Marine Ornamental Fish Research Articles

Effect of Spirulina Flour Addition in Feed on the Increase of Colour Brightness Nemo Fish (Premnas biaculeatus)

The nemo fish (Premnas biaculeatus) is a type of marine ornamental fish in Indonesia that is in high demand among the general public. The popularity of this fish can be attributed to several factors, one of which is the brightness of its coloration. One of the plants that can be employed as a color enhancer for ornamental fish is spirulina. Spirulina is a microalgae that has been demonstrated to enhance the brightness of fish coloration. Therefore, it is necessary to research on the effect of adding spirulina flour to feed on increasing the brightness of the color of nemo fish (Premnas biaculeatus). The method used in this research is an experimental method with a completely randomized design. This treatment was carried out with 5 treatments and 3 repetitions, namely: P0 : 0%/kg, P1 : 2%/kg, P2 : 4%/kg, P3 : 6%/kg and P4 : 8%/kg. The 5 treatments were repeated 3 times, resulting in 15 experimental units. The results of the researches carried out, it can be concluded that the addition of spirulina flour to feed on the brightness of the color of nemo fish (Premnas biaculeatus) is proven to increase the brightness of the color of nemo fish and the best treatment is p3 with a dose of 6%. The addition of spirulina flour to feed on the growth of length and absolute weight of nemo fish (Premnas biaculeatus) has a significant effect, while the survival rate has no significant effect.

REPRODUCCIÓN Y CULTIVO LARVARIO DEL PEZ PAYASO MARRÓN (Premnas biaculeatus) BAJO CONDICIONES CONTROLADAS

<p><strong>Background:</strong> Interest in ornamental marine fish, especially species associated with coral reefs, is rapidly growing. Most of the fish traded come from the wild, and collection methods harm coral reefs and cause massive mortalities in non-target species. To make the activity sustainable, it is necessary to develop aquaculture biotechnologies to reduce the collection of wild organisms and lessen the pressure on their natural environment. <strong>Objective:</strong> To develop protocols for the reproduction and larval rearing of the maroon clownfish (<em>Premnas biaculeatus</em>) for the sustained production of juveniles in captivity. <strong>Methodology:</strong> Two pairs of <em>P. biaculeatus</em> were placed in two aquariums of a recirculating system with filtered seawater. The obtained eggs were incubated in 100 L tanks. The larvae were fed with rotifers <em>Brachionus rotundiformis</em>, <em>Artemia</em> sp. nauplii, and weaned onto a commercial diet. The larvae were measured at hatching and every four days until weaning. <strong>Results:</strong> The clownfish pairs began spawning 4-5 months after being placed in the recirculating system and continued spawning every 15-20 days. The eggs hatched 6-7 days after fertilization (DAF), and the hatched larvae measured 3.4±0.06 mm in total length (TL). At 19 days after hatching (DAH), after completing weaning, they measured between 9.8 to 11.5 mm in TL; at 26 DAH, they measured between 10.8 to 13.1 mm. After one month, between 800 to 1,000 juveniles were obtained for commercialization. <strong>Implications:</strong> The reproduction and larval rearing protocols of the maroon clownfish <em>P. biaculeatus</em> described in this work can be used to obtain juveniles in captivity for commercialization; additionally, they can serve as a basis for developing other protocols for obtaining juveniles of other ornamental marine fish species for commercialization, contributing to the protection of their natural environment. <strong>Conclusion:</strong> The results obtained demonstrated the viability of maintaining <em>P. biaculeatus</em> breeders in captivity and achieving their natural reproduction, larval rearing, and mass production of juveniles throughout the year.</p>

Assessing exploitation vulnerability risk of marine ornamental reef fish in Sri Lanka: A productivity susceptibility analysis

We conducted a Productivity Susceptibility Analysis (PSA) to empirically assess the vulnerability risk of marine ornamental reef fish in Sri Lanka for exploitation. We considered distribution, accessibility, ecological niche, and market price as susceptibility attributes, while fecundity, larval development, maximum length, and longevity were productivity attributes. The vulnerability score, demand, and market price were used to assess species prioritization, and then compositions of the prioritized species were computed. The veracity of primary and secondary data collected on susceptibility and productivity attributes was confirmed by interviewing traditional fishers in situ. The IUCN and present PSA classifications for the medium susceptibility risk species were comparatively assessed. Four species out of 17 medium susceptibility risk species were encountered as the medium vulnerability risk species for exploitation. The Pacific cleaner shrimp (Lysmata amboinensis) emerged as the highest prioritized species. In addition, we observed significant differences in the species’ status assessed through the PSA approach compared to the IUCN status. The study affirms that demand and market prices substantially influence the exploitation vulnerability of species, and the PSA offers a promising multidisciplinary approach to evaluating intrinsic and extrinsic factors in conservation ecology compared to widely used IUCN status for assessing extinction risk. Furthermore, the present findings have practical implications, as they warrant essential policy changes for conserving the prioritized species and the medium vulnerability risk species encountered in the present research to extinction risk.

The Influence of Price, Lifestyle and Place on Purchasing Decisions in Marine Ornamental Fish with Buying Interest as an Intervening Variable

The Influence of Price, Lifestyle and Place on Purchasing Decisions in Marine Ornamental Fish with Buying Interest as an Intervening Variable

An Updated Review of the Marine Ornamental Fish Trade in the European Union

Wild-caught fish from coral reefs, one of the most threatened ecosystems on the planet, continue to supply the marine aquarium trade. Despite customs and veterinary checks during imports, comprehensive data on this global industry remain scarce. This study provides consolidated data on the largest import market by value, the European Union (EU): a 24-million-euro annual trade value, detailing the main exporting and importing countries, as well as the species and families of the 26 million specimens imported between 2014 and 2021. A watchlist alert system based on the number of specimens traded, import trends, and vulnerability index according to FishBase and the IUCN Red List conservation status is presented, providing key information on which species should require closer scrutiny by authorities. While the European TRAde Control and Expert System (TRACES) electronically monitors the movement of live animals to respond quickly to biosecurity risks, one-third of marine ornamental fish imported lack species-level information. With minor adjustments, TRACES holds the potential to significantly enhance data granularity and the monitoring of wildlife trade, with marine ornamental fish being an interesting case study to validate this approach.

Understanding the captive breeding, spawning behavior and early ontogeny of Chromis viridis (Cuvier, 1830): A systematic study

The sustainability of aquarium trade relies on successful captive breeding and seed production practices to prevent the long-term consequences of wild collection, which can result in irreversible damage to natural populations. To establish comprehensive breeding and seed production protocols, it is imperative to gain a deep understanding of the reproductive characteristics of the fish, encompassing aspects such as sexual dimorphism, spawning behavior, embryogenesis, and the crucial period of larval survival. Hence, in this study, we document the captive breeding, spawning behavior, embryonic development, and early larval stages of Chromis viridis, a highly sought-after marine ornamental fish that plays a prominent role in the aquarium trade. Fish were sourced from Agatti Island, Lakshadweep, and reared in controlled conditions. Mature fish (6–9 cm) were kept in 500 L FRP tanks with regulated salinity (35.4 ± 0.5 g/L), temperature (27.1 ± 0.54 °C), and a 12-h light-dark photoperiod. After four months in captivity, spawning commenced, characterized by intense substrate cleaning and rapid swimming motions of the male. Each spawning event yielded 3562 to 20,651 eggs. Egg development included five stages over three days at 27.1 ± 0.54 °C, with hatching on the third day. Egg dimensions varied along both axes and egg volume changed over three days. Newly hatched larvae lacked eye pigments and paired fins, with an average total length (TL) of 1.97 ± 0.35 mm. Larval mouth opening occurred at 38 h, and yolk absorption was complete by the third day post-hatch. Continuous captive reproduction was observed with a spawning frequency of 5.59 ± 0.96 days. This study offers valuable insights for standardizing captive propagation techniques and advancing marine ornamental aquaculture for C. viridis by documenting its breeding, embryonic development, and early larval stages in captivity.

Characterisation of phenotypic stock diversity of the crescent perch, Terapon jarbua (Forsskål, 1775) along the Indian coast using morphology and otolith shape analysis

Crescent Perch, Terapon jarbua is one of the important food cum marine ornamental fish in India. The present study deals with the delineation of T. jarbua stocks along the Indian coast using the morphology of fish and otolith shape analysis. A total of 609 fish samples were collected from six major fishing harbours representing the Indian coast from February to May 2022. The conventional morphometry, truss network analysis and otolith shape indices revealed the morphological divergence for the fish among the stocks. However, meristic traits could not show the variations among the different stocks. The morphometric and otolith shape variability for the species revealed the existence of different phenotypic stocks along the Indian coast, which might be due to the ability of the T. jarbua to adapt to different environmental conditions. The study highlights the need for separate biological and stock assessment studies for developing effective management strategies.

Pengaruh Adaptasi Pakan Terhadap Efisiensi Dan Konversi Pakan Benih Ikan Nemo (Amphiprion sp.)

Nemo fish (Amphiprion sp.) is a type of marine ornamental fish that is popular because it is unique in terms of color, shape and movement. Feed is a factor in the growth and survival process of nemo fish. The aim of this research was to determine feed adaptation to the efficiency and feed conversion of nemo fish seeds. The research used an experimental method using a Completely Randomized Design consisting of 3 treatments and 3 replications. Treatment A (silk worms), treatment B (pellets) and treatment C (combination of 70% silk worms and 30% pellets). The best absolute weight growth results were in treatment C, namely 0.33 grams, while the lowest were in treatment B, namely 0.28. The survival rate (SR) during maintenance in each treatment was 100%. The best feed efficiency was in treatment C at 16.17% and the best feed conversion ratio was in treatment C with the lowest conversion ratio value of 4.81. Based on the results of the research conducted, it was concluded that feed adaptation for nemo fish seeds did not have a real influence on the efficiency and feed conversion of nemo fish seeds (Sig. > 0.05).

Detection of Viral Haemorrhagic Septicemia in Marine Fisheries Commodity Using Real Time–PCR at Fish Quarantine Inspection Agency Denpasar, Bali

Marine fish commodities in Indonesia, both exported and imported, have experienced a significant increase. This increase opens up opportunities for the risk of entry and spread of fish pests and diseases, both on an export scale between countries and between areas within Indonesia. One of the pathogens that is acute that can cause major losses is the virus. The virus that often attacks sea water ornamental fish is Viral haemorrhagic septicemia. The purpose of this study was to detect the presence of VHSV that infects marine ornamental fish commodities using namely: necropsy, fixation, extraction, amplification, and reading of results. This research was conducted at Fish Quarantine Inspection Agency Denpasar, Bali. Based on the test results, VHS was found to attack six samples of marine fish species with codes namely NTC, BC 8.2, BC 9.2, BAR 8.2, 1252, NSR 8.2.

PENGUNAAN EKSTRAK TOMAT SEBAGAI INOVASI PAKAN ALAMI UNTUK MENINGKATKAN KUALITAS WARNA IKAN BADUT MERAH MARUN (Amphiprion biaculeatus, Bloch 1790)

Background: Amphiprion biaculeatus, Bloch 1790 is one of the exported marine ornamental fish commodities. To meet export demand, must be from cultivation fish. However, the problem faced in cultivation conditions is that the color of the fish is not as attractive as in nature. This is due to uniform feeding. Therefore, alternative solutions are needed to enrich feed with natural pigment sources. One of them is red ripe tomato extract with high carotene content. Methods: The study used a completely randomized design with extract concentration treatments (0, 25%, 50%, 75%). Natural feed is made by coating, then applied to non-breeder sized fish obtained from BPBL Ambon. Extract efficiency parameters were measured through color characteristics, carotene content in the skin and fins, total length and body weight. The data obtained were analyzed using ANOVA and continued with the DMRT test at a significance level of 95%. Results: The results showed that tomato extract had a significant effect on color characteristics, carotenoid content, total length and body weight in maroon clownfish. The concentration of tomato extract which had the highest value for all parameters measured was in treatment 75% : 75 mL tomato extract + 10 mL binder + 15 g commercial feed). Conclusion: Tomato extract has the potential as a natural feed that can improve the color quality of A. biaculeatus with a usable concentration of 75%.

First feeding of a marine ornamental fish, the White‐barred Goby Amblygobius phalaena: Investigating the optimal initial live feed organisms and optimal feeding density

AbstractObjectiveThe White‐barred Goby Amblygobius phalaena is a popular ornamental fish in the marine aquarium market. To achieve successful commercial production, efficient larval rearing techniques are crucial. Previous studies have achieved successful cultivation of White‐barred Goby larvae by using a combination of three live feed organisms—the ciliate Euplotes sp., the rotifer Brachionus rotundiformis, and the copepod Apocyclops royi nauplii—during the first feeding stage. However, the specific contributions of these live feed organisms to larval survival and growth remain unclear. Moreover, the optimal feeding density for the critical initial live feed organism has not been determined experimentally. In this study, we aimed to enhance the larviculture protocol for White‐barred Goby by introducing Portuguese oyster Crassostrea angulata trochophores and by addressing these knowledge gaps.MethodsLarvae were initially cultured through individual and combined feeding with four live feed organisms: Euplotes sp., Portuguese oyster trochophores, B. rotundiformis, and A. royi nauplii. The objective was to identify the optimal initial live feed organism during the first feeding stage by assessing the survival and growth performance of larvae. Subsequently, using this optimal live feed organism, larvae were cultured at four feeding densities (2, 5, 10, and 20 individuals/mL). Through evaluating feeding incidence, feeding intensity, survival, and growth performance, the aim was to determine the optimal feeding density for the selected live prey.ResultOur experiments revealed that White‐barred Goby larvae could consume both oyster trochophores and Euplotes sp. during the first feeding stage. However, larvae exhibited superior survival and growth performance when fed oyster trochophores. The optimal feeding density of oyster trochophores was determined to be 10 individuals/mL, while a feeding density as high as 20 individuals/mL resulted in decreased larval feeding incidence.ConclusionThese findings have significant implications for enhancing larval production programs for marine ornamental gobies and promoting their sustainable commercialization.

Growth and Oxidative Stress of Clownfish Amphiprion ocellaris Reared at Different Salinities

Aquaculture of ornamental marine fish is often conducted in recirculating aquaculture systems (RAS) using artificial seawater. Considering the cost of salts to produce artificial seawater (salinity 35‰), we investigated the effect of different salinities (5, 15, 25, and 35‰) on survival, growth, and oxidative stress responses of juvenile clownfish Amphiprion ocellaris. All fish died when reared at salinity 5‰, but at all other salinities survival was ≥95% in the other treatment groups. There was no influence of salinity on growth and oxidative stress responses of clownfish reared at salinities 15, 25, and 35‰, except for the activity of glutathione S-transferase (GST) of fish reared at 25‰, which was significantly lower compared to those reared in salinity 35‰. The salinity of home aquariums is usually 35‰, so even though clownfish can be reared in brackish water, they need to be transferred to full strength seawater (35‰) in order to be commercialized. Therefore, we also evaluated the responses of acute transference of fish reared at 15 to salinity 35‰. There were no mortalities associated with acute salinity transference and no oxidative damage was observed either. The total capacity against peroxyl radicals (ACAP) was immediately increased after fish were placed in salinity 35‰, and remained high after 168 h (7 days), helping fish to deal with oxidative threats. In conclusion, it is possible to rear juvenile clownfish at 15‰ without harming growth or inducing oxidative stress, possibly reducing costs of water salinization. They can be transferred from brackish water to salinity 35‰ immediately before going to the retail market, with no mortality or oxidative damage.

Comparison of RT-PCR and rRT-PCR Methods in Detection of Viral Hemorrhagic Septicemia Virus (VHSV) in Marine Ornamental Fish

Reverse Transcription PCR (RT-PCR) and Real Time Reverse Transcription PCR (rRT-PCR) are methods that can be used to detect VHSV (Viral Hemorrhagic Septicemia Virus) on freshwater and seawater fish. rRT-PCR is more widely used than the RT-PCR method because of several advantages such as requiring shorter time and fewer stages. Both methods have their own advantages and disadvantages, so it is necessary to compare the two methods in detecting the presence of VHSV in marine ornamental fish. The research was carried out with 3 steps: sensitivity test, specificity test, and sample test. The sensitivity test showed that the smallest dilution concentration that could be detected by both methods was the same at 10-3 with 100 copies in the 77bp band. Specificity tests on both methods showed that VHSV primers used are specific. Sample tests in both methods showed the same results in each of the samples tested. The results of sensitivity, specificity and sample tests conducted on RT-PCR and rRT-PCR methods showed the same results (positive) thus both methods can be used to detect the VHSV in marine ornamental fish.

Effectiveness of small-scale marine ornamental fish rearing and community-based coral transplantation technique in Tanjung Tiram, Tondonggeu and Mekar village, Indonesia

Indonesia is the second largest exporter of ornamental fish in the world, with the value more than USD 20.5 million in the first semester of 2023. Ornamental corals are also being traded under strict supervision since several coral species are listed in Appendix II of the CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora). To harvest these high-value commodities in sustainable manner, we designed a small scale of marine ornamental fish rearing and community-based coral transplantation techniques in coastal waters of Tanjung Tiram village, Tondonggeu village and Mekar village by utilizing its suitable natural habitat and involving coastal communities. A study then carried out to analyse the growth rate of 480 fragments of transplanted ornamental coral and survival rate of 200 reared Banggai cardinalfish (Pterapogon kauderni) using fixed net cage in each site. This study reveals that the growth rate of ornamental corals in Mekar Village is better than in other sites. The survival rate (SR) of ornamental corals in Mekar Village is also higher than in Tanjung Tiram Village. This result indicates that the water quality conditions in Mekar Village are better for ornamental coral transplantation, then transplantation activities should be focused surround this island. This initiative looks promising and can also be developed further as marine tourism site that generate additional income for coastal communities.

Socio-ecological status of marine ornamental reef fishery in Trincomalee, Sri Lanka - An application of strategic SWOT analysis

The present study elucidates the socio-ecological status of the marine ornamental reef fish (MORF) fishery in Trincomalee, Sri Lanka, through strategic SWOT analysis. Data were collected through interviews with full-time fishers (n = 49) fishing at Pulmodai, Sampur, and Kuchchaweli reef sites, focus group discussions (n = 3), and participant observations during 2019–2020. Data gathered in-situ were further investigated in detail, analyzed, and grouped into attributes of SWOT analysis. Results revealed higher fishing income (90–900 USD) by 91.84% of respondents as the major strength of the fishery, followed by low production costs (24–240 USD), a low labor force, and others. Seasonality of the fishery, multiple ownership of reefs, and the limited number of fishing hours (4-6 hrs.) were the main weaknesses identified in the system. High global demand, the fish-to-order concept, and the intervention of local buyers were the major opportunities for the fishery. Long market chains, bopyrid isopod infection on Pacific cleaner shrimp, and poor monitoring systems were the major threats to the industry. The MORF fishery in Trincomalee, Sri Lanka, results in higher living standards for fisher communities and empowers them. The present study has policy implications for the MORF fishery and the long-term sustainability of the industry.

Year-Round Spawning, Filial Cannibalism, and Embryonic and Larval Development of the Coral Reef Fish Orchid Dottyback, Pseudochromis fridmani

Aquaculture of marine ornamental fish could potentially reduce the fishing pressure on wild stocks by the global aquarium trade, but its expansion is often constrained by the limited understanding on the biology and early life history of candidate species. The orchid dottyback Pseudochromis fridmani is a valuable and popular marine ornamental fish, but scientific reports on its baseline biology, especially the egg filial cannibalistic behaviour, are scarce. The present study documented key aspects of reproductive biology and early ontogeny of P. fridmani in captivity, including reproductive behaviour, patterns of spawning and filial cannibalism throughout a 12-month period by seven pairs of brood fish, as well as the embryonic and larval development. The results showed that the captive spawning of the broodstock pairs generally occurred every 5–11 days, most commonly every 6–8 days, throughout a year. Despite feeding the brood fish to satiation throughout the data collection period, the average monthly rate of egg filial cannibalism reached 55 ± 37%, but the cannibalism frequency appeared to be pair-specific. The egg incubation duration was approximately 96 h at 27 ± 1 °C, and the development of embryos from cleavage, blastula, gastrula, and segmentation to the pharyngula stage is herein described in detail. The newly hatched P. fridmani larvae possessed important structures and organs for first feeding, including pigmented eyes, developed jaws, and a straight-tube gut. The 0 to 14 days post-hatching (DPH) period appeared to be an important larval stage, as P. fridmani larvae were observed to complete major changes in morphology, gut development, and phototactic behaviour by 14 DPH. Under the culture conditions of this study, the earliest transition to the juvenile stage was observed on 31 DPH, and the majority of fish became juveniles by 56 DPH. The results of this study inform baseline aquaculture production protocols and direct future research, particularly to reduce filial cannibalism through broodstock management and to improve larval culture through supporting the early ontogenetic development of P. fridmani. Additionally, these findings form a foundation for further studying the biology and ecology of P. fridmani in the wild.

Development of recombinant major capsid protein Vaccine and assessment of its efficacy against SRDV in similar damselfish (Pomacentrus similis)

Viral vaccines against emerging viral diseases are crucial for encouraging successful aquaculture production. In this research, an experimental recombinant major capsid protein vaccine of similar damselfish virus was prepared and examined for its efficacy in marine ornamental fish, similar damselfish (Pomacentrus similis). The MCP gene of the SRDV was amplified from the viral DNA by a specific primer set viz bamHI and XhoI- restriction sites and confirmed by agarose gel electrophoresis with a target size of 1416 bp. The gel-purified PCR product was double-digested with the said enzymes and incorporated into the pTriEx1.1 vector, which was subsequently transformed to E. coli DH5α. The plasmids of the two clones pTriEx-MCP-1416-1 and pTriEx-MCP-1416-3 were transformed to E. coli BL21 (DE-3) pLacI. A crude protein compound derived from a colony of E. coli BL21 (DE-3) with expressed MCP inserts was used to evaluate efficacy in similar damselfish by intra-peritoneal injection. After the challenge with SRDV, damselfish vaccinated with recombinant protein showed a lower protection level, while the fish vaccinated with recombinant protein supplemented Quil-A® adjuvant showed an RPS of 26%. According to RPS values recorded from the vaccinated and non-vaccinated damselfish group, the recombinant protein vaccine conferred only marginal protection against the SRDV challenge.

Feasibility Analysis and Production Increase Strategy for Marine Ornamental Fish Agribusiness

The marine ornamental fish business has experienced significant growth every year in Indonesia. This study aims to conduct feasible business analysis for marine ornamental fish commodities at PT. Indotama Putra Wahana. This study aims to evaluate the financial feasibility and investment in the marine ornamental fish business by achieving maximum sustainable profits. The research was conducted from March to July 2023. Data collection was carried out using primary and secondary data using interview methods and direct field observations (PT. Indotama Putra Wahana, DKI Jakarta). Data were analyzed using NPV (Net Present Value), Payback Period, Profitability Index, IRR (Internal Rate of Return), and BEP (Break Even Point). The results show that the NPV of cash flows for 10 years with a discount rate of 20% has a Profitability Index of 1.2. This indicates that the marine ornamental fish business has promising prospects. Data analysis also shows that the payback period is 3.4 years, the Net Present Value is IDR 9.972.734.254, and the IRR (Internal Rate of Return) is 21.8% which exceeds the interest rate of 11.5%. Break Even Point (BEP) of IDR 1.489.913.724 or 8.343 fish. These values indicate that this marine ornamental fish business generates positive income or profits.

Narrowing the Horizon: Using Known Invasives and Propagule Pressure to Focus Risk Screening Efforts on Potential Invasives

About 11 million marine ornamental fish of ca 1800 non-native species are imported into the USA each year. Selecting species for risk assessment is daunting for such a diverse pathway. Herein, we discuss a focused method for species selection: choosing important taxa related to known invaders in high-volume pathways and narrowing prospective species lists to manageable groups of potential hazards. We provide an example using 11 damselfishes, a family with high volume in trade and one of the species established in USA waters. We used a specialized literature review and a risk screening tool (Aquatic Species Invasiveness Screening Kit) to provide an estimate of risk of invasiveness of marine waters of Florida. The established species was identified as a hazard and potential invasive. All other species scored well below the threshold for invasiveness and future climate had little effect on estimates of invasiveness. The analysis revealed little need for additional risk assessment or prohibitions on damselfishes in trade. Education, monitoring, and early detection and rapid response were the main risk management recommendations. The focused species selection process employed herein provided hazard identification and preliminary risk estimates for just 11 species, but collectively, they represent 40% by volume of fishes imported in the marine ornamental trade.

WATER QUALITY IMPROVEMENT AND ANALYSIS FOR CLOWN FISH (Amphiprion ocellaris) CULTIVATION IN A RECIRCULATION SYSTEM

The demand for ornamental fish is currently increasing while the availability in nature is decreasing due to overfishing. Clownfish (Amphiprion ocellaris) is a type of marine ornamental fish that is widely kept in aquariums, but the problem is the rapid decline in water quality due to the activity of these fish. The recirculation system is one way that can be used in water quality management. The study aimed to analyze the type of filter used to stabilize seawater quality in clownfish (rearing containers. This research was conducted from January to April 2021 at the Research Centre of Sibolga Fisheries College. The method used was an experimental method using a one-factor Completely Randomized Design (CRD) with four treatment levels and three replications. The treatments in this study were P0 (unfiltered), P1 (cotton filter), P2 (fiber filter), and P3 (activated charcoal filter). The fish used was 2 – 3 cm in size, kept in an aquarium measuring 60x40x40cm with a stocking density of 2 fish/L of water and fed tubifex 2 times a day, at 08.00 and 18.00 WIB as much as 5% of their body weight. Parameters measured were temperature, pH, DO, salinity, ammonia, phosphate, abundance of bacteria, phytoplankton, and survival of clownfish. Water quality measurements are carried out every 7 days. The results obtained from the improvement and analysis of water quality for the cultivation of clownfish in the recirculation system provide an influence on water quality in the rearing container. The results obtained were temperature 27.9–28.0 0C, pH 8.3–8.4, DO 7.5–8.0 mg/L, salinity 33-34 ppt, ammonia 0.04–0.06 mg/L, phosphate 0.47–0.48 mg/L and bacterial abundance 2.35x104 CFU/mL with a survival rate of 95.55%.