Family Haemulidae Research Articles

Grunts (Actinopterygii: Perciformes: Haemulidae) of Bangladesh with two new distributional records from the northern Bay of Bengal assessed by morphometric characters and DNA barcoding

Grunts (family Haemulidae) are among the most commercially important fish in Bangladesh. This paper provides brief diagnostic characters of five previously reported grunt species: Plectorhinchus pictus (Thunberg, 1792); Pomadasys andamanensis McKay et Satapoomin, 1994; Pomadasys argenteus (Forsskål, 1775); Pomadasys argyreus (Valenciennes, 1833); Pomadasys maculatus (Bloch, 1793) and two new distributional records: Pomadasys guoraca (Cuvier, 1829) and Plectorhinchus macrospilus Satapoomin et Randall, 2000. The fishes were collected from the Saint Martin’s Island coral reef-like ecosystem and the adjacent sea of the Sundarbans mangrove forest of Bangladesh. The examined specimens were identified and diagnosed based on their morphometric characters and DNA barcoding COI gene. The new records of Pomadasys guoraca and Plectorhinchus macrospilus from Bangladesh greatly extend their distributional range in the Bay of Bengal. An updated checklist of grunts of Bangladesh is provided.

The complete mitochondrial genome of Diagramma pictum (Perciformes: Haemulidae)

The painted sweetlips Diagramma pictum (Thunberg 1792) is an important fish for commercial fisheries which is widely distributed in the Indo-West Pacific Ocean. It can change its external coloration and pattern during their lives. The complete mitochondrial genome of D. pictum was determined in this study. The genome was 16,531 bp in length and consisted of 13 protein coding genes, 22 transfer RNA (tRNA), 2 ribosomal RNA (rRNA), and one noncoding control region. The overall base composition was estimated to be A: 27.5%; T: 24.7%; C: 30.9% and G: 16.9% with AT bias of 52.2%. The molecular phylogenetic result revealed that D. pictum did not form an independent branch but was tightly clustered inside the Plectorhinchus groups, closely related to the species Plectorhinchus chaetodonoides, indicating the close relationships between genera Diagramma and Plectorhinchus. These results may provide important genomic information for species evolution and mitogenome based phylogenetic analyses of D. pictum in the family Haemulidae.

Population-level morphological variation of Anisotremus interruptus (Gill, 1862) (Perciformes: Haemulidae) in the Tropical Eastern Pacific, with the description of two new species.

The family Haemulidae is a wide-ranging group of marine fishes that are of significant commercial value in the Tropical Eastern Pacific (TEP). Phylogenetic studies on the species Anisotremus interruptus have revealed high levels of genetic diversity as well as divergence among populations in the TEP, which suggests that the taxonomic diversity of A. interruptus could be underestimated. Anisotremus interruptus has a large distribution, ranging from central Baja California, Mexico to northern Peru, including all oceanic islands except Clipperton. Recent genetic studies on this taxon indicate the presence of a species complex of at least three distinctive lineages. We performed a comparative study of the population-level meristic and morphometric variation of A. interruptus in the TEP to evaluate and identify possible morphological features concordant with the genetic differentiation of populations. Our results provide evidence of the presence of two new species of the genus Anisotremus, A. perezponcedeleoni sp. n. from the Revillagigedo Archipelago and A. espinozai sp.n. from Galapagos Archipelago-Cocos Island.

The bastard grunt Pomadasys incisus (Bowdich, 1825) (Teleostei: Haemulidae) in Cyprus (eastern Mediterranean Sea) - a late arrival or just a neglected species?

Pomadasys incisus is a thermophilous coastal subtropical fish species belonging to the family Haemulidae. Originally described from Gambia, this species is widely distributed in the Eastern Atlantic from Galicia to South Africa. It has also been recorded in the Mediterranean Sea since 1840, presumably expanding its distribution in the next decades, although the species could have been already present in the basin, but simply overlooked until the mid XIX century. In this study, we first record P. incisus from Cyprus (eastern Mediterranean Sea), based on two opportunistic observations obtained through a citizen-science project and review the distribution of this species in the Mediterranean Sea. The present sighting raises the question on whether this species is a late arrival in the country or its presence has just been neglected until now. Based on present data, the most likely hypothesis is the latter one, with P. incisus occurring in low densities and being overlooked due to the absence of field studies. Whatever is true, some intrinsic or extrinsic factors may have played a role in limiting its spread or wide establishment in the above-mentioned country.

Inventory of commercially important coral reef fishes in Tawi-Tawi Islands, Southern Philippines: The Heart of the Coral Triangle

Tawi-Tawi, Southern Philippines, which has over 300 islands and huge reef systems, is geographically located at the heart of the Coral Triangle, the global center of coral reef biodiversity. In this study, we conducted an inventory survey of market fishes in Tawi-Tawi from October 2015 to December 2018. We considered 11 major commercially important coral reef fishes, namely, surgeonfish (family Acanthuridae), parrotfish (subfamily Scarinae, family Labridae), snapper (family Lutjanidae), grouper (subfamily Epinephelinae, family Serranidae), sweetlips (family Haemulidae), goatfish (family Mullidae), emperor (family Lethrinidae), triggerfish (family Balistidae), coral bream (family Nemipteridae except genus Nemipterus), fusilier (family Caesionidae) and rabbitfish (family Siganidae). We further compared the results with published reports from Palawan and Panay Island which are also located along the Sulu Sea, the region with the highest coral reef fish diversity in the Philippines. Overall, we recorded a total of 266 species of reef fish in Tawi-Tawi with Epinephelinae (48 species), Lutjanidae (40 species) and Acanthuridae (33 species) as the most speciose groups. Further investigation showed that the average relative abundance of the three most abundant species in each family/subfamily is about 64.5% (range, 51.6% for Acanthuridae to 87.6% for Balistidae) of their respective groups. Based on the status assessment of the International Union for Conservation of Nature, one species (Scarus hypselopterus) was considered as Near Threatened (NT), four species (Bolbometopon muricatum, Epinephelus fuscoguttatus, Epinephelus polyphekadion and Plectropomus areolatus) as Vulnerable (VU) while the majority were considered as Least Concern (LC). The number of species recorded in Tawi-Tawi was much higher than in Palawan and Panay Island which had a total of only 159 species and 139 species, respectively. Moreover, Tawi-Tawi had about five times more unique species than either of the two other areas. Our study indicates the importance of the reefs of Tawi-Tawi and the Sulu Archipelago in general as the richest in the Philippines in terms of commercially important coral reef fish species diversity. Various factors that explain the high diversity of reef fishes on the reefs of Tawi-Tawi and the importance of conserving these valuable ecosystems are discussed.

Constructing the mitochondrial genome of the Peruvian grunt Anisotremus scapularis Tschudi, 1846 (Lutjaniformes: Haemulidae) using RNA-seq data

Haemulidae is a widely diverse and widespread family of New World teleost fish. The Peruvian grunt, Anisotremus scapular, inhabits the South American Pacific coast where its overexploitation for human consumption. Fishing has led to the populational decline of the species and raised the need for conservation and aquaculture developments. Here we describe the complete mitogenome of the Peruvian grunt assembled from an RNA-seq dataset. The mitogenome length is 16,785 bp and, as expected for a vertebrate, composed of 13 PCGs, 22 transfer RNA, 2 ribosomal RNA genes. Phylogenetic reconstruction, including all available 25 Lutjaniformes mitogenomes, places A. scapularis within the family Haemulidae, more precisely within the subfamily Haemulinae. Furthermore, paraphyletic relationships were observed within the other groups represented in the phylogeny. Overall, our results highlight the usefulness of using mitochondrial genomes for phylogenetic analysis in Haemulinae as well as the necessity to increase taxonomic sampling within the group.

Structure of the Community of Dominant Fish Species Associated to Soft-Bottoms in the Lagoon of La Paz, B.C.S., México

The study of fish communities from coastal lagoons allows a better understanding of role of these organisms in these systems, and the effect of anthropogenic impact. The aim of the present study was to determine the community structure, in particular dominance of fish species associated to soft bottoms in the lagoon of La Paz. Six bimonthly samplings were carried out in seven localities from November 2016 to September 2017 and physicochemical parameters were recorded. Analysis of temperature showed differences between two marked seasons, warm and cold. Species richness showed differences between months and localities. Shannon-Weaver index and Pielou’s evenness showed significant differences only between months. Simpson’s index suggests a high diversity. According to the BVI, 15 species from the families Haemulidae, Sciaenidae and Gerreidae, were the most biologically important. Zoogeographic affinity analysis showed that 58% of the species prefer the Province of Cortez. Dominant species recorded in this study play a key role in soft-bottom systems like the lagoon of La Paz.

Effectiveness of small locally-managed marine protected areas for coral reef fisheries management in the Philippines

The Philippines has more than 1600 locally managed marine protected areas (MPAs), the most in the world. However, their effectiveness for coral reef fisheries management is often questionable because most of these MPAs are small and ineffectively managed. In this study, we assessed the fish biomass of commercially important coral reef fishes (e.g. surgeonfish (family Acanthuridae), parrotfish (subfamily Scarinae), snapper (family Lutjanidae), grouper (subfamily Epinephelinae), sweetlips (family Haemulidae), goatfish (Mullidae) and emperor (family Lethrinidae)) in 57 locally managed MPAs in the Philippines. We used the fish biomass level at the nationally managed, large (332.0 km2), remote, old and well enforced (i.e. strictly protected for >20 years) Tubbataha Reefs National Marine Park (TRNMP) as a proxy for “unfished” ecosystems (Bo). We considered fish biomass levels between 25 and 50% of Bo as biomass within the maximum sustainable yield for multi-species coral reef fisheries (BMMSY) (McClanahan et al., 2014). Results showed that fish biomass levels in 7%, 25% and 68% of the surveyed MPAs were “above BMMSY”, “within BMMSY” and “below BMMSY”, respectively. None of the reefs outside MPAs was “above BMMSY”. About 86% were “below BMMSY” and the rest of the 14% of the sites outside MPAs were “within BMMSY” (14%). The mean (±S.E.) fish biomass levels on reefs inside and outside MPAs were only about 20.4 ± 2.2% and 10.9 ± 1.3%, respectively, of the TRNMP level. Neither size nor age of MPAs was significantly associated with fish biomass. Overall, our study showed that the current locally managed MPAs are not effective enough for coral reef fisheries management but, nonetheless, better than having no MPA at all.

HUBUNGAN KONDISI TERUMBU KARANG DENGAN KELIMPAHAN IKAN KARANG TARGET DI PERAIRAN PULAU TINABO BESAR, TAMAN NASIONAL TAKA BONERATE, SULAWESI SELATAN

This research aims to understand the condition of coral reef (life coral), the abundance of reef target fishes, and the corellation between those two variables. This research has been conducted in Tinabo Besar Island with 6 sampling stations in 5-6 meter depth. Data collected are substrate cover precentage (life form), and the number of reef target fish appeared from 7 specified families (Serranidae, Lutjanidae, Haemulidae, Lethrinidae, Scaridae, Siganidae, and Acanthuridae) using Underwater Photo Transect (UPT) and Underwater Visual Census (UVC). Substrate cover analyzed using CPCe software with life coral, dead coral, algae, abiotic, and other biota cover output. Mortality Index (MI) obtained from the ratio of life coral and dead coral. The result shows that percentage of life coral coverlie between 11.87% to 38.80%, with dominance of Coral Masive (CM). It’s mean that the coral reef condition is in poor to moderate category. Coral death ratio is low with MI between 0.15 to 0.30. Reef target fish total abundance is 493 individual/2100m2 from 31 species, with dominance from Lutjanidae family (173 individual). The result shows positive and strong enough correlation between coral reef coverage and reef target fish abundance (r=0.65) with Determinantion Coefficient at 42.55%. Linear regression is y=-12.929+3.7562x, where in every addition of coral reef cover percentage, resulted in addition of 4 fishes.Keyword: life coral, abundance, reef target fish, correlation, Tinabo Besar Island

Superposición de la dieta del pez león Pterois volitans (Teleostei: Scorpaenidae) con la de peces nativos de nivel trófico similar en Cuba

The spread of the Indo-Pacific lionfish has been one of the most rapid marine fish invasions in the history of the tropical and subtropical western Atlantic, and populations of this species pose a threat to native fishes feeding at similar trophic levels due to competition for food. To determine dietary overlap, 899 lionfish and 377 native fishes of the families Haemulidae, Holocentridae, Serranidae and Lutjanidae were caught in three Cuban localities, and their stomach contents were analyzed based on the number of items, frequency, volume and index of relative importance. Diet composition was similar in the studied localities; Lutjanidae, Serranidae and lionfish mainly fed on fish while Haemulidae and Holocentridae primarily consumed small benthic invertebrates. Mantel correlations showed that the consumption of fish and crustaceans did not increase as lionfish increased in size. The degree of dietary overlap between lionfish and some native fishes depends on locality, ecological zone and the characteristics of each family, confirming the opportunistic nature of the invader. It is likely that native fishes are not affected by competition with lionfish for food because they feed on the mostabundant and available organisms; therefore, food availability is not a limiting factor for these groups.

Altered juvenile fish communities associated with invasive Halophila stipulacea seagrass habitats in the U.S. Virgin Islands.

Caribbean seagrass habitats provide food and protection for reef-associated juvenile fish. The invasive seagrass Halophila stipulacea is rapidly altering these seascapes. Since its arrival in the Caribbean in 2002, H. stipulacea has colonized and displaced native seagrasses, but the function of this invasive seagrass as a juvenile fish habitat remains unknown. To compare diversity, community structure, and abundance of juvenile fish between H. stipulacea and native seagrass beds, fish traps were deployed in four nearshore bays around St. Thomas, U.S. Virgin Islands. Traps were deployed in Frenchman, Lindbergh, and Sprat Bays for 24 h intervals in patches of bare sand, patches of H. stipulacea and patches of the native Caribbean seagrasses Thalassia testudinum and Syringodium filiforme. Traps were then deployed in Brewers Bay for 12 h intervals in stands of H. stipulacea and S. filiforme. Relative and total abundances of juvenile fish, identified at least to family, were compared across treatment habitats for each trap deployment period. The catch from H. stipulacea, compared to native seagrasses, comprised a greater abundance of nocturnal carnivores Lutjanus synagris (family Lutjanidae) and Haemulon flavolineatum (family Haemulidae). Additionally, the herbivore species Sparisoma aurofrenatum (family Labridae) and Acanthurus bahianus (family Acanthuridae) and the diurnal carnivore species Pseudopeneus maculatus (family Mullidae) were relatively scarce in H. stipulacea. The catch from sand was much smaller, compared to vegetated habitats, and comprised only L. synagris, H. flavolineatum, and H. aurolineatum. These results provide evidence of reduced family diversity and altered juvenile fish assemblages in H. stipulacea, driven by an abundance of some nocturnal carnivores and scarcity of herbivores and diurnal carnivores. The findings from the present work underpin the need for further investigation and mitigation of this invasion, particularly where H. stipulacea is driving seascape-alterations of key juvenile fish habitats.

Determination of CPUA and distribution pattern of families Haemulidae, Nemipteridae and Ariidae in the Oman Sea

This trawl survey was carried out during 2013 for the stock assessment of families Haemulids, Nemipterids and Ariids in the Oman Sea. Sampling was carried out at five different stratum and depths. The highest value of CPUA of Haemulidae was estimated for Pomadasys stridens in “B” stratum (885.78 kg nm-2), for Pomadasys kaakan at depths of 10-20 m (330.35 kg nm-2), and for Nemipteridae it was estimated for Nemipterus japonicus in “D” stratum (1042.31 kg nm-2) at 30-50 m depths (1734.97 kg nm-2), and for Ariidae, it was estimated for Netuma thalassina in the stratum B (752.64 kg nm-2) at 20-30 m depths (428.33 kg nm-2). The highest biomass for Haemulidae was estimated in stratum B (320.53 ton) at 50-100 m depths (282.98 tons), and for Nemipteridae in “D” stratum (559.72 tons) and at depths of 30-50 m (604.04 tons), and for Ariidae it was estimated in “B” stratum (272.35 tons) and at 50-100 m depths (255.12 ton). Based on the results obtained, the highest species diversity for Haemulids was in “A” stratum at depths less than 50 m, while for Nemipterids it was similar in the total study area and different depth layers. Highest species diversity for Ariids were found in “A” and “D” strata at depth layers of 10-20 m and 30-50 m, respectively. In light of the fact that fishing efforts decreased during these years, our results illustrate that CPUA and biomass have ascending trends which indicate the relative stability of the stocks of these families.

Pemantauan Kondisi Ikan Karang Menggunakan Metode Reef Check Di Perairan Selat Sempu Malang Selatan

Reef Check is an activity to find out the condition of coral reefs and its surrounding ecosystems be then described and categorized its healthiness. The island of Java is one of the Islands in Indonesia that has lots of beaches, especially for East Java, here they have several areas that has become our research site in Sempu Strait, Sendang Biru, South Malang they are called Teluk Semut, Watu Meja, and Waru-waru. Underwater Visual Census (UVC) was used as a method for this research to identify reef fish in a transect of 100 x 5 x 5m scale in (Length, Width, and Height). Results shows several fishes was used to identify yet the family of Chaetodontidae with mean abundance 8 in Teluk Semut 1 station, 2.25 in Teluk Semut 2 station, 12.5 in Rumah Ikan station, & 13.5 in Watu Meja station. Watu Meja and Fish Apartment station shows higher mean abundance than other station, this indicates coral reefs ecosystem in this station have a better health & condition compare to the other stations. Results for family family Haemulidae, Snapper and Grouper shows low mean abundance, that indicates overfishing on Sempu Strait, South Malang. In other cases, the purposes of Reef Check is to determine the extents of human activities and its impact against the distribution and the healthiness of coral reefs in the area. For further extent, there has been still indications toward its management system yet fisheries potential in certain areas for this research.

Nocturnal migration reduces exposure to micropredation in a coral reef fish

Tropical Atlantic reef fishes in the family Haemulidae (grunts) remain quiescent on reefs during the day and migrate to seagrass beds or sand flats at night. Hypothesized advantages of such nocturnal migrations are increased food availability and/or decreased predation risk. Here, we tested predictions of an alternative hypothesis that nocturnal migrations of French grunt, Haemulon flavolineatum (Desmarest, 1823), reduce exposure to blood-feeding gnathiid isopods. The departure of grunts from the reef coincides with increasing gnathiid activity. In field experiments, subadult fish placed in cages and deployed on the reef at night harbored significantly more gnathiids than those placed in the seagrass habitat. However, this was not the case during the day when gnathiid activity in all habitats is low. In another experiment, the timing of return to the reef was determined to coincide with the postdawn decrease in gnathiid activity. Estimates of cumulative gnathiid exposure at two sites revealed that grunts remaining in reef habitat at night would experience an average of 3 and 44 times more gnathiids than if they spent the night in the seagrass bed, and could reach more than 300 gnathiids on a single fish. In a final field experiment, even recently-settled (<2 cm) juvenile grunts were infested by gnathiids, supporting previous laboratory experiments showing that a single third-stage gnathiid will infest and kill grunts of this size. Combined, these findings suggest that nocturnal feeding migrations of French grunts and ecologically similar fishes result in reduced exposure to blood-feeding gnathiid isopods.

First Record of Abnormal Body Coloration in Fishes Obtained from Jubail Area, Arabian Gulf, Saudi Arabia

Three specimens of the family Epinephelidae and two specimens of the family Haemulidae with abnormal coloration, were obtained from Jubail City, Saudi Arabia, Arabian Gulf coast. The epaulet grouper Epinephelus stoliczkae specimens were obtained from the fish market at Jubail City originated from Sultanate of Oman, while the two haemulid species, Plectorhinchus stoliczkae and P. sordidus were collected from the Saudi Arabian waters of the Arabian Gulf at Jubail City. These are the first documented cases of color aberration in those species. A description of the color anomalies is provided.

Biogeographical affinities of fish associated to the shrimp trawl fishery in the Gulf of Tehuantepec, Mexico.

Fish by-catch of shrimp fishery from the Gulf of Tehuantepec is composed of several species that are mainly discarded. In this study, fish by-catch species composition, distribution and biogeographical affinities were analyzed. For this, a total of 15 cruises were carried out on the continental shelf, at depths from 15 to 64 m, during 2003, 2004, 2005 and 2013. Results showed that fish by-catch was represented by 58 families, 129 genera and 242 species. The families Haemulidae, Sciaenidae, Paralichthyidae, Gerreidae and Carangidae accounted for > 70 % of the catch. Haemulopsis axillaris, Syacium ovale, Selene peruviana, Diapterus peruvianus, Larimus acclivins and Stellifer erycimba were the most frequent species at < 40 m depth (inner shelf), and Prionotus stephanophrys, Scorpaena russula, Porichthys analis and Synodus scituliceps were dominant at 40-60 m depth (outer shelf). Analysis of biogeographical affinities showed that 36.1 % of species had a wide distribution, from San Diego Province to the Panamic Province, while 13.2 % had a restricted distribution in the Mexican and Panamic Provinces. The ichthyofaunal composition was markedly influenced by the local environment and seasonal conditions.

Fish-derived nutrient hotspots shape coral reef benthic communities.

Animal-derived nutrients play an important role in structuring nutrient regimes within and between ecosystems. When animals undergo repetitive, aggregating behavior through time, they can create nutrient hotspots where rates of biogeochemical activity are higher than those found in the surrounding environment. In turn, these hotspots can influence ecosystem processes and community structure. We examined the potential for reef fishes from the family Haemulidae (grunts) to create nutrient hotspots and the potential impact of these hotspots on reef communities. To do so, we tracked the schooling locations of diurnally migrating grunts, which shelter at reef sites during the day but forage off reef each night, and measured the impact of these fish schools on benthic communities. We found that grunt schools showed a high degree of site fidelity, repeatedly returning to the same coral heads. These aggregations created nutrient hotspots around coral heads where nitrogen and phosphorus delivery was roughly 10 and 7 times the respective rates of delivery to structurally similar sites that lacked schools of these fishes. In turn, grazing rates of herbivorous fishes at grunt-derived hotspots were approximately 3 times those of sites where grunts were rare. These differences in nutrient delivery and grazing led to distinct benthic communities with higher cover of crustose coralline algae and less total algal abundance at grunt aggregation sites. Importantly, coral growth was roughly 1.5 times greater at grunt hotspots, likely due to the important nutrient subsidy. Our results suggest that schooling reef fish and their nutrient subsidies play an important role in mediating community structure on coral reefs and that overfishing may have important negative consequences on ecosystem functions. As such, management strategies must consider mesopredatory fishes in addition to current protection often offered to herbivores and top-tier predators. Furthermore, our results suggest that restoration strategies may benefit from focusing on providing structure for aggregating fishes on reefs with low topographic complexity or focusing the restoration of nursery raised corals around existing nutrient hotspots.

A new gonad-infecting species of Philometra, P. barnesi sp. n. (Nematoda: Philometridae), from the marine fish Pomadasys argenteus (Haemulidae) off the northern coast of Australia.

A new nematode species, Philometra barnesi sp. n. (Philometridae), is described from the ovary of the marine teleost Pomadasys argenteus (Fosskål) (Haemulidae) off the northern coast of Australia (near Darwin). The new species is characterized by short subequal spicules (84 and 87μm long), a gubernaculum without a dorsal protuberance at its distal tip, the structure of male anterior and posterior body ends, the body lengths of males (1.67mm) and gravid females (320-597mm) and the structure of the oesophagus and caudal end of gravid females. Philometra barnesi is the sixth nominal gonad-infecting species of this genus recorded from marine fishes in Australian waters and the third species of philometrids described from fishes of the family Haemulidae.

Candidate Species for Marine Ornamental Aquaculture: French Grunt, Haemulon flavolineatum

Grunts (family Haemulidae) are some of the most economically and ecologically important fishes found throughout the world. Their common name refers to the characteristic grunting sound they make when they are agitated and during courtship. Many species of grunts are popular in public and private aquariums due to their schooling behavior and bright colors that create interest in aquarium exhibits. The French grunt has recently been identified as a candidate species for aquaculture due to its popularity in aquarium displays and the development of culture protocols. This 4-page fact sheet was written by Kevin P. Barden, Matthew L. Wittenrich, and Eric J. Cassiano, and published by the UF Department of Fisheries and Aquatic Sciences, March 2014.&#x0D; FA186/FA186: Candidate Species for Marine Ornamental Aquaculture: French Grunt, Haemulon flavolineatum (ufl.edu)

Foraging behavior, prey distribution, and microhabitat use by bottlenose dolphins Tursiops truncatus in a tropical atoll

The study of habitat use by top predators is important for understanding community interactions and is necessary for sound ecosystem management. In marine systems, top predators such as sharks and cetaceans have a strong impact on the structure and function of communities. While the observation of habitat use and foraging behavior of most marine predators is logistically difficult, bottlenose dolphins Tursiops truncatus offer less of a challenge due to visible surface behavior and well-documented populations. We examined bottlenose dolphin behavior in relation to microhabitat classes at Turneffe Atoll, Belize. The dolphins were found to feed proportionally more in boundary microhabitats, areas where dense seagrass beds adjoined open sand flats, than in other microhabitats. Fish density, particularly schools of grunts (family Haemulidae), were higher in the boundary microhabitat than in seagrass or sand microhabitats. Extensive acoustic recordings yielded few fish calls, suggesting that passive listening for soniferous fish was not the dominant means of diurnal prey detection. The dolphins’ disproportionate use of boundary microhabitats for feeding was likely due to the abundance and accessibility of prey.