Effect of water quality on the parasite assemblages infecting Nile tilapia in selected fish farms in Nakuru County, Kenya

Abstract

Aquaculture has been documented as the fastest developing food industry in Kenya with increased production since the Government initiated the Economic Stimulus Programme (ESP) in 2009. However, the production has not yet reached the maximum level (20,000 metric tons per year) anticipated in the country. This is due to a number of challenges, top of which is poor water quality resulting from the uncontrolled addition of inputs (fish feeds, inorganic fertilizers, and organic fertilizers) into the ponds. These deteriorate water quality, cause increased incidences of parasite infections, and impede fish production. Therefore, this study investigated the effect of water quality on parasite assemblages infecting Oreochromis niloticus (Linnaeus 1758) in selected fish farms within Nakuru County from November 2016 to February 2017. Selected physico-chemical parameters namely: dissolved oxygen, temperature, pH, conductivity, and turbidity were measured in situ using appropriate meters. Water samples from each fish farm were analyzed for nutrient concentrations using standard methods. A total of 300 fish were examined for parasites. Parasites were counted, preserved, and identified using identification keys and parasitological parameters determined. The results indicated that certain water quality parameters, such as dissolved oxygen, were significantly different for all the six fish farms (one-way ANOVA, p < 0.05). A total of 15 species of parasites were recovered. Trichodina sp. and Cichlidogyrus halli were found in all the studied fish farms. Correspondence analysis revealed that some parasites' occurrences were highly correlated (positively) with certain water quality parameters. Therefore, regular monitoring and control of water quality in fish ponds are recommended to reduce levels of parasite infestations.

Kimia Fisik Perairan dan Ektoparasit Ikan Nila dan Patin Di Situ Gintung, Tangerang Selatan, Banten

“…Pengetahuan tentang identifikasi ektoparasit pada ikan merupakan hal yang mendasar dan penting, karena jenis penyakit yang seringkali dijumpai berpotensi menjadi kendala pada budidaya (El Amin dan Al-Harbi, 2016;Ojwala et al, 2018) maupun habitat alami ikan (Galli et al, 2001;Sari dan Ekawaty, 2019). Lebih lanjut, informasi parasit, seperti keanekaragaman dan prevalensi kehadiran ektoparasit pada ikan di Situ Gintung belum tersedia.…”

“…Nilai suhu dan pH perairan Situ Gintung tergolong cukup baik untuk kehidupan ikan. Suhu mempunyai peranan penting dalam menentukan pertumbuhan ikan, kisaran yang baik untuk menunjang pertumbuhan optimal organisme perairan adalah 28-32˚C (Tatangnindatu dkk., 2013) dengan suhu yang optimum untuk ikan nila dilaporkan mulai dari 18-32 o C dan pH 5-9 (El Amin dan Al-Harbi, 2016; Ojwala et al, 2018), sedangkan nilai pH yang ideal untuk kehidupan organisme air pada umumnya adalah 7-8,5 (Barus, 2004). Berdasarkan standar baku mutu air PP No.…”

“…DO di KJA dan lokasi pancing tidak berbeda nyata (MANOVA, p>0.05), hal ini karena kedua lokasi dekat dengan inlet dan suhu yang tidak berbeda. Menurut Ojwala et al, (2018) bahwa suhu berkorelasi dengan DO sehingga nilai nya dapat saling mempengaruhi satu sama lain. Nilai TDS masih di bawah standar baku mutu yang disyaratkan dan berada dalam kisaran penelitian sebelumnya (Thakur et al, 2013;Assuyuti dkk., 2017).…”

“…Selain itu, kehadiran kedua ektoparasit tersebut dipengaruhi kimia fisik perairan (Gambar 4). Menurut Ojwala et al, (2018) Trichodina sp. dan Chilodonella sp.…”

Supplementation with arginine in the diet of Nile tilapia reared in net cages

“…Fish raised in cages are in constant stressful situations because of the high-stocking density, water physicochemical variations, and constant water stream (Sadhu et al, 2014;Calabrese et al, 2017). These stressors unbalance the host-pathogen-environment relationship, provoking diseases (Ojwala et al, 2018).…”