Bursatella Leachii Research Articles

First record of Bursatella leachii de Blainville 1817 (Mollusca; Gastropoda; Aplysiidae) in Black Sea

This study reports the presence of the ragged sea hare Bursatella leachii de Blainville 1817 in the Black Sea. A total of 484 specimens of this species were observed during scuba diving and snorkeling at depths ranging from 1.0 to 4.0 meters in September 2023. The samples were observed on the sandy-muddy bottom of Kumbaba Beach and the sandy bottom of Uzunkum Beach in Şile district (Istanbul province). The density of individuals per square meter of the seabed was calculated and the highest number of individuals was detected on the Kumbaba Beach near the mouth of the Türknil River. Considering the location of discovery, it is logical to assume that the introduction of this species into the Black Sea may have occurred naturally. This hypothesis can be supported for two main reasons; a) Şile beaches are a few kilometers away from the Bosphorus Channel, b) the report of B. leachii closest to Şile district dates back to January 2020, when the species was observed on the seabed on the southern coast of the Dardanelles. Long-term monitoring and more in-depth studies should be conducted in the region to give certainty to these hypotheses.

The biologically and ecologically important natural products from the Chinese sea hare Bursatella leachii: structures, stereochemistry and beyond

A novel amide alkaloid, bursatamide A (1), featuring an unprecedented propyl-hexahydronaphthalene carbon framework, was isolated from the infrequently studied sea hare Bursatella leachi, alongside a new 3-phenoxypropanenitrile alkaloid, bursatellin B (2), and twelve known compounds. The structures of 1 and 2 were elucidated through comprehensive spectroscopic data analyses, while their relative and absolute configurations (ACs) were established through total synthesis and a series of quantum chemical calculations, including calculated electronic circular dichroism (ECD) spectra, optical rotatory dispersion (ORD) methods, and DP4+ probability analyses. Bursatamide A (1) demonstrated inhibitory effects against the human pathogenic bacteria Listeria monocytogenes and Vibrio cholerae. Erythro-bursatellin B (21), a diastereoisomer of 2, exhibited notable antibacterial activity against the fish pathogenic bacterium Streptococcus parauberis FP KSP28, with an MIC90 value of 0.0472 μg·mL−1.

First record of Bursatella leachii de Blainville, 1817 (Mollusca: Gastropoda: Aplysiidae) in Corsica (France, NW Mediterranean)

This study reports for the first time the occurrence of ragged sea hare Bursatella leachii de Blainville, 1817 in Corsica (France, NW Mediterranean Sea). The species has colonized the shallow waters (0.1–0.5 m depth) of Diana Lagoon mainly constituted of sandy-muddy bottoms and Cymodocea nodosa and Zostera noltei seagrass beds. A total of 166 individuals were inventoried in June 2023 during the survey carried out along more than 300 m of shoreline. The highest density of individuals (0.63 ind m−2) was mainly reported in very warm and sheltered water basins formed by the accumulation of woody debris (mean ± SE: 0.17 ± 0.06 ind m−2). Morphometric measurements of specimens showed an average body length of 54.3 ± 1.7 mm and weight of 14.7 ± 0.8 g. The introduction pathways of this species into this coastal lagoon may have resulted from the natural dispersal of larvae or juveniles or via the shellfish farming located in the lagoon. Extensive monitoring should be carried out along the coast of Corsica to shed light on the occurrence of the species and its spatio-temporal spread. A literature review on B. leachii has enabled us to update the existing dataset on the species distribution. The species is now confirmed from 21 out of 23 countries surrounding the Mediterranean basin.

Bursatella leachii Purple Ink Secretion Concentrate Exerts Cytotoxic Properties against Human Hepatocarcinoma Cell Line (HepG2): In Vitro and In Silico Studies.

Liver cancer is a leading cause of cancer death globally. Marine mollusc-derived drugs have gained attention as potential natural-based anti-cancer agents to overcome the side effects caused by conventional chemotherapeutic drugs during cancer therapy. Using liquid chromatography-mass spectrometry, the main biomolecules in the purple ink secretion released by the sea hare, named Bursatella leachii (B. leachii), were identified as hectochlorin, malyngamide X, malyngolide S, bursatellin and lyngbyatoxin A. The cytotoxic effects of B. leachii ink concentrate against human hepatocarcinoma (HepG2) cells were determined to be dose- and time-dependent, and further exploration of the underlying mechanisms causing the programmed cell death (apoptosis) were performed. The expression of cleaved-caspase-8 and cleaved-caspase-3, key cysteine-aspartic proteases involved in the initiation and completion of the apoptosis process, appeared after HepG2 cell exposure to the B. leachii ink concentrate. The gene expression levels of pro-apoptotic BAX, TP53 and Cyclin D1 were increased after treatment with the B. leachii ink concentrate. Applying in silico approaches, the high scores predicted that bioactivities for the five compounds were protease and kinase inhibitors. The ADME and cytochrome profiles for the compounds were also predicted. Altogether, the B. leachii ink concentrate has high pro-apoptotic potentials, suggesting it as a promising safe natural product-based drug for the treatment of liver cancer.

Anticoagulant Properties from Marine Algae – A Systemic Review

The anticoagulants are used to eliminate mainly blood clots. They are offered to patients who are at risk of developing clots, in order to improve their general wellbeing. Anticoagulant namely heparin, has many disadvantages like thrombocytopenia, antithrombin defensives, bleeding disorders and etc. The marine algae are sulphated polysaccharides has many advantages from commercially available anticoagulant which is derived from the animal's sources. The anticoagulant is found in various species of marine algae, mainly from the red, brown and green algae and its determined by various methods, namely APTT, PT, TT, CT. The marine algae species are Padina tetrastromatica, Ulva fasciata, Corallina, Asparagopsis taxiformis, Grateloupia filicina, Ulva rigida, Bursatella leachii, Agardhiella subulate, Turbinaria ornate, Monostroma angicava, Arthrospira platensis, Sargassum tenerrimum, Sargassum wightii, Turbinaria conoides, Lomentaria catenate, Gracilaria debilis, and Monostroma nitidum are some of the species revealed its anticoagulant properties. The anticoagulant produced by the marine species are compared with standard namely heparin by in vitro and in vivo methods and the review result reveal that the anticoagulant values produced are nearer to the standard and in some species, the value are more than that of standard. The sample are crude extracted one and some samples are isolated from different fraction.

New distributional record of Ragged Sea Hare, Bursatella leachii Blainville, 1817 along western Bay of Bengal

Thirty specimens of Bursatella leachii (Ragged sea hare) of average total length as 30.93 mm and weight as 3.33 g were collected from marine cage site, Ramakrishna beach, Visakhapatnam and Krishna estuary, Nagayalanka along Andhra Pradesh coast during July, 2017 and June, 2019. A literature review on the distribution of this species revealed that, this is the first report of Bursatella leachii from the coast of Andhra Pradesh. Earlier it was recorded from the south east coast and west coast of India. This report provides a new distributional record of the species along western Bay of Bengal. A note on the morphological features of this specimen is detailed in this paper.

Genetic confirmation of ragged sea hare Bursatella leachii (De Blainville 1817) of Pulicat lake India with Mar Menor (SE Spain) species

This study was to investigate the Genetic characteristic of ragged sea hare Bursatella leachii found in Indian water is similar to the species found in Mar Menor (SE Spain) water since pathways/ vector of species introduced into the world wide by the way of transportation activity (shipping activity such as ballast water, sedimentation, anchoring & fouling), aquarium trading (trading of live marine species) and aquaculture activity. The species found in Pulicate Lake, India is genetically matching with the species found in SE Spain water species by 99%. The genetic homogeneity pattern of Bursatella leachii found in Mar Menor (SE Spain) and Pulicat Lake in India is the same species available here.

Extraction, Characterization, and Anticoagulant Activity of a Sulfated Polysaccharide from Bursatella leachii Viscera.

Bioactive compounds for drug discovery are increasingly extracted and purified from natural sources including marine organisms. Heparin is a therapeutic agent that has been used for several decades as an anticoagulant. However, heparin is known to cause many undesirable complications such as thrombocytopenia and risk of hemorrhage. Hence, there is a need to find alternatives to current widely used anticoagulant drugs. Here, we extract a sulfated polysaccharide from sea hare, that is, Bursatella leachii viscera, by enzymatic digestion. Several analytical approaches including elemental analysis, Fourier-transform infrared spectroscopy, nuclear magnetic resonance, and high-performance liquid chromatography–mass spectrometry analysis show that B. leachii polysaccharides have chemical structures similar to glycosaminoglycans. We explore the anticoagulant activity of the B. leachii extract using the activated partial thromboplastin time and the thrombin time. Our results demonstrate that the extracted sulfated polysaccharide has heparin-like anticoagulant activity, thus showing great promise as an alternative anticoagulant therapy.

Impact of Natural and Anthropogenic Perturbations on Animal Behavior: A Cellular Approach

The nervous systems of gastropod molluscs contain large neurons that can be identified in all specimens. They are therefore useful for elucidating the cellular basis of behavior and its modification due to extrinsic factors. Our studies examine two tropical marine gastropod species, Bursatella leachii and Dolabrifera dolabrifera, to determine the impact of natural perturbations and anthropogenic contaminants on identified neurons and motor circuits. Here, we report a census for Bursatella leachii during 2019 and compare it to previous years. We find a reduced population that may be recovering during the two years since the major hurricanes of 2017. Specimens were collected to perform immunohistochemistry with the goal of characterizing the localization of specific neurotransmitters in the nervous system. We found that the catecholamine dopamine is likely to be involved in the regulation of feeding and reproductive behaviors. RNA was also extracted from the CNS of Bursatella in order to generate a nervous system transcriptome. These observations provide a platform for future investigation of the impact of natural and man‐made disturbances on the cellular control of behavior in these model organisms.Support or Funding InformationFunding: NIH (USA): RCMI MD007600, NIGMS‐RISE R25 GM061838 NSF (USA): CREST HRD‐1137725

Molecular and morphological systematics of Bursatella leachii de Blainville, 1817 and Stylocheilus striatus Quoy & Gaimard, 1832 reveal cryptic diversity in pantropically distributed taxa (Mollusca : Gastropoda : Heterobranchia)

The ragged sea hare (Bursatella leachii) and the long-tailed sea hare (Stylocheilus striatus) are two widely distributed species of benthic heterobranch sea slugs. In this paper, integrative taxonomic analyses have been conducted to detect possible cryptic diversity. Our results revealed that both nominal species are actually species complexes, consisting of five genetically distinct taxa. Two of them belong to the genus Bursatella and three to the genus Stylocheilus. The name B. leachii is retained for a widely distributed species, present in the Atlantic, the Mediterranean, and parts of the Indo-Pacific region. The name B. ocelligera is resurrected for the other species, restricted to the Indo-Pacific and co-occurring with B. leachii in that area. With the present data, it is not possible to test whether B. leachii and B. ocelligera have evolved allopatrically in the Atlantic and Indo-Pacific or sympatrically in the latter. Bursatella leachii has been able to maintain gene flow between the Atlantic and the Indo-Pacific Oceans, possibly because of a combined effect of the Agulhas Leakage process and the ability to survive the colder waters of South Africa. On the contrary, the three species of Stylocheilus are allopatric; the name S. striatus is retained for an Indo-Pacific species, while the names S. polyomma and S. rickettsi are resurrected for species inhabiting the Western Atlantic and the Eastern Pacific respectively. Finally, the discovery of a museum specimen mistakenly identified as B. leachii, but bearing a shell in its adult form, led to the resurrection of the genus Phycophila, previously synonymised with Aplysia. Phycophila euchlora, the only species described to date, is distributed in the Central and Western Pacific Ocean.

First confirmed record of the ragged sea hare Bursatella leachii Blainville, 1817 in Libyan waters

First confirmed record of the ragged sea hare Bursatella leachii Blainville, 1817 in Libyan waters

Population genetics of Bursatella leachii (De Blainville, 1817) and implications for the origin of the Mediterranean population

The sea hare Bursatella leachii (de Blainville 1817) (Mollusca: Gastropoda: Heterobranchia: Aplysiidae) is a pantropical sea slug that has colonized the Mediterranean Sea in modern times. Because the initial records in the non-native range started in the Eastern Mediterranean, and its pattern of spread was relatively consistent with those observed in well-known Lessepsian invaders, B. leachii is commonly considered to be a migrant from the Red Sea. In this study, we investigate for the first time the origin of the Mediterranean populations of B. leachii inferring their population structure and assessing relatedness levels of different regional populations. Sequence data from the cytochrome oxidase I were used to conduct population genetic analyses on this species, particularly by investigating the genetic structure of Atlantic, Mediterranean, and Indo-Pacific populations. Our results confirm that B. leachii is a truly pantropical species which displays geographic structure among major ocean basins. More importantly, sequenced Mediterranean and Atlantic animals share similar or identical haplotypes, which are distinct in at least 5 substitutions from haplotypes recovered from Indo-Pacific specimens. The results suggest that the Mediterranean population of B. leachii here examined probably have an Atlantic origin, and for the first time casts doubts on the assumed primary pathway of migration into the Mediterranean Sea.

Natural History Collections and Alien Species: an Overlooked Sample of Bursatella leachii Blainville, 1817 (Mollusca: Gastropoda: Aplysiida) Backdates its Confirmed Presence in Italy

The ragged sea hare Bursatella leachii Blainville, 1817 is a heterobranch mollusc with a circumtropical distribution, that since the mid-1900s colonized the Mediterranean Sea and is now considered as one of the alien taxa most widespread in the basin. Here, we backdate its confirmed presence in the Gulf of Naples and Italy as a whole based on an overlooked sample preserved in the natural history collections of Stazione Zoologica Anton Dohrn (Naples, Italy). The finding reported in the present paper confirms the importance of natural history museums in documenting biogeographic distribution patterns. It also casts doubts on the often assumed pattern of colonization of the Mediterranean basin (combining a Lessepsian origin and natural secondary spread), as it contributes to disrupt the nearly perfect Lessepsian-like spreading highlighted in recent articles.

Bursatella leachii from Mar Menor as a Source of Bioactive Molecules: Preliminary Evaluation of the Nutritional Profile, In Vitro Biological Activities, and Fatty Acids Contents

ABSTRACTMarine invertebrates contain nutritionally important elements that make them suitable to be included in the human diet, and they are considered an outstanding source of secondary metabolites with multiple biotechnological uses. The sea hare Bursatella leachii is an invasive species in Mar Menor that can be managed through the control of its reproduction and/or by massive biomass removal. In this context, this work evaluated the possible use of biomass from B. leachii in the food and cosmetics industries. Biomass was appraised for nutritional properties, and extracts were prepared and evaluated in vitro for antioxidant and anti-inflammatory capacity, cholinesterase and tyrosinase inhibition, and for total contents in different phenolic groups. It had a moderate moisture level, low ash and fat levels, and an adequate protein amount and protein/lipid ratio. The fatty acids (FA) profile was mainly saturated, dominated by palmitic acid. The methanol extract had the highest acetylcholinesterase inhibition. The acetone extract had the strongest capacity to scavenge 1,1-diphenyl-2 picrylhydrazyl (DPPH) radical, reduce iron, inhibit tyrosinase, decrease nitric oxide production in lipopolysaccharide (LPS)-stimulated microglia cells, and the upmost levels of total phenolics, flavonoids, and tannins. Our results suggest multiple biotechnological applications for B. leachii biomass in different economic areas.

“New Mediterranean Biodiversity Records” (March 2017)

This Collective Article presents information on 22 species belonging to 5 Phyla, arranged geographically from from west to east. The new records were found in 8 countries as follows: Spain: first record of the two scarcely known nemerteans Baseodiscus delineatus and Notospermus geniculatus in Formentera; Malta: second record of the alien fish Lagocephalus sceleratus; Italy: the alien polychaete Syllis pectinans and the isopod Paranthura japonica, as well as the cryptogenic opisthobranch Anteaeolidiella lurana, were found in the fouling assemblages along the docks of the port of Livorno. New decapod records are reported from Sicily (the alien Callinectes sapidus and the native Pachygrapsus maurus) and Apulia (Percnon gibbosus and Procambarus clarkii); the lesser amberjack Seriola fasciata extended its geographical range to the Egadi Isands and Siganus luridus was documented for the first time along the Ionian coasts of Apulia and Calabria. Slovenia: the first record of the alien bivalve Brachidontes pharaonis is reported, together with a survey of up to date Adriatic records. Greece: the first record of the gastropod Rhinoclavis kochi is reported from Gavdos island. In addition, two records of endangered and rare cartilaginous fish were reported, namely, the shark Hexanchus griseus and the ray Leucoraja fullonica, as well as additional records of Siganus luridus for Lesvos and Malleus regula and Fulvia fragilis from Astypalaia. Turkey: the black wing flyingfish Hirundichthys rondeletii is reported for the very first time from the Black Sea. Egypt: the Indo-Pacific crab Halimede ochtodes is reported as established in Port Said. In addition, biometric parameters and meristic counts are reported for Anthias anthias in Damietta. Cyprus: the alien opisthobranch gastropod Bursatella leachii is reported for first time.

Closing the circle in the Mediterranean Sea: Bursatella leachii Blainville, 1817 (Mollusca: Gastropoda: Anaspidea) has reached Morocco

Closing the circle in the Mediterranean Sea: Bursatella leachii Blainville, 1817 (Mollusca: Gastropoda: Anaspidea) has reached Morocco

“Opisthobranch” (mollusks) inventory of the Faro Lake: a Sicilian biodiversity hot spot

A census of the “opisthobranch” fauna in the Faro Lake and connected canals (NE Sicily) has been realized by photo documentation and specimen samplings, carried out monthly from February 2010 to the present. A total of 47 species have been reported, nine of which are cited in the historic and recent literature (from 1969 to 2016) vs. 38 first records; six were non-indigenous species. A major number of species, 16, was found exclusively in the lake with respect to the four species localized in the canals, whilst 10 were shared species. Based on the frequency of records, 24 “occasional”, 20 “settled” and three “invasive” species have been distinguished; these latter included two non-indigenous species, Aplysia dactylomela and Bursatella leachii, plus the Mediterranean Dendrodoris limbata, whose recent introduction in the Faro Lake from other Mediterranean lagoons is here postulated.

Sequestration of Dimethylsulfoniopropionate (DMSP) and Acrylate from the Green Alga Ulva Spp. by the Sea Hare Aplysia juliana.

Many animals sequester secondary metabolites from their food. In this study, we hypothesized that the sea hare Aplysia juliana sequesters secondary metabolites from green algae. To test this, we performed NMR-based metabolomic analysis on methanol extracts of Ulva spp. and A. juliana. Another sea hare, Bursatella leachii, which mainly feeds on another type of alga, was added to this analysis as an outgroup. Two body parts of the sea hares, skin and digestive glands, were used in the analysis. Principal component analysis (PCA) on the NMR data of these samples detected biomarkers common to Ulva spp. and A. juliana. This result indicates sequestration of secondary metabolites by the herbivore from the plants. The biomarker metabolites were identified as dimethylsulfoniopropionate (DMSP) and acrylate, which were concentrated in skin of A. juliana and were released from the skin of live animals when physically stressed. Thus, our NMR-based metabolomic study revealed sequestration of algae-derived secondary metabolites in skin of A. Juliana, and in the discharge of the metabolites under conditions that mimic attack by predators.

New records of marine “sea slugs” (Mollusca: Gastropoda: Heterobranchia) in the outlets of the estuary systems in Paraná, southern Brazil

Four species of shell-less marine gastropods, col­lectively called “sea slugs”, are newly recorded from outlets of estuarine systems, the Paranaguá estuarine complex and Guaratuba Bay, on the coast of Paraná state. These include a marine pulmonate slug, Onchidella indolens (Gould, 1852) (Eu­pulmonata: Systellommatophora: Onchidellidae); two species of sea hares, Bursatella leachii de Blainville, 1817 (Euthyneu­ra: Sacoglossa: Aplysiidae) and Elysia serca Er. Marcus, 1955 (Euthyneura: Sacoglossa: Plakobranchidae); and one species of nudibranch, Spurilla braziliana MacFarland, 1909 (Nudi­pleura: Aeolidiidae). Egg mass shapes of E. serca and B. leachii are newly described.

Comparative analysis of early ontogeny in Bursatella leachii and Aplysia californica.

Opisthobranch molluscs exhibit fascinating body plans associated with the evolution of shell loss in multiple lineages. Sea hares in particular are interesting because Aplysia californica is a well-studied model organism that offers a large suite of genetic tools. Bursatella leachii is a related tropical sea hare that lacks a shell as an adult and therefore lends itself to comparative analysis with A. californica. We have established an enhanced culturing procedure for B. leachii in husbandry that enabled the study of shell formation and loss in this lineage with respect to A. californica life staging.