Dascyllus Trimaculatus Research Articles

Life history, larval dispersal, and connectivity in coral reef fish among the Scattered Islands of the Mozambique Channel

The Western Indian Ocean harbors one of the world’s most diverse marine biota yet is threatened by exploitation with few conservation measures in place. Primary candidates for conservation in the region are the Scattered Islands (Iles Eparses), a group of relatively pristine and uninhabited islands in the Mozambique Channel. However, while optimal conservation strategies depend on the degree of population connectivity among spatially isolated habitats, very few studies have been conducted in the area. Here, we use highly variable microsatellite markers from two damselfishes (Amphiprion akallopisos and Dascyllus trimaculatus) with differing life history traits [pelagic larval duration (PLD), adult habitat] to compare genetic structure and connectivity among these islands using classic population structure indices as well as Bayesian clustering methods. All classical fixation indexes F ST, R ST, G′ST, and Jost’s D show stronger genetic differentiation among islands for A. akallopisos compared to D. trimaculatus, consistent with the former species’ shorter PLD and stronger adult site attachment, which may restrict larval dispersal potential. In agreement with these results, the Bayesian analysis revealed clear genetic differentiation among the islands in A. akallopisos, separating the southern group (Bassas da India and Europa) from the center (Juan de Nova) and northern (Iles Glorieuses) islands, but not for D. trimaculatus. Local oceanographic patterns such as eddies that occur along the Mozambique Channel appear to parallel the results reported for A. akallopisos, but such features seem to have little effect on the genetic differentiation of D. trimaculatus. The contrasting patterns of genetic differentiation between species within the same family highlight the importance of accounting for diverse life history traits when assessing community-wide connectivity, an increasingly common consideration in conservation planning.

Sea anemones modify their hiding time based on their commensal damselfish.

Animals often retreat to refugia when alarmed and the time they spend hiding reflects an economic decision that trades off reducing predation risk with other beneficial activities. Typically, refugia such as burrows are static, but some refugia are dynamic. For species with defensive mutualisms, hiding might be contingent on their mutualist's behaviour. We disturbed and quantified hiding time in magnificent sea anemones, Heteractis magnifica, and their associated domino damselfish, Dascyllus trimaculatus. We found that sea anemone hiding behaviour was dependent on the number and behaviour of their commensal fish: anemones emerged sooner when they had more associated fish and faster returning fish. Together, these results demonstrate that hiding behaviour can be influenced by the behaviour of a commensal; such dynamic mutualisms may be found in other systems.

Repeated exposure to noise increases tolerance in a coral reef fish

Some anthropogenic noise is now considered pollution, with evidence building that noise from human activities such as transportation, construction and exploration can impact behaviour and physiology in a broad range of taxa. However, relatively little research has considered the effects of repeated or chronic noise; extended exposures may result in habituation or sensitisation, and thus changes in response. We conducted a field-based experiment at Moorea Island to investigate how repeated exposure to playback of motorboat noise affected a coral reef fish (Dascyllus trimaculatus). We found that juvenile D. trimaculatus increased hiding behaviour during motorboat noise after two days of repeated exposure, but no longer did so after one and two weeks of exposure. We also found that naïve individuals responded to playback of motorboat noise with elevated ventilation rates, but that this response was diminished after one and two weeks of repeated exposure. We found no strong evidence that baseline blood cortisol levels, growth or body condition were affected by three weeks of repeated motorboat-noise playback. Our study reveals the importance of considering how tolerance levels may change over time, rather than simply extrapolating from results of short-term studies, if we are to make decisions about regulation and mitigation.

Seascape features, rather than dispersal traits, predict spatial genetic patterns in co‐distributed reef fishes

AbstractAimTo determine which seascape features have shaped the spatial genetic patterns of coral reef fishes, and to identify common patterns among species related to dispersal traits [egg type and pelagic larval duration (PLD)].LocationIndian and Pacific Oceans, including the Indo‐Australian Archipelago.MethodsWe sampled coral reef fishes with differing dispersal traits (Pomacentrus coelestis, Dascyllus trimaculatus, Hailchoeres hortulanus and Acanthurus triostegus) and characterized spatial (mtDNA) genetic patterns using AMOVA‐clustering and measures of genetic differentiation. Similarity in the spatial genetic patterns among species was assessed using the congruence among distance matrices method and the seascape features associated with the genetic differentiation of each species were identified using multiple regression of distance matrices (MRDM) and stepwise model selection.ResultsSimilar spatial genetic patterns were found for P. coelestis and H. hortulanus, despite their differing egg type (benthic versus pelagic). MRDM indicated that geographical distance was underlying their correlated genetic patterns. Species with pelagic eggs (A. triostegus and H. hortulanus) also had correlated patterns of genetic differentiation (Dest); however, a common underlying seascape feature could not be inferred. Additionally, the common influence of the Torres Strait and the Lydekker/Weber's line was identified for the genetic patterns of differentiation for P. coelestis and A. triostegus, despite their differing dispersal traits, and the uncorrelated spatial genetic patterns of these species.Main conclusionsOur study demonstrates the value of a quantitative, hypothesis‐testing framework in comparative phylogeography. We found that dispersal traits (egg type and PLD) did not predict which species had similar spatial genetic patterns or which seascape features were associated with these patterns. Furthermore, even in the absence of visually similar, or correlated spatial genetic patterns, our approach enabled us to identify seascape features that had a common influence on the spatial genetic patterns of co‐distributed species.

Full-sibs in cohorts of newly settled coral reef fishes.

Reef fishes exhibit a bipartite life cycle where a benthic adult stage is preceded by a pelagic dispersal phase during which larvae are presumed to be mixed and transported by oceanic currents. Genetic analyses based on twelve microsatellite loci of 181 three-spot dascyllus (Dascyllus trimaculatus) that settled concurrently on a small reef in French Polynesia revealed 11 groups of siblings (1 full sibs and 10 half-sibs). This is the first evidence that fish siblings can journey together throughout their entire planktonic dispersal phase (nearly a month long for three-spot dascyllus). Our findings have critical implications for the dynamics and genetic structure of fish populations, as well as for the design of marine protected areas and management of fisheries.

Mangrove plant, Rhizophora mucronata (Lamk, 1804) mediated one pot green synthesis of silver nanoparticles and its antibacterial activity against aquatic pathogens

BackgroundBiosynthesis of nanoparticles has received increasing attention due to the growing need to develop safe, time-effective and environmentally friendly technologies for nano-materials synthesis. This paper reports the one pot green synthesis of silver nanoparticles (AgNPs) using the leaf bud extract of a mangrove plant, Rhizophora mucronata and their antimicrobial effects against aquatic pathogens. Highly stable AgNPs were synthesized by treating the mangrove leaf bud extract with aqueous silver nitrate solution at 15 psi pressure and 121°C for 5 minutes.ResultsThe biosynthesized AgNPs were characterized by UV-visible spectrum, at 426 nm. The X-Ray Diffraction (XRD) pattern revealed the face-centered cubic geometry of AgNPs. Fourier Transform Infra Red (FTIR) spectroscopic analysis was carried out to identify the possible biomolecules responsible for biosynthesis of AgNPs from the leaf bud extract. The size and shape of the well-dispersed AgNPs were documented with the help of High Resolution Transmission Electron Microscopy (HRTEM) with a diameter ranged from 4 to 26 nm. However a maximum number of particles were observed at 4 nm in size. The antibacterial effects of AgNPs were studied against aquatic pathogens Proteus spp., Pseudomonas fluorescens and Flavobacterium spp., isolated from infected marine ornamental fish, Dascyllus trimaculatus.ConclusionThis study reveals that the biosynthesized AgNPs using the leaf bud extract of a mangrove plant (R. mucronata) were found equally potent to synthetic antibiotics. The size of the inhibition zone increases when the concentration of the AgNPs increased and varies according to species.

Vicariance and dispersal across an intermittent barrier: population genetic structure of marine animals across the Torres Strait land bridge

Biogeographic barriers, some transitory in duration, are likely to have been important contributing factors to modern marine biodiversity in the Indo-Pacific region. One such barrier was the Torres Strait land bridge between continental Australia and New Guinea that persisted through much of the late Pleistocene and separated Indian and Pacific Ocean taxa. Here, we examine the patterns of mitochondrial DNA diversity for marine animals with present-day distributions spanning the Torres Strait. Specifically, we investigate whether there are concordant signatures across species, consistent with either vicariance or recent colonization from either ocean basin. We survey four species of reef fishes (Apogon doederleini, Pomacentrus coelestis, Dascyllus trimaculatus, and Acanthurus triostegus) for mtDNA cytochrome oxidase 1 and control region variation and contrast these results to previous mtDNA studies in diverse marine animals with similar distributions. We find substantial genetic partitioning (estimated from F-statistics and coalescent approaches) between Indian and Pacific Ocean populations for many species, consistent with regional persistence through the late Pleistocene in both ocean basins. The species-specific estimates of genetic divergence, however, vary greatly and for reef fishes we estimate substantially different divergence times among species. It is likely that Indian and Pacific Ocean populations have been isolated for multiple glacial cycles for some species, whereas for other species genetic connections have been more recent. Regional estimates of genetic diversity and directionality of gene flow also vary among species. Thus, there is no apparent consistency among historical patterns across the Torres Strait for these co-distributed marine animals.

Evolution of ontogenetic allometry shaping giant species: a case study from the damselfish genus Dascyllus (Pomacentridae)

The evolution of body size, the paired phenomena of giantism and dwarfism, has long been studied by biologists and paleontologists. However, detailed investigations devoted to the study of the evolution of ontogenetic patterns shaping giant species are scarce. The damselfishes of the genus Dascyllus appear as an excellent model for such a study. Their well understood phylogeny reveals that large-bodied species have evolved in two different clades. Geometric morphometric methods were used to compare the ontogenetic trajectories of the neurocranium and the mandible in both small-bodied (Dascyllus aruanus and Dascyllus carneus; maximum size: 50–65 mm standard length) and giant (Dascyllus trimaculatus and Dascyllus flavicaudus; maximum size: 90–110 mm standard length) Dascyllus species. At their respective maximum body size, the neurocranium of the giant species is significantly shorter and have a higher supraoccipital crest relative to the small-bodied species, whereas mandible shape variation is more limited and is not related to the ‘giant’ trait. The hypothesis of ontogenetic scaling whereby the giant species evolved by extending the allometric trajectory of the small-bodied ones (i.e. hypermorphosis) is rejected. Instead, the allometric trajectories vary among species by lateral transpositions. The rate of shape changes and the type of lateral transposition also differ according to the skeletal unit among Dascyllus species. Differences seen between the two giant species in the present study demonstrate that giant species may appear by varied alterations of the ancestor allometric pattern. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99, 99–117. ADDITIONAL KEYWORDS: coral reef fishes – development – geometric morphometrics – giantism – growth – heterochrony – trajectory – shape – size – skull.

ALLOPATRIC DIVERGENCE AND SPECIATION IN CORAL REEF FISH: THE THREE-SPOT DASCYLLUS,DASCYLLUS TRIMACULATUS,SPECIES COMPLEX

Long pelagic larval phases and the absence of physical barriers impede rapid speciation and contrast the high diversity observed in marine ecosystems such as coral reefs. In this study, we used the three-spot dascyllus (Dascyllus trimaculatus) species complex to evaluate speciation modes at the spatial scale of the Indo-Pacific. The complex includes four recognized species and four main color morphs that differ in distribution. Previous studies of the group using mitochondrial DNA revealed a noncongruence between color morphs and genetic groupings; with two of the color morphs grouped together and one color morph separated into three clades. Using extensive geographic sampling of 563 individuals and a combination of mitochondrial DNA sequences and 13 nuclear microsatellites, we defined population/species boundaries and inferred different speciation modes. The complex is composed of seven genetically distinct entities, some of which are distinct morphologically. Despite extensive dispersal abilities and an apparent lack of barriers, observed genetic partitions are consistent with allopatric speciation. However, ecological pressure, assortative mating, and sexual selection, were likely important during periods of geographical isolation. This study therefore suggests that primarily historical factors later followed by ecological factors caused divergence and speciation in this group of coral reef fish.

Controlled Breeding and Larval Rearing Techniques of Marine Ornamental Fishes

International trade of marine ornamental fishes has been expanding rapidly in recent years, and the fact that nearly 98% of the species traded are collected from reef habitats is of vital concern for the conservation of the fragile coral reef ecosystem. Hence, it is widely accepted that the ultimate answer to a long-term sustainable trade of marine ornamental fishes is only through the development of hatchery production technologies. The techniques for broodstock development, breeding and seed production of three species of damsel fishes viz. the three spot damsel, Dascyllus trimaculatus, the humbug damsel, Dascyllus aruanus and the blue damsel, Pomacentrus caeruleus, were developed and standardised, which can be scaled up for commercial level production. Broodstock development was done in one-tonne Fiber Reinforced Plastic (FRP) tanks with biological filter and by feeding with natural feeds. The size range of broodstock fish of D. trimaculatus, D. aruanus and P. caeruleus were 9-10, 7-8 and 7-9 cm, respectively. The number of eggs per spawning ranged from 5000 to 15000. The interval between two successive spawnings ranged from 3 to 14 days. The eggs were attached either on the sides of the broodstock tank or on the substratum provided in the broodstock tank. Parental care by the male was noted. Hatching occurred on the evening of the fourth day of incubation. The larvae were altricial type with no mouth opening at the time of hatching for D. trimaculatus and D. aruanus. The larvae of P. caeruleus were with mouth opening at the time of hatching. The length range of newly hatched larvae was 1.5-2.5 mm and the range of mouth opening was 150-200 µ. Larviculture was done in five-tonne capacity FRP tank by employing greenwater technique. Copepod nauplii were used as the starter feed and after about two weeks when the mouth opening of the larvae had reached around 450 µ, newly hatched Artemia nauplii were supplemented. The metamorphosis period ranged from 20 to 40 days. Several batches of the three species were hatchery produced, and the technique can be scaled up for commercial level production for ornamental fish trade.

Sound production in four damselfish (Dascyllus) species: phyletic relationships?

Most studies of fish sounds show that the sounds are species-specific, with unique spectral and timing characteristics. This raises the question as to whether these sounds can be used to understand phyletic relationships between species and which acoustic parameters are subject to variation between species. In the present study, 597 sounds (and 2540 pulses) related to signal jumps of four Dascyllus species (Dascyllus aruanus, Dascyllus trimaculatus, Dascyllus albisella, and Dascyllus flavicaudus) from different geographic regions (Madagascar, Moorea, Rangiroa, and Hawaii) were analysed. It was possible to discern species-specific sounds, but also variation in sounds between populations. Large variations in sound length were found between Dascyllus species, whereas differences in interpulse duration were found to be variable between populations. In the regions where species live in sympatry, it appears that they restrict the variability in their sounds. This could comprise evidence of adaptation with character displacement of sonic characteristics where different species co-occur. However, sonic characteristics still overlapped substantially between species, suggesting that females would need to sample more than one sound and potentially use other cues to discriminate between species. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 97, 928‐940.

Use of Copepods as Live Feed for Larviculture of Damselfishes

It is well established that small-sized live feed with sufficient DHA, EPA and ARA as starter feed is the key factor for the success in larviculture of marine fishes with altricial larvae having limited yolk, which are in an undeveloped state at hatching. Copepods form a major component of the natural diet of many fish larvae and the wide range of body sizes of copepods both within and between species is extremely useful for employing the early stage nauplii and copepodites as starter feed for very small larvae with small mouth opening. Improved survival, growth and normal pigmentation have been documented in the larviculture of several marine finfishes reared with the early stage nauplii and copepodites. This is generally attributed to the levels of DHA, EPA and or arachidomic acid (ARA) in the diet and particularly to the DHA: EPA ratio in the diet. Two species of copepods viz. Euterpina acutifrons, a harpacticoid copepod and Pseudodiaptomus serricaudatus, a calanoid copepod were selected and cultured. They were employed as starter feed for the larviculture of three species of damsel fishes viz. the three spot damselfish, Dascyllus trimaculatus, the humbug damselfish, Dascyllus aruanus and the blue damselfish, Pomacentrus caeruleus. It was found that co-culturing of copepods in greenwater in the larviculture tank is the most effective method for initiating the exogenous feeding of the species studied.

Hormonal stimulation of maturation and ovulation, gamete morphology, and raising of larvae in Dascyllus trimaculatus (Pomacentridae)

The experiments on hormonal stimulation of the maturation and ovulation of oocytes of Dascyllus trimaculatus (Pomacentridae) are carried out. Double injections of surfagon (LH-RH-a) (5 + 15 μg/kg of fish body weight) with (or without) the addition of eglonil (5 + 15 mg/kg) are used, and the interval between the injections ranges from 12 to 17 h. Ovulation is registered 33.5–42.0 h after injection I. Morphological changes in oocytes are followed during the process of their maturation. The ultrastructure of spermatozoa and oocyte envelopes is studied. The quality of ovulated oocytes is assessed after their in vitro storage at 25 and 5°C. Preliminary results on the transition of the larvae to exogenous feeding are obtained.

Fertility of ovulated oocytes after their short-term storage in water in several species of marine tropical fishes

Fertilizing ability of ovulated oocytes of Zebrasoma scopas (Acanthuridae), Dascyllus trimaculatus, and Abudefduf sexfasciatus (Pomacentridae) is assessed after their short-term storage in marine water. The proportion of eggs exhibiting normal cleavage is not decreased after the storage of oocytes for 5, 40, and 15 min, respectively. The storage of oocytes in water for a longer time leads to a lower fertilization rate and to increasing number of eggs with abnormal cleavage characterized by a low adhesion between cells and appearance of cells with unclear margins with subsequent cell degradation. Morphological changes in the oocytes accompanied by the decrease of their fertility are analyzed.

Trophic niches of thirteen damselfishes (Pomacentridae) at the Grand Récif of Toliara, Madagascar

The damselfishes, with more than 340 species, constitute one of the most important families that live in the coral reef environment. Most of our knowledge of reef-fish ecology is based on this family, but their trophic ecology is poorly understood. The aim of the present study was to determine the trophic niches of 13 sympatric species of damselfishes by combining stable isotope (δ15N and δ13C) and stomach content analyses. Isotopic signatures reveal three main groups according to their foraging strategies: pelagic feeders (Abudefduf sexfasciatus, A. sparoides, A. vaigiensis, Chromis ternatensis, C. dimidiata, Dascyllus trimaculatus and Pomacentrus caeruleus), benthic feeders (Chrysiptera unimaculata, Plectroglyphidodon lacrymatus and Amphiprion akallopisos) and an intermediate group (D. aruanus, P. baenschi and P. trilineatus). Stomach contents reveal that planktonic copepods and filamentous algae mainly represent the diets of pelagic feeders and benthic feeders, respectively. The intermediate position of the third group resulted from a partitioning of small planktonic prey, small vagile invertebrates and filamentous algae. In this last feeding group, the presence of a wide range of δ13C values in P. trilineatus suggests a larger trophic niche width, related to diet-switching over time. Some general considerations about the feeding habits of damselfishes reveal that their choice of habitat on the reef and their behavior appear to be good predictors of diet in this group. Benthic (algae and/or small invertebrates) feeders appear to be solitary and defend a small territory on the bottom; zooplankton feeders remain in groups just above the reef, in the water column.

Feeding Ecology of The Domino Damselfish, Dascyllus Albisella

Damselfishes have served as a model fish for the study of planktivory. The feeding ecology of the diurnal planktivorous Domino Damselfish, Dascyllus albisella (Pomacentridae), was studied in the lagoon of Johnston Atoll (Central Pacific Ocean). Time budgets based on daytime focal observations showed that damselfish spent most (>85%) of their time feeding. Larger D. albisella foraged higher in the water column than smaller damselfish. Individual damselfish fed higher in the water column when the current speeds were lower. All size ranges of damselfish fed primarily on caridean zoea and copepods. The water column was vertically structured with greater caridean and brachyuran zoea concentrations at mid-depths and near the surface than near the bottom. Copepod concentrations, though low, were higher near the bottom than at mid-depths. During the spawning season males had much smaller stomach contents than similarly sized females, which is presumably due to reduced time spent feeding during courtship and nest guarding. These data show an interaction between damselfish size, plankton distributions, feeding heights, and currents. When currents are low, damselfish forage higher in the water column where the flux of plankton is generally greater, with larger damselfish foraging higher than small damselfish. When current speeds increase, damselfish forage closer to the bottom, with less of a difference in the depth distribution of differently sized damselfish. Since damselfish spend most of the daytime hours foraging, the distribution of plankton could be a major selective pressure for larger-sized damselfish.

Protection from fishing alters the species composition of fish assemblages in a temperate-tropical transition zone

Closure of areas to fishing is expected to result in an increase in the abundance of targeted species; however, changes to populations of species not targeted by fishermen will depend upon their role in the ecosystem and their relationship with targeted species. The effects of protection on targeted and non-targeted reef fish species at the Houtman Abrolhos Islands, Western Australia were studied using baited remote underwater stereo–video cameras. Video images were collected from shallow (8–12 m) and deep (22–26 m) reef sites inside a Marine Protected Area (MPA) at each of three island groups and from three replicate fished locations at each of these groups that span a temperate-tropical transition area. The MPAs were established in 1994 and vary in size from 13.72 km2 at the Pelsaert group in the south to 22.29 km2 at the Easter group to 27.44 km2 at the Wallabi group in the north. The relative abundances of 137 fish species from 42 families were recorded. Large differences in fish assemblage structure existed between MPA and fished locations, and also between shallow and deep regions. Targeted fish species Plectropomus leopardus, Lethrinus miniatus, Lethrinus nebulosus, Pagrus auratus and Glaucosoma hebraicum were more abundant inside MPAs than in areas open to fishing. Their abundance inside MPAs was between 1.13 and 8 times greater than their abundance at fished locations. For non-targeted fish species many were more abundant in areas open to fishing, e.g. Coris auricularis, Thalassoma lutescens, Thalassoma lunare, Dascyllus trimaculatus, however others were conversely more abundant inside MPAs, e.g. Gymnothorax spp, Kyphosus sydneyanus, Scarus microhinos, Chromis westaustralis, Chaetodon spp. This study demonstrates that the removal of abundant targeted species from an ecosystem by fishing can indirectly impact non-fished species and alter the trophic structure of fish assemblages.

When cleanerfish become anemonefish

Here we report on a previously undocumented facultative symbiosis involving the wrasses Labroides dimidiatus and Thallasoma amblycephalum living in association with two species of sea anemones, on coral reefs in the north-western Pacific. By SCUBA diving we observed juvenile L. dimidiatus occurring in Entacmaea quadricolor (solitary type) cleaning the anemonefish Amphiprion frenatus and in Heteractis magnifica cleaning the anemonefish Dascyllus trimaculatus. Thallasoma amblycephalum co-existed in H. magnifica with the anemonefish D. trimaculatus, A. ocellaris and L. dimidiatus.

Sperm motility in three coral reef fish species

A method of computer assisted sperm analysis (CASA) is used to determine the parameters of sperm motility in three fish species from the coral reefs of the Nha Trang Bay, South China Sea, Vietnam: Zebrasoma scopas (Acanthuridae), Abudefduf sexfasciatus, and Dascyllus trimaculatus (Pomacentridae). The representatives of the families are characterized by different reproductive tactics and possess pelagic and demersal eggs, respectively. The main morphological parameters of spermatozoa have been measured. The average curvilinear velocity of spermatozoa movement along the real trajectory (VCL) after 1 min of sperm activation ranges from 15.3 to 74.5 μm/s in Z. scopas, it is comparatively low (12.7–21.6 μm/s) in A. sexfasciatus, and high (58.4–92.2 μm/s) in D. trimaculatus. The duration of progressive movements in more than 50% of spermatozoa at 25°C is 3–20, 5–11, and 6–9 min after sperm activation, respectively. Following storage of the sperm of three species at 4.5°C for 7, 20, and 28 h, respectively, spermatozoa retain the ability of progressive movements. The results are discussed based on the available information on the activity of sperm in fish.

Detection of betanodaviruses in apparently healthy aquarium fishes and invertebrates

Betanodaviruses are the causative agents of viral nervous necrosis (VNN) in cultured marine fish. A total of 237 apparently healthy aquarium fish, marine (65 species) and freshwater (12 species) fishes and marine invertebrates (4 species), which were stocked in a commercial aquarium in Seoul, South Korea, were collected from November 2005 to February 2006. The brains of the fish and other tissues of the invertebrates were examined by reverse transcriptase-polymerase chain reaction (RT-PCR) and nested PCR to detect betanodavirus. Positive nested PCR results were obtained from the brains of 8 marine fish species (shrimp fish Aeoliscus strigatus, milkfish Chanos chanos, three spot damsel Dascyllus trimaculatus, Japanese anchovy Engraulis japonicus, pinecone fish Monocentris japonica, blue ribbon eel Rhinomuraena quaesita, look down fish Selene vomer, yellow tang Zebrasoma flavesenes), 1 marine invertebrate species (spiny lobster Pamulirus versicolor), and 2 freshwater fish species (South American leaf fish Monocirrhus polyacanthus and red piranha Pygocentrus nattereri). The detection rate in nested PCR was 11/237 (4.64%). These subclinically infected aquarium fish and invertebrates may constitute an inoculum source of betanodaviruses for cultured fishes in the Korean Peninsula.