Analysis Of Mitochondrial Sequences Research Articles

Climate change will lead to range shifts and genetic diversity losses of dung beetles in the Gobi Desert and Mongolian Steppe

Desertification is known to be a major threat to biodiversity, yet our understanding of the consequent decline in biodiversity remains insufficient. Here, we predicted climate change-induced range shifts and genetic diversity losses in three model dung beetles: Colobopterus erraticus, Cheironitis eumenes, and Gymnopleurus mopsus, distributed across the Gobi Desert and Mongolian Steppe, areas known for desertification. Phylogeographic analyses of mitochondrial COI sequences and species distribution modeling, based on extensive field investigations spanning 14 years, were performed. Species confined to a single biome were predicted to contract and shift their distribution in response to climate change, whereas widespread species was predicted to expand even if affected by range shifts. We indicated that all species are expected to experience significant haplotype losses, yet the presence of high singleton frequencies and low genetic divergence across geographic configurations and lineages mitigate loss of genetic diversity. Notably, Cheironitis eumenes, a desert species with low genetic diversity, appears to be the most vulnerable to climate change due to the extensive degradation in the Gobi Desert. This is the first study to predict the response of insects to desertification in the Gobi Desert. Our findings highlight that dung beetles in the Gobi Desert and Mongolian Steppe might experience high rates of occupancy turnover and genetic loss, which could reshuffle the species composition.

Molecular Identification, Multigenic Characterization and Phylogenetic Analysis of Ctenocephalides Canis Fleas from Humans and Domestic Animals in Iran.

Fleas belonging to the Pulicidae are prevalent ectoparasites infesting mammals and birds in Iran. This study focused on genetically identifying and characterizing Ctenocephalides canis collected both off-host and infesting humans and various domestic animals in the country. A total of 918 adult flea samples were collected from 10 sites in western and northwestern Iran between April 2018 and May 2019. Out of these, 71 specimens were found off-host, while the remaining fleas were collected from humans (121), sheep (126), goats (184), and dogs (416). Morphological identification at the genus level was performed on all fleas, and ten selected specimens selected based on the sampling sites and hosts were subjected to molecular detection at the species level by using partial amplification and sequencing of the internal transcribed spacer 1 and 2, as well as the cytochrome oxidase I (COXI) markers. The morphological identification confirmed all fleas as Ctenocephalides spp. Alignment and phylogenetic analysis of nuclear and mitochondrial partial sequences confirmed the presence of C. canis. However, molecular divergence was observed among the ten isolates based on the ITS1 and ITS2 with diversity rates estimated at 0.15% and 3.36%, respectively. Notably, the analysis of the COXI marker revealed no molecular divergence among the partial sequences representing the ten studied isolates from C. canis. This study explores the diversity of C. canis in the western and northwestern regions of Iran, providing insights into their molecular taxonomy and potential role as disease vectors in these areas.

A first report of Pseudosuccinea columella (Say, 1817), an alien intermediate host for liver fluke, in Malawi

Starting in October 2021, quarterly malacological surveys have been undertaken in Malawi, with the sampling of 12 specified freshwater habitats throughout a calendar year. Each survey monitors the presence of aquatic intermediate snail hosts of medical and veterinary importance. In March 2023, the alien lymnaeid species Pseudosuccinea columella was encountered for the first time in the surveys, in Nsanje District. This species identity was later confirmed upon DNA analysis of mitochondrial ribosomal 16S sequences. In July 2023, P. columella was also noted at single sites within Mangochi and Chikwawa Districts, and again in Nsanje District, with an additional location observed. Of particular importance, our sampled location in Mangochi District was directly connected to Lake Malawi, which expands the species list of invasive molluscs in this lake. While P. columella is a well-known intermediate snail host for human and animal fascioliasis, screening collected snails for trematode cercariae, alongside molecular xenomonitoring, did not yield equivocal evidence of active fluke infection. However, the newly recognized presence of this alien intermediate snail host within Lake Malawi, and along the Shire River Valley, flags a new concern in altered local transmission potential for human and animal fascioliasis.Graphical

Systematic revision of the eastern Queensland land snail genus Figuladra Köhler and Bouchet, 2020 based on mitochondrial phylogenetics and comparative morpho-anatomy (Eupulmonata, Camaenidae)

ABSTRACT The current study revises the systematic taxonomy of Figuladra, a genus of camaenid land snails endemic to eastern Queensland, based on the investigation of many recently collected ethanol-preserved samples as well as historic museum material, including types. We employed comparative analyses to investigate the variation in morphological features (shell, penial anatomy) and performed phylogenetic analyses of mitochondrial 16S rDNA sequences to test species hypotheses. Phylogenetic analyses recovered three principal mitochondrial clades, one occurring in mid-east Queensland, one in south-east Queensland, and another in the upland areas of south-east Queensland. We recognise altogether 15 accepted species, including four that are newly described herein (i.e., Figuladra finlaysoni sp. nov., F. robertirwini sp. nov., F. bromileyorum sp. nov. and F. vidulus sp. nov.). The status of 11 previously described species has been assessed and revised diagnoses are provided for each of these. Species of the south-east Queensland clade revealed comparatively low levels of genetic and morphological differentiation and may represent examples of more recent, conceivably ongoing, speciation. Figuladra species have allopatric distributions with their ranges being separated by altitudinal or riverine barriers. Particularly the St Lawrence Gap dry corridor has been identified as a major biogeographic barrier separating two principal clades of Figuladra.

Genetic diversity and population structure analysis of blunt snout bream (Megalobrama amblycephala) in the Yangtze River Basin: Implications for conservation and utilization

The blunt snout bream, Megalobrama amblycephala, is a commercially significant freshwater fish species indigenous to China. In recent decades, fishery resources of blunt snout bream in the Yangtze River have been severely depleted owing to human activities, and limited information is available regarding their genetic characteristics. This study aimed to assess the genetic diversity and population structure of different native populations of blunt snout bream in the Yangtze River. We analyzed 222 samples from six natural populations in the middle reaches of the Yangtze River and its affiliated lakes were analyzed using ten microsatellite DNA markers and concatenated sequences of two mitochondrial DNA markers (Cytb and ND2). Microsatellite analysis showed that the average observed heterozygosity (Ho), expected heterozygosity (He), and polymorphic information content (PIC) for all populations were determined as 0.687, 0.739, and 0.748 respectively. Mitochondrial sequence analysis showed that the number of haplotypes (h), haplotype diversity (Hd) and nucleotide diversity (π) of the six populations were 29, 0.768, and 0.00641, respectively. The above findings reveal high genetic diversity within blunt snout bream populations, suggesting a robust potential for selective breeding. The phylogenetic relationship results showed that the six blunt snout bream populations clustered into two branches, indicating a measurable degree of differentiation among the populations in the middle reaches of the Yangtze River Basin and its affiliated lakes. The populations may represent distinct spawning grounds, and corresponding conservation units should be implemented to protect them. In summary, these findings provide vital genetic information for the conservation and commercialization of blunt snout bream in the Yangtze River Basin of China.

Population structure and microscale morphological differentiation in a freshwater snail from the Chilean Altiplano

BackgroundThe diversity and population genetic structure of many species have been shaped by historical and contemporary climatic changes. For the species of the South American Altiplano, the historical climatic changes are mainly related to the wet events of great magnitude and regional influence that occurred during the Pleistocene climatic oscillations (PCOs). In contrast, contemporary climate changes are associated with events of lesser magnitude and local influence related to intensifications of the South American Summer Monsoon (SASM). Although multiple studies have analyzed the effect of PCOs on the genetic patterns of highland aquatic species, little is known about the impact of contemporary climate changes in recent evolutionary history. Therefore, in this study, we investigated the change in population structure and connectivity using nuclear and mitochondrial markers throughout the distribution range of Heleobia ascotanensis, a freshwater Cochliopidae endemic to the Ascotán Saltpan. In addition, using geometric morphometric analyses, we evaluated the concomitance of genetic divergence and morphological differentiation.ResultsThe mitochondrial sequence analysis results revealed the presence of highly divergent co-distributed and geographically nested haplotypes. This pattern reflects an extension in the distribution of groups that previously would have differentiated allopatrically. These changes in distribution would have covered the entire saltpan and would be associated with the large-scale wet events of the PCOs. On the other hand, the microsatellite results defined five spatially isolated populations, separated primarily by geographic barriers. Contemporary gene flow analyses suggest that post-PCO, climatic events that would have connected all populations did not occur. The morphometric analyses results indicate that there is significant morphological differentiation in the populations that are more isolated and that present the greatest genetic divergence.ConclusionsThe contemporary population structure and morphological variation of H. ascotanensis mainly reflect the post-PCO climatic influence. Although both markers exhibit high genetic structuring, the microsatellite and morphology results show the preponderant influence of fragmentation in recent evolutionary history. The contemporary genetic pattern shows that in species that have limited dispersal capabilities, genetic discontinuities can appear rapidly, erasing signs of historical connectivity.

Cryptic diversity and phylogeographic patterns of Deto echinata (Isopoda: Detonidae) in southern Africa

Recent phylogeographic studies of poorly-dispersing coastal invertebrates in highly biodiverse regions have led to the discovery of high levels of cryptic diversity and complex phylogeographic patterns that suggest isolation, geological, and ecological processes have shaped their biodiversity. Studies of southern African coastal invertebrates have uncovered cryptic diversity for various taxa and phylogeographic patterns that, although sharing some similarities across taxa, do differ. These findings underscore the need for additional studies to better understand the biodiversity levels, distributional patterns, and processes responsible for producing coastal biodiversity in that region. The coastal isopod Deto echinata is of particular interest, as its complex taxonomic history, poor dispersal capabilities, and broad geographic distribution suggest the potential for cryptic diversity. We use mitochondrial and nuclear sequences to characterize D. echinata individuals from localities ranging from northern Namibia to Glentana, about 2,500 km along the coastline on the south coast of South Africa. These are used to assess whether D. echinata harbors cryptic genetic diversity and whether phylogeographic distributional patterns correlate with those previously documented for other coastal isopods in the region. Analysis of mitochondrial and nuclear sequences revealed two deeply-divergent lineages that exhibit a distributional break in the Cape Peninsula region. These findings suggest D. echinata is a cryptic species complex in need of taxonomic revision and highlight the need for further taxonomic and phylogeographic studies of similarly poorly-dispersing coastal invertebrates in southern Africa.

Phylogenetic characterization of two common sand flies Phlebotomus major and P. kandelakii in the West Black Sea Region of Turkey based on mitochondrial genes sequence analysis

Research on the taxonomy and phylogenetic characterization of sand flies (Diptera, Psychodidae, Phlebotominae) has received increasing attention due to their potential role in the transmission of medically significant diseases, including leishmaniasis, bartonellosis, and sand fly fever. Phlebotomus major and Phlebotomus kandelakii are the members of Larroussius subgenus that includes important vector sand fly species. P. major, P. neglectus and P. syriacus from a well-known sand fly “Major” species group are present widely while P. kandelakii has constricted distribution in Turkey. All have the capability to transmit Leishmania infantum, the causative agent of visceral leishmaniasis. Here, we investigated the genetic diversity within each species collected from the West Black Sea Region of Turkey using mitochondrial DNA markers, specifically cytochrome oxidase I (COI) and cytochrome b gene sequences (Cytb). A total of 1889 sand flies specimens were collected from the study area in June 2021 and August 2022, 1596 (84.49%) were identified as P. major s.l., and 253 (13.40%) were identified as P. kandelakii. Nine and four haplotypes of P. major were determined in the study area based on COI and Cytb sequences, respectively. Analysis of the phylogenetic data sets generated from our isolates and published isolates in Genbank revealed high haplotype diversities within P. major (COI = 0.933, Cytb = 0.714). For P. kandelakii, we detected four and three haplotypes within the COI and Cytb sequences, and the haplotype diversities were also high in the datasets including our isolates and published isolates in Genbank (COI = 0.978, Cytb = 1.000). Pairwise mean genetic distance calculated from the COI and Cytb datasets were 0.4% and 1.4% for P. major, and 1.0% and 0.2% for P. kandelakii, respectively, suggesting the absence of cryptic species. Phylogenetic analyses revealed three and two major clusters of Larroussius subgenus in the COI and Cytb datasets, respectively.

Genetics, Age Demographics, and Shell Size of Atlantic Surfclams from the Southern Edge of Their Range

The Atlantic surfclam (Spisula solidissima solidissima) is an economically valuable clam species that supports a major US fishery. Until recently, fishery efforts along the southern edge of the surfclam range were low due to clam mortalities there in the 1990s. Recent surfclam fishing efforts off Virginia raised questions of whether the surfclam population has returned in the southern region or if a single cohort is supporting the fishery there. Questions have also arisen about whether S. s. similis is among the population fished off the coast of VA. Spisula solidissima similis is a warm-water cryptic subspecies of the Atlantic surfclam. Although morphologically indistinguishable, S. s. similis grows to a smaller size and is genetically distinct. Atlantic surfclams (n = 103) were collected from the fishing grounds off the coast of VA. Each surfclam was aged, and shell length and tissue weight recorded for comparison to surfclams of the same age from the center of the population. Analyses of mitochondrial (mtCOI) sequences suggests that the two groups sampled off VA are genetically homogeneous, both groups contain two divergent mitochondrial lineages, and one surfclam sampled shares the S. s. similis mtCOI sequence. There are multiple cohorts of surfclams, suggesting that environmental conditions may have improved for surfclams in the south, or that this population has acclimated to altered conditions. Further research should investigate the potential for subspecies hybridization.

Population genetic diversity in Nezara viridula by analysis of mitochondrial control region sequences

Abstract Here, we examine genetic diversity and dispersal patterns in populations of the agricultural pest Nezara viridula from Argentina using mitochondrial control region sequences. The DNA sequence comparisons of 1837 base pairs of the control region revealed 60 haplotypes determined by a total of 108 variable sites. The observed total haplotype diversity (Hd) value was 0.99, and the nucleotide diversity was 0.00423 and 0.00571 according to π and θW, respectively. The high haplotype diversity and low nucleotide diversity, as well as both neutrality tests and unimodal mismatch distributions, suggested a recent expansion in the populations of N. viridula from Argentina. The expansion of the populations of this insect is probably due to the recent agricultural expansion and intensification of soybean cultivation in this country. No significant levels of genetic differentiation were detected, suggesting that gene flow predominates over genetic drift. In addition, the Bayesian individual assignment analysis revealed that all populations share ancestry. It is probable that the growth in the area cultivated with soybean has generated stable and continuous habitats that allow gene flow among populations of N. viridula. The results of demographic history analysis suggest that the direction of migration of N. viridula would be associated with the growth pattern of soybean crops in Argentina.

Genome-wide single-nucleotide polymorphism data and mitochondrial hypervariable region 1 nucleotide sequence reveal the origin of the Akhal-Teke horse.

The study investigated the origin of the Akhal-Teke horse using genome-wide single-nucleotide polymorphism (SNP) data and mitochondrial hypervariable region 1 (HVR-1) nucleotide sequences. Genome-wide SNP data from 22 breeds (481 horses) and mitochondrial HVR-1 sequences from 24 breeds (544 sequences) worldwide to examine the origin of the Akhal- Teke horse. The data were analyzed using principal component analysis, linkage disequilibrium analysis, neighbor-joining dendrograms, and ancestry inference to determine the population relationships, ancestral source, genetic structure, and relationships with other varieties. A close genetic relationship between the Akhal-Teke horse and horses from the Middle East was found. Analysis of mitochondrial HVR-1 sequences showed that there were no shared haplotypes between the Akhal-Teke and Tarpan horses, and the mitochondrial data indicated that the Akhal-Teke horse has not historically expanded its group. Ancestral inference suggested that Arabian and Caspian horses were the likely ancestors of the Akhal- Teke horse. The Akhal-Teke horse originated in the Middle East.

Two new species of green treefrogs (Pelodryadidae: Litoria) from the northern slopes of Papua New Guinea's Central Cordillera.

We describe two new species of moderate-sized (male body length 26.5-29.8 mm and 41.0 mm), predominantly green treefrogs in the genus Litoria from hill forest on the northern slopes of Papua New Guinea's Central Cordillera. Phylogenetic analysis of mitochondrial ND4 nucleotide sequences shows that the first species is related to Litoria iris (Tyler) and its allies. It is morphologically most similar to Litoria mystax, a small green treefrog known only from the holotype that was described more than 100 years ago from the north coast of western New Guinea but differs from that species in having longer legs and a broader head. The second species is closest to Litoria gasconi, a species known only from the foothills of the Foja Mountains in Papua Province, Indonesian New Guinea, and the Prince Alexander Mountains in northern Papua New Guinea. It has a net average sequence divergence of 10% from L. gasconi and can be distinguished morphologically from it and from other pelodryadids by the presence of a striking pattern of spots and blotches on the ventral surfaces and on the hidden surfaces of the limbs. These descriptions add to the rapidly increasing known diversity of frogs in hill and lower montane forest, habitats that support the most diverse frog communities on mainland New Guinea.

A New Species of the Genus Pelodiscus (Testudines, Trionychia) from Jiangxi China

A new species of softshell turtle (Pelodiscus jiangxiensis sp. nov.) is described based on five specimens from Jiangxi, China. Phylogenetic analysis of mitochondrial sequences indicated that the new species is the sister lineage to a Pelodiscus clade that includes two currently recognized species, namely P. axenaria from Hunan and P. huangshanensis Gong, et al. from Anhui. Morphologically, the new species is most similar to P. axenaria but can be distinguished by its plain, yellowish white plastron, the absence of the single dark gray central figure, and a distinct carapace pattern. The description of this species increases the number of recognized Pelodiscus species to seven, of which six are distributed in China and four are endemic.

Molecular data from the holotype of the enigmatic Bornean Black Shrew, Suncusater Medway, 1965 (Soricidae, Crocidurinae), place it in the genus Palawanosorex.

Although Borneo has received more attention from biologists than most other islands in the Malay Archipelago, many questions regarding the systematic relationships of Bornean mammals remain. Using next-generation sequencing technology, we obtained mitochondrial DNA sequences from the holotype of Suncusater, the only known specimen of this shrew. Several shrews collected recently in Sarawak are closely aligned, both morphologically and mitochondrially, with the holotype of S.ater. Phylogenetic analyses of mitochondrial sequences indicate that the S.ater holotype and new Sarawak specimens do not belong to the genus Suncus, but instead are most closely related to Palawanosorexmuscorum. Until now Palawanosorex has been known only from the neighboring Philippine island of Palawan. Additional sequences from nuclear ultra-conserved elements from the new Sarawak specimens strongly support a sister relationship to P.muscorum. We therefore transfer ater to Palawanosorex. The new specimens demonstrate that P.ater is more widespread in northern Borneo than previously recorded. Continued sampling of Bornean mammal diversity and reexamination of type material are critical in understanding the evolutionary history of the biologically rich Malay Archipelago.

Detection and characterization of Hyaloklossia kasumiensis (Apicomplexa: Sarcocystidae) from Nagoya Daruma pond frog, Pelophylax porosus brevipodus.

The Nagoya Daruma pond frog (Pelophylax porosus brevipodus) is an endangered anuran species endemic to the semi-aquatic environment of Japan. On June 11, 2021, four of the six Nagoya Daruma pond frogs captured from the wild and kept in an aquarium died in rapid succession. Pathological and/or parasitological examinations of two of the four carcasses revealed protozoan infection in their kidneys. The pathogen identified as Hyaloklossia kasumiensis (Apicomplexa: Sarcocystidae: Hyaloklossiinae) based on their morphological and molecular characterization. This is a new host record of H. kasumiensis. Mitochondrial cox1 sequence analysis suggest that the present species detected from Nagoya Daruma pond frog belongs to the same lineage as those found in the Tokyo Daruma pond frog (P. p. porosus) from Ibaraki Prefecture, Japan. This particular lineage may be prevalent among Pelophylax porosus ssp. distributed in Japan.

Universal Mitochondrial Multi-Locus Sequence Analysis (mtMLSA) to Characterise Populations of Unanticipated Plant Pest Biosecurity Detections.

Simple SummaryAgricultural and environmental sustainability requires effective biosecurity responses that prevent the establishment or spread of exotic insect pests. Understanding where new detections may have come from or if recurrent detections are connected contributes to this. Suitable population genetic markers use relatively rapidly evolving gene regions which render the PCR method species-specific at best. Because resource limitations mean these are pre-emptively developed for the highest risk species, populations of other exotic pests are unable to be characterised at the time. Here we have developed a generic method that is useful across species within the same taxonomic Order, including where there is little or no prior knowledge of their gene sequences. Markers are formed by concomitant sequencing of four gene regions. Sequence concatenation was shown to retrieve higher resolution signatures than standard DNA barcoding. The method is encouragingly universal, as illustrated across species in ten fly and 11 moth superfamilies. Although as-yet untested in a biosecurity situation, this relatively low-tech, off-the-shelf method makes a proactive contribution to the toolbox of quarantine agencies at the time of detection without the need for impromptu species-specific research and development.Biosecurity responses to post-border exotic pest detections are more effective with knowledge of where the species may have originated from or if recurrent detections are connected. Population genetic markers for this are typically species-specific and not available in advance for any but the highest risk species, leaving other less anticipated species difficult to assess at the time. Here, new degenerate PCR primer sets are designed for within the Lepidoptera and Diptera for the 3′ COI, ND3, ND6, and 3′ plus 5′ 16S gene regions. These are shown to be universal at the ordinal level amongst species of 14 and 15 families across 10 and 11 dipteran and lepidopteran superfamilies, respectively. Sequencing the ND3 amplicons as an example of all the loci confirmed detection of population-level variation. This supported finding multiple population haplotypes from the publicly available sequences. Concatenation of the sequences also confirmed that higher population resolution is achieved than for the individual genes. Although as-yet untested in a biosecurity situation, this method is a relatively simple, off-the-shelf means to characterise populations. This makes a proactive contribution to the toolbox of quarantine agencies at the time of detection without the need for unprepared species-specific research and development.

Variable social organization among tuco-tucos (genusCtenomys) in theopimusclade

AbstractComparative studies of closely related species provide a powerful means of identifying the ecological and demographic factors associated with variation in mammalian social systems. Although most members of the subterranean rodent genus Ctenomys are thought to be solitary, the highland tuco-tuco (C. opimus) is group living, meaning that multiple adults share a burrow system and underground nest site. These animals are part of the opimus clade, a monophyletic collection of four named species that occur in northwestern Argentina and adjacent portions of Chile and Bolivia. As a first step toward generating a comparative assessment of social organization within this clade, we characterized spatial relationships among members of a population of Ctenomys at Antofagasta de la Sierra, Catamarca Province, Argentina. Based on geographic location and natural history, these animals were expected to be part of the opimus clade; analyses of mitochondrial cytochrome-b sequences from our study population confirmed this general phylogenetic placement. Radiotelemetry data indicated that the animals at Antofagasta were group living, with up to three adult females and one adult male sharing a burrow system. In contrast to other group-living ctenomyids, however, individuals did not consistently share nest sites. Comparisons of these data with re-analyses of spatial relationships among members of the population of C. opimus studied by O’Brien et al. (2020) revealed several intriguing differences in social organization, potential explanations for which include short-term responses to variable demographic and ecological conditions as well as more enduring responses to differences in local selective pressures. Further comparative analyses of these populations and, more generally, members of this subclade of Ctenomys will help to elucidate the factors contributing to variation in social behavior within this speciose and geographically widespread genus.

Phylogeography and Genetic Structure of the Swimming Crabs Portunus sanguinolentus (Herbst, 1783) in East Asia

The three-spot swimming crab (Portunus sanguinolentus) is mainly distributed in South East Asia. An analysis of mitochondrial control region partial sequences allows us to determine the population genetic structure, phylogeography and historical demography of this species in East Asia. The seven populations, which included 110 individuals, were collected from mainland China (Shanghai, SH, Xiamen, XM and Hong Kong, HK), Taiwan (Yilan, YL, Taichung, TC, Donggang, DG) and Singapore (Singapore, SGP). The nucleotide diversity (π) of all individuals was 0.01149, with values ranging from 0.00372 (SGP) to 0.01345 (YL). In total, 90 haplotypes have been identified, which can be divided into two major lineages: lineage A consists of specimens from SH, YL, XM, TC and DG, and lineage B corresponds to specimen from SGP. From the second to the most recent interglacial period, population expansion was observed in each lineage. However, a low level of genetic differentiation was also observed in the three-spotted swimming crab, P. sanguinolentus, according to FST values. Our results suggest that several past and present habitat configurations have shaped the genetic patterns of P. sanguinolentus until now. During Pleistocene glaciations, when sea levels were low, this species may have moved along the coast from Southeast Asia to China. It first colonized the Hong Kong area during this era. After sea levels rose and shorelines receded, it subsequently spread to the coast of mainland China.

Occurrence and molecular identification of Monogenea from blue-spotted flathead Platycephalus caeruleopunctatus (Scorpaeniformes: Platycephalidae) in Australian 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.

Discordance of genetic diversification between deep‐ and shallow‐water species of Kobeltocochlea Lindholm, 1909 (Caenogastropoda: Truncatelloidea: Benedictiidae) endemic to Lake Baikal with the description of a new species, review of the genus, and notes on its origin

We describe a new species, Kobeltocochlea tamarae Sitnikova, Teterina & Maximova sp. nov., from Lake Baikal discovered in the Saint Petersburg methane seep at a depth of approximately 1400 m. The uncorrected genetic distance was 4.26% of the COI gene between this new species and K. falsipumyla collected from the Academic Ridge at depths between 157 and 163 m. The two shallow-water species, K. martensiana and K. olchonensis, differed in substrate preference and geographic habitats, with a genetic distance of 0.97% for COI. Phylogenetic analysis of mitochondrial (COI, 16S) and nuclear (ITSI, 28S) sequences indicated that Kobeltocochlea was paraphyletic with respect to other benedictiid genera Benedictia and Yaroslawiella, formed well-supported monophyletic groups. We revealed the discordance of morphological and genetic data within Kobeltocochlea and other benedictiids, which reflected their complicated history. The current knowledge of benedictiids does not allow for significant changes in the taxonomy of the Benedictiidae, except for synonymizing K. lindholmiana with K. olchonensis and Pseudobenedictia with Benedictia that were also investigated. We speculate that three main lineages of benedictiids originated from three populations of a single ancient species approximately 3.2 Ma. The speciation of deep-water species was probably driven independently by bathymetric isolation in the cold methane seeps of different geomorphological structures. The diversification of the third lineage consisting of littoral (including K. martensiana/K. olchonensis), deep-water, and eurybathic benedictiids may be explained by rapid adaptive radiation to intralacustrine environments.