Cox1 Gene Sequences Research Articles

Genetic Diversity of Strongyloides stercoralis with Attention to Clinical Features in Patients Originated from Three Endemic Provinces in the North and South of Iran

Background: Strongyloides stercoralis is one of the neglected tropical diseases. We aimed to verify the genetic diversity of S. stercoralis with attention to clinical features of the infection in patients using the Cox1 gene and DNA sequencing. Methods: Using parasitological methods, S. stercoralis was isolated from stool samples of patients who had been referred to Tehran University of Medical Sciences, Tehran, Iran. The patients originated from three endemic provinces of Iran including Guilan and Mazandaran in the north and Khouzestan in the south of Iran. After recording the clinical symptoms of the patients, DNA extraction of the isolates, PCR, and sequencing of the Cox1 gene region were performed. The gene sequences were analyzed by Chromas, Bio edit, and Dna SP 6.0, and phylogenetic analysis using MEGA 7. Results: Overall 10 isolates of S. stercoralis were collected from patients 55 to 73 years old. Among the patients, gastrointestinal, respiratory, and cutaneous clinical symptoms were the most common, respectively. Ten isolates were classified into 4 haplotypes, 2 of which were specific to this study. Haplotypes 2 and 3 were placed in a subclade with haplotypes including isolates from dogs in Cambodia. Haplotype 4 which is hereby introduced in the world for the first time included an isolate from a patient with hyper-infection syndrome and disseminated strongyloidiasis. Conclusion: The Cox1 gene showed genetic diversity for S. stercoralis isolates. Accordingly, no significant genetic difference was observed between the sequences from patients with hyper-infection and non-hyper-infection. The only isolate from a patient with disseminated and hyper-infection strongyloidiasis was genetically different from all other isolates in the present study.

Morphometric and Molecular Characterization of Fasciola spp. in Livestock From Northwestern Provinces of Iran.

Liver flukes from the genus Fasciola are the causative agents for human and livestock fascioliasis. Accurate identification of Fasciola spp. is essential to understanding the epidemiology of fascioliasis. This study aimed to determine the morphometric and molecular characterization of Fasciola spp. in livestock from Northwestern provinces of Iran. Five hundred adult Fasciola flukes were obtained from different definitive hosts (cattle, sheep, goats, and buffaloes) in four local abattoirs in the northwestern provinces of Iran (West-Azerbaijan, East-Azerbaijan, Ardabil, and Zanjan) from September 2021 to August 2022. All samples were examined by morphometric criteria; then, 49 samples were identified using PCR-RFLP based on ITS1 region and 23 sequence of isolates analyzed by cox1 marker. PCR-RFLP methods compared morphometric results, and cox1 gene sequences were used to confirm PCR-RFLP results and phylogenetic analysis. The differences between the body length, body width, cephalic cone length, cephalic cone width, body area, and distance between the ventral sucker and posterior end of the body in two species were significant (p < 0.05). Based on the morphometric criteria, 139 samples (27.8%) were identified as Fasciola gigantica and 361 (72.2%) as Fasciola hepatica. Similarly, PCR-RFLP analysis of ITS1 region confirmed morphometric results. No hybrid forms of Fasciola were detected. Partial sequences of cox1 showed 13 variable sites with eight haplotypes in F. hepatica and 12 variable sites with five haplotypes in F. gigantica. Based on the results of this study, the PCR-RFLP method can be used to confirm the morphological method of Fasciola species, but it is insufficient to study their genetic diversity. Also, sequences of cox1 results of the present study showed that F. hepatica and F. gigantica species in the Northern provinces of Iran have different genetic structures and haplotypes.

Human Schistosomiasis due to Schistosoma bovis in Nigeria.

Schistosomiasis is a global public health challenge, especially in sub-Saharan Africa, where Nigeria has the highest burden of disease. Schistosoma hybrids have been discovered in various countries, including Nigeria, where livestock and human beings share common water resources. This study, carried out in three communities, two of which are endemic for urinary schistosomiasis, aimed to identify the urinary schistosomiasis causative agent by using a species-specific molecular technique and their evolutionary relationship. Polymerase chain reaction using primers specific for a partial DNA sequence of the mitochondrial cox1 gene of Schistosoma haematobium was carried out on pooled urine sediments preserved in 70% ethanol. DNA from the high-intensity pooled samples from Onye-Uku camp amplified, and a BLAST search identified the pooled samples as Schistosoma bovis, whereas S. haematobium DNA did not amplify. The phylogenetic relationship of the sequence showed that it clustered with an S. bovis hybrid obtained from a human host in Côte d'Ivoire and had close ancestry with isolates from cattle in Cameroon. This finding revealed the prevalence of S. bovis among some inhabitants in a zone in Nigeria where schistosomiasis is endemic.

Generation and characterization of a novel ovariole cell line derived from Spodoptera frugiperda in China with sensitivity to both SfMNPV and AcMNPV

Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV), belonging to the species Alphabaculovirus spofrugiperdae, has been recently registered as an insecticide in China. This virus has a specific effect on the global major agricultural pest Spodoptera frugiperda. To gain insights into viral infection, replication processes, and the complex formation of viral particles, in vitro studies using cell lines are essential tools. Although the IPLB-Sf9 and IPLB-Sf21 cell lines derived from S. frugiperda are widely used for studies on the infection and replication mechanisms of Autographa californica multiple nucleopolyhedrovirus (AcMNPV), their capacity to produce viral polyhedra after SfMNPV infection is not optimal. To address this limitation, a novel cell line named IOZCAS-Sf-1 has been developed from a S. frugiperda population sourced Yunnan, China. The mitochondrial COX1 gene analysis confirmed the species origin of the IOZCAS-Sf-1 cell line. Furthermore, a comparative study was carried out to contrast the COX1 gene sequence of this novel cell line with that of IPLB-Sf9, highlighting the distinctions between the two. Importantly, the IOZCAS-Sf-1 cells exhibited a remarkable ability to generate polyhedra when infected with AcMNPV and SfMNPV, respectively. Consequently, this cellular lineage is considered a promising and valuable resource. It serves not only to investigate the molecular mechanisms of viral replication and its impact on host cells, but also to explore the transfection efficiency of SfMNPV DNA. This exploration further expands into its potential application in recombinant DNA experiments, laying a theoretical groundwork for the advancement of more effective biopesticides and sustainable agricultural practices.

Genetic variation and population structure of Taenia multiceps (Coenurus cerebralis) based on mitochondrial cox1 gene: A comprehensive global analysis

Taenia multiceps is a neglected parasite having veterinary and public health importance. The predilection sites of the parasite larva (Coenurus cerebralis) are brain (cerebral coenurosis) and subcutaneous (non-cerebral coenurosis). There is a dearth of data regarding molecular characterization of T. multiceps and even fewer population structure-based studies on T. multiceps. The current study was conducted to provide epidemiological information regarding the global population structure of the parasite. The NCBI GenBank database was accessed to download the sequences of cox1 gene, which were further subjected to PopArt software to construct median-joining networks. The DnaSp software was used to compute neutrality and diversity indices. Host and region-wise indices of neutrality and diversity were also computed. There were 166 gene sequences found in the NCBI database. Followed by removal of short gene sequences, 143 were considered to perform bioinformatic analyses. A total of 30 haplotypes with 46 mutations and 23 parsimony informative sites were found. High diversity (Hd = 0.889, π = 0.01186) and negative but statistically insignificant neutrality indices (Tajima's D = −1.57659, Fu's Fs = −10.552) were found. Region-wise results revealed highest haplotype diversities in isolates from KSA (Hd = 1.00) followed by Greece and Italy (Hd = 0.962), and China (Hd = 0.931). Host-wise data analysis showed an overall negative Tajima's D value and there exists highest haplotype diversity in cattle (Hd = 1.00) followed by dogs (Hd = 0.833), sheep (Hd = 0.795) and goats (Hd = 0.788). The findings of the study indicate that the population diversity of T. multiceps will increase worldwide as shown by high diversity and negative neutrality indices. The findings of the study significantly add-in to the existing bank of knowledge about population structure of T. multiceps. We recommend conducting more studies employing different genetic markers to better comprehend the epidemiology of the parasite.

Acanthocephalan Profilicollis altmani infecting the mole crab Emerita brasiliensis in southeastern Brazil

Acanthocephalan parasites, specifically from the genus Profilicollis, are known to infect decapod crustaceans, including mole crabs like Emerita brasiliensis, which serve as intermediate hosts in their complex life cycles. This study reports the first occurrence of the acanthocephalan parasite Profilicollis altmani infecting the mole crab Emerita brasiliensis on a sandy beach in southeastern Brazil, thereby expanding the known geographic range of this parasite. Additionally, the study provides novel molecular data that enhance our understanding of the parasite’s taxonomy and distribution, including the first evidence of genetic variation within populations of the intermediate host E. brasiliensis. Phylogenetic analysis based on mitochondrial COX1 gene sequences confirmed the identification of the parasite and underlined small genetic differences among P. altmani populations. These findings suggest a weak genetic population structure of the parasite and underscore the need for further studies to understand gene flow among these populations. This work contributes to the knowledge of parasite-host interactions in sandy beach ecosystems. It highlights the importance of monitoring parasitic infections in species like E. brasiliensis, which play a crucial ecological role in these environments.

The First Report of Sphaerirostris picae Infection in the Oriental Magpie (Pica serica) in Beijing, China.

Background: Sphaerirostris picae is a parasitic species known for its ability to infect and transmit between hosts in the gastrointestinal tracts of wild avian species. However, there is limited information on its presence and impact on urban avian populations, particularly in China. Materials and Methods: In this study, morphological observations were conducted to detect the presence of Sphaerirostris sp. within the intestinal tract of the Oriental Magpie (Pica serica) collected in Beijing, China. Further confirmation of the parasite's identity was achieved through phylogenetic analysis using COX1 gene sequencing to compare with previously documented Sphaerirostris picae isolates. Results: The morphological and molecular analyses confirmed the presence of Sphaerirostris picae in the Oriental Magpie. Phylogenetic analysis indicated a close relationship with known Sphaerirostris picae isolates. This represents the first reported case of Sphaerirostris picae infection in magpies from Beijing, China. Conclusion: The findings highlight the potential health hazards posed by Sphaerirostris picae to urban avian populations and public health. The study suggests that additional research and surveillance efforts are necessary to better understand the risks associated with this parasite and to develop effective mitigation strategies.

Molecular identification and genetic variability of equine and bovine ocular setariasis in india: molecular profiling by mitochondrial genes.

Ocular setariasis is an ectopic infection caused by a parasite under the genus Setaria. Adult worms belong to the Setariidae family and typically reside in the peritoneal cavity of ungulates. However, immature forms of these species may aberrantly migrate to the eyes of cattle, buffalo, goats, horses and several other hosts, leading to corneal opacity and blindness. Here, we have distinguished the Setaria digitata collected from both equine and buffalo hosts based on the morphology, molecular profiling of mitochondrial cytochrome c oxidase subunit 1 (Cox1), cytochrome c oxidase subunit 3 (Cox3) and, Nicotinamide Adenine Dinucleotide dehydrogenase subunit 1 (NAD1) genes. A single filarial worm was collected from the eye of one equine and one bovine host. These worms were then processed for morphological examination and DNA isolation. Cox1, Cox3 and NAD1 genes were amplified using specific primers and subjected to custom sequencing. The sequences were then used for multiple sequence alignment, assessment of entropy, similarity and haplotype diversity analysis. Key morphological features confirmed the worms collected were male and female Setaria digitata from equine and buffalo hosts, respectively. Cox1, Cox3 and NAD1 gene sequence analysis showed a close association of S.digitata Indian isolates with its counterparts from Sri Lanka and China isolates. The phylogram of bovine S. digitata sequences shows a close relationship to other equine S. digitata sequences, indicating the need for further in-depth studies on the prevalence of infection across various host species and intermediate hosts. Although the sequence results suggest that S. digitata is likely the causative agent of ocular setariasis in India, additional samples are needed to confirm this conclusion. Comprehensive analysis of the transcriptome and proteome of S. digitata from both bovine and equine hosts is necessary to explore variations in host-parasite interactions. These findings will aid in future parasite identification, investigations into vector prevalence in India, and the development of control measures against ocular setariasis.

Molecular identification of Sarcocystis aucheniae in the wild South American camelid Vicugna vicugna.

Vicuñas (Vicugna vicugna) are wild South American camelids (SACs) protected by law in Argentina, and information on pathogens that infect them is scarce. In this study, an adult vicuña found dead in the province of Salta was examined, and evidence of infection by Sarcocystis sp. protozoans was sought. Infection of skeletal muscles by S. aucheniae, with the production of macroscopic sarcocysts, a disease known as SAC sarcocystosis, has been described in the other three SACs - llamas, alpacas, and guanacos - but its occurrence in vicuñas has so far remained unknown. In the analyzed individual, many macroscopic cysts compatible with S. aucheniae were found upon necropsy in the muscular tissue of the neck and diaphragm. Analysis of 18S rRNA and cytochrome c oxidase subunit 1 (cox-1) gene sequences by BLAST searches and construction of phylogenetic trees demonstrated that the etiological agent was S. aucheniae. Our results show for the first time that vicuñas act as intermediate hosts in the life cycle of this parasite. In addition, this study provides the first cox-1 sequences for S. aucheniae isolates from the four SAC species acting as intermediate hosts and suggests that this marker could be useful for genotypification of this parasite species. The impact of SAC sarcocystosis on the health, well-being, and fitness of vicuñas, and the relevance of vicuña infections in the epidemiology of S. auchaniae, remain to be elucidated.

Morphometrical and molecular identification of Echinococcus granulosus genotypes in wild canids in north of Iran.

The cestode Echinococcus granulosus causes cystic echinococcosis, a zoonotic parasitic infection that constitutes a significant public health risk. This parasite has been documented to have potential reservoirs and carriers among wild canids, namely wolves, foxes and jackals. This study aimed to determine the prevalence and molecular characteristics of E. granulosus sensu lato species/genotypes among wild canids in three northern, northeastern and north-western Iran regions. From 2019 to 2022, 93 wild canid carcasses (69 jackals), (22 foxes) and (2 wolves) were collected that were killed in car accidents or illnesses. Analyses of morphology and morphometry were performed to verify the presence of E. granulosus. To determine E. granulosus s.l. species/genotypes, polymerase chain reaction (PCR)-RFLP (ITS1) was performed utilizing the Bsh1236I (BstUI) restriction enzyme. COX1, NADH1 and ITS1 gene sequencing were also performed to confirm the PCR-RFLP results. During this study, 93 wild canids were examined, and 3.2% (95% CI: 0%-7%) of the 93 were infected with Echinococcus. The north-western region of Iran showed two out of 30 jackals (6.6%) infected with adult Echinococcus compared to one out of 35 jackals (2.8%) in the northern region. DNA from Echinococcus was detected in these individuals by PCR. Based on PCR-RFLP analysis of the ITS1 gene and sequencing of COX1, NADH1 and ITS1 gene, E. granulosus sensu stricto genotype was confirmed in the jackals that had been infected. Evidence shows that E. granulosus occurs in jackals in Iran, with the E. granulosus s.s. genotype being the most common. This parasite has been identified as a zoonotic parasite with a genotype that can be transmitted to livestock and humans. Establishing effective control measures to prevent the spread of echinococcosis and ensure public health is crucial.

Molecular based identification and phylogenetic relationship of the leech Hirudinaria manillensis from India by using mitochondrial cytochrome c oxidase subunit I gene.

A molecular approach for the identification of unknown species by the using mitochondrial cox1 gene is an effective and reliable as compared with morphological-based identification. Hirudinaria manillensis referred to as Asian Buffalo Leech, is found in South Asia and traditionally used as medicine owing to its medicinal properties. The study aimed to isolate and identify the leech species using cox1 gene sequencing and their phylogenetic relationships. The nucleotide sequences of cytochrome c oxidase subunit I (cox1) mitochondrial genes were analyzed for species identification and the phylogenetic relationship of crucial therapeutic leech Hirudinaria manillensis. The isolated DNA from the leech sample was amplified with cox1 gene-specific primers. BLAST results with the H. manillensis sequence showed 89.24% homology with H. manillensis and phylogenetic tree analysis revealed the genetic relationship with other GenBank submitted sequences. The present study concluded that the cox1 gene could be an effective way to identify the leech H. manillensis and provided sufficient phylogenetic information to distinguish H. manillensis indicating a significant mtDNA-based approach to species identification.

Complete Mitochondrial Genome of Clupeonella abrau (Maliatsky, 1930) (Clupeiformes), an Endemic Freshwater Fish from the Lake Abrau (Russia).

The Abrau sprat (tyulka or sardelka) Clupeonella abrau (Maliatsky, 1930) is an endemic fish of the Lake Abrau (Krasnodar Krai, Russia). The full C. abrau mitochondrial genome (16 650 bp) showed a gene arrangement conserved in Clupeidae and 98.8% similarity with the mitochondrial genome of the related species Black and Caspian Sea sprat C. cultriventris from the Black Sea. The COX1 gene sequence was additionally studied in a museum specimen collected in the Lake Abrau in 1938. Variability in modern Abrau sprat COX1 gene locus was estimated at approximately 0.15%, the difference between C. abrau and C. cultriventris was 1.2%, and the difference between the museum and modern C. abrau specimens from the Lake Abrau was 0.92%. The study confirmed that the Abrau sprat is present in the fish community and is capable of reproducing in the lake. Various scenarios were proposed to explain colonization of the Lake Abrau by C. abrau.

Molecular characterization and genetic variability of Toxocara vitulorum from naturally infected buffalo calves for the first time in Bangladesh.

Toxocara vitulorum is one of the deadliest parasite of buffalo calves in Bangladesh. This study was conducted to explore genetic variability within and among the T. vitulorum populations in buffalo calves of Bangladesh. Genomic DNA was extracted, ITS2, COX1 and NAD1 gene were amplified and sequenced. Distinct 29 ITS2, 21 unique NAD1 and 24 COX1 genotypes were detected among the T. vitulorum of different geographic regions. These three gene genotypes similarities ranged from 97 to 99%, when these were compared to best hit scoring T. vitulorum sequences retrieved from GenBank. A total of 12 and 6 unique haplotypes were detected for COX1 and NAD1 gene sequences. The average nucleotide and haplotype diversity for COX1 and NAD1 were 0.0931 & 0.89493 and 0.00658 & 0.77895 respectively and the recorded values were more dispersed than previously published values. The pairwise Nst values ranged from −0.050 to 0.602 and Fst from −0.050 to 0.600 between all the T. vitulorum genotypes indicated huge genetic differentiation which were reportedly higher than other published reports Fst values. This is the first report of T. vitulorum on the basis of COX1 gene in Bangladesh. The study findings will be helpful for further extensive epidemiological studies regarding anthelmintic resistance, control and prevention of T. vitulorum infection in buffalo calves.

Phylogeography of the giant honey bees based on mitochondrial gene sequences

Our goal was to resolve phylogenetic relationships among Apis laboriosa, and the Apis dorsata subspecies A. d. dorsata, A. d. binghami, and A. d. breviligula, the last two of which have been proposed as full species by several authors. We carried out a phylogenetic analysis of the giant honey bees using mitochondrial cox1 and cox2 gene sequences analyzed with maximum likelihood methods. We obtained strong support for four clades within A. dorsata in the broad sense: the three subspecies or species mentioned above, and a fourth lineage from south India. However, our analysis did not resolve the phylogenetic relationships among the four lineages. The presence of two genetically distinguishable groups of “A. dorsata” in India parallels the presence there of two cavity-nesting honey bees, A. cerana cerana and A. c. indica (the black hill bees and yellow plains bees, respectively). This suggests that past climatic or geological events may have temporarily isolated Indian populations from populations of the Asian mainland, leading to divergence and possibly speciation of Indian giant and cavity-nesting bees, followed by recolonization of India by eastern Asian forms. Recognition of these distinct lineages is important for conservation planning, so that their individual distributions, ecologies, and migration patterns can be considered, and so that the genetic diversity they represent can be maintained.

A study on the intertidal animal diversity of Xia-Sanheng Island by using morphological and DNA barcoding identification

Intertidal animals are an essential part of the ecosystem, and species diversity can reflect the state of the local ecological environment. However, traditional morphological identification is prone to corresponding classification errors or research limitations. With the development of molecular biology, many techniques and bioinformatics classification methods have been applied to identify species efficiently in recent years. This research aimed to examine the feasibility of DNA barcoding within the identification of intertidal animal species collected from the Xia-Sanheng Island. A total of 41 cox1 gene sequences were obtained by experimentalization or downloaded from the National Center for Biotechnology Information (NCBI) database. Then morphological classification, molecular identification, phylogenetic tree analysis, and Automatic Barcode Gap Discovery (ABGD) method were used to analyze the animal samples. We found that although the molecular classification of molluscs was not accurate enough, the collected specimens could be divided into 15 species, 12 families, and 4 phyla. Tetraclita japonica, Thais luteostoma, and Mytilus coruscus were the dominant species on the Xia-Sanheng Island. Additionally, there may be a new species, Platynereis sp., which needs further confirmation. We suggest that further identification of marine biodiversity should be carried out by combining morphological and molecular biological methods.

Resolving fusilier puzzles: The identity of Squamosicaesio marri and Pterocaesio flavifasciata, and a new record of Flavicaesio suevica from the Western Indian Ocean.

A phylogenetic analysis incorporating mitochondrial cox1 gene sequences of members of the family Caesionidae revealed the conspecificity of Pterocaesio flavifasciata and Squamosicaesio marri, which was also supported by the absence of any clear morphological diagnostic characters and meristic counts to separate the two species. Additionally, we provide the first record of the Suez fusilier, Flavicaesio suevica, from outside the Red Sea, based on specimens collected from the Laccadive archipelago, Western Indian Ocean. Together, these results show that the taxonomy, diversity, and distribution of members of the family Caesionidae continue to be poorly known, necessitating a comprehensive range-wide study.

Speciation patterns of Aedes mosquitoes in the Scutellaris Group: a mitochondrial perspective

The Scutellaris Group of Aedes comprises 47 mosquito species, including Aedes albopictus. While Ae. albopictus is widely distributed, the other species are mostly found in the Asia–Pacific region. Evolutionary history researches of Aedes species within the Scutellaris Group have mainly focused on Ae. albopictus, a species that raises significant public health concerns, neglecting the other species. In this study, we aimed to assess genetic diversity and estimate speciation times of several species within the Scutellaris Group. Mosquitoes were therefore collected from various Asia–Pacific countries. Their mitochondrial cytochrome c oxidase subunit 1 (cox1) and subunit 3 (cox3) sequences were analyzed alongside those of other Scutellaris Group species available in the GenBank database. To estimate the divergence time, we analyzed 1849 cox1 gene sequences from 21 species, using three species (Aedes aegypti, Aedes notoscriptus and Aedes vigilax) as outgroups. We found that most of the speciation dates occurred during the Paleogene and the Neogene periods. A separation between the Scutellaris Subgroup and the Albopictus Subgroup occurred approximately 64–61 million years ago (MYA). We also identified a split between species found in Asia/Micronesia and those collected in Melanesia/Polynesia approximately 36–35 MYA. Our findings suggest that the speciation of Aedes species within the Scutellaris Group may be driven by diversity in mammalian hosts, climate and environmental changes, and geological dynamics rather than human migration.

Evaluation of Molecular Genetic Diversity and DNA Barcoding of Rita gogra (Family Bagridae) from Narmada River Revealed through Mitochondrial COX1 Gene Sequencing

Evaluation of Molecular Genetic Diversity and DNA Barcoding of Rita gogra (Family Bagridae) from Narmada River Revealed through Mitochondrial COX1 Gene Sequencing

Description and molecular data of a new cestode parasite, Cladotaenia anomala n. sp. (Paruterinidae) from the Australasian harrier (Circus approximans Peale) in New Zealand

Currently comprising 12 species infecting the gastrointestinal tracts of diurnal raptors (Falconiformes, Accipitriformes), species of Cladotaenia are diagnosed by their branching uterus, testes in two fields reaching the same level anteriorly, and small rostellum armed with taenioid hooks arranged in two rows. In this study we describe a new species of Cladotaenia recovered from a number of Australasian harriers Circus approximans, from the southern half of South Island, New Zealand. The new species is distinguished from other species by its single circle of hooks. It is closest, morphologically, to C. circi, but differs in the shape of the terminal proglottids and the number of uterine branches. Sequences of 28S and cox1 gene are presented. Genetically, Cladotaenia anomalan. sp. is closest to Cladotaenia globifera but differs morphologically in the size of the suckers, testes and eggs. This description constitutes the first record of a Cladotaenia species in New Zealand. We discuss some potential routes this parasite may have taken to arrive in New Zealand.

Contribution to the knowledge of Gongolaria barbata (Sargassaceae, Fucales) from the Mediterranean: insights into infraspecific diversity

Gongolaria barbata (Sargassaceae, Fucales) is a widespread species for which several infraspecific taxa have been described, indicating its polymorphism. This study contributes to the understanding of the molecular, nomenclatural, morphological and ecological aspects of G. barbata in the Mediterranean and sheds light on the infraspecific diversity and its implications for the taxonomy of this species. Molecular analyses were performed using sequencing of the mitochondrial cox1 gene on both haptophytic and pleustophytic forms from different sites in the Adriatic and Tyrrhenian Seas. Vegetative and reproductive morphology was studied on thalli samples from the Adriatic. Our results showed that there are different morphotypes within G. barbata populations related to specific environmental conditions, suggesting infraspecific variation. In contrast, molecular analyses showed no differences between samples, regardless of whether individuals are growing “attached” to a substrate or “unattached”. We also discussed the taxonomic status and nomenclatural issues related to certain infraspecific taxa previously proposed for G. barbata. In particular, the confusion surrounding Cystoseira aurantia is clarified.