Ectoparasite Prevalences of Grouper Fish (Epinephelus fuscogutatus x Epinephelus polyphekadion) Cultured in Floating Net Cages

Abstract

Monitoring the health of the reared fish in a floating net cage (FNC) is often conducted by examining their ectoparasites. This study determines ectoparasite prevalences of grouper fish (Epinephelus fuscogutatus x E. polyphekadion). It was conducted in the waters surrounding Pongok Island, South Bangka Regency. The health examination of both fish and ectoparasites was carried out by applying simple random sampling during three periods, November 2016 (I), February 2017 (II) and May 2017 (III). Hydro-oceanography surveys were done every month during the three years. The grouper checkings (I, II and III) indicated the prevalences of ectoparasites in these periods were 43.3%, 8.8% and 13.5%, respectively. Fish death highly occurred in the period I, and the grouper survival rate at harvesting time was only 70% from initial seed stocking of 1,500 fish. The ectoparasite intensities during the research periods were 1.6, 1.6 and 1.5, respectively. This condition implies that every 10 groupers would potentially be attacked by at least 15-16 ectoparasites. A slow seawater current flow triggered the quick uplifting of the ectoparasites from the seafloor. The water condition at the FNC location in 2011 and 2017 was still under the quality standard. The ectoparasites were coming from the surrounding environment of the FNC location. It is inevitable that the fish culture management should focus on cleansing the ectoparasites attaching on the groupers, dusting the net cage clean, and arranging the harvest pattern on a particular month following the surrounding environmental condition to prevent ectoparasite attacks.

Contamination of Heavy Metals (Pb and Cu) at Tin Sea Mining Field and Its Impact to Marine Tourism and Fisheries

“…The value of heavy metals (Pb) in grouper meat of 6,500 mg.L -1 indicates that this value is far above the quality standard threshold value of 0.050 mg.L -1 with a difference of 6,450 mg.L -1 above the quality standard, it is suspected that grouper may have experienced biomagnification from the food he ate (Adibrata et al, 2013), found heavy metal concentrations (Pb and Cu) in fish and shellfish (Arifin, 2011). Besides, the presence of fish parasites such as ectoparasites attached to the fish skins of floating net cage systems (KJA) is thought to be related to the hydro-oceanographic dynamics such as current conditions and water temperatures (Adibrata et al, 2020). The weaker water currents and the lower the water temperature can increase ectoparasites against fish in floating cage, this is certainly very detrimental to grouper fish farmers.…”

Deteksi Parasit Dan Virus pada Pembesaran Ikan Kerapu Cantang (Epinephelus fuscoguttatus vs Epinephelus lanceolatus)

“…menyebabkan abnormalitas pada ikan antara lain insang berwarna pucat, bernafas lebih cepat dan overculum selalu terbuka. Hasil penelitian dilaporkan bahwa parasit ini tergolong berbahaya dalam budidaya kerapu cantang (Epinephelus fuscoguttatuslanceolatus) seperti yang terjadi di pantai timur Pangandaran, prevalensi mencapai 66,6% dan ikan dipelihara di KJA tradisional mencapai 44,4% disebabkan parasit Diplectanum (Adibrata et al, 2020).…”

The prevalence and intensity of ectoparasites that infects tilapia (Oreochromis niloticus) in floating net cages

“…Ectoparasites are one of the most common diseases that often attack tilapia (Irwandi et al, 2017). The ectoparasites Melanie et al (2022) usually attach to the outer body part or gill of the fish, inhibiting their growth and even resulting in mortality (Adibrata et al, 2020). The types of parasites that commonly attack tilapia include Trichodina sp., Dactylogyrus sp., Gyrodactylus sp., Argulus sp., Steinernema sp., and Epistylis sp.…”