Lutjanus Fulvus Research Articles

Spawning aggregation of blacktail snapper (Lutjanus fulvus) in an okinawan coral reef: lunar-phase periodicity of aggregation formation, seasonal consistency in fish spatial distribution, and fish size and age frequency in the aggregation site

Spawning aggregation of blacktail snapper (Lutjanus fulvus) in an okinawan coral reef: lunar-phase periodicity of aggregation formation, seasonal consistency in fish spatial distribution, and fish size and age frequency in the aggregation site

LENGTH-WEIGHT RELATIONSHIP OF EIGHT SPECIES OF FISH CAUGHT BY TRADITIONAL PAPUAN FISHERS IN YOUTEFA BAY, INDONESIA

In this study, data on length and weight of fish were used to determine the length-weight relationship and condition factors of eight fish species that are targeted by traditional Papuan fishers and have high economic value (Lutjanus fulvus, Gerres oyena, Parupeneus barberinus, Siganus spinus, Siganus canaliculatus, Pelates quadrilineatus. Mugil cephalus, and Hemiramphus far) in Youtefa Bay, Papua Province, Indonesia. A total of 245 fish specimens were collected from Papuan fishermen during the period January to March 2020. The total length and body-weight of the fish specimens studied ranged from 15.2 to 32.1 cm (average 20.26±3.73 cm) and 42.72 to 371.86 g (average 124.10±52.45 g), respectively. The b value ​​for all fish species studied ranged from 2.6919 to 3.0791, with the coefficient of determination (R2) ranging from 0.9022 to 0.9947. The growth patterns of the eight fish species were allometric (b ≠ 3; t-test < t-tab), where L. fulvus (2.824), P. barberinus (2.9136), S. canaliculatus (2.989), P. quadrilineatus (2.9577), M. cephalus (2.9096), and H. far (2.6919) were negative allometric (b < 3), while G. oyena (3.0596) and S. spinus (3.0791) are positive allometric (b > 3). Meanwhile, the relative condition factor and Fulton condition factor values ​​ranged from 0.874 to 1.201 (average 0.999±0.321) and 0.204 to 2.726 (average 1.612±0.515). M. cephalus had a higher relative condition factor, while L. fulvus had a higher Fulton condition factor than other fish species

Length-Weight Relationship and Condition Factors of Some Commercial Fish from Youtefa Bay, Jayapura City, Indonesia

In this study, we used data on the length and weight of fish to determine the length-weight relationship and condition factors of eight commercial fish targeted by traditional Papuan fishers in Youtefa Bay, Papua Province, Indonesia. The fish species were Lutjanus fulvus, Gerres oyena, Parupeneus barberinus, Siganus spinus, Siganus canaliculatus, Pelates quadrilineatus. Mugil cephalus, and Hemiramphus far. A total of 245 fish specimens were collected from Papuan fishermen from January to March 2020. The total body length and weight ranged from 15.2 to 32.1 cm (average 20.26±3.73 cm) and 42.72 to 371.86 gr (average 124.10±52.45 gr), respectively. The b value ranged from 2.692 to 3.079, with the coefficient of determination (R2) ranging from 0.902 to 0.995. The growth patterns of the eight fish species were allometric (b≠3; t-test<t-tab), where L. fulvus (2.824), P. barberinus (2.914), S. canaliculatus (2.989), P. quadrilineatus (2.958), M. cephalus (2.910), and H. far (2.692) have negative allometric growth (b<3). In contrast, G. oyena (3.060) and S. spinus (3.079) have positive allometric growth (b>3). The relative condition factor and Fulton condition factor values ranged from 0.874 to 1.201 (average 0.999±0.321) and 0.204 to 2.726 (average 1.612±0.515). M. cephalus had a higher relative condition factor, while L. fulvus had a higher Fulton condition factor compared to other fish species.

Phylogenetic of red snapper (Lutjanidae) in Yapen Island Waters, Papua, Indonesia

Abstract. Sala R, Kusuma AB, Pranata B. 2022. Phylogenetic of red snapper (Lutjanidae) in Yapen Island Waters, Papua, Indonesia. Biodiversitas 23: 6428-6436. Red snappers are an economically valuable fishery resource. Most of these snapper species are inhabitants of coral reef ecosystems. A variety of red snapper species can be found in the northern waters of Papua, particularly in the Yapen Regency. However, information regarding the biological and ecological aspects of these fish is virtually unavailable. On the other hand, the utilization intensity of red snapper as a source of community income continues to increase. By using DNA barcode sequences, this study attempted to examine species diversity and relationships among Lutjanidae family species. The study was carried out from June to August 2022 in the waters of Yapen Regency by taking fish samples from the fish caught by local hand-lining fishers. Red snapper samples were identified morphologically and molecularly. According to molecular analyses, it was identified nine red snapper species from the genera of Lutjanus, Aphareus and Pristipomoides. The morphological characteristics of the species from the genus of Aphareus are similar to those from the genus of Pristipomoides yet different from those of the species from the genus of Lutjanus. The phylogenetic tree consisted of four clades with significant bootstrap values ranging from 98 to 99%. Clades 1, 2 and 3 comprise the species from the genus of Lutjanus, while clade 4 contains species from the genera of Aphareus and Pristipomoides. The greatest genetic distance was found between Lutjanus fulvus and Pristipomoides multidens, while the smallest genetic distance was found between Lutjanus vitta and Lutjanus ehrenbergii. Based on the study results, some management implications are discussed. For example, information on species biodiversity maps is needed to determine the target stock of a managed species so that management objectives are more focused on the species level and not on the genus or family level.

Two New Records of Snapper (Perciformes, Lutjanidae) from Saint Martin’s Island, Bangladesh

The present work documented two snapper species, Lutjanus fulvus Forster, 1801 and Lutjanus erythropterus Bloch, 1790, recently collected from the Saint Martin’s Island, Bay of Bengal, Bangladesh, during a survey on coral associated fishes of Bangladesh from July 2017 to September 2018. These two species were identified with morphological characteristics and by analyzing partial mitochondrial COI sequences. The document also included an updated checklist of snappers available in Bangladesh.

Retroporomonorchis pansho n. g., n. sp., an unusual monorchiid trematode exploiting an atypical host.

The Monorchiidae Odhner, 1911 are well represented in tropical and subtropical marine fishes worldwide but rarely reported from the Lutjanidae, an important family of tropical fishes that prey mainly on demersal fishes, decapods and cephalopods. Here, we report the first monorchiid from a lutjanid in Australian waters, Retroporomonorchis pansho n. g., n. sp. in Lutjanus fulvus (Forster), off Lizard Island on the northern Great Barrier Reef. It is morphologically and phylogenetically distinct among known monorchiids, resolves within the Monorchiinae Odhner, 1911, and is characterised by a relatively large ventral sucker, a sinistral genital pore immediately posterior to the ventral sucker, unfilamented eggs, a single testis, and vitelline follicles restricted to the level of the gonads. We assessed all previous records of monorchiids from lutjanid fishes and found only one to be convincing, that of Infundiburictus overstreeti (Gupta & Gupta, 1990) Wee, Cutmore, Pérez-del-Olmo & Cribb, 2020 from Lutjanus monostigma (Cuvier) in the Bay of Bengal. Another, Monorcheides xishaensis Shen, 1985, from Lutjanus argentimaculatus (Forsskål) in the Paracel Islands, South China Sea, is here recognised as a cryptogonimid, and is synonymised with Siphoderina asiatica Gu & Shen, 1979. In the remaining reports, the identity of the host is either ambiguous or doubtful, or the identity of the worm is not supported with sufficient evidence.

Molecular identification of Lutjanus species by PCR-RFLP analysis of mitochondrial 12S rRNA region

A PCR-RFLP was developed by targeting the mitochondrial 12S rRNA region to authenticate the six species viz., Lutjanus fulvus, L. rivulatus, L. quinquelineatus, L. fulviflamma, L. madras and L. decussatus available along the Indian coast. A newly designed primer set, 12SU-F/12SU-R, was used for PCR amplification to obtain a product size of 550 bp, which was then digested using three endonucleases viz., BseDI, Mn1I and MspA1I. All the six species were unambiguously differentiated by BseDI enzyme. Mn1I differentiated only four species viz., L. fulvus, L. quinquelineatus, L. fulviflamma and L. madras; while MspAI differentiated four species viz., L. rivulatus, L. quinquelineatus, L. fulviflamma and L. madras from the rest. The developed PCR-RFLP protocol using BseDI enzyme can therefore be easily adopted by regulatory authorities to the prevention of possible adulteration of species for red snappers.

Length-Weight Relationships for 16 Snapper Fishes fromVisakhapatnam Coast, India

This study presents the length-weight relationships (LWRs) for 16 lutjanid species from Visakhapatnam coastal waters, India (16.98°N-20°.2 N, Long. 82.19°-86.53°E). The samples were collected fortnightly between December 2013 and December 2018 from commercially operated fishing gears viz.: the reef fish trap with single and double horse necked funnel (mesh aperture size 4.5 cm) trap measured about 3 ft in length, 4 ft in width and 2.5 ft in height, having a volume of 30 cu ft. The soak time was between 18 to 22 h. Gill nets made of monofilament nylon netting with a mesh size of 80 mm were used in the collection of snapper fishes. The nets were operated 3 h before morning (sunrise) and hauled 1 h after the sunrise. The depth of the net operated varied from 3 to 8 m, whereas the head rope of the net is around 20–25 m in length. The hook number 8 to 11 is used for the fishing of snapper fishery resources in water depth more than 75 m in Visakhapatnam region. The soak time varied from 5 to 10 h. The bottom trawlers (43 mm with a cod end mesh size of 15–25 mm) a depth range of 10 to 55 m, whereas during each fishing period, 3 to 4 hauls are made with a towing period ranging from 1 to 2 h; trawlers (a depth regime of 12 to 55 m, with a mesh size of 400 mm to 25 mm at the cod end). Around 3 to 6 hauls are made during each fishing trip with a towing period of 1to 2 h. All LWRs were significant with r2 values ranged from 0.9504 for Lutjanus lemniscatus to 0.9951 for Lutjanus fulvus and ‘b’ values ranging from Pinjalo pinjalo for 2.5982 Lutjanus quinquelineatus for 3.4993. In addition, new maximum total length for each of the three species L. indicus, L. xanthopinnis and P. pinjalo was also found. The parameters are found great importance to evaluate the relative condition of populations, biology, ecology, species management and their fisheries and stock assessment.

IKAN YANG BERUAYA DI DAERAH MANGROVE PANTAI TASIK RIA

This study is intended to find out the fish that are cultured into the mangrove area of Tasik Ria beach, Mokupa, Minahasa Regency. Fish is obtained through gill jarring at high tide. The fish that were identified were Archamia fucata, Lutjanus fulvus, Lutjanus eherenbergii, Lethrinus ornatus, Scolopsis lineate, Sargocentron diadema, Epinephelus merra and Scorpaenopsis oxycephala. The fish are generally carnivorous, and are nocturnal.Key words: Tasik Ria Beach, the fishes, carnivorous, mangroves

Random PCR-based genotyping by sequencing technologyGRAS-Di (genotyping by random amplicon sequencing, direct) reveals genetic structure of mangrove fishes.

While various technologies for high-throughput genotyping have been developed for ecological studies, simple methods tolerant to low-quality DNA samples are still limited. In this study, we tested the availability of a random PCR-based genotyping-by-sequencing technology, genotyping by random amplicon sequencing, direct (GRAS-Di). We focused on population genetic analysis of estuarine mangrove fishes, including two resident species, the Amboina cardinalfish (Fibramia amboinensis, Bleeker, 1853) and the Duncker's river garfish (Zenarchopterus dunckeri, Mohr, 1926), and a marine migrant, the blacktail snapper (Lutjanus fulvus, Forster, 1801). Collections were from the Ryukyu Islands, southern Japan. PCR amplicons derived from ~130 individuals were pooled and sequenced in a single lane on a HiSeq2500 platform, and an average of three million reads was obtained per individual. Consensus contigs were assembled for each species and used for genotyping of single nucleotide polymorphisms by mapping trimmed reads onto the contigs. After quality filtering steps, 4,000-9,000 putative single nucleotide polymorphisms were detected for each species. Although DNA fragmentation can diminish genotyping performance when analysed on next-generation sequencing technology, the effect was small. Genetic differentiation and a clear pattern of isolation-by-distance was observed in F.amboinensis and Z.dunckeri by means of principal component analysis, FST and the admixture analysis. By contrast, L.fulvus comprised a genetically homogeneous population with directional recent gene flow. These genetic differentiation patterns reflect patterns of estuary use through life history. These results showed the power of GRAS-Di for fine-grained genetic analysis using field samples, including mangrove fishes.

Fisheries selectivity and annual exploitation of the principal species harvested in a data-limited artisanal fishery at a remote atoll in French Polynesia

Artisanal fisheries are critically important to food security and economic opportunity in coastal communities throughout the developing world. However, the dynamics of these fisheries are poorly understood, and a basic understanding of the gear types and species harvested, is required to promote effective fisheries management. To this aim, we surveyed artisanal fishers at Anaa atoll from May 14th, 2016 to May 19th, 2017 and described the selectivity and exploitation of the fishery's dominant species. The harvested marine life included 98 species from 31 families, which were captured with seven gear types including artisanal fish traps, monofilament nets, spear guns, handlines, pole and line, hand, and harpoons. Bonefish (Albula glossodonta) were the most abundant species and comprised 25% of the overall catch, followed by Chaetodon auriga, Kuhlia sandvicensis, Lutjanus fulvus, and Chanos chanos. Artisanal fish traps and spearguns harvested a higher proportion of overexploited fishes, captured a more diverse range of species, and removed the most biomass from the atoll. An analysis of the size distribution of harvested fishes, with length-based catch curves, indicates that species with high natural mortality rates such as Chanos chanos and Selar crumenophthalmus were underexploited. While in contrast, slow growing, late maturing, and long-lived species such as Naso lituratus and Epinephelus polyphekadion were overexploited. The results of this research provided the community with the basis for making local management decisions regarding their fisheries resources, including the development of an Educational Managed Marine Area and a seasonal closure of the artisanal trap fishery to allow for movement, predominantly A. glossodonta during their offshore spawning migrations.

Dependence of fish on subtropical riverine mangroves as habitat in the Ryukyu Islands, Japan

To examine whether fish were dependent on mangrove habitat in the Ryukyu Islands (southern Japan), fish assemblage structures were compared on the downstream side between mangrove-rich and mangrove-free rivers on Ishigaki and Okinawa Islands in 2014 and 2015. The mean species richness and abundance of fish were significantly higher in mangrove-rich rivers than in mangrove-free rivers. Mangrove-related food feeders (e.g., benthic invertebrate and detritus) were more abundant in mangrove-rich than mangrove-free rivers while mangrove-unrelated food feeders (e.g., zooplankton feeders) showed no difference between river types. Cluster and ordination analyses demonstrated that fish assemblage structures were clearly different between mangrove-rich and mangrove-free rivers. Of all of the fish species collected (88 species), half of the species (45 species, 51%) occurred exclusively in the mangrove-rich rivers, 9 species (10%) in the mangrove-free rivers and 34 species (39%) were common in both types of rivers. Commercially important fish (e.g., Lutjanus fulvus and L. argentimaculatus) showed greater abundance of juveniles in mangrove-rich rivers than in the mangrove-free rivers, indicating that mangrove-rich rivers can provide important habitat for a variety of fish, including those commercially important to fisheries.

Karyotypic study of five Lutjanid species using conventional and Ag-NORs banding techniques

The first cytogenetic comparisons of five snapper species from Thailand were presented here. Renal cell samples were taken from blacktail snapper (Lutjanus fulvus), five lined snapper (L. quinquelineatus), dory snapper (L. fulviflamma), brownstripe red snapper (L. vitta), and mangrove red snapper (L. argentimaculatus). The mitotic chromosome preparation was prepared directly from kidney cells. Conventional staining and Ag-NOR banding techniques were applied to stain the chromosomes. The results exhibited that all five snapper species have the diploid chromosome numbers of 2n = 48 and the fundamental numbers (NF) of 48. The presences of large, medium, and small telocentric chromosomes were 22-24-2, 24-20-4, 36-10-2, 28-16-4 and 36-10-2, respectively. The Ag- NORs banding technique provides the pair of nucleolar organizer regions (NORs) at subcentromeric region of the long arm of the respective telocentric chromosome pairs 9, 1, 3, 4 and 9. Their karyotype formulas is as follows: L. fulvus (2n = 48): L 22 t + M 24 t + S 2 t , L. quinquelineatus (2n = 48): L 24 t + M 20 t + S 4 t , L. fulviflamma (2n = 48): Lt36 + Mt10 + St2, L. vitta (2n = 48): L 28 t + M 16 t + S 4 t , and L. argentimaculatus (2n = 48): L 36 t + M 10 t + S 2 t .

Assessment of human health hazard due to metal uptake via fish consumption from coastal area of Tanzania

Heavy metals are serious threat because of their toxicity, long persistence, bioaccumulation and biomagnification in the food chain. This research deals with human health risk assessment of metal contamination through the consumption of commonly consumed fish from Dar es Salaam City. The fish species of interest were Rastrellieger kanagurta, Lutjanus fulvus and Fenneropenaeus indicus. The aim is to determine the concentration of Pb, As, Cd, Fe and Cu contaminant in these fish samples. By using AAS the maximum concentration of Pb, As, Cd, Fe and Cu was 0.14, 1.09, 0.16, 60.29 and 12.11 mg/kg respectively. The estimated daily intake (EDI) of heavy metals with the respective type of fish can be arranged as Fe > Cu > As > Cd > Pb in which values are higher than Provisional Tolerable Weekly Intake (PTWI) for metals. Therefore the consumption of fish samples is questionable. Target Hazard Quotient (THQ) was used in the health risk assessment to determine carcinogenicity of the sample. The result shows that the concentration and THQ of As in all fish samples ranges from 1.173 – 2.325 which is > 1, hence signified that a daily exposure at this level are in risk of cancer during a person lifetime. It is well known that fishes can accumulate variety of toxic chemicals including persistent organic contaminants such as dioxins and chlorinated pesticides; hence similar study has to be conducted for such compounds at different sampling sites including river and personal fish ponds.Keywords: Target Hazard Quotient, Arsenic, Health Risk, Concentration, Heavy Metals

Fish communities and juvenile habitat associated with non-native Rhizophora mangle L. in Hawai‘i

There are many well-documented ecosystem services for which mangroves have received protection globally; however, in Hawai‘i, where no species of mangroves are native, these services have not been thoroughly evaluated. Twelve permanently open stream mouth estuaries on O‘ahu were sampled from September to October 2014. Abiotic factors and fish community data were correlated with percent mangrove cover and the Landscape Development Intensity Index to examine potential relationships among mangroves, humans, and fish communities. The three most abundant species, of 20 species caught, were Kuhlia xenura, Mugil cephalus, and Mulloidichthys flavolineatus. Of these three native species, 99% of the individuals caught were juveniles indicating the overall importance of stream mouth estuaries as juvenile habitat. Non-metric multidimensional scaling analysis of fish community data showed that K. xenura, M. cephalus, and Lutjanus fulvus were more abundant in shallower sites with lower salinity and higher percent mangrove cover. Stream mouth estuaries with mangroves are important juvenile habitats for the native K. xenura and M. cephalus and the non-native Osteomugil engeli. These species, two of which are important in recreational and subsistence fisheries, will be most likely affected by mangrove removal based on abundance and distribution in mangrove-dominated stream mouth estuaries.

Two new gonad-infecting species of Philometra (Nematoda: Philometridae) parasitic in Lutjanus spp. (Osteichthyes: Lutjanidae) in the Bay of Bengal, India.

Based on light and scanning electron microscopical studies, two new gonad-infecting species of Philometra Costa, 1845 (Nematoda: Philometridae) are described from marine fishes of the genus Lutjanus Bloch (Lutjanidae, Perciformes) in the Bay of Bengal, off the eastern coast of India: Philometra argentimaculati sp. n. and Philometra fulvi sp. n. from the mangrove red snapper Lutjanus argentimaculatus (Forsskål) and blacktail snapper Lutjanus fulvus (Foerster), respectively. P. argentimaculati is mainly characterised by the body length of male 2.56-3.07 mm, needle-like spicules 183-228 μm long, length of the gubernaculum at 90-120 μm, distal end of the gubernaculum with lamellar structures without a dorsal protuberance and by the dorsally non-interrupted male caudal mound. P. fulvi differs from all Philometra spp. with described males in the rectangular shape of the distal tip of the gubernaculum and is noted for the length of needle-like spicules 123-138 μm, that of the gubernaculum 69-93 μm and for the presence of a dorsal protuberance and lamella-like structures on the gubernaculum distal end. These are the first nominal species of philometrids reported from fishes of the family Lutjanidae in the region of the Indian Ocean. A necessity of further detailed studies on philometrids parasitising marine fishes worlwide is stressed.

Age, growth, and reproductive biology of blacktail snapper, Lutjanus fulvus, around the Yaeyama Islands, Okinawa, Japan

Age, growth, and reproductive characteristics of blacktail snapper, Lutjanus fulvus, which is a commercial fish species, were investigated using 322 specimens (40–332 mm in fork length) caught around the Yaeyama Islands, Okinawa, Japan. Spawning season was estimated to be from April to October, and spawning was confirmed around the full moon and the last quarter moon. Age determination using sectioned otoliths revealed that ages ranged from 0 to 34 years and the majority was ≥ 3 years. Parameters of the von Bertalanffy growth function were estimated to be L∞ = 270 mm, k = 0.40, and t0 = −0.48 years for females, and 257 mm, 0.44, and −0.42 years for males. Initial growth was rapid during the first 3 years, attaining over 200 mm for both sexes, and then females grew larger than males. Sizes (ages) at the first sexual maturity were 225 mm (4 years) for females and 207 mm (3 years) for males. The wide range of age composition in catch with majority of ≥3 years old implied that the current fishing effort to harvest was not sufficiently large enough to collapse the stock immediately.

Coming out of the starting blocks: extended lag time rearranges genetic diversity in introduced marine fishes of Hawai‘i

Biological invasions with known histories are rare, especially in the sea, and empirical studies of the genetic consequences are even rarer. Fifty-five years ago, the state of Hawai'i began a remarkable, if unintentional, 'experiment' with the introduction of three reef fishes, Lutjanus fulvus, Cephalopholis argus and Lutjanus kasmira. All have since expanded from the initial introduction of 2204 to 3163 individuals; however, historical records show that initially L. fulvus remained scarce, C. argus had modest population expansion and L. kasmira experienced rapid population growth. The consequences of differential population growth rates are apparent in F-statistics: Hawaiian L. fulvus demonstrate strong and significant haplotype frequency shifts from the founder location (F(ST) = 0.449), C. argus shows low but significant differentiation (F(ST) = 0.066) and L. kasmira is nearly identical to the founder location (F(ST) = 0.008). All three species had higher mtDNA diversity in the introduced range, which can be explained by multiple sources for L. fulvus and L. kasmira, but not for C. argus. We conclude that lag time before population expansion, in conjunction with genetic drift, has defined the genetic architecture of these three species in the introduced range.

Determination of Metal Levels in Thirteen Fish Species from Lakshadweep Sea

A bio-monitoring study was performed to investigate the concentration of certain metals (cadmium, cobalt, copper, iron, magnesium, manganese, nickel, lead and zinc) in gill, skin and muscle of thirteen demersal fish species of Agatti Coast of Lakshadweep Sea. All the metal concentrations in gill are higher than skin and muscle. Concentrations of toxic metals such as Cd (0.61±0.67μgg(-1) in Gerres longirostris), Mn (0.83±1.21μgg(-1) in Lutjanus fulvus) and Ni (0.56±0.83μgg(-1) in L. bengalensis) were well above the permissible limits suggested by World Health Organization and Food and Agricultural Organizations.

Genetic evaluation of marine biogeographical barriers: perspectives from two widespread Indo‐Pacific snappers (Lutjanus kasmira and Lutjanus fulvus)

AbstractAim In the Indo‐Pacific, the mass of islands of the Indonesian archipelago constitute a major biogeographical barrier (the Indo‐Pacific Barrier, IPB) separating the Pacific and Indian oceans. Evidence for other, more localized barriers include high rates of endemism at the Marquesas and other isolated peripheral islands in the Pacific. Here we use mitochondrial‐sequence comparisons to evaluate the efficacy of biogeographical barriers on populations of the snappers Lutjanus kasmira and Lutjanus fulvus across their natural ranges.Location Pacific and Indian oceans.Methods Mitochondrial cytochrome b sequence data were obtained from 370 individuals of L. kasmira and 203 individuals of L. fulvus collected from across each species’ range. Allele frequency data for two nuclear introns were collected from L. kasmira. Phylogenetic and population‐level analyses were used to determine patterns of population structure in these species and to identify barriers to dispersal.Results Lutjanus kasmira lacks genetic structure across the IPB and throughout 12,000 km of its central Indo‐Pacific range. In contrast, L. fulvus demonstrates high levels of population structure at all geographical scales. In both species, highly significant population structure results primarily from the phylogenetic distinctiveness of their Marquesas Islands populations (L. kasmira, d = 0.50–0.53%; L. fulvus, d = 0.87–1.50%). Coalescence analyses of the L. kasmira data indicate that populations at opposite ends of its range (western Indian Ocean and the Marquesas) are the oldest. Coalescence analyses for L. fulvus are less robust but also indicate colonization from the Indian to the Pacific Ocean.Main conclusions The IPB does not act as a biogeographical barrier to L. kasmira, and, in L. fulvus, its effects are no stronger than isolating mechanisms elsewhere. Both species demonstrate a strong genetic break at the Marquesas. Population divergence and high endemism in that archipelago may be a product of geographical isolation enhanced by oceanographic currents that limit gene flow to and from those islands, and adaptation to unusual ecological conditions. Lutjanus kasmira shows evidence of Pleistocene population expansion throughout the Indo‐central Pacific that originated in the western Indian Ocean rather than the Marquesas, further demonstrating a strong barrier at the latter location.