Snakehead fish (Channa striata) is a freshwater fish with high economic value both as ornamental and consumed fish. However, the ability to adapt to fluctuating environmental states prompts snakehead fish to be susceptible to parasites, ectoparasites, and endoparasites. Gills, skin, and fins are the major body parts that are often infected with ectoparasites. This study aims to discover the macro pathology in gills, skin, and fins of ectoparasites-infected snakehead fish and its histopathology. This study was conducted from April to June 2021. Observational data on macro pathology and histopathology were analyzed qualitatively. The results indicated that the macro pathology of the skin, gills, and fins of snakehead fish infected with ectoparasites indicates discoloration, excess mucus production, the dull coloration of the gills, and irritation of the gills body surfaces, and skin hemorrhages. In conclusion, infection of ectoparasites affects several alterations in the skin, gills, and fins, both macro pathological and histopathological.

Desa Mesjid Lama sebagai salah satu daerah pesisir di Kabupaten Batu Bara yang memiliki potensi sumber daya perikanan khususnya tambak ikan kerapu, namun permasalahan pada tambak kerapu adalah kurangnya pemahaman pengeloaan kualitas air hingga produksi panen menurun. Hal ini diakibatkan banyaknya ikan yang sakit hingga mengalami kematian. Program pengabdian masyarakat akan dilaksanakan di kelompok pembudidayaan ikan kerapu “Kompak Bersama” Desa Kampung Mesjid Kabupaten Batu Bara. Metode yang digunakan dalam kegiatan ini adalah memberikan pendidikan, pelatihan, dan pendampingan manajemen kualitas  air  bagi  pembesaran  kerapu. Kegiatan  difokuskan  pada  upaya  perbaikan  mutu kualitas   air   dengan   menggunakan   bahan-bahan   yang   ramah   lingkungan,   dan   upaya pencegahan penyakit ikan. Kegiatan pelatihan dan pendampingan pengelolaan kualitas air dan pembuatan pakan ikan mandiri sebagai pakan alternative yang dapat menekan biaya pengeluran pakan, serta peningkatan keterampilan mitra terkait cara budidaya ikan yang baik (CBIB) yang ramah lingkungan dan dilanjutkan dengan proses pengelolaan manajemen kualitas air di tambak kerapu.  pendidikan, pelatihan, dan pendampingan manajemen kualitas air akan dilakukan menyeluruh dan merata pada lokasi usaha mitra. Bentuk Luaran yang ditargetkan adalah jurnal nasional tidak terakreditasi, modul dan buku ajar yang berjudul Manajemen Kualitas Air pada Tambak Ikan Kerapu, publikasi pada seminar nasional, media cetak dan youtube.

Mercury is a dangerous contaminant for aquatic organisms. Seurukan fish (Osteochilus vittatus) is a type of fish in the Krueng Sabee river that is vulnerable to mercury exposure. The study's purposes were to investigate the effect of mercury on the biometric conditions of Seurukan Fish in the Krueng Sabee River, Aceh Jaya Regency. A total of 90 Seurukan fish consisting of 50 males and 40 females were collected from 3 research stations. The research stations represent the upstream area (Station 1), median river bodies (Station 2), and the downstream area (Station 3). Fish samples were taken from July to August 2019. The main parameters observed included class interval, sex ratio, length-weight relationship, condition factors, mercury concentration in sediment and liver, and hepatosomatic index. The results showed that the mercury content in the sediments of the Krung Sabee River was increased both spatially and temporally. Station 1, located in the upstream area, has the highest mercury content in the sediment was 6.278 ± 0.987 mg/kg. Mercury content in liver of Seurukan Fish ranged from 0.182 ± 0.100 mg/kg to 0.198±0.152 mg/kg. Mercury contamination in the Krueng Sabee river caused a decrease in biometric conditions of Seurukan Fish. Seurukan Fish exposed to mercury tended to have smaller size, an unbalanced sex ratio, low hepatosomatic index value, and negative allometric growth pattern.Abstrak: Merkuri merupakan salah satu jenis kontaminan berbahaya bagi organisme akuatik. Ikan seurukan (Osteochilus vittatus) merupakan salah satu jenis ikan di sungai Krueng Sabee yang rentan terpapar merkuri. Penelitian ini bertujuan untuk mengkaji pengaruh merkuri terhadap kondisi biometrik ikan seurukan di sungai Krueng Sabee, Kabupaten Aceh Jaya. Sebanyak 90 ekor ikan Seurukan yang terdiri dari 50 ekor jantan dan 40 ekor betina dikoleksi dari 3 stasiun penelitian. Stasiun penelitian mewakili wilayah hulu (stasiun 1), badan sungai (stasiun 2) dan wilayah hilir (stasiun 3). Pengambilan  sampel ikan dilakukan pada bulan Juli hingga Agustus 2019. Parameter utama yang diamati meliputi selang kelas, nisbah kelamin dan hubungan panjang bobot ikan, faktor kondisi, konsentrasi merkuri pada sedimen dan hati serta indeks hepatosomatik. Hasil penelitian menunjukkan bahwa kandungan merkuri di sedimen Sungai Krung Sabee mengalami peningkatan baik secara spasial dan temporal. Stasiun 1 yang terletak di wilayah hulu memiliki kandungan merkuri dalam sedimen paling tinggi yaitu sebesar 6,278 ± 0,987 mg/kg. Kandungan merkuri pada hati ikan seurukan di Sungai Krueng Sabee berkisar antara 0,182 ± 0,100 mg/kg hingga 0,198 ± 0,152 mg/kg. Kontaminasi merkuri pada sungai Krueng Sabee menyebabkan dampak negatif terhadap kondisi biometrik ikan seurukan. Ikan seurukan yang terpapar merkuri cenderung memiliki ukuran panjang dan bobot yang lebih kecil, nisbah kelamin yang tidak seimbang, dan nilai indeks hepatosomatik yang rendah serta pola pertumbuhan alometrik negatif.

Batu Bara Regency is a region with abundant natural resources, one of which is the cultivation of grouper fish. Grouper is a member of the Serranidae family of coral reef fish. Many groupers are raised in ponds, which makes them susceptible to disease due to environmental and dietary factors that are not adapted to grouper fish, which is a native species. Parasites are one of the grouper-infecting diseases that, if left untreated, can result in mass mortality and harm farmers. The aim of this study was to identify parasites in ponds in Mesjid Lama Village, Talawi District, so that it would be easier to determine the type of parasite, its level of attack, and subsequent efforts to eradicate it. This research employs a sampling technique, specifically a random sampling of orange-spotted grouper. The results of the performed analysis include analyses of both ectoparasites and endoparasites. Several types of ectoparasites were identified, including Cryptocaryon irritans, Pseudorhabdosynochus sp, Benedenia epinepheli, and Caligus sp, while Prosorynchus sp was identified as the endoparasite. The most prevalent parasite found in the fish is Cryptocaryon irritans.Keywords: EndoparasiteParasitesGrouper

Abstract. Fishpond is one of the habitats from organisme such as plankton which is have a role as main food resources for organisms with high trophic level (such as fish). This objectives of the study were to determine the condition of plankton in grouper fishponds in Mesjid Lama Village, Talawi District, Batu Bara District. Plankton sampling and water quality measurements were carried out from February to June 2019. The abundance of phytoplankton in grouper fish ponds varied between 1,765-4,113 ind/L. The composition of phytoplankton species found during observation was dominated by diatom groups or Bacillariophyceae classes. The abundance of zooplankton in grouper ponds varied from 330-1,165 ind/L with the lowest abundance found at station 6 with a total of 330 ind/L and the highest abundance was found at station 4 with a number of 1,165 ind/L. The zooplankton genus that is often found is Acartia. Diversity value H '