closer.

Download Full-text

INTENSITAS PARASIT INSANG (TREMATODA MONOGENEA: Pseudorhabdosynochus sp.) PADA IKAN KERAPU HIBRIDA MELALUI INFEKSI BUATAN

Jurnal Riset Akuakultur ◽

10.15578/jra.13.2.2018.169-177 ◽

2018 ◽

Vol 13 (2) ◽

pp. 169

Author(s):

Ketut Mahardika ◽

Indah Mastuti ◽

Zafran Zafran

Keyword(s):

Fresh Water ◽

Experimental Infection ◽

Egg Production ◽

Parasite Infection ◽

Mass Mortality ◽

Gill Lamella ◽

Control Group ◽

Hybrid Grouper ◽

Test Fish ◽

The Right

Infeksi trematoda monogenea: Pseudorhabdosynochus sp. dapat menyebabkan kematian massal pada ikan kerapu. Prevalensi infeksi trematoda ini mencapai 100%, namun intensitasnya hingga menimbulkan gejala klinis dan kematian ikan belum diketahui. Tujuan dari penelitian ini adalah untuk mengetahui intensitas parasit insang (Pseudorhabdosynochus sp.) pada ikan kerapu hibrida “cantik” melalui infeksi buatan. Ikan uji direndam dalam air tawar dengan 100 mg/L formalin selama satu jam sebelum digunakan. Infeksi buatan dilakukan melalui (A) kohabitasi antara ikan sehat dengan ikan sakit dan (B) penempelan potongan lamella insang ikan yang terinfeksi parasit ke lamella insang ikan sehat. Pada perlakuan (A) sebanyak lima ekor ikan uji dipelihara bersama dengan dua ekor ikan sakit selama 3-4 hari, sedangkan perlakuan (B) penempelan lamella insang ikan sakit (1 g lamella insang/ikan) dilakukan pada lima ekor ikan uji selama lima menit. Masing-masing perlakuan diulang tiga kali. Pada Kontrol kepadatan ikan uji sehat sebanyak enam ekor dan lima ekor. Wadah yang digunakan berupa bak plastik volume 100 L. Pengamatan intensitas parasit dan telurnya pada setiap lamella insang bagian kanan dan kiri dari lima ekor ikan uji dilakukan selama tiga minggu dengan interval waktu satu minggu. Hasil pengamatan menunjukkan bahwa kohabitasi antara ikan sehat dan ikan sakit menyebabkan intensitas parasit Pseudorhabdosynochus sp. dan telurnya lebih tinggi dibandingkan dengan penempelan lamella insang. Pada kontrol, Pseudorhabdosynochus sp. maupun telurnya tidak ditemukan selama tiga minggu pemeliharaan. Hasil ini menunjukkan penyebaran Pseudorhabdosynochus sp. dari ikan sakit ke ikan sehat lebih cepat dibandingkan dengan penempelan dari lamella insang ikan sakit.Monogenetic trematode (Pseudorhabdosynochus sp.) infection often leads to mass mortality in groupers, with prevalency reaching 100%. However, the intensity of this parasite to infect grouper fish has yet to be reported. The purpose of this research was to study the intensity of Pseudorhabdosynochus sp. in hybrid grouper “cantik” through experimental infection. The test fish were soaked with 100 mg/L of formalin in fresh water before used. The experimental infections were performed through: (A) cohabitation between healthy fish with sick fish and (B) infection with attached of gills lamella of sick fish to gill lamella of healthy fish. In treatment (A), a total of five test fish were cohabited with two sick fish for 3-4 days, while in treatment (B), attachment of gills lamella (1 g/fish) was done on five test fish for five minutes. Each treatment was repeated for three times. Six and five test fish were maintened as controls. The containers used were 100 L plastic tanks volume. Observation of intensity of the parasite infection and its egg production in each lamella along the right and left gills of five fish were conducted for three weeks with one week intervals. The result showed that the cohabitation between healthy and sick fish caused an increase in total of Pseudorhabdosynochus sp. and its eggs compared with the attachment of chopped-gills. In the control group, Pseudorhabdosynochus sp. and its eggs were not found for three weeks. These results indicate the spread of Pseudorhabdosynochus sp. from the sick fish to the healthy is fish faster than the attachment of gill lamella from the sick fish.

Download Full-text