Aquarium Industry Research Articles

The Impact of Microalgae-Based Diet Enriched Mesocyclopsaspericornis Copepod on the Growth Performance and Biochemical Assessment of Ornamental Fish (Brachydanio rerio)

The cultivation of emerging species in aquaculture and the aquarium industry presents challenges, particularly during the sensitive larval stage, which often has a small mouth. Developing appropriate early feeding protocols is crucial. Copepods have gained recognition as a viable alternative to traditional live fish feeds, as they are natural prey for many fish species and do not necessarily require additional nutritional enrichment. This study aimed to assess the effect of enriching Mesocyclopsaspericornis with different microalgae (Spirulina, Azolla, Chlorella) when fed to Brachydanio rerio, focusing on growth, survival, and biochemical performance of the ornamental fish. Results revealed that Brachydanio rerio exhibited the highest specific growth rate (SGR) when fed with copepods enriched with Spirulina (1.49±0.022), and the highest survival rate was observed when copepods were enriched with Spirulina (93.4±2.549). Further analysis of the biochemical composition of enriched copepods indicated that Chlorella resulted in the highest protein and carbohydrate content, along with lower lipid content compared to other enrichment groups. This suggests that microalgae, particularly Spirulina and Chlorella can serve as a potential feed to enhance the nutritional status of copepods and support the early stages of fish development.

The complete mitochondrial genome of bamboo shrimp Atyopsis moluccensis (Atyidae, Decapoda)

Atyopsis moluccensis, belonging to the family Atyidae, is one of the popular species in aquarium industry. Here, we sequenced the mitochondrial genome of A. moluccensis. The mitogenome of A. moluccensis is 15,933 bp in length, consisting 22 transfer RNAs, 13 protein-coding genes (PCGs), and two ribosomal RNAs. The composition of A. moluccensis mitogenome is 33.77% for A, 13.81% for G, 28.74% for T, and 23.68% for C. The A + T content of the heavy-strand was 62.51%. Except ND5, most of the PCGs had ATN as the start codon. Only COX2 and ND4 were stopped by incomplete stop codon. The phylogenetic relationship was reconstructed with 16 shrimp from six genera of family Atyidae, which revealed that A. moluccensis and A. gabonensis clustered together and species of the same genus were grouped together in a clade. The data are beneficial in understanding the evolution and phylogenetic relationships of Atyidae shrimp.

The role of aquaculture in the international trade of giant clams (Tridacninae) for the aquarium industry (2001–2019)

An overview over the international trade in live giant clams (Bivalvia: Tridacninae) from 2001 to 2019 was made based on worldwide import data from the CITES Trade Database. A distinction was made between trade records of wild-caught clams and maricultured ones. A general decline in the trade of wild giant clams was observed. Since these bivalves naturally live attached to rocky substrate in coral reefs and their forceful removal is harmful to surrounding corals, this trend helped to prevent damage to their natural environment. Possible reasons behind this decline are lower population numbers, trade restrictions, and a decrease in demand. Trade in wild-caught Tridacna crocea decreased, whereas that of T. maxima increased, taking over the former's position as most popular species. From 2015 onwards, over 50% of the source was made up by aquaculture, up to 2019. Aquaculture of live giant clams can be profitable, but there are still obstacles to overcome in order to ensure stable production numbers and long-term profit. With more research and support from governments, aquaculture can help to take pressure off wild populations of giant clams that are already suffering from exploitation for the sea-food market and souvenir industry, and also from habitat degradation due to climate change and other anthropogenic disturbances.

First description of post-flexion larvae of the West Atlantic trumpetfish, Aulostomus maculatus

Abstract The West Atlantic trumpetfish Aulostomus maculatus is a species of little commercial importance, but it is frequently used as a study organism in behavioural ecology, and it has been traded in the aquarium industry to some extent. The adult life stage is well described, however its early life history is nearly unknown. This paper provides the first description of post-flexion larvae of A. maculatus, including detailed illustrations, photographs, morphological data, and collection site data of specimens collected during a multipurpose research survey conducted within the Sargasso Sea Subtropical Convergence Zone. The collection site also implies a geographic range expansion, off the continental shelf, of the pelagic larvae stage. This paper hence advances the scientific knowledge about the early life stages, distribution and ecology of this species.

Retailer perspectives reveal knowledge gaps in the traceability of the scleractinian coral trade in Singapore

Scleractinian corals are key reef-builders in tropical marine ecosystems. Harvests of wild stocks for the global marine aquarium trade have raised concerns about unsustainable exploitation. While it is important to ensure that marine ornamental species are used legally and sustainably, it is challenging to trace them through the trade due to the fragmented and complex supply chain. Retailers can provide unique perspectives to narrow knowledge gaps as they interact closely with both suppliers and consumers. Through semi-structured interviews of retailers based in Singapore, we investigated their knowledge of the supply chain, trade practices, and consumer preferences. We also surveyed taxa available for sale at these brick-and-mortar aquarium shops. Our study revealed at least 42 genera from 14 families of scleractinian corals present across 20 shops in Singapore. Retailers displayed a lack of familiarity in coral provenance and trade regulations, suggesting that they have limited awareness of traceability along the supply chain. Import decisions were not guided by traceability and environmental sustainability, but instead were driven by demand and supply factors such as aesthetics, rarity, and availability. This underscores the need for more outreach and engagement efforts to raise awareness among commercial stakeholders towards improving traceability and sustainable management in the marine aquarium industry.

Effects of Substituting Activated Carbon with Titanium-Dioxide-Coated Cenospheres in Conventional Aquarium Filters

We investigated the effectiveness of TiO2 cenospheres in reducing the concentrations of three common harmful compounds, ammonium, nitrate, and nitrite, in fish aquariums. These cenospheres can contribute to more sustainable and eco-friendly aquarium filtration systems while also improving the health of fish. We designed a 30-day experiment with three treatment groups based on the filter type: (1) a control group with a conventional aquarium filter, (2) a group with a TiO2 cenosphere filter, and (3) a group with a dark TiO2 cenosphere filter. The water quality was the same baseline in all groups, and each tank was monitored daily for changes in temperature, pH, ammonia, nitrate, and nitrite concentrations. We found that the TiO2 cenosphere filter was effective in reducing the concentrations of all three pollutants. By the end of the experimental period, the average concentration of nitrite in the control group was 10.7 µM, while the average concentration in the TiO2 cenosphere filter group dropped 55% to 4.7 µM from the baseline. The average concentration of nitrate was reduced by 17% and ammonia by 28% in the cenosphere-treated group. Hence, the cenospheres were effective in reducing the concentrations of all three pollutants, with the greatest reduction seen for nitrite. These findings support further investigation for incorporating TiO2 cenospheres into aquarium filtration to help reduce the environmental burden of the aquarium industry.

Live Microalgae-Based Diets as Enrichment to Improve the Nutritional Profile of the Calanoid Copepod Acartia tonsa (Dana, 1849) Nauplii

Most emerging species in marine aquaculture and the aquarium industry have a sensitive and small-mouthed larval stage, and their culture is very challenging due to a lack of appropriate early feeding protocols. The use of copepods has been widely recognized as a good alternative to traditional fish live feeds (rotifers and Artemia spp.), especially for new species targeted for the multibillion-dollar marine aquarium trade. However, most copepod culture trials are focused on biomass production, while their nutritional requirements and enrichment protocols remain scarcely known. The main objective of this study was to determine the dietary contribution of three microalgae-based diets, provided as a mono R (Rhodomonas salina) or binary I–R (Isochrysis galbana + R. salina) and T–R (Tetraselmis suecica + R. salina), on the biochemical composition (proximate and fatty acids (FAs)) and survival of the calanoid copepod Acartia tonsa (nauplii) versus the conventional rotifer Brachionus plicatilis throughout 96 hr exposure. Both live preys were characterized by the highest protein and total n-3 long-chain polyunsaturated FAs (LC-PUFAs) content when fed with the binary diet I–R compared to other treatments, although the nutritional value of A. tonsa nauplii was always much higher compared to B. plicatilis. In general, there was a wide difference in proximate and FAs composition between the two preys, denoting A. tonsa as better live feed in terms of capacity to retain n-3 LC-PUFAs, especially eicosapentanoic acid (20 : 5n-3) and docosahexanoic acid (22 : 6n-3). The present study highlights the nutritional profile of enriched A. tonsa nauplii and contributes to the production of high-quality live feeds, which may be able to reach the nutritional needs of new marine fish species during their larval development, as well as contributing to the improvement of A. tonsa culture.

Potential of Live Rock Culture in Coastal Environments of Sri Lanka Based on Shape, Substrate, and Monsoon Pattern

Purpose: Live rocks are very important and highly demanded in the global aquarium industry and can be cultured easily without sophisticated techniques or knowledge. Marine Live rock culture may become a conceivable alternative industry among the resource utilizing coastal communities in Sri Lanka. However, it has not been scientifically studied yet. Research Method: Nine types of cement rocks were made by changing three types of shapes and three types of substrates and those were placed in different study locations on the Southern and Eastern coast of Sri Lanka covering all four types of monsoon patterns prevail in the country. Findings: Live species attachments, their attachment rates, and consumer preferences differed with the shape, substrate, monsoon pattern, study location, and growth period in the sea and most of those differences were statistically significant. Consumer preference was mainly dependent on the nature of biota attachments on top of the different rock types. Therefore, their preferences were also changing with the types of rock, monsoon pattern, and location. Originality/ Value: Findings can be effectively utilized for establishing live rock culture as an alternative industry, especially in ecosystems where resources are depleted or degraded.

Ornamental Aquatic Plant Production in Florida

Florida has a unique and diverse aquaculture industry consisting of ornamental fish, food fish, shellfish, alligators, aquatic plants, and more. Although some aquatic plants are produced for food or wetland restoration, most aquatic plant production in Florida is for the water garden and aquarium industries. There are over 1000 different species and varieties of ornamental aquatic plants produced in Florida. Since most ornamental aquatic plants are tropical in origin, Florida’s warm climate makes it ideal for growing them year-round. This publication covers ornamental aquatic plant production in Florida including permitting and licensing, production techniques, farm design, pests and diseases, and marketing.

Identification of sex-linked marker and candidate sex determination gene in ornamental fish, African scat (Scatophagus tetracanthus)

The aquarium industry greatly threatens biological diversity via biological invasion. Mono-sex culturing is an important technique to reduce the possible biological invasion introduced by the aquarium fish, which escape into their non-native environment. African scat (Scatophagus tetracanthus) is a valuable aquarium fish species worldwide. Herein, its sex-linked marker and candidate sex determination (SD) gene were identified through genome sequencing. The whole genome of the male African scat was sequenced using the next-generation sequencing technology. The assembled genome is 630.96 Mb with a scaffold N50 of 38,217 bp. Phylogenetic analysis revealed that African scat diverged from spotted scat (S. argus) approximately 10.5 million years ago. One sex-linked marker (Marker-1) was detected in African scat. Marker-1 amplified a single band of 873 bp in female African scat, and double bands of 873 bp and specific 772 bp in male African scat. Next, Marker-1 was validated in 60 cultured African scat with 100% consistency. Sequence analysis revealed that the 873 and 772 bp fragments were both Dmrt1 homologous sequences. These results imply that the African scat possesses the XY sex-determination system (XX females, XY males), with Dmrt1 as its sex-linked gene. Dmrt1 cDNA sequences on the X and Y chromosomes were also cloned and labeled as Dmrt1∆X and Dmrt1Y, respectively. The amino acid (aa) sequences coded by Dmrt1∆X and Dmrt1Y were 143 aa and 300 aa, respectively. Dmrt1Y mRNA was specifically expressed in the testis, with no expression in the ovary. Therefore, Dmrt1Y is male-specific and a candidate SD gene. The genome data and sex-linked marker of African scat will be helpful for its commercial management to prevent its biological invasion. Besides, the identification of its candidate SD gene contributes to the basic research of SD in vertebrates.

Transcriptome analysis of flathead grey mullet (Mugil cephalus) ovarian development induced by recombinant gonadotropin hormones.

Background: Treatment with recombinant gonadotropin hormones (rGths), follicle-stimulating hormone (rFsh) and luteinizing hormone (rLh), was shown to induce and complete vitellogenesis to finally obtain viable eggs and larvae in the flathead grey mullet (Mugil cephalus), a teleost arrested at early stages of gametogenesis in intensive captivity conditions. This study aimed to investigate the transcriptomic changes that occur in the ovary of females during the rGths-induced vitellogenesis. Methods: Ovarian samples were collected through biopsies from the same five females at four stages of ovarian development. RNASeq libraries were constructed for all stages studied, sequenced on an Illumina HiSeq4000, and a de novo transcriptome was constructed. Differentially expressed genes (DEGs) were identified between stages and the functional properties of DEGs were characterized by comparison with the gene ontology and Kyoto Encyclopedia. An enrichment analysis of molecular pathways was performed. Results: The de novo transcriptome comprised 287,089 transcripts after filtering. As vitellogenesis progressed, more genes were significantly upregulated than downregulated. The rFsh application induced ovarian development from previtellogenesis to early-to-mid-vitellogenesis with associated pathways enriched from upregulated DEGs related to ovarian steroidogenesis and reproductive development, cholesterol metabolism, ovarian growth and differentiation, lipid accumulation, and cell-to-cell adhesion pathways. The application of rFsh and rLh at early-to-mid-vitellogenesis induced the growth of oocytes to late-vitellogenesis and, with it, the enrichment of pathways from upregulated DEGs related to the production of energy, such as the lysosomes activity. The application of rLh at late-vitellogenesis induced the completion of vitellogenesis with the enrichment of pathways linked with the switch from vitellogenesis to oocyte maturation. Conclusion: The DEGs and enriched molecular pathways described during the induced vitellogenesis of flathead grey mullet with rGths were typical of natural oogenesis reported for other fish species. Present results add new knowledge to the rGths action to further raise the possibility of using rGths in species that present similar reproductive disorders in aquaculture, the aquarium industry as well as the conservation of endangered species.

Size-weight relationships for estimating harvestable biomass of Acropora corals on Australia's Great Barrier Reef

Although hard corals (order Scleractinia) are listed in Appendix II of the Convention for the International Trade in Endangered Species (CITES), there is significant ongoing wild harvest and international trade, mostly for the aquarium industry. Acropora corals account for the majority of aquarium corals harvested and traded, but are also extremely vulnerable to fisheries-independent threats, especially climate-induced coral bleaching. Reconciling effects of coral harvesting is complicated as harvest limits are based on weight, while there is limited data on standing biomass of Acropora from different reef environments. Here, a management-friendly methodology that allows for quantification of Acropora spp. biomass is described and demonstrated, thus providing means for the development and implementation of a rigorous sustainable harvest strategy. We establish size-weight relationships for four growth forms of Acropora spp. harvested from Australia's Great Barrier Reef, to facilitate estimates of harvestable biomass and better understand the ecological context of current weight-based harvest levels and limits. Using these relationships, and field-based sampling at 12 sites across seven distinct reefs, the estimated biomass of Acropora spp. ranges from 0.12 kg ⋅ m−2 to 4.7 kg ⋅ m−2. These estimates necessitate further consideration of catch composition and the specific abundance of individual species that are heavily harvested, and how impacts of current harvest practices interact with species-specific vulnerability to climate change and other escalating human pressures contributing to the degradation of coral reef ecosystems. This study is a crucial first step towards quantifying the ecological impacts of the fishery to develop management strategies that are underpinned by research.

Recent Trends in Live Feeds for Marine Larviculture: A Mini Review

In marine larviculture, farmed larvae mainly rely on the alimentation of a group of small-sized phytoplankton and zooplankton referred to as live feed. Under the diversifying demands of human consumption and ornamental aquarium industry, new species of live feed and their innovative production methods are essential focuses for sustainable larviculture of many emerging fish and invertebrate species. The selection of proper live feed for larval feeding is based on several parameters, such as size, morphology, nutritional value, stock density, and growth rate. This review aims to highlight the biological characteristics, production approach, common larviculture applications as well as recent innovations in the aquaculture technology of live feed organisms (microalgae, ciliated protists, rotifer, Artemia, copepod, and others).

Risks associated with the global demand for novel exotic pets: A new and emerging trade in snakehead fish (Channa spp.) from India

Ornamental fish keeping is a popular hobby worldwide, supporting a significant global aquarium industry. Using export records of live snakeheads (Channa spp.) from India, we show a six-fold increase in the numbers of these (wild-sourced, freshwater) species exported worldwide between 2014 and 2019, driven by an increase in exports from West Bengal to China, Taiwan, and Hong Kong. We highlight issues associated with exploitation of a poorly-known taxonomic group (in this case, the genus Channa), species that have restricted ranges, are rare, recently described, and difficult for non-experts to distinguish from others, and the risks associated with global transport of a potentially invasive species. We outline knowledge gaps relevant to national-level management; more broadly, we suggest a fundamental change of approach whereby traders of ‘luxury’ wildlife products (e.g. exotic pets) are required to demonstrate that trade is sustainable and safe, rather than conservationists to demonstrate that it is not.

Aquascape ornamental industry in Malaysia: A perspective review

Aquascape is the skill of combining aquatic plants with soil, sand, wood, and rock to create an aquarium underwater environment either marine or freshwater as a beautiful decoration at home or in the office. The aquatic plant consisted as a major component in aquascape where the ornamental fish completed the ecosystem. However, poor management and lack of experience handling aquatic plants and ornamental fish could lead to freshwater environment issues. This study is essential to collect data on hobbyist preference on aquatic plants and ornamental fish and to monitor the aquascape practices; daily and weekly routine and effect on the environment. The main concerns that should be taking care of an aquascape are the discharge of ornamental fish, aquatic plants and effluents in the local waters that may threaten Malaysia’s natural ecosystem. As far as aquatic plants are concerned, the key cause of the introduction of exotic species is from the aquarium industry, leading to invasive aquatic plant species associated with aquarium leaks. Invasive alien aquatic plants (IAAPs) endanger biodiversity due to their complex overgrowth and consequences that may be impacted to the environment and socioeconomic.

In Vitro Rapid Multiplication of a Highly Valuable Ornamental Aquatic Plant Anubias Heterophylla

The present study focuses on the development of a micropropagation protocol for true to type plants of Anubias heterophylla, a valuable ornamental aquatic plant. Natural propagation of aquatic species is limited due to the production of a small number of plants with a long cultivation period, disease and requirement of a large space for propagation. Surface-disinfected shoot tip explants were cultured on MS medium containing 0.1 % (w/v) activated charcoal (AC) and supplemented with 6-benzylaminopurine (BAP) at different concentrations (0, 1.0, 3.0 and 5.0 mg/L) either singly or in combination with alpha Naphthalene acetic acid (NAA) and 2,4-Dichlorophenoxy acetic acid (2,4-D) (0.5 and 1.0 mg/L). Among different auxins and cytokinin used, the number of shoots initiated per explant varied significantly among the different auxin and cytokinin combinations. The highest number of shoots per explants (3.60 ± 0.24) was formed in the culture medium containing 1.0 mg/L NAA in combination with 1.0 mg/L BAP, followed by in the culture medium with 3.0 mg/L BAP (2.40 ± 0.24). In the culture medium with 1.0 mg/L NAA and 1.0 mg/L BAP, 100 % of the cultured explants regenerated new shoots within 60 days. The maximum number of roots (19.80 ± 0.20 roots) per explant was observed after 60 days of culture on MS medium contained 0.1 % (w/v) AC and supplemented with 1.0 mg/L NAA and 1.0 mg/L BAP. With a 100% survival rate, the regenerated plantlets were effectively acclimatized to submerged underwater environments. Plantlets exhibited phenotypic traits that were comparable to those of their donor plant. This protocol is suited for commercial Anubias heterophylla propagation in the aquarium industry. HIGHLIGHTS The development of a micropropagation protocol for true to type plants of Anubias heterophylla The initiation of aseptic cultures of Anubias heterophylla from shoot tip explants Optimization of culture medium for shoot proliferation Rooting micro shoots and hardening of rooted micro shoots

Molecular diagnostic based on 18S rDNA and supplemental taxonomic data of the cnidarian coelozoic Ceratomyxa (Cnidaria, Myxosporea) and comments on the intraspecific morphological variation

Ceratomyxa amazonensis is a cnidarian myxosporean originally described with strongly arcuate crescent-shaped myxospores, absence of vegetative stages and infecting Symphysodon discus, an important Amazonian ornamental fish in the aquarium industry. As part of a long-term investigation concerning myxosporeans that infect discus fish Symphysodon spp. from different rivers of the Amazon Basin, thirty specimens of S. discus collected from Unini River were examined. Plasmodial vegetative stages therefrom were found freely floating in the bile of gall bladders from eighteen fish. Mature myxospores were slightly crescent-shaped, measuring 4.72 ± 0.1 (4.52–4.81) μm in length, 24.2 ± 0.4 (23.9–25.3) μm in thickness with polar capsules 2.31 ± 0.1 (2.29–2.33) μm in length and 2.15 ± 0.1 (2.13–2.17) μm in width. Strong morphological differences were observed between the newly isolated myxospores obtained and the previously described C. amazonensis; however, molecular assessment, based on 18S rDNA, revealed a high similarity (99.91%), with only a single nucleotide base change. This study provides new data, expanding the original description of the species with a discussion on differences in myxospore-morphology in the context of intraspecific morphological plasticity.

The European Union Is Still Unable to Find Nemo and Dory-Time for a Reliable Traceability System for the Marine Aquarium Trade.

Simple SummaryThe EU is one of the main markets for marine ornamental species. Their entrance into the EU, as well as their circulation between member states, is supposed to be highly regulated. Surprisingly, it is currently impossible to answer simple questions, such as how many Nemos and Dorys are imported each year into the EU, or where do they come from? This lack of knowledge is difficult to understand, as all these organisms enter the EU by air-shipping and must be controlled at customs offices in international airports. This scenario favors “business as usual” and does not allow to verify the claims on sustainability commonly made by the marine aquarium industry. However, the EU already operates a platform that may allow to collect such information in a reliable way and shed light on this blurry industry, the Trade Control and Expert System (TRACES). This platform can start by surveying marine ornamental fishes, so the EU can finally know how many Nemos and Dorys are being imported and where they are sourced from. If this approach works, marine ornamental invertebrates can also be monitored, and reliable databases can finally be assembled to document the marine aquarium trade in the EU.The EU is one of the main importers of marine ornamental species sourced from tropical coral reefs around the world. While the entrance of live organisms into the EU, along with their intra-EU circulation, is framed within stringent control mechanisms, to date, no reliable figures exist concerning which marine ornamental species are imported, in what numbers, and where they are sourced from. This lack of reliable data in the EU on the trade of marine ornamental species is puzzling if one considers that all these imported specimens must be controlled at customs offices located in international airports. Such data deficiency favors the prevalence of blurry supply chains and a “business as usual” mindset that hampers any serious effort to promote sustainability in the marine aquarium industry. To safeguard the collection of findable, accessible, interoperable, and reusable (FAIR) data, we suggest that the EU platform Trade Control and Expert System (TRACES) refines its surveillance on the trade of marine ornamental species. The detailed survey of marine ornamental fishes alone can be used as a proof of concept to validate the use of TRACES for this purpose and, if successful, it can later be expanded to all other taxonomic groups of marine ornamental species.

Diversity of Seahorse Species (Hippocampus spp.) in the International Aquarium Trade

Seahorses (Hippocampus spp.) are threatened as a result of habitat degradation and overfishing. They have commercial value as traditional medicine, curio objects, and pets in the aquarium industry. There are 48 valid species, 27 of which are represented in the international aquarium trade. Most species in the aquarium industry are relatively large and were described early in the history of seahorse taxonomy. In 2002, seahorses became the first marine fishes for which the international trade became regulated by CITES (Convention for the International Trade in Endangered Species of Wild Fauna and Flora), with implementation in 2004. Since then, aquaculture has been developed to improve the sustainability of the seahorse trade. This review provides analyses of the roles of wild-caught and cultured individuals in the international aquarium trade of various Hippocampus species for the period 1997–2018. For all species, trade numbers declined after 2011. The proportion of cultured seahorses in the aquarium trade increased rapidly after their listing in CITES, although the industry is still struggling to produce large numbers of young in a cost-effective way, and its economic viability is technically challenging in terms of diet and disease. Whether seahorse aquaculture can benefit wild populations will largely depend on its capacity to provide an alternative livelihood for subsistence fishers in the source countries. For most species, CITES trade records of live animals in the aquarium industry started a few years earlier than those of dead bodies in the traditional medicine trade, despite the latter being 15 times higher in number. The use of DNA analysis in the species identification of seahorses has predominantly been applied to animals in the traditional medicine market, but not to the aquarium trade. Genetic tools have already been used in the description of new species and will also help to discover new species and in various other kinds of applications.

Does acidification lead to impairments on oxidative status and survival of orange clownfish Amphiprion percula juveniles?

The nitrification process in recirculating aquaculture systems can reduce water pH. Fish can also be exposed to water acidification during transport, an important feature in the aquarium industry, as live fish can be kept in a closed environment for more than 24 h during overseas aerial transportation. Therefore, it is important to study the responses of fish to acidic environments. We investigated the impacts of acute exposure to decreasing pH levels in orange clownfish Amphiprion percula juveniles on their survival and oxidative stress status. Fish were exposed to pH 5, 6, 7, and 8 for 96 h. We observed a significant reduction in survival (85%) and protein damage as measured by P-SH (protein thiol) for fish maintained at pH 5. Despite no effects on survival or oxidative damage, fish exposed to pH 6 showed an increase in their antioxidant defense systems, demonstrating this pH level could not be suitable for them as well. Furthermore, there were no negative effects for fish kept at pH 7, compared to those maintained at pH 8 during this short-term evaluation.