Indo-Pacific Research Articles

Identification and Variability Analysis of New Homogeneous Summer Monsoon Rainfall Regions Over India by Using K‐Means Clustering Technique

ABSTRACTThe identification of new homogeneous Indian summer monsoon rainfall regions is important for both research and operational forecasting purposes. The homogeneous rainfall regions used by the India Meteorological Department include areas that are actually dissimilar in terms of both the amount of rainfall and its variability. In the present study, we have identified three primary clusters of homogenous summer monsoon rainfall zones (low, medium and high rainfall) of India by using K‐means clustering technique and Calinski–Harabasz (CH) index. The identified clusters are again subdivided based on the distance between the clusters into six homogenous rainfall zones such as Southeast India (SI), West India (WI), Central India (CI), West Coast of India (WC), Northeast India1&2 (NE1 & NE2). Summer monsoon rainfall exhibit a positive trend over the western and southern region of India (SI, WC, and WI) while the eastern part of India (CI, NE1 and NE2) exhibit a negative trend. The increased sea surface temperature of tropical north Atlantic during May is conducive for the enhanced summer monsoon rainfall activity over low rainfall zone (Southeast India and West India). Tropical North Atlantic SST during May is related with the subsequent warming of Indo Pacific Ocean and cooling of Central Pacific Ocean, which induces southeasterlies towards Indian region and strengthen the rainfall activity over SI and WI. The position and intensity of the upper‐level circulations have profound impact on the interannual variability of rainfall over different homogenous regions. Above‐normal rainfall over SI and WI (CI and WC) is enhanced by the upper‐level anticyclonic (cyclonic) circulation in Bay of Bengal (West Asia), which extends north westward (south eastward) to the Indian landmass. Indian Ocean warming during May is associated with above (below) normal rainfall over NE2 region (the eastern part of CI). Southern Ocean SST during May is significantly correlated with the rainfall over southwest coast of India, which is also indicated by the positive correlation between April southern Annular Mode and south west coast rainfall. Sea surface temperature during May in different ocean basins can be used as the potential predictors for improving the long‐range forecast of seasonal rainfall over newly identified homogenous rainfall zones.

Macrophytes and Phytoplankton, Two Primary Antithetical Producers in Degraded Water Systems

One year of monthly sampling in some lagoons of the Po Delta and a pond in the Comacchio Valleys helped fill a gap in the knowledge of the primary producers of these degraded environments, focusing on the competition between macrophytes and phytoplankton. Key water column and surface sediment parameters showed a strong association with the different primary producers, explaining the main factors influencing the dominance of one group over the other. Phytoplankton, recorded as Chlorophyll-a and Phaeophytin-a, and Chlorophyceae among the macrophytes, dominated in conditions of high water turbidity and elevated nutrient concentrations. In contrast, macrophytes, particularly Rhodophyceae, their abundance, total biomass, and number of taxa. prevailed in clear, oxygenated waters. Under optimal conditions, sensitive macroalgae and aquatic angiosperms were also present. Additionally, the current list of macroalgal taxa has been updated, highlighting the dominance of some nonindigenous species (NIS) that had not been recorded before the 2000s. Specifically, Gracilaria vermiculophylla and Ulva australis, native to the North West Pacific (Japan, Korea, China, and Vietnam) and to South Australia, as well as the Indo-West Pacific (India, South Africa, Japan, and Korea), respectively, are now the most frequent and abundant taxa in these lagoons.

Submarine cave sponges of the genus Rhabderemia (Demospongiae, Biemnida, Rhabderemiidae) from the Ryukyu Islands, southwestern Japan: rediscovery of R. forcipula and description of a new species

Two species of Rhabderemia, R. ginamaensis sp. nov. and R. forcipula (Lévi & Lévi, 1989), are reported from submarine anchialine caves of the Ryukyu Islands, Japan. Rhabderemia ginamaensis sp. nov., collected from the submarine cave of Ginama, Okinawa Island, differs from other congeners by its thinly encrusting morphology and the presence of microxea. Rhabderemia forcipula (Lévi & Lévi, 1989), once collected from the mesophotic zone of the Philippine Sea, was rediscovered for the first time since its original description in the dark nearshore submarine cave of Shimoji Island, Miyako Island Group. The species is characterized by a plumo-reticulate skeleton and spiculation: rhabdostyles, rugose microstyles, and sigmoid microscleres in two size classes, the larger ones being spirosigma and thraustosigma. A redescription of the type specimen and a detailed description of the newly collected specimens are provided to understand the morphological variation of the spicules, and to confirm the conspecificity of the type specimen and the submarine cave specimens. The two species, R. ginamaensis sp. nov. and R. forcipula are a new record of Rhabderemia and the family Rhabderemiidae from Japan, and the first report of Rhabderemia from submarine anchialine caves in the Indo-West Pacific. In addition, R. forcipula is the first species of the genus to be found from both a submarine cave and a mesophotic zone in the Indo-West Pacific.

The genome of the sapphire damselfish Chrysiptera cyanea: anew resource to support further investigation of the evolution of Pomacentrids.

The number of high-quality genomes is rapidly increasing across taxa. However, it remains limited for coral reef fish of the Pomacentrid family, with most research focused on anemonefish. Here, we present the first assembly for a Pomacentrid of the genus Chrysiptera. Using PacBio long-read sequencing with 94.5× coverage, the genome of the Sapphire Devil, Chrysiptera cyanea, was assembled and annotated. The final assembly comprises 896 Mb pairs across 91 contigs, with a BUSCO completeness of 97.6%, and 28,173 genes. Comparative analyses with chromosome-scale assemblies of related species identified contig-chromosome correspondences. This genome will be useful as a comparison to study specific adaptations linked to the symbiotic life of closely related anemonefish. Furthermore, C.cyanea is found in most tropical coastal areas of the Indo-West Pacific and could become a model for environmental monitoring. This work will expand coral reef research efforts, highlighting the power of long-read assemblies to retrieve high quality genomes.

A new species of Synalpheus Spence Bate, 1888 (Caridea: Alpheidae) from Aldabra

The material used in the present study was collected by the crew of Cousteau’s vessel Calypso during the 1954 expedition to Aldabra, Seychelles. Synalpheus calypso sp. nov. is one of the few species in the Indo-West Pacific with a minor cheliped dactylus furnished with densely arranged tufts of distally-curved setae (known as gambarelloides setae). Amongst all these sponge-dweller species, the new species appears to be morphologically closest to S. spongicola Banner & Banner, 1981. Yet, S. calypso sp. nov. can be distinguished from the latter by the shape of the superior tooth of the basicerite, the dorsodistal tooth of the major cheliped merus, the shape of the posteroventral angle of the first pleuron in males, and the position of the dorsal spiniform setae on the telson. Other features differentiating the new species from the remaining Indo-West Pacific species with such a minor cheliped, include a subacute rostrum and orbital teeth reaching to the distal third and midlength of the first antennular article, respectively; a stylocerite overreaching the first antennular article; a well-developed scaphocerite blade; a major cheliped palm with a prominent up-turned dorsodistal tooth; and a complete uropodal diaeresis.

Microenvironments of black-tip reef sharks (Carcharhinus melanopterus) provide niche habitats for distinct bacterial communities

AbstractAnimal holobionts constitute diverse yet interconnected landscapes of microenvironments that harbor specific bacterial communities with distinct functions. An increasing body of literature suggests a partitioning and distinct functional profiles of bacterial communities across shark microenvironments, which has led to the proposition that beneficial bacterial functions may contribute to shark health. Here, we provide a first assessment of bacterial communities in different microenvironments of black-tip reef sharks (Carcharhinus melanopterus), the most abundant reef shark species across the Indo-West Pacific. Collecting samples from 34 sharks from the Amirante Islands, Seychelles, we characterized the corresponding bacterial communities of two external skin locations, within the buccal cavity, and of the cloaca (representing the gut microbiome) using 16S rRNA gene amplicon sequencing. Overall, shark-associated bacterial communities were distinct from seawater, and skin, buccal, and cloaca samples were distinct from each other. Shark cloaca samples and seawater exhibited lower bacterial alpha diversity and richness compared to the other microenvironments. Predicted functional profiles and Linear Discriminant Effect Size analysis suggest potential differences in metabolic pathways present in the different shark-associated bacterial communities and in the seawater. Taxonomy-based functional inference suggests cloaca-associated bacterial communities specialize in the consumption and breakdown of various food items. Taken together, our data suggest distinct bacterial niche habitats within the ‘microbial landscape’ of black-tip reef sharks, as indicated by distinct bacterial communities and their predicted metabolic functions. Future (meta)genomic and functional work will help reveal potential roles of bacteria in the health of their shark hosts.

Taxonomic review of the genus Johnius (Perciformes: Sciaenidae) from East Malaysian waters, with comments on newly recorded Johnius species

In terms of sheer abundance, taxonomic diversity, and species richness, Malaysia has one of the most diverse Sciaenidae in the Indo-West Pacific. Up to ten valid species of the sciaenid fish genus Johnius (e.g., J. amblycephalus (Bleeker, 1855), J. belangerii (Cuvier, 1830), J. borneensis (Bleeker, 1850), J. carouna (Cuvier, 1830), J. coitor (Hamilton, 1822), J. heterolepis Bleeker, 1873, J. macrorhynus (Lal Mohan, 1976), J. plagiostoma (Bleeker, 1849), J. sasakii Hanafi et al., 2022 and J. weberi Hardenberg, 1936), and with additional newly recorded species as J. trewavasae Sasaki, 1992, have been recorded to occur in East Malaysia (Borneo Island) coastal waters. The newly recorded species is a close congener to J. heterolepis Sasaki, 1992 and can be well distinguished by several characters and molecular evidence. The goal of this study is to review the taxonomic status of Johnius species in East Malaysia, Borneo Island, by using a literature review, morphological inference and molecular characters. Principal Component Analysis (PCA) successfully discriminates based on second anal spine length and gill raker length within sampled specimens. A phylogenetic tree based on cytochrome oxidase subunit I (COI) showed intraspecific levels of genetic differentiation within Johnius of East Malaysia, which forms a monophyletic group. Moreover, the new record of Johnius trewavasae in East Malaysia represented that the distribution of the subtropical genus Johnius extended to the southernmost part of the tropical region.

First record of the blue-and-yellow grouper Epinephelus flavocaeruleus (Lacepède 1802) (Perciformes: Epinephelidae) from the Borneo waters, Malaysia

Groupers of the family Epinephelidae constitute a diverse and commercially valuable group of reef fishes globally. They comprise an assemblage of carnivorous marine fishes, comprising more than 177 species across 16 genera. The epinephelid genus Epinephelus, which consists of over 90 species, is found worldwide in the tropics and subtropics. To date, the ichthyofauna of Malaysia has documented a total of 43 epinephelid species. Apart from these, Epinephelus flavocaeruleus (Lacepède, 1802), commonly known as the blue-and-yellow grouper, is rarely reported in the Indo-Pacific Ocean. The present study extends the documented distribution range of E. flavocaeruleus eastwards from the Andaman Sea to the Borneo waters of Sabah, Malaysia. Five specimens of the blue-and-yellow grouper were collected from a local fish market. Species identification was confirmed by the color patterns and DNA barcoding of 630 base pairs of the cytochrome C oxidase I gene for all E. flavocaeruleus specimens, Epinephelus cyanopodus (Richardson, 1846), and 10 closely related Epinephelus species. The interspecies genetic distance ranged from 0.002–0.168. Results from the Templeton, Crandall, and Sing (TCS) haplotype network analysis and maximum likelihood phylogeny based on the COI marker indicate a close genetic relationship between E. flavocaeruleus and E. cyanopodus. However, we refrain from proposing any taxonomic revisions given that more in-depth studies using multiple molecular markers or phylogenomic analysis on a larger sample size are necessary to confirm the taxonomic status of both species. This study significantly contributes to a better understanding of the taxonomy, phylogenetic relationship, and genetic diversity of E. flavocaeruleus.

The Effect of Southern Ocean Topography on the Global MOC and Abyssal Water Mass Distribution

Abstract We investigate the role of Southern Ocean topography and wind stress in the deep and abyssal ocean overturning and water mass composition using a suite of idealized global ocean circulation models. Specifically, we address how the presence of a meridional ridge in the vicinity of Drake Passage and the formation of an associated Southern Ocean gyre influence the water mass composition of the abyssal cell. Our experiments are carried out using a numerical representation of the global ocean circulation in an idealized two-basin geometry under varying wind stress and Drake Passage ridge height. In the presence of a low Drake Passage ridge, the overall strength of the meridional overturning circulation is primarily influenced by wind stress, with a topographically induced weakening of the middepth cell and concurrent strengthening of the abyssal cell occurring only after ridge height passes 2500 m. Passive tracer experiments show that a strengthening middepth cell leads to increased abyssal ventilation by North Atlantic water masses, as more North Atlantic Deep Water (NADW) enters the Southern Ocean and then spreads into the Indo-Pacific. We repeat our tracer experiments without restoring in the high-latitude Southern Ocean in order to identify the origin of water masses that circulate through the Southern Ocean before sinking into the abyss as Antarctic Bottom Water. Our results from these “exchange” tracer experiments show that an increasing ridge height in Drake Passage and the concurrent gyre spinup lead to substantially decreased NADW-origin waters in the abyssal ocean, as more surface waters from north of the Antarctic Circumpolar Current (ACC) are transferred into the Antarctic Bottom Water formation region. Significance Statement The objective of this study is to investigate how topographic features in the Southern Ocean can affect the overall structure of Earth’s large-scale ocean circulation and the distribution of water masses in the abyssal ocean. We focus on the Southern Ocean because the region is of central importance for exchange between the Atlantic and Indo-Pacific Ocean basins and for CO2 and heat uptake into the abyssal ocean. Our results indicate that Southern Ocean topography plays a major role in the overall circulation by 1) controlling the direct transfer of abyssal waters from the Atlantic to the Indo-Pacific via its influence on the Atlantic meridional overturning circulation and 2) controlling the coupling between the abyssal ocean and surface waters north of the Antarctic Circumpolar Current via the Southern Ocean gyre.

Taxonomy and systematics of Emprostiotrema Cianferoni and Ceccolini, 2021 (Digenea: Emprostiotrematidae), parasites of rabbitfish (Siganidae) from the Indo-West Pacific marine region.

Emprostiotrema contains just 3 species: E. fusum, E. kuntzi and E. sigani. As adults, all 3 species infect rabbitfishes (Siganidae: Siganus). New collections from 11 species of Siganus from northern Australia, Indonesia, New Caledonia, French Polynesia, Palau and Japan enabled an exploration of species composition within this genus. Phylogenetic analyses demonstrate a deep distinction between 2 major clades; clade 1 comprises most of the sequences of specimens from Australia as well as all of those from Japan, Palau and New Caledonia and clade 2 comprises all sequences of specimens from French Polynesia, 2 sequences from Australia and the single sequence from Bali. In all analyses, both major clades have genetic structuring leading to distinct geographic lineages. Morphologically, specimens relating to clades 1 and 2 differ but overlap in body shape, oral sucker and egg size. Principle component analysis shows a general (but not complete) separation between specimens relating to the 2 clades. We interpret the 2 clades as representing 2 species: clade 1 is identified as E. fusum and is reported in this study from 10 species of siganids from Australia, Japan, Palau and New Caledonia; clade 2 is described as E. gotozakiorum n. sp., for all specimens from French Polynesia and rare specimens from Australia and Indonesia. We recognize E. sigani as a junior synonym of E. fusum. Although species of Emprostiotrema occur widely in the tropical Indo-Pacific, they have not been detected from Ningaloo Reef (Western Australia), the southern Great Barrier Reef or Moreton Bay (southern Queensland).

Genomic Single Nucleotide Polymorphism (SNP) markers and mitochondrial haplotypes illuminate the origins of Crown-of-Thorns Starfish (Acanthaster solaris) outbreaks in the South China Sea

BackgroundOutbreaks of the coral predator Crown-of-Thorns Starfish (CoTS) pose a severe threat to coral reefs in the Indo-Pacific Ocean. In 2018, the South China Sea (SCS) experienced significant CoTS outbreaks, leading to extensive coral mortality across the Xisha, Zhongsha, Dongsha, and Nansha Islands, severely impacting the coral reef ecosystem.ResultsTo explore the origins of these outbreaks, we conducted a comprehensive genomic analysis using data from genomic single nucleotide polymorphism sites (SNPs) and mitochondrial haplotypes. Our analysis reveals that CoTS populations in the SCS, which exhibit moderate genetic diversity and may have undergone positive selection or population expansion. There was limited genetic differentiation among CoTS populations from XS, ZS, and NS groups. Especially between the XS and ZS groups, there was almost no genetic differentiation. The populations from XS, ZS, and NS groups have strong genetic connections with populations in Vietnam and the Philippines. There was high gene flow from Vietnam to the Xisha Islands and from the Philippines to the Nansha Islands, suggesting that the CoTS populations in these regions primarily originate from these neighboring countries.ConclusionThe comprehensive analyses of SNP and mitochondrial genomes have provided valuable insights into the population genetics of CoTS. This research has generated significant genomic resources and facilitated important studies on the genetics of the CoTS species. By identifying potential source populations and understanding the genetic basis of their spread, managers can develop more effective conservation strategies to protect vulnerable coral reef ecosystems in the SCS.

A Whole-Genome Survey and the Mitochondrial Genome of Acanthocepola indica Provide Insights into Its Phylogenetic Relationships in Priacanthiformes.

Acanthocepola indica, a deep-sea snake fish, is primarily found in the Indo-west Pacific region, including India, Korea, Japan, and the South China Sea. The taxonomic classification of A. indica based on morphological characteristics remains inaccurate and unclear. In this study, we utilized next-generation sequencing to generate comprehensive genomic data for A. indica. The estimated genome size of A. indica was 422.95 Mb, with a heterozygosity ratio of 1.02% and a sequence repeat ratio of 22.43%. Our analysis suggested that A. indica is diploid, and the draft genome assembly consists of 1,059,784 contigs with a contig N50 of 1942 bp. We identified a total of 444,728 simple sequence repeats in the genome of A. indica. Furthermore, we successfully assembled the complete mitochondrial genome (16,439 bp) of A. indica, which included 13 protein-coding genes, 22 tRNA genes and 2 rRNA genes. Phylogenetic analysis based on mitochondrial genomes revealed that A. indica is closely related to Acanthocepola krusensternii and Cepola schlegelii, providing evidence that the family Cepolidae belongs to the order Priacanthiformes. Population size dynamics analysis indicated that A. indica experienced a bottleneck effect during the Pleistocene Glacial Epoch, likely due to the changes in glacial cycles and sea level fluctuations since ~800 Kya.

Botanical, phytochemical and pharmacological profile of the mangrove plant Kandelia candel (L.) Druce

Kandelia candel L. Druce (family Rhizophoraceae) is a true / major mangrove that has a wide-spread distribution along the coastal areas of the Indo-west Pacific region of the earth. It is commonly found along the coasts of India and a few South East Asian countries. Its parts have numerous applications in leather, textile, furniture industries, and is also used by the traditional health practitioners / healers to treat diabetes. It is known to be producing a variety of phytochemicals. Extracts and compounds isolated from K. candel have exhibited noteworthy biological activities. An attempt has been made to compile the up-to-date information on this mangrove plant from globally recognised scientific databases. This review would provide necessary informationtoformulate the possible application of this common mangrove in standard as well as complementary medicine.

Diversity, environments, and biogeography of Homoloida (Decapoda: Brachyura) from the Late Jurassic to the present

ABSTRACT The section Homoloida with the sole superfamily Homoloidea comprises both extinct and extant brachyuran crab taxa, with records ranging from the Tithonian (Jurassic) to the present. Examination of fossil and modern occurrence records for this clade provides insight into the biogeography, biodiversity, and environmental preference of the homoloid crabs over time. The fossil record of Homoloidea, comprised of the families Tithonohomolidae, Mithracitidae, Homolidae, Latreilliidae, and Poupiniidae, is global in distribution and peaks in diversity during the uppermost Cretaceous with the most recent fossils known from the Miocene. Modern homoloids are absent from only a handful of regions globally, with particularly high diversity and abundance in the tropical Indo-West Pacific. Comparison of interpreted depositional environments for fossil occurrences and depth records for modern occurrences sheds light on the environmental preferences and potential spatial sampling biases of this clade. By assessing both fossil and modern records of Homoloidea, patterns (e.g., absence from cold-water latitudes, Oligo-Miocene disappearance from the northeastern Pacific) emerge that may have important implications for future study of this clade, particularly in relation to dispersal/turnover events and environmental constraints.

Elucidating the Mitogenomic Blueprint of Pomadasys perotaei from the Eastern Atlantic: Characterization and Matrilineal Phylogenetic Insights into Haemulid Grunts (Teleostei: Lutjaniformes).

The parrot grunt fish, Pomadasys perotaei, has a limited distribution in the Eastern Atlantic Ocean and is an important species in marine capture fisheries across several West African countries. Despite its ecological and economic significance, the mitogenomic information for this species is lacking. This study utilized next-generation sequencing to generate the de novo mitogenome of P. perotaei from Eastern Atlantic. The resulting mitogenome is 16,691 base pairs and includes 13 protein-coding genes (PCGs), 22 transfer RNAs, two ribosomal RNAs, and an AT-rich control region (CR). Most of the PCGs exhibit nonsynonymous (Ka) and synonymous (Ks) substitution rates of less than '1', indicating strong negative selection across haemulid fishes. The control region of Pomadasys species contains four conserved domains, as seen in other teleost's, with polymorphic nucleotides that can be used to study population structures through the amplification of short mitochondrial gene fragments. Additionally, Bayesian phylogenetic analysis based on PCGs revealed a non-monophyletic clustering pattern of Pomadasys within the haemulid matrilineal tree. Overall, the structural characterization and phylogenetic analysis enhance our understanding of the genetic composition and evolutionary history of Pomadasys species from the Indo-West Pacific and Eastern Atlantic Oceans.

Hidden in plain sight: Systematic review of Indo-West Pacific Siphonariidae uncovers extensive cryptic diversity based on comparative morphology and mitochondrial phylogenetics (Mollusca, Gastropoda)

This study combines phylogenetic analyses of mitochondrial DNA sequences with comparative morphological analyses to revise the taxonomy of 101 nominal siphonariid species from the Indo-West Pacific belonging to the genera Siphonaria Sowerby I, 1823 and Williamia Monterosato, 1884. We have examined preserved specimens that have been newly collected at 462 sites across Australasia, the Indo-West Pacific, and in temperate zones of the northern and southern Pacific. Critically, our sampling includes topotypic specimens of 98 nominal species. The study area covered herein extends between the latitudes of 60°N and 55°S and the longitudes of 37°E and 175°W. We have sequenced two mitochondrial genes (COI and 16S) from 546 individuals and conducted a phylogenetic analysis including additional sequences from GenBank. We also studied the anatomy of 436 individuals using dissections and scanning electron microscopy. This study offers a comprehensive documentation and taxonomic assessment of type specimens for nearly all examined nominal species. Our taxonomic revision leads us to accept 88 species, which are thoroughly redescribed. 52 nominal species are treated as synonyms of earlier names, 41 of which are newly synonymized herein. Thirteen species names are deemed unavailable or invalid under the rules of zoological nomenclature, and six names are considered as nomina dubia or nomina inquirenda, notably including the oldest name, Patella laciniosa, which was widely used previously. In addition, we describe 40 new species. We have identified eleven species with broad distributions in the IWP and beyond and four species with more limited distributions than previously accepted. Notably, many species have narrow ranges, some being single island endemics. To stabilize taxonomic names, we have designated neotypes for seven species (Siphonaria sipho Sowerby I, 1823, Patella japonica Donovan, 1824, S. obliquata Sowerby I, 1825, Pileopsis radiata Blainville, 1826, S. radians H. Adams & A. Adams, 1855, S. incerta Deshayes, 1863, and S. tasmanica Tenison Woods, 1877) and lectotypes for 25 species (Patella javanica Lamarck, 1819, S. albicante Quoy & Gaimard, 1833, S. atra Quoy & Gaimard, 1833, S. capensis Quoy & Gaimard, 1833, S. denticulata Quoy & Gaimard, 1833, S. diemenensis Quoy & Gaimard, 1833, S. guamensis Quoy & Gaimard, 1833, S. plana Quoy & Gaimard, 1833, S. plicata Quoy & Gaimard, 1833, S. punctata Quoy & Gaimard, 1833, S. viridis Quoy & Gaimard, 1833, S. savignyi Krauss, 1848, S. cancer Reeve, 1856, S. bifurcata Reeve, 1856, S. funiculata Reeve, 1856, S. kurracheensis Reeve, 1856, S. lirata Reeve, 1856, S. scabra Reeve, 1856, S. belcheri Hanley, 1858, S. nuttallii Hanley, 1858, S. nigerrima Smith, 1903, S. madagascariensis Odhner, 1919, S. alba Hubendick, 1943, M. lentulus Iredale, 1940, H. monticulus Iredale, 1940 and M. oppositus Iredale, 1940).

Evidence for the proposal that Palisada corallopsis and P. furcata (Ceramiales, Rhodophyta) are conspecific

Abstract Palisada corallopsis has a widely reported distribution in the western and eastern Atlantic and some areas of the Indo-Pacific Ocean, whereas P. furcata has a more restricted distribution, reported only from Brazil and Cuba. Palisada corallopsis and P. furcata were collected from their type localities, Havana, Cuba and Ceará, Brazil, respectively, and compared by morphological and molecular analyses using rbcL and COI-5P genes. The molecular results placed the sequences from the type locality of both species in the same clade, showing low genetic divergence, 0.95 % for rbcL and 1.6 % for COI-5P. Morphologically, the species share similar habits, with branchlets bi-to trifurcated, cortical cells that may be arranged as a palisade and connected by secondary pit-connections. Our detailed morphological observations, including examination of the type specimens, and molecular analyses demonstrate that P. corallopsis and P. furcata are conspecific, P. furcata being a later taxonomic synonym of P. corallopsis.

Mitogenomic Architecture of Atlantic Emperor Lethrinus atlanticus (Actinopterygii: Spariformes): Insights into the Lineage Diversification in Atlantic Ocean.

The evolutionary history of emperors, particularly in the Atlantic and Indo-West Pacific Oceans, remains largely unmapped. This study explores the maternal lineage evolution of Lethrinids by examining the complete mitogenome of Lethrinus atlanticus, which is endemic to the Eastern Atlantic Ocean. Utilizing advanced next-generation sequencing, we found that the mitogenome spans 16,789 base pairs and encompasses 37 genes, including 13 protein-coding genes (PCGs), two ribosomal RNAs, 22 transfer RNAs, and an AT-rich control region (CR). Our analysis indicates a preference for AT base pairs in the L. atlanticus mitogenome (53.10%). Most PCGs begin with the ATG codon, except for COI, which starts with GTG. Relative synonymous codon usage reveals high frequencies for alanine, leucine, proline, serine, and threonine. The ratio of nonsynonymous to synonymous substitutions suggests strong negative selection across all PCGs in Lethrinus species. Most transfer RNAs exhibit typical cloverleaf structures, with the exception of tRNA-serine (GCT), which lacks a dihydrouracil stem. Comparative analysis of conserved sequence blocks across the CRs of three Lethrinus species shows notable differences in length and nucleotide composition. Phylogenetic analysis using concatenated PCGs clearly distinguishes all Lethrinus species, including L. atlanticus, and sheds light on the evolutionary relationships among Spariformes species. The estimated divergence time of approximately 20.67 million years between L. atlanticus and its Indo-West Pacific relatives provides insights into their historical separation and colonization during the late Oligocene. The distribution of Lethrinids may be influenced by ocean currents and ecological factors, potentially leading to their speciation across the Eastern Atlantic and Indo-West Pacific. This study enhances our understanding of the genetic diversity and phylogenetic relationships within Lethrinus species. Further exploration of other emperor fish mitogenomes and comprehensive genomic data could provide vital insights into their genetic makeup, evolutionary history, and environmental adaptability in marine ecosystems globally.

Characterization of complete mitochondrial genome of Periclimenes brevicarpalis (Decapoda: Palaemonidae)

Periclimenes brevicarpalis is widely distributed in the Indo West Pacific oceans. The mitochondrial genome of P. brevicarpalis was sequenced and assembled firstly by next generation sequencing technology in our study. The complete mitochondrial genome of P. brevicarpalis was 16,673 bp in size, consisted of 22 transfer RNA genes, 13 protein coding genes and two ribosomal RNA genes. The contents of the four bases were C (25.62%), T (28.73%), A (31.64%), and G (14.01%). The result of phylogenetic analysis showed that P. brevicarpaliswas clustered with Anchistus australis. In conclusion, our research provided valuable data for phylogenetic analysis of the Palaemonidae family as the first report about mitochondrial genomes in Periclimenes.

Transnational Broadcasting in the Indo Pacific: The Battle for Trusted News and Information, Alexandra Wake (ed.) (2024)

Review of: Transnational Broadcasting in the Indo Pacific: The Battle for Trusted News and Information, Alexandra Wake (ed.) (2024) London: Palgrave Macmillan, 227 pp., ISBN 978-3-03147-570-2, h/bk, AUD 169.00 ISBN 978-3-03147-571-9, e-book, AUD 157.94