Cheilinus Undulatus Research Articles

Implementasi Teknologi Genetika Untuk Konservasi Spesies Laut Terancam: Tinjauan Literatur Tentang Metode dan Keberhasilan

The pace of global environmental change and the intensification of human activities have put significant pressure on marine ecosystems, threatening the sustainability of many species that are important both for ecosystems and the economies of coastal communities. In this context, this study aims to evaluate the application of genetic technologies in the conservation of endangered marine species, focusing on environmental DNA (eDNA) monitoring, CRISPR genetic engineering techniques and population genetic analysis. The method used was a literature review that examined current academic sources related to genetic technologies and their implementation in conservation. Findings show that eDNA is a highly effective tool in species and habitat monitoring, and has been successful in specific cases such as Napoleon fish and green turtles in Raja Ampat. In contrast, CRISPR techniques offer the potential to improve the genetic resilience of species, despite significant regulatory and ethical challenges. The implications of this study emphasize the need for strong policy support and international collaboration to address these challenges and optimize the use of genetic technologies in more effective conservation strategies in the future.

Jazan's Catch Chronicles: A Statistical Exploration of Lethrinus Nebulous and Acanthocybium Solandri Fishing (2012-2022)

This study delves into the fascinating world of fisheries data, specifically focusing on two commercially important fish species in the Red Sea: The Lethrinus nebulous (cloud emperor) and the Acanthocybium solandri (wahoo). Through the lens of statistics, this study aims to uncover valuable insights into the population dynamics, catch patterns and potential management strategies for these fish species. By analyzing data from "Jazan's Catch Chronicles," from General Administration of Fisheries Resources (Ministry of Environment, Water and Agriculture) -the Statistical Yearbook 2022-, we employ statistical methods to extract meaningful patterns from the data and answer critical questions. This knowledge can then inform fisheries management practices, ensuring the long-term sustainability of these valuable resources. The findings suggest that the diversity of the catch may have increased slightly over the study period. The number of species with a catch of more than 100 tonnes increased from 5 in 2017 to 7 in 2022. The number of species with a catch of more than 10 tonnes also increased from 14 in 2017 to 17 in 2022. However, further statistical analysis, such as a chi-squared test, is needed to determine if this difference is statistically significant. The study also highlights the importance of balancing data disclosure with species conservation. While detailed location data can be valuable for scientific research, it can also pose threats to endangered species. In the case of the IUCN-listed Cheilinus undulatus (humphead wrasse), a decision tree approach was employed to weigh the risks and rewards of disclosing location data. Considering the species' endangered status and declining population, the study recommends restricting data by masking species IDs and areas or restricting information by publishing high-resolution habitat maps without specific location details. This approach helps balance the need for scientific knowledge with protecting vulnerable species. Overall, this study sheds light on the dynamics of fish populations in the Red Sea, emphasizing the need for sustainable management practices and responsible data handling to ensure the long-term health of these vital marine resources.

De Novo Genome Assembly of the Whitespot Parrotfish (Scarus forsteni): A Valuable Scaridae Genomic Resource.

Scarus forsteni, a whitespot parrotfish from the Scaridae family, is a herbivorous fish inhabiting coral reef ecosystems. The deterioration of coral reefs has highly affected the habitats of the parrotfish. The decline in genetic diversity of parrotfish emphasizes the critical importance of conserving their genetic variability to ensure the resilience and sustainability of marine ecosystems for future generations. In this study, a genome of S. forsteni was assembled de novo through using Illumina and Nanopore sequencing. The 1.71-Gb genome of S. forsteni, was assembled into 544 contigs (assembly level: contig). It exhibited an N50 length of 17.97 Mb and a GC content percentage of 39.32%. Our BUSCO analysis revealed that the complete protein of the S. forsteni genome had 98.10% integrity. Combined with structure annotation data, 34,140 (74.81%) genes were functionally annotated out of 45,638 predicted protein-coding genes. Upon comparing the genome size and TE content of teleost fishes, a roughly linear relationship was observed between these two parameters. However, TE content is not a decisive factor in determining the genome size of S. forsteni. Population history analysis results indicate that S. forsteni experienced two major population expansions, both of which occurred before the last interglacial period. In addition, through a comparative genomic analysis of the evolutionary relationship of other species, it was found that S. forsteni had the closest relationship with Cheilinus undulatus, another member of the Labridae family. Our expansion and contraction analysis of the gene family showed that the expansion genes were mainly associated with immune diseases, organismal systems, and cellular processes. At the same time, cell transcription and translation, sex hormone regulation, and other related pathways were also more prominent in the positive selection genes. The genomic sequence of S. forsteni offers valuable resources for future investigations on the conservation, evolution, and behavior of fish species.

Intact shallow and mesophotic assemblages of large carnivorous reef fishes underscore the importance of large and remote protected areas in the Coral Triangle

Abstract Overfishing remains a threat to coral reef fishes worldwide, with large carnivores often disproportionately vulnerable. Marine protected areas (MPAs) can restore fish populations and biodiversity, but their effect has been understudied in mesophotic coral ecosystems (MCEs), particularly in the Coral Triangle. Videos were analysed from baited remote underwater video systems deployed in 2016 to investigate the assemblage structure of large carnivorous fishes at shallow (4–12 m) and mesophotic (45–96 m) depths in two of the largest and most isolated MPAs in the Philippines: an uninhabited, fully no‐take MPA enacted in 1988 (Tubbataha Reefs Natural Park) and an archipelagic municipality surrounded by an extensive but not fully no‐take MPA declared in 2016 (Cagayancillo). Taxa focused on were groupers (Serranidae), snappers (Lutjanidae), emperors (Lethrinidae), jacks (Carangidae) and the endangered Cheilinus undulatus (Labridae). Mean abundance and species richness were not greater in TRNP than in Cagayancillo regardless of depth despite long‐term protection in the former. Limited impacts of fishing in Cagayancillo may explain this result. Differentiation of fish assemblages was evident between TRNP and Cagayancillo but more obvious between depths at each location, probably due more to habitat than MPA effects. In Cagayancillo, overall carnivorous reef fish, grouper and jack mean abundance were 2, 2 and 10 times higher, respectively, at mesophotic depths, suggesting that MCEs can serve as deep refugia from fishing. These findings of differentiation between depths and higher abundance of certain taxa in mesophotic depths emphasize that MCEs are distinct from shallow reefs, serve as important habitat for species susceptible to overfishing and, thus, must be explicitly included in the design of MPAs. This study also highlights the value of maintaining strict protection of MPAs like TRNP for the Coral Triangle and an opportunity to safeguard intact fish assemblages in Cagayancillo by expanding its no‐take zones.

Sacred offerings and secular foods on Reao Atoll, Tuamotu Archipelago, East Polynesia

ABSTRACTIn 1976, Yosihiko H. Sinoto conducted extensive archaeological survey and excavations on Reao Atoll, Tuamotu Archipelago as part of a Japanese, multi‐disciplinary expedition led by Prof. Sachiko Hatanaka. Primarily excavating three marae and four habitation sites totalling ∼180 m2, more than 25000 vertebrate remains were recovered. We report the jidentification and analysis of the fauna and contrast the inventories from secular and sacred contexts inferring the ritual use of pig, dog, turtle and tuna (Scombridae), as well as identifying relatively larger parrotfish (Scaridae), groupers (Serranidae), snappers (Lutjanidae), the Humphead wrasse (Cheilinus undulatus) and sharks/rays (Elasmobranchii) on marae. With a suite of 11 new AMS age determinations, we report the first directly dated precontact records for pig and dog and anchor the marae chronology possibly beginning in the thirteenth century. The 800 calBP dates imply that at least one of the Tuamotu atolls may have emerged nearly two centuries prior to the hypothesised ‘cross‐over’ date of 600 BP. Consequently, the earliest chronology of atoll emergence along the 1000 km length of the Tuamotus might vary, thus providing landscapes for human colonisation at slightly different times which has implications for the speed and tempo of colonisation.

Eco-environmental assessment in the Sembilan Archipelago, Indonesia: its relation to the abundance of humphead wrasse and coral reef fish composition

Eco-environmental assessment in the Sembilan Archipelago, Indonesia: its relation to the abundance of humphead wrasse and coral reef fish composition

Production and trade of Napoleon wrasse (Cheilinus undulatus) in selected Municipalities of Bohol, Philippines

Production and trade of Napoleon wrasse (Cheilinus undulatus) in selected Municipalities of Bohol, Philippines

Assessing and managing charismatic marine megafauna in Palau: Bumphead parrotfish (Bolbometopon muricatum) and Napoleon wrasse (Cheilinus undulatus)

Abstract Bumphead parrotfish (Bolbometopon muricatum) and Napoleon wrasse (Cheilinus undulatus) are large, charismatic species with high economic and cultural value in Palau and are important for ecosystem function. As a result of intense fishing pressure, landings in Palau for both species declined dramatically in the 1990s and, in response, national legislation was enacted in 2006 that imposed a total ban on the extraction, possession, and sale of both species. In 2013 and 2021, fisheries‐independent stock assessments were conducted and found that the spawning potential ratios (SPRs) for bumphead parrotfish increased slightly from 30% to 34%. Conversely, the SPRs for Napoleon wrasse declined from 12% in 2013 to 4% in 2021. Despite the fishery being closed since 2006, these data suggest the likelihood of significant poaching, resulting in low SPR values, particularly for Napoleon wrasse. Prior to the COVID‐19 pandemic, marine tourism played a central role in the economic and social life of Palau. A willingness‐to‐pay survey found that divers would pay $1.27 million (2020 USD) more for strictly managed catches of both species, and nearly $3.00 million more if the fishery remained closed. The total market value for bumphead parrotfish peaked in 1995 at $112,190. The peak total market value for Napoleon wrasse was $66,434 in 2002. The welfare gain/loss for diver tourism is an order of magnitude greater than the fishery market gain/loss, and healthy marine ecosystems are essential for the post‐COVID‐19 economic recovery of Palau. However, because of the cultural importance of these species, there is a desire to manage this fishery for customary use. Opening a general subsistence harvest season is not recommended ecologically; however, the results suggest that if the SPR of bumphead parrotfish can recover to 40%, a limited quota of individuals with a total length of >95 cm could be sustained, which could be allocated via lottery. However, the fishery for Napoleon wrasse should remain closed given the extremely low SPR values and limited number of large adults in the population.

Mortality and management matter: Case study on use and misuse of ‘ranching’ for a CITES Appendix II-listed fish, humphead wrasse (Cheilinus undulatus)

CITES is the most important international instrument for managing threatened or potentially threatened wildlife trade. If listed organisms are removed from the wild at stages of highest natural mortality and held in captivity to increase survivorship and hence make more organisms available for trade without impact on wild populations, this form of production is termed ‘ranching’ (coded ‘R’ under CITES). To gain benefits for livelihoods and species, ranching must be managed effectively and wild capture conducted sustainably. CITES-listed species are increasingly being ranched, yet in many cases key information on natural and captive mortality and implications for trade controls of introducing ranching is lacking. Endangered (IUCN Red List) fish humphead wrasse (Cheilinus undulatus) was traded in wild (W-code) form after its CITES App II-listing in 2004, with ranching subsequently introduced in 2018. This well-studied species is used as a case study to examine the outcomes and implications of uncontrolled ranching (capture and grow-out) operations. For humphead wrasse, ranching is currently unjustifiable according to CITES provisions and poses a further potential threat to the species. Fourteen recommendations call for action by CITES as well as along much of the trade chain. CITES must review and define when ranching can be applied and operate sustainably. Exporting countries must ensure sustainable catches accounting for mortality levels at capture and during ranching, and conduct an appropriate non-detriment finding, while import destinations need to effectively distinguish and control the trade in W- and R-coded fish. A Review of Significant Trade, assessment of legal acquisition and communications between Parties are recommended.

Detection of the Types of Consumable Saltwater Fish in the Coastal Area of Likupang

In the coastal area of Likupang, many types of saltwater fish can be consumed, such as tuna and skipjack. Yet, there are also types of saltwater fish that cannot be consumed or protected by the government, such as Napoleon fish and sea kingfish. Thus, this research aimed to build a desktop application that can automatically classify consumable and non-consumable saltwater fish species more accurately and promptly using a suitable image recognition method like the Convolutional Neural Network (CNN). CNN has abilities to distinguish images by recognizing several pixels in a two-dimensional image and RGB (Red, Green, Blue) colors which are then converted into a matrix with various values, making it easier for the system to recognize the two-dimensional image. By using 40% test data (143 images) and 60% training data (213 images), test accuracy in identifying and classifying images of consumable fish, non-consumable fish, and non-fish images with each percentage of 94%, 98%, and 95% respectively.

Establishment and Application of Microsatellite Multiplex PCR System for Cheilinus undulatus

Cheilinus undulatus is a valuable seawater economic fish with tender meat, fresh taste, and high nutritional value; however, its population is rapidly declining because of massive fishing and habitat destruction. Assessing changes in genetic diversity and inbreeding levels is a very valuable monitoring tool, and multiplex PCR has the advantages of being time-efficient and economical. Here, we selected 12 pairs of polymorphic microsatellite loci, developed two multiplex PCR amplification systems based on these microsatellites, and used them to examine 30 C. undulatus specimens. The number of alleles (Na) for the 12 microsatellite markers ranged from 2 to 8. The effective allele number (Ne) ranged from 1.724 to 4.592. The expected heterozygosity (He) and observed heterozygosity (Ho) ranged from 0.420 to 0.782 and 0.100 to 0.900, respectively. The polymorphic information content (PIC) ranged from 0.422 to 0.746, with a mean value of 0.557. 5 loci deviated from Hardy-Weinberg equilibrium (HWE, p < 0.05 after Bonferroni correction). The multiplex PCR amplification system established in this study provides a basis for germplasm identification, genetic diversity analysis, and assessment of the effects of accretion and release of C. undulatus.

Calling for institutional arrangements in Napoleon Wrasse conservation and management in Indonesia: The Anambas Islands case

Cheilinus undulatus, or Napoleon wrasse – though severely vulnerable to extinction - has become a highly sought-after luxury food for certain societies and has intensified its continuous market demand. Overfishing has been the key factor driving the collapse of its populations. Therefore, conservation and management have never been more urgent. This study explores Napoleon wrasse farming in Anambas, Indonesia. Data gathering was conducted through interviews, exploring the farming practices and export trade. The findings are showing the history of overfishing of adult fish, leading to larval capture as the tragedy of the commons in the nursery grounds. Farming practices causing no stocks replenishment. The government supports the promotion of sustainable activities such as spatial protection. LMMA shows the success of community based coral reef rehabilitation, and this bring opportunity to local communities to utilize Napoleon fish other than farming. However, even though spatial protection leads to institutional arrangement to control unsustainable practices, it needs an integration with calculation based on science to determine the sustainable export quota. Unfortunately, the Non Detriment Findings on Napoleon fish trade was not based on biological assessment, so even though the recent export practice is legal, but it cannot be considered as sustainable. It is also important to allocate the benefit of the farming to broader group so the power of the dominant becomes uncentralized. The more benefit earned by the farmers from sustainable fishery, the more easier it is to institutionalize social norms to avoid overfishing and achieve the conservation goals.

Climate change disturbances contextualize the outcomes of coral-reef fisheries management across Micronesia

Climate change is increasing disturbance events on coral reefs with poorly understood consequences for fish population dynamics and fisheries management. Given growing concerns over food security for the tropical Pacific, we assessed fisheries management policies across a suite of Micronesian islands since 2014 as climate disturbance events have intensified. Disturbances associated with the 2015–2017 ENSO led to significant mortality of corals and calcifying substrates and replacement with algae and detritus, followed by a doubling of biomass across all fish guilds that was proportional to their starting points for all islands. Increased fish biomass was equally attributed to growth of individuals evidenced by increased size structures, and recruitment/survival evidenced by larger population densities. However, the pulsed increase of fish biomass lasted 1–2 years for islands with limited and isolated MPA but remained high for islands with effective MPA networks for 4 years until the study ended. Meanwhile, policies to protect grouper spawning seasons resulted in increased occurrences that were magnified by disturbances and MPA. Grouper increases were largest where both spawning season bans and MPA networks existed, helping to tease apart the management-from-disturbance responses. Smaller rates of increases over longer time were observed for species with commercial fishing bans (bumphead parrotfish, Napoleon wrasse, and sharks). Yet, occurrences remain low in comparison to remote-island baselines, and MPA only provided benefits for juveniles in inner lagoons. Recent trends for these species were less influenced by climate disturbances compared to groupers. The results cautioned how short-term responses of fish assemblages following climate disturbances can provide false signs of success for some management policies without contextual reference baselines that may not exist. Positively, improvements were noted for both MPA and species policies in our region that are expected to benefit reef resilience.

Identification of SF-1 and FOXL2 and Their Effect on Activating P450 Aromatase Transcription via Specific Binding to the Promoter Motifs in Sex Reversing Cheilinus undulatus.

The giant wrasse Cheilinus undulatus is a protogynous socially hermaphroditic fish. However, the physiological basis of its sex reversal remains largely unknown. cyp19 is a key gender-related gene encoding P450 aromatase, which converts androgens to estrogens. cyp19 transcription regulation is currently unknown in socially sexually reversible fish. We identified NR5A1 by encoding SF-1, and FOXL2 from giant wrasse cDNA and cyp19a1a and cyp19a1b promoter regions were cloned from genomic DNA to determine the function of both genes in cyp19a1 regulation. Structural analysis showed that SF-1 contained a conserved DNA-binding domain (DBD) and a C-terminal ligand-binding domain (LBD). FOXL2 was comprised of an evolutionarily conserved Forkhead domain. In vitro transfection assays showed that SF-1 could upregulate cyp19a1 promoter activities, but FOXL2 could only enhance cyp19a1b promoter transcriptional activity in the HEK293T cell line. Furthermore, HEK293T and COS-7 cell lines showed that co-transfecting the two transcription factors significantly increased cyp19a1 promoter activity. The −120 to −112 bp (5′-CAAGGGCAC-3′) and −890 to −872 bp (5′-AGAGGAGAACAAGGGGAG-3′) regions of the cyp19a1a promoter were the core regulatory elements for SF-1 and FOXL2, respectively, to regulate cyp19a1b promoter transcriptional activity. Collectively, these results suggest that both FOXL2 and SF-1 are involved in giant wrasse sex reversal.

PUTTING AN END TO THE TRAGEDY OF RANCHING IN NAPOLEON WRASSE FISHERY IN INDONESIA: A SOCIOLOGICAL APPROACH

This study aims to look into Napoleon wrasse ranching in Anambas Islands Regency. Historically, the society in Anambas Islands has been socially constructed an unsustainable view of exploiting marine resources. In Napoleon wrasse fishery, overfishing has played a significant role in the loss of its populations. Due of the lack of adult Napoleon wrasse stock in marine ecosystem, larvae despite its high mortality rate are also sought as ranching target. It is found a tremendous amount of larvae are wasted in ranching period due low survival capacity to adapt to a caged ecosystem, so that the effectiveness of larvae ranching is questianable. Larvae fishing has become the object of the tragedy of the commons, whereas this particular activity plays an important role in the fishery. As a result, conservation and management have never been more important. The reflection to establish sustainable view is seen from discussion between Agent-Structure theory by Bourdieu and Agent-Network Theory by Latour. Local capacity to perform Locally Managed Marine Areas (LMMA) created major initiatives in delivering sustainable coral reef ecosystems which also form a natural environment of Napoleon wrasse

Status of Napoleon wrasse in Laamu Atoll, Maldives, after three decades of protection

The Napoleon or humphead wrasse Cheilinus undulatus is a large, globally threatened coral reef fish. In recognition of suspected declines and considering its ecotourism importance, the Maldives was the first country to ban its export in 1995. The present study, a quarter-century after the ban, documents the species around Laamu Atoll, southern Maldives, using dive guides and researchers to conduct surveys during commercial dive tourism trips. Data were collected on abundance, body size, and potential spawning sites in 4 habitat types: channels (reef passes to open ocean), inner reefs (reef slopes inside the atoll), outer reefs (reef slopes outside the atoll), and faros (isolated submerged reefs inside the atoll). Abundance was recorded in number of fish per hectare, and fish length was classified as <100 cm, ≥100 cm, or unknown size. Possible spawning aggregation sites were identified based on multiple occasions of temporarily increased fish density associated with large male presence. Mean densities ranged from 6.02 fish ha-1 in channels, 2.65 and 2.29 fish ha-1 in outer and inner reefs, respectively, and 0.73 fish ha-1 in faros. These densities are consistent with those found in unexploited areas in similar habitats elsewhere and indicate successful protection of the species on Laamu Atoll. The data highlight the significance of reef channel habitat for this species as important megafauna and the need for management to conserve both species and channel habitats. The value of non-specialist observers for conducting labour-intensive surveys on large, wide-ranging species is demonstrated.

Utilization and Linkage of Oceanic Energy in Natuna Island: A Review

Rachmayani, R.; Ningsih, N.S.; Ardiansyah, I.; Yani, L.F.; Rizal, A.M.; Kartadikaria, A.R.; Sari, N.T, and Park, H., 2021. Utilization and linkage of oceanic energy in Natuna Island: A review. In: Lee, J.L.; Suh, K.-S.; Lee, B.; Shin, S., and Lee, J. (eds.), Crisis and Integrated Management for Coastal and Marine Safety. Journal of Coastal Research, Special Issue No. 114, pp. 599–603. Coconut Creek (Florida), ISSN 0749-0208. Natuna Regency is known as the northernmost regency in the Karimata Strait with its abundant captured fisheries up to 104.879,81 tons, oil up to 3.138.143 barrels and natural gas up to 34.772.019 MMBTU in 2019, respectively. Moreover, Natuna is famous for aquaculture fisheries of Napoleon (Cheilinus undulatus) with allowed-export capacity up to 30,000 kg. However, resource development in Natuna is often constrained by poor infrastructure such as limited fish unloading berths and natural gas pipelines, obscure electricity, and inadequate energy resources. Thus, the utilization of resources in Natuna has not been maximized. Currently, Natuna has been partially improved on distribution services through the sea toll and the establishment of the Integrated Marine and Fisheries Centre (SKPT) of the Lampa Strait. To carry out the challenge and manifest the resources in Natuna, researches on marine renewable energy in Natuna have been conducted and revealed significant wave height up to ∼1.5 m, ocean current velocity per year ranged from 0.255 to 0.340 m/s, and thermal gradient's Carnot efficiency up to 0.67. Despite these lacking numbers on ocean currents, waves, and thermal gradients for renewable energy development, this study exhibits that the Natuna region has a great energy potential from wind farm and solar power plant development. There are four recommended sites namely Pulau Tiga, Sabang Mawang, Sedanau Island, and SKPT Natuna as places to develop hybrid renewable energy development from pumped hydro storage system, wind farm, and/or solar power plant. The renewable energy development at these locations will support smart city concept in Natuna.

Evaluation of the Humphead Wrasse, Cheilinus undulatus, in Shallow Water Habitats in Saipan Lagoon, Commonwealth of the Northern Mariana Islands1

Visual census surveys utilizing a distance sampling approach were undertaken in Saipan Lagoon to determine the density of humphead wrasse (HHW) in four shallow water habitats, and compared to observations in the Saipan nighttime commercial spear fishery. Fish observed from the survey ranged in total length from 6.5 to 35 cm total length, generally smaller than the range of fish sampled from the commercial fishery of 16 to 47 cm total length. The majority of survey observations occurred in the central and northern part of Saipan Lagoon, which correlated with capture locations documented in the commercial fishery landings. Analysis of contemporary and historical commercial fishery data showed that HHW could not be considered primary fishery target species. Distance sampling results indicated that coral/hard bottom and Enhalus acroroides seagrass were the habitats most important to HHW, as reflected by higher density estimates. The use of distance sampling was useful in estimating the spatial distribution and density of HHW, and should be considered when assessing other rare marine finfish species.

Climate change impacts on the ecological dynamics of two coral reef species, the humphead wrasse (Cheilinus undulatus) and crown-of-thorns starfish (Ancanthaster planci)

This study investigates the hypothesis that climate change influences the distribution of the corallivore crown-of-thorns starfish Ancanthaster planci L. and one of its predators, the endangered humphead wrasse Cheilinus undulatus (Rüpell 1835). The aim is to provide a robust global distribution estimation examining the potential habitat gaps and overlays between the two species considering the predator-prey interaction. A single-parameter perturbation design with the species distribution model MaxEnt was applied to select the best performing model run for analysing the global and local trends in Indonesia based upon projected climate change under the IPCC RCP6.0 emission scenario. The paper represents the first global modelling study about the future distributions for both species by 2050. The simulations showed a slight decline of potential suitability for A. planci but gains for C. undulatus with a poleward shift for both. C. undulatus thrives under higher temperatures, whereas A. planci seems to be sensitive to increasing temperature in Indonesia. However, whilst future climate change is expected to benefit C. undulatus, the species remain highly vulnerable to (often illegal) fishing pressures and appropriate monitoring and management measures remain a priority to ensure their conservation in the long term.

Chromosome‐level genome assembly of the endangered humphead wrasse Cheilinus undulatus: Insight into the expansion of opsin genes in fishes

Wrasses represent dominant component of major coral reef systems. Among wrasses, Cheilinus undulatus is an endangered species with high economic and ecological value that exhibits sex reversal of female into male, while sexual selection occurs in breeding aggregations. However, the molecular-associated mechanism remains unclear. Opsin gene diversification is regarded as a potent force in sexual selection. Here we present genome assembly of C. undulatus, using Illumina, Nanopore, and Hi-C sequencing. The 1.17Gb genome was generated from 328 contigs with an N50 length of 16.5Mb and anchored to 24 chromosomes. Total 22,218 genes were functionally annotated, and 96.36% of BUSCO genes were fully represented. Transcriptomic analyses showed that 96.79% of the predicted genes were expressed. Transposons were most abundant, accounting for 39.88% of genome, with low divergence, owing to their evolution with close species approximately 60.53 million years ago. 567/1,826 gene families were expanded and contracted in the reconstructed phylogeny, respectively. Forty-six genes were under positive selection. Comparative genomic analyses with other fish revealed expansion of opsin SWS2B, LWS1, and Rh2. The elevated duplicates of SWS2B were generated by gene conversions via transposition of transposons followed by nonallelic homologous recombination. Amino acid substitutions of opsin paralogs occurred at key tuning sites, causing a spectral shift in maximal absorbance of visual pigment to capture functional changes. Among these opsin genes, SWS2B-3 & 4 and Rh1 are expressed in the retina. The genome sequence of C. undulatus provides valuable resources for future investigation on conservation, evolution, and behavior of fishes.