Chaetodontidae Research Articles

Structure of Reef Fish Families (Butterflyfishes and Angelfishes) at Isolated Oceanic Reefs in the Indian Ocean: Christmas Island and the Cocos (Keeling) Islands

There has been substantial research on the factors that structure reef fish assemblages, but this has mostly focused on nearshore or continental reefs. This study examines patterns of abundance and species composition for two iconic groups of coral reef fishes, angelfishes (family Pomacanthidae) and butterflyfishes (family Chaetodontidae) at two isolated, oceanic reefs in the Indian Ocean: Christmas Island and the Cocos (Keeling) Islands. Six explanatory variables were investigated to determine whether large-scale physical factors are more important than fine-scale biotic factors in structuring reef fish communities on oceanic islands. For angelfishes, depth was the factor that most explained patterns in abundance (explaining 46.5% of the variation), species richness (44.8%) and composition (15.3%), with both abundance and species richness being greater at 20 m than at 5 m. Differences in species composition were greater between depths than between islands. For butterflyfishes, variation in abundance and species richness was best explained by the difference in aspect or exposure among sites, though abundance and composition also differed significantly between Christmas Island and the Cocos (Keeling) Islands. Large-scale variation in the structure of these reef fish assemblages could not be explained based on differences in habitat diversity, or coral and algal cover. This study indicates that large-scale physical factors (island location, exposure, depth) are more important than fine-scale biotic factors in structuring reef fish assemblages on oceanic islands.

The distribution of coral reef fish biodiversity on Bontosua Island, Spermonde Archipelago, South Sulawesi Province

Background: Bontosua Island, located in the Spermonde Archipelago, is one of the strategic and historical islands in the region. The island plays a vital role in ecosystem conservation efforts by the local community, who are committed to preserving their natural environment. With dynamic ecosystem conditions, it is essential to understand the seabed cover and biodiversity on the island to support more effective conservation efforts. Methods: This study was conducted from March to September 2022 to mark the seabed cover of Bontosua Island and understand the relationships between coral reef fish species and the ecosystem. The method used was a stationary visual census, followed by descriptive analysis and one-way ANOVA to assess the biodiversity and diversity of coral reefs. Findings: The results showed a total of 1,306 coral reef fish from 9 families with 63 species identified, including the families Chaetodontidae, Serranidae, Lutjanidae, Haemulidae, Lethrinidae, Scaridae, Acanthuridae, and Siganidae. The families with the highest citations were Scaridae, Acanthuridae, and Siganidae. The highest coral reef fish were found in the north, west, and southwest of the island, where live coral areas are more dominant. Conclusion: This study shows that Bontosua Island has significant coral reef diversity, and certain areas, such as the north and southwest sides, have higher reported fish. These findings indicate the importance of these areas in conservation efforts. Novelty/Originality: This study provides a comprehensive picture of the seabed cover and coral reef fish diversity in Bontosua Island, which has yet to be widely discussed in previous studies. These findings provide a scientific basis for more targeted conservation strategies and help improve understanding of the dynamics of coral reef ecosystems in the Spermonde Islands.. Novelty/Originality of this article: This study proposes developing a community-based coral reef monitoring system that integrates local knowledge with digital mapping technology, aiming to increase the effectiveness of conservation and management efforts of marine resources on small islands.

The gas bladder of Heterotis niloticus (Cuvier, 1829).

This work reports on the structural characteristics of the respiratory gas bladder of the osteoglossiform fish Heterotis niloticus. The bladder-vertebrae relationships are also analyzed. A slit-shaped orifice in the mediodorsal pharyngeal wall is surrounded by a muscle sphincter and serves as a glottis-like opening to the gas bladder. The dorsolateral internal surface of the gas bladder is lined by a parenchyma of highly vascularized trabeculae and septa displaying an alveolar-like structure. The trabeculae contain, in addition to vessels, numerous eosinophils probably involved in immune responses. The air spaces are endowed with a thin exchange barrier indicating a good potential for respiratory gas exchange. The ventral wall of the gas bladder is a well-vascularized membrane that exhibits an exchange barrier in the luminal face and an inner structure dominated by the presence of a layer of richly innervated smooth muscle. This is suggestive of an autonomous adjustability of the gas bladder ventral wall. The trunk vertebrae show large transverse processes (parapophyses) and numerous surface openings that lead into intravertebral spaces that become invaded by the bladder parenchyma. Curiously, the caudal vertebrae show a regular teleost morphology with neural and hemal arches, but have similar surface openings and intravertebral pneumatic spaces. The African Arowana hence rivals the freshwater butterfly fish Pantodon in its exceptional role of displaying postcranial skeletal pneumaticity outside of Archosauria. The possible significance of these findings is discussed.

Analysis of the complete mitochondrial genome sequence of Japanese butterflyfish, Chaetodon nippon (Chaetodontiformes, Chaetodontidae)

Japanese butterflyfish (Chaetodon nippon) belong to the family Chaetodontidae and order Chaetodontiformes. It has circular mitochondrial genome of 16,507 bp in length with 55.4% of A + T content and has 37 genes, including 22 tRNA, 2 rRNA, and 13 protein-coding genes, in addition to a control region. The results of phylogenetic analysis indicated that the C. nippon, C. wiebeli, C. auripes, C. auriga, C. octofasciatus, C. speculum, and C. modestus are closely related to each other. The findings of this study will provide useful genetic information for further phylogenetic and taxonomic classifications of Chaetodontidae.

The condition of megabenthos and reef fish in coral reef ecosystems in Aru Islands National Conservation Area, Southeast Maluku, Indonesia

The waters of the Aru Islands are part of the National Marine Protected Areas (MNR), and have extensive coral reefs with high biodiversity. The study was conducted in October 2016 at twelve stations to determine the status of coral cover, composition, and density of megabenthos and reef fishes. Coral reef data collection refers to the Underwater Photo Transect (UPT), and data processing uses Coral Point Count for Excel (CPCe). The Benthos Belt Transect (BBT) method was used for megabenthos data, and the Underwater Visual Census (UVC) method was used for reef fish observations.The result of the benthic component analysis showed that the proportion of live corals at each station ranged from 10.60% to 54.27%, with an average cover value of 31.21%, which fell into the “fairly good” category. Megabenthos density analysis revealed that Drupella cornus had the highest density value (0.29 individuals/m2) and Holohuria edulis (0.01 individuals/m2) had the lowest density. Analysis of the reef fish community revealed that the indicator fish were 168 individuals from the family Chaetodontidae. The group of herbivore fish recorded 116 individuals from threee families: Acanthuridae, Scaridae, and Siganidae. Acanthurus auranticavus and Acanthurus pyroferus are common species found in the waters of the Aru Islands.

The complete mitochondrial genome of threadfin butterflyfish, Chaetodon auriga (Chaetodontiformes: Chaetodontidae) and phylogenetic analysis

Chaetodon auriga (Forsskal, 1775) belongs to the family Chaetodontidae and the order Chaetodontiformes. Here, we report the complete mitochondrial genome of C. auriga assembled using the Illumina MiSeq platform. The circular mitochondrial genome of C. auriga is 16,527 bp long, has an A + T content of 54.53%, and contains 37 genes (13 protein-coding genes, 22 tRNA genes, and 2 rRNA genes), and a non-coding region. The overall nucleotide composition was A: 28.19%, T: 26.34%, G: 16.27%, and C: 29.20%. The mitochondrial genome of C. auriga contributes to revealing the phylogenetic relationships among species of the Chaetodontidae family.

MAINTENANCE OF THE BUTTERFLYFISH Chaetodon striatus (PERCIFOMES: CHAETODONTIDAE) IN A RECIRCULATION SYSTEM

The hight extractivism of marine fish to supply the demand of the aquarium market has worried the researchers and, in this context,, the aquaculture consists of an alternative to the problem. The family Chaetodontidae represents one of the main families of ornamental marine fish and has not received enough attention on their cultivation research. Considering the absence of this information about the butterflyfish Chaetodon striatus, the present work had the objective of obtaining information about the species in captivity. The fishes were kept in tanks of 100, 200, 300 and 1,000 L, with 6 fishes in each tank, with 3 repetitions for each volume, totaling 72 individuals and were observed for 30 days, being offered living small invertebrates and frozen and fresh mussels for the feeding. Also, for the attempt of reproduction in captivity, two couples, collected directly from the sea, with the entry of only two adults in the trap at a time, were used. Each couple was acclimated in a 100 L tank and we observed their behaviors for 8 hours a day. There was no mortality in tanks of 300 and 1,000 L and, for feeding, small invertebrates and fresh mussels were well accepted. Some behaviors were observed, most of which were already described for chaetodontids. This is the first report of C. striatus in captivity and this contribution may provide subsidies for a future technologi­cal package.

A RUPELIAN CORAL REEF FISH ASSEMBLAGE FROM THE VENETIAN SOUTHERN ALPS (BERICI HILLS, NE ITALY)

Here we describe a new bony fish assemblage collected from a fossiliferous outcrop located in Perarolo, Berici Hills, Venetian southern Alps. The fossiliferous deposits pertain to the Rupelian (lower Oligocene) Castelgomberto Calcarenite and are indicative of a tropical marine shallow water setting associated with coral reefs. The assemblage is characterized by diminutive putative cryptobenthic fishes, including a single goby (family Gobiidae) and several cardinalfishes of the subfamily Pseudmiinae (family Apogonidae. Furthermore, a new apogonine of the extinct tribe †Eoapogonini, a new butteflyfish (family Chaetodontidae), and an indeterminate viviparous brotula belonging to the ophidiiform family Dinematichthyidae, are also present, and likely represented part of the epibenthic community. Some of the taxa described herein are among the first occurrences for their respective lineages in the fossil record. The Perarolo taxa document the first Oligocene coral reef fish assemblage known to date. Four taxa are described as new: †Arconiapogon deangelii gen. et sp. n., †Chaetodon (Blumchaetodon) wattsi subgen. et sp. n., †Oligopseudamia iancurtisi gen. et sp. n., and †Oniketia akihitoi gen. et sp. n.

The condition of reef fish (family Chaetodontidae) in Krueng Raya and Ujong Pancu waters, Aceh Besar District

This study aims to determine the condition of reef fish of the Chaetodontidae family in Krueng Raya and Ujong Pancu waters, Aceh Besar District. The study was conducted in October 2019, where six observation locations were representing the two regions. Fish observations were carried out using the Underwater Visual Census (UVC) method. The results of the study found four genera of Chaetodontidae fish consisting of 21 species. Benteng Inong Balee Station is the location with the highest number of individuals and species of Chaetodontidae fish, 38 individuals belonging to 11 species. On the other hand, Lhok Mee Station is the location with the least number of individuals and species of Chaetodontidae fish found, only 13 individuals belonging to 6 species. The highest abundance of Chaetodontidae fish was found at Ahmad Rhang Mayang Station (521.11 ind/ha). Meanwhile, the least abundance of Chaetodontidae fish was found at Lhok Mee Station, ( 115.38 ind/ha). The number of species, Krueng Raya waters have a higher number of Chaetodontidae fish species than Ujong Pancu waters. On the other hand, the abundance value Ujong Pancu waters have a higher average abundance value of Chaetodontidae fish than Krueng Raya waters. Overall, based on the biological index, the community structure of reef fish of the Chaetodontidae is still stable. Compared to previous study, the present study shows that, within a period of 6 years, the condition of Chaetodontidae fish in Aceh Besar waters has increased in the number of species, abundance, and diversity of fish.

STRUKTUR KOMUNITAS IKAN FAMILY CHAETODONTIDAE SEBAGAI INDIKATOR KONDISI KESEHATAN LINGKUNGAN EKOSISTEM TERUMBU KARANG DI ZONA TRADISIONAL PULAU BUNAKEN TAMAN NASIONAL BUNAKEN

The presence of coral reef fishes, especially family Chaetodontidae is one of bioindicators to environment health condition of coral reef. Fish indicator research in Bunaken Island waters aims to find out the community structure, such as the composition, abundance, density, equality, diversity and dominance. Data collection was conducted at 5 (five) locations in the Bunaken Island Traditional Zone where there are 5 (five) observation points respectively, namely TP-1 Mandolin, TP-2 Alung Banua, TP-3 Sachiko, TP-4 Muka Kampung, and TP-5 Bunaken Timur. Data collection by underwater visual census (UVC) techniques using SCUBA. The results showed there were 23 species of indicator fish from family Chaetodontidae, total individuals number of each species in 5 research sites as many as 97 individuals. The highest fish density is 0.06 at TP-5 while the lowest value in TP-2 with density value 0.02. Through indicator fish community structure indicates that the coral reef quality conditions is stable indicated by diversity values (H') in all locations were moderate category and inversely proportional by low dominance values, high leveling values (E). The similarity rate (IS) of indicator fish species in all locations differs from each other indicating the condition of coral reefs in each location grows independently without being influenced by other locations.Keywords: Reef Fish, Coral Reef, Indicator Fish.

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Contributors

Expression of acetylcholine, its contribution to regulation of immune function and O2 sensing and phylogenetic interpretations of the African butterfly fish Pantodon buchholzi (Osteoglossiformes, Pantodontidae)

Acetylcholine (Ach) is the main neurotransmitter in the neuronal cholinergic system and also works as a signaling molecule in non-neuronal cells and tissues. The diversity of signaling pathways mediated by Ach provides a basis for understanding the biology of the cholinergic epithelial cells and immune cells in the gill of the species studied.NECs in the gill were not found surprisingly, but specialized cells showing the morphological, histochemical and ultrastructural characteristics of eosinophils were located in the gill filaments and respiratory lamellae.Much remains unknown about the interaction between the nerves and eosinophils that modulate both the release of acetylcholine and its nicotinic and muscarinic receptors including the role of acetylcholine in the mechanisms of O2 chemosensing. In this study we report for the first time the expression of Ach in the pavement cells of the gill lamellae in fish, the mast cells associated with eosinophils and nerve interaction for both immune cell types, in the gill of the extant butterfly fish Pantodon buchholzi. Multiple roles have been hypothesized for Ach and alpha nAChR in the gills. Among these there are the possible involvement of the pavement cells of the gill lamellae as O2 chemosensitive cells, the interaction of Ach positive mast cells with eosinophils and interaction of eosinophils with nerve terminals. This could be related to the use of the vesicular acetylcholine transporter (VAChT) and the alpha 2 subunit of the acetylcholine nicotinic receptor (alpha 2 nAChR). These data demonstrate the presence of Ach multiple sites of neuronal and non-neuronal release and reception within the gill and its ancestral signaling that arose during the evolutionary history of this conservative fish species.

Constraints on the Ecomorphological Convergence of Zooplanktivorous Butterflyfishes.

SynopsisWhether distantly related organisms evolve similar strategies to meet the demands of a shared ecological niche depends on their evolutionary history and the nature of form–function relationships. In fishes, the visual identification and consumption of microscopic zooplankters, selective zooplanktivory, is a distinct type of foraging often associated with a suite of morphological specializations. Previous work has identified inconsistencies in the trajectory and magnitude of morphological change following transitions to selective zooplanktivory, alluding to the diversity and importance of ancestral effects. Here we investigate whether transitions to selective zooplanktivory have influenced the morphological evolution of marine butterflyfishes (family Chaetodontidae), a group of small-prey specialists well known for several types of high-precision benthivory. Using Bayesian ancestral state estimation, we inferred the recent evolution of zooplanktivory among benthivorous ancestors that hunted small invertebrates and browsed by picking or scraping coral polyps. Traits related to the capture of prey appear to be functionally versatile, with little morphological distinction between species with benthivorous and planktivorous foraging modes. In contrast, multiple traits related to prey detection or swimming performance are evolving toward novel, zooplanktivore-specific optima. Despite a relatively short evolutionary history, general morphological indistinctiveness, and evidence of constraint on the evolution of body size, convergent evolution has closed a near significant amount of the morphological distance between zooplanktivorous species. Overall, our findings describe the extent to which the functional demands associated with selective zooplanktivory have led to generalizable morphological features among butterflyfishes and highlight the importance of ancestral effects in shaping patterns of morphological convergence.

Demographics of Butterfly Fish, Heniochus acuminatus (Perciformes, Chaetodontidae) from the Gulf of Mannar, India

Butterfly fishes are widely distributed throughout the Indo-Pacific Ocean and are often caught in large quantity by shrimp trawlers as a by-catch species. These fish are ecologically and commercially important, as they are ecological indicators of coral health and a major component of ornamental and by-product fisheries. However, owing to their low value for direct human consumption as a food, there is dearth of research on their demographics and life–history traits. The present study was therefore conducted using Heniochus acuminatus, one of the common butterfly fish that is captured as a by-catch in the Gulf of Mannar (GoM) to generate basic data on its demographic estimates. Specimens (n = 833) were collected monthly from the four reef-fish landing stations for two consecutive years and the demographic parameters were estimated using a FAO–ICLARM Stock Assessment Tool (FiSAT). Fish in the length class of 10–11 cm dominated the landings. The length-weight relationship (LWR) was defined as the equation, BW = 0.0234TL3.156 suggesting positive allometric growth pattern of H. acuminatus in GoM. Estimated demographic parameters (asymptotic length, L∞ = 17.85 cm) showed low growth rate and growth performance index (K = 0.95 and ϕ = 2.481 respectively) in study species. The estimated potential longevity (tmax) and the observed length at first capture (Lc) were found to be 3.15 years and 7.9 cm respectively. The higher natural mortality rate (M = 2.00 yr−1) than the fishing mortality rate (F = 0.39 yr−1) with exploitation level (E = 0.16) below the optimum level indicates that the state of the stock of H. acuminatus in the GoM is sustainable. The current study provides the first population demographic report of the genus Heniochus and is likely to have a significant conservation and commercial impact.

Composition of reef fish as a success indicator of the bio-transplants method in Tunda Island, Serang Regency, Banten Province

The Bio-Transplants method is a coral grafting method by inoculating coral seedlings/fragments using natural materials. They are dead corals in the DC and DCA categories as a place of attachment. This study aims to see the success of the Bio-Transplants method in compiling indicators of fish species associated with the field of Bio-Transplants. They have conducted this research in 10 x 10 square meters on the north side of Tunda Island waters in July 2019 (T0), November 2019 (T1), and July 2020 (T2). The sampling method used a stationary visual census. In July 2019, as many as 11 species from 7 families, November 2019 was 31 species from 10 families, and July 2020 was 47 species from 10 families. Composition of fish species as an indicator of the health of coral ecosystems from the Chaetodontidae family fish species. In July, when Bio-Transplants started production, there were no fish groups from the Chaetodontidae family. The composition of the fish species found in November was Chelmon sp. and Henichus varius. After its age, the Bio Transplants area was one year (July 2020) consisting of 4 fish species from the family Chaetodontidae, namely: Heniochus chrysostomus, Chaetodon trifasciatus, Chelmon sp., and Heniochus varius.

The gas bladder of Pantodon buchholzi: Structure and relationships with the vertebrae.

We report here on the histological and structural characteristics of the gas bladder, the vertebral morphology, and the bladder-vertebra relationships of the butterfly fish, Pantodon buchholzi. The bladder opens at the boundary between the pharynx and the esophagus by a middle slit. A pneumatic duct is absent. The bladder shows a dorsolateral wall that adapts to the anfractuosities of the coelomic cavity and a ventral wall in contact with the abdominal organs. The vertebral bodies are formed by an hourglass shaped autocentrum, and by an arcocentrum reduced to several longitudinal ridges. The transverse processes adopt the structure of a cage whose walls are formed by bone trabeculae of variable size and distribution pattern. The dorsolateral wall of the bladder is a membrane that covers the kidney, adapts to the irregular shape of the vertebrae, and invades the transverse processes at several points before extending laterally. However, invasion of the vertebral bodies, the presence of a labyrinth, or the formation of respiratory parenchyma were not observed. The luminal surface of this wall is a thin respiratory barrier containing a single epithelial cell type. In addition, the wall contains numerous eosinophils that may be implicated in immune defense. The bladder ventral wall is a membrane rich in collagen, vessels, smooth muscle, and nerves that lacks a respiratory barrier. Its luminal surface contains ciliated and nonciliated cells. The two cell types appear implicated in surfactant production.

Relationship Between Species Composition of Butterflyfishes and Coral Cover (Study case: Taka Bonerate National Park)

The coral reef environment has a strong influence on associated organisms such as fishes, mollusks, and others. Wherein, the butterflyfishes are marine fishes which closely associated with the tropic group as dietary specialization i.e. obligate coral feeder, facultative, and generalist. The obligate may respond only to change in preferred corals and not indicate others. However, generalist show in different response in habitat deteriorates and may allow switching feeding to a less preferred one. Many questions remain about food specific at the species level which may potentially as bio-indicator for coral conditions. Here, we studied the species composition among coral coverage. We explore the environmental degradation in Taka Bonerate National Park impact on food resources and fishes especially for butterflyfishes community. This study focused on family Chaetodontidae with UVC method and UPT method for coral cover. This study was carried out at Taka Bonerate National Park, South Sulawesi between May and June 2019. There were 342 individuals observed and dominated by Chaetodon kleinii, Hemitaurichthys polylepis, Heniochus chrysostomus, C. lunulatus, C. melannotus, C punctatofasciatus, and Forcipiger flavissimus. However, we found a site with diversity index and coral cover has across conditions. Whilst, these benthic communities mostly dominated by Acropora, which may be preferenced by specific species. Butterflyfishes have several types of foraging tasks and may impact in utilizing the coral reef and other social habitats used. The species composition and abundance of butterflyfishes had relations not only by coral coverage but also benthic compositions. However, factors that regulate its specific species distribution and species compositions are still under study.

Spatial distribution and feeding substrate of butterflyfishes (family Chaetodontidae) on an Okinawan coral reef.

Coral reefs support diverse communities, and relationships among organisms within these communities are quite complex. Among the relationships, clarifying the habitat association and foraging substrate selection relative to habitat characteristics is of central importance to ecology since these two aspects are the fundamentals for survival and growth of organisms. The aims of the present study were to investigate the spatial distribution and feeding substrate selection of 14 species of butterflyfishes on an Okinawan coral reef in Japan. Species-specific spatial distributions varied with habitat characteristics (e.g., encrusting corals, massive corals, branching Acropora and rock). For feeding substrates, seven species of obligate coral polyp feeders exhibited significant positive selectivity for tabular Acropora, corymbose Acropora, encrusting corals and massive corals but significant negative selectivity for dead corals, coral rubble and rock. Among six species of facultative coral polyp feeders, two species exhibited significant positive selectivity for encrusting corals and massive corals, and one species showed significant positive selectivity for dead corals as feeding substrates. In contrast, three species exhibited no significant positive selectivity for any feeding substrates. A similar result was observed for one non-coralline invertebrate feeder. Among the 14 species, 12 species showed a relatively close relationship between spatial distribution and feeding substrates but the remaining two species did not. The present study is the first study to elucidate species-specific spatial distributions and feeding substrate selection of butterflyfishes on an Okinawan coral reef. The results of the present study suggest that diverse substrates, including various types of living corals (especially encrusting corals, massive corals, tabular Acropora, corymbose Acropora and branching Acropora) and non-coralline substrates (rock) are the primary determinants of spatial distributions and feeding sites. Thus, diverse substrates are important for maintaining high species diversity of butterflyfishes and changes of the substrates would likely change the spatial patterns and foraging behavior, although species-specific responses may be found, depending on their species-specific dependence on vulnerable substrates.

Growth parameters and length-weight relationship of Heniochus acuminatus (Linnaeus, 1758) (Perciformes: Chaetodontidae) from the southeast coast of India

To study the growth parameters of long fin banner fish, Heniochus acuminatus , samples were monthly collected from the trawl catches of five major fish landing centers (Pondicherry, Cuddalore, Parangipettai, Karaikkal, and Nagapattinam) of the southeast coast of India during January to December 2015. A total of 475 longfin bannerfish (222 males and 253 females), ranging in size from 6.0-15.2cm for males and 5.6-15.7cm for females were collected. The total body weight of male and female were ranged from 11.06-25.34g and 10.90-27.15g, respectively. The b -value estimated for male (3.006) was greater than 3 (isometric) and for female (2.809) was less than 3 (slightly negative allometric). The correlation coefficient values (r) for male (0.984) and for female (0.995) was highly significant, with a high degree of the positive correlation between total body length and weight. The relative condition factor (K n ) values were found higher in females than males during various seasons. The asymptotic length L α values obtained using various methods for females ranged from 16.8 to 18.3cm (TL) and similarly, for males, it ranged from 16.77 and 176.4cm (TL). Most appropriate values of growth rate (K) for males and females were 1.20 yr -1 and 1.80 yr -1 , respectively. The estimated t 0 for males and females were -0.191 and -0.166, respectively. The growth parameters obtained during the present study will be used for stock assessment of this species.

The composition and abundance of reef fish (Family Chaetodontidae) in Aceh Besar Waters, Aceh, Indonesia

The objective of the present study was to study the composition and abundance of reef fish (Family Chaetodontidae) in coral reef area in Aceh Besar waters. This research was conducted in September 2012 until February 2013. The study was conducted in eight locations in the waters of Aceh Besar district: Amat Ramanyang, LhokKetapang, PulauDituan, Lampuuk, LhokSeudu, Leupung, Pulo Aceh and Lamteng. The fish was recorded using Visual Census Method in two different depth (3-4 m and 6-8m) with three replication in each depth. The result found eight species of fish in 3-4 m depth and 11 species in 6-8 m depth. The total individuals of fish that was found were 83 individuals in 3-4 m deep and 117 individuals in 6-8 m depth. The diversity index in 3-4 m depth ranged 0.3 to 1.1 where this value included in low to medium category and 6-8 m depth ranged 0.3 to 1.6 where this value included in low to mediumcategory.