Explore the vast range of titles available.

Two hundred and seven species of fish, mostly Australian marine fish, were sequenced (barcoded) for a 655 bp region of the mitochondrial cytochrome oxidase subunit I gene (cox1). Most species were represented by multiple specimens, and 754 sequences were generated. The GC content of the 143 species of teleosts was higher than the 61 species of sharks and rays (47.1% versus 42.2%), largely due to a higher GC content of codon position 3 in the former (41.1% versus 29.9%). Rays had higher GC than sharks (44.7% versus 41.0%), again largely due to higher GC in the 3rd codon position in the former (36.3% versus 26.8%). Average within-species, genus, family, order and class Kimura two parameter (K2P) distances were 0.39%, 9.93%, 15.46%, 22.18% and 23.27%, respectively. All species could be differentiated by their cox1 sequence, although single individuals of each of two species had haplotypes characteristic of a congener. Although DNA barcoding aims to develop species identification systems, some phylogenetic signal was apparent in the data. In the neighbour-joining tree for all 754 sequences, four major clusters were apparent: chimaerids, rays, sharks and teleosts. Species within genera invariably clustered, and generally so did genera within families. Three taxonomic groups-dogfishes of the genus Squalus, flatheads of the family Platycephalidae, and tunas of the genus Thunnus-were examined more closely. The clades revealed after bootstrapping generally corresponded well with expectations. Individuals from operational taxonomic units designated as Squalus species B through F formed individual clades, supporting morphological evidence for each of these being separate species. We conclude that cox1 sequencing, or 'barcoding', can be used to identify fish species.

The behaviour of coastal fishes to new habitats and trophic opportunities provided by artificial reefs may reveal the key processes which sustain fish production at these reefs. We quantified the trophic link between benthic predators and pelagic forage fish from the movement and foraging behaviour of an ambush predator, the bluespotted flathead Platycephalus caeruleopunctatus, around an artificial reef in relation to schools of small pelagic fish. We used a network of acoustic receivers to monitor the fine-scale movements of 48 acoustically tagged flathead around 5 groups of artificial reef modules for 8 mo in conjunction with acoustic surveys of pelagic bait fish and sustained monitoring of current speed and direction. Flathead were highly associated with the artificial reef, with 44% of detections within 10 m of the modules. Flathead had a considerable degree of fidelity to the reef system, with an average residency period of 84 d yr−1 (residency index = 0.23, SD = 24 d). Low activity was recorded by accelerometers in the north-east of the artificial reef. This coincided with high densities of forage fish which were also found inside the stomachs of the flathead. Artificial reefs with high vertical relief allow planktivores to feed through more of the water column, fixing more pelagic biomass into the system. Defining the residency and trophic connectivity of fish at artificial reefs is critical to clarify the production−attraction debate and the sustainability of fishing at artificial reefs.

Background Flathead fishes of the genus Platycephalus are economically important demersal fishes that widely inhabit the continental shelves of tropical and temperate sea waters. This genus has a long history of taxonomic revision, and recently four Platycephalus species ( Platycephalus sp. 1, Platycephalus sp. 2, P. indicus, and P. cultellatus ) in the northwestern Pacific Ocean (NWP) have been recognized and redescribed. However, many aspects of their systematics and evolutionary history are unclear. Results A total of 411 individuals were sampled from 22 different sites across their distributions in the NWP. Three mitochondrial loci were sequenced to clarify the phylogeny and phylogeographic history of the fishes. The results showed significant differentiation of four Platycephalus species in the NWP with well-supported clades in which Platycephalus sp. 1 and Platycephalus sp. 2 were the closest, clustered with P. cultellatus , while their genetic relationship with P. indicus was the furthest. There were significant genealogical branches corresponding to P. indicus but not to other Platycephalus lineages. We further examined the phylogeographic patterns of 16 Platycephalus sp. 1 populations along the coastlines of China and Japan. A total of 69 haplotypes were obtained, with 23 shared among populations. One dominant haplotypic group, with a modest lineage structure and low levels of haplotype diversity and nucleotide diversity, was observed among Platycephalus sp. 1 populations. The demographic history reconstruction suggested a Platycephalus sp. 1 population expansion event dating back to the late Pleistocene. Conclusions Distributional rang variations may be the crucial factors shaping the genetic relationships of the genus Platycephalus . Reproductive schooling and potential egg/larval dispersal ability, coupled with the effects of ocean currents, are responsible for the present phylogeographic pattern of Platycephalus sp. 1.

In this study, 76 specimens of Platycephalus indicus collected from the coasts of Iraq were examined, assessing the asymmetric square coefficient of variation (CV ) among three features: the length, width, and weight of the otolith from both sides of the fish head. In the statistical analysis, the squared coefficient of fluctuating asymmetry (FA) deviation (CV ) for the three sagitta features based on formula was used to assess the values of FA in the three otolith features examined. The feasible source of the FA in the sagitta features considered has been resolved relative to the discrepancy in growing driven by environmental influence accompanying with the incongruence in water temperature, salinity, depth and impurities occurring in the coasts of Iraq. The application of bilateral irregularities in otolith parameters of was discussed. Future studies will incorporate the collection of otoliths FA data from additional species in the marine waters of Iraq eventually improving the consistency and exactness of niches stress estimations in this marine waters.

This study describes the occurrence and molecular identification of Monogenea from blue-spotted flathead Platycephalus caeruleopunctatus (McCulloch) (Scorpaeniformes: Platycephalidae) from waters off the NSW coast, Australia. Platycephalus spp. are favoured by consumers for delicate, white, mild flavoured flesh and therefore are commercially important species within Australia. Platycephalus spp. are also extensively targeted by Australian recreational fishers. There has been no previous study that has exclusively focused on Pl.caeruleopunctatus in Australia or globally. Although a single study by Dillon (1985), of monogeneans infecting Platycephalus spp. from Australian waters, identified Microcotyle bassensis Murray, 1931 in Pl. caeruleopunctatus. The present study combines both morphological and molecular methods to identify both host and parasites. A total of 116 fish, sourced from the waters off the coast of New South Wales, Australia, were examined. A total of 1498 Monogenea were recovered from the gills. The overall prevalence, mean intensity, and mean abundance were 72%, 18.05, and 12.91, respectively. Monogenea were initially classified morphologically as two different species M. bassensis (family: Microcotylidae) and Platycephalotrema bassense (Hughes, 1928) Kritsky & Nitta, 2019 (family: Ancyrocephalidae). Molecular identification of Monogenea was conducted through sequencing of their mitochondrial cytochrome c oxidase subunit 1 (cox1) and nuclear 28S genes. The specific identification of host Pl. caeruleopunctatus was confirmed through sequencing the cox1 gene. There was no comparable sequence for cox1 and 28S genes available in GenBank for the monogenean species found in the present study. Only a single sequence (obtained from the nuclear ITS2-rDNA) was deposited in GenBank for M. bassensis. However, the phylogenetic analyses of mitochondrial and nuclear sequences revealed that the identified Monogenea clustered according to their familial groups. Platycephalotrema bassense was identified for the first time in Pl. caeruleopunctatus in the present study. This study has provided the first evidence for the exploration of both cox1 and 28S sequences of all Monogenea. The findings of this study serve as a foundation for future monogenean research on other Platycephalus spp. from Australian waters.

Purple-spotted bigeyes Priacanthus tayenus Richardson (Priacanthidae) and bartail flathead Platycephalus indicus (Linnaeus) (Platycephalidae) were collected from the Arabian Gulf and examined for species of Monogenoidea (Polyonchoinea) from February to December 2020. Diplectanum robustitubum Wu & Li, 2003 and an undescribed species of Platycephalotrema Kritsky & Nitta, 2019 were recovered from the gill lamellae of these hosts, respectively. Diplectanum robustitubum from Iraq was redescribed and transferred to Oliveriplectanum Domingues & Boeger, 2008 (Diplectanidae) as Oliveriplectanum robustitubum (Wu & Li, 2003) n. comb. Platycephalotrema parile n. sp. (Dactylogyridae) from Iraq and Kuwait was described and differentiated from the similar species, Haliotrema indicum Tripathi, 1959, Platycephalotrema ogawai Kritsky & Nitta, 2019, and Platycephalotrema platycephali (Yin & Sproston, 1948) Kritsky & Nitta, 2019, based primarily on the comparative morphologies of the vaginal sclerites. Haliotrema indicum was transferred to Platycephalotrema as Platycephalotrema indicum (Tripathi, 1959) n. comb. and Haliotrema swatowense Yao, Wang, Xia, & Chen, 1998 was considered a junior subjective synonym of P. indicum . The finding of O. robustitubum in the Arabian Gulf represents a new geographic record for the species. Background The present paper represents the third installment concerning the monogenoids collected during surveys to explore their diversity on the marine and freshwater fishes of Iraq. Previous installments on the monogenoids emanating from the surveys included the dactylogyrid and gyrodactylid species parasitizing mugilid fishes. Purpose The purpose of this paper is to further document the diversity of monogenoids infecting the fishes of Iraq. Methods Marine fishes were necropsied for parasites, and standard procedures for collecting, mounting, drawing, and measuring of monogenoids were employed. Results Oliveriplectanum robustitubum n. comb. (Diplectanidae) and Platycephalotrema parile n. sp. (Dactylogyridae) were collected. The occurrence of O. robustitubum in the Arabian Gulf represented a new locality record for the species. Conclusion The recorded presence of O. robustitubum and P. parile n. sp. suggests that the diversity of monogenoids in Iraq is under estimated in the literature.

This study aimed to determine the integrative characterisation of nematodes from three species of edible flathead fishes (Scorpaeniformes: Platycephalidae) in New South Wales, Australia, and describe nematode communities within three species of flatheads. Tiger (Platycephalus richardsoni (Castelnau); n = 20) and sand flatheads (Platycephalus bassensis (Cuvier); n = 20), sourced from the Nelson Bay area, and dusky flathead (Platycephalus fuscus (Cuvier); n = 20) from the Manning River, Taree, were examined for the presence of nematodes. The nematodes were initially classified morphologically as 12 different morphotypes belonging to the families Anisakidae (Anisakis types I, II, and III, Contracaecum type II, Terranova types I and II), Raphidascarididae (Hysterothylacium types IV, VI, VIII, and H. zhoushanense larva), and Gnathostomatidae (Echinocephalus sp. larva), Capillariidae (Capillaria sp.), followed by genetic identification through sequencing of the internal transcribed spacer (ITS-1, 5.8S, ITS-2) regions. Phylogenetic analyses revealed the evolutionary relationship between the identified larval specimens in the present study with available GenBank larval and adult nematodes. Sand flathead was 90% infected with nematodes followed by tiger flathead at 85% and dusky flathead at 15%. Nematodes infecting estuarine dusky and oceanic sand and tiger flatheads contrasted markedly. The analysis of similarities (ANOSIM) showed significant differences (p < 0.001) in the composition of taxa within nematode communities between the three species of flatheads (global R = 0.208) with the highest difference being between sand and dusky flatheads (R = 0.308, p < 0.001). The findings of the present study provide a foundation for future investigations of the community composition, life cycles, and distribution of nematode populations in edible fish in Australia and explore and clarify their significance to public health.

Being a biologically diversed hotspot in the global marine ecosystem, the Beibu Gulf is inhabited by a high diversity of fish and serves as a vital fishing ground in China. Due to continuous overfishing, the fishery resource has drastically declined in the Beibu Gulf. However, information about the ichthyoplankton assemblages in this area is still lacking. In this present study, ichthyoplankton diversity, spatial and temporal distribution patterns, and assemblage structures were examined using the specimens collected in the late summer–autumn and winter of 2022 in the Beibu Gulf, and the relationship between ichthyoplankton assemblage and environmental variables was studied. A total of 117 ichthyoplankton taxa, belonging to 13 orders and 42 families, were recorded. The most abundant families were Gerreidae, Leiognathidae, and Sillaginidae in late summer–autumn, accounting for 38.74%, 27.95%, and 9.94%, respectively. Sparidae, Platycephalidae, and Sillaginidae were the most abundant families in winter, accounting for 34.03%, 17.15%, and 8.20%, respectively. Cluster analysis identified five assemblages in late summer-autumn and four assemblages in winter. The most characteristic species in each cluster were Terapon jarbua, Sillago sihama, Leiognathus brevirostris, Mene maculate, and Scomberoides tol in late summer-autumn and Scomberomorus commerson, Acanthopagrus latus, Sillago sp., and Evynnis cardinalis in winter. The results of the canonical correspondence analysis indicated that pH, chlorophyll-a (Chl-a), depth, dissolved oxygen (DO), sea surface salinity (SSS), total nitrogen (TN), and total phosphorus (TP) were the major environmental variables affecting the ichthyoplankton assemblage structure in the Beibu Gulf. The finding of this study will provide valuable information in conserving fish spawning grounds and developing fishery management practices to protect fishery resources in the Beibu Gulf.

Aim To develop a comparative phylogeographic framework to understand the origins, evolution, taxonomic richness, and distribution of Australian demersal fish endemics in the context of the Indo‐West Pacific (IWP). Location Southern Australia and the IWP. Taxon Platycephalidae (flathead fishes). Methods Nuclear and mitochondrial phylogenies of flathead fishes were inferred from 46 of 85 nominal species, and 14 additional cryptic species‐level lineages, representing 17 of the 18 genera. Molecular clocks and habitat trait reconstructions were used to infer the palaeoclimatic and geological events responsible for shaping the evolution and diversification of the group. Results The family Platycephalidae comprises two sister subfamilies; Platycephalinae and Onigociinae, which diverged in the Eocene into predominantly temperate and tropical assemblages respectively. The basal platycephalin taxa are confined to southern Australia with the most derived groups in the tropics, following a high‐ to low‐latitudinal evolutionary trajectory. In contrast, the onigociins are predominantly associated with the tropics, and have diversified across the region since the early Miocene with very few introductions into temperate Australia. Main conclusions Platycephalinae and Onigociinae show contrasting evolutionary scenarios. Platycephalins have a temperate to tropical evolutionary trajectory consistent with their arrival into the region via tectonic rafting and subsequent dispersal. This dispersal was likely facilitated by formation of shallow‐water environments along the Sunda Arc margin following collision of the Australian and Eurasian Plates. In contrast, the Onigociinae has likely maintained a tropical presence across the IWP since the Eocene and has experienced higher diversification rates leading to circa three times the species diversity found in the Platycephalinae. Rounds of dispersal and allopatric speciation have subsequently played out across both low and high latitudes with both subfamilies harbouring cryptic species‐level lineages. This work provides an explicit working hypothesis for exploring origins and diversification in other demersal fishes endemic to the Australian continent.

Although Cymbacephalus staigeri (Castelnau 1875) has been regarded as a valid species, several authors have suggested that it may be a junior synonym of Cymbacephalus nematophthalmus (Günther 1860). Because the whereabouts of the holotype of C. staigeri is unknown, this study compared the original description of C. staigeri with two syntypes and 18 non-type specimens of C. nematophthalmus. It was confirmed that C. staigeri is conspecific with C. nematophthalmus, with the latter name having priority. Accordingly, Cymbacephalus parilis (McCulloch 1914), having been treated as a junior synonym of C. staigeri, becomes the valid name of the species, because no species having priority over C. parilis exist.