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Preliminary study on antimicrobial activities of skin mucus from by-catch of Elasmobranch species

100%

Aydoğdu E. Ö. A. , Kesiktaş M. , Sanli N. O. , Güngör N. D. , Sancar S. , Yildiz T. , Yemişken E.

Oceanological and Hydrobiological Studies

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2023

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tom Vol. 52, No. 2

137--146

EN

Skates and rays, which are widely encountered in the by-catch of fisheries activities from the Sea of Marmara and banned for sale by regulation, are species that are discardedif caught. For this reason, in our study, we aimed to determine the bioactive potentials of these species, considered fishing waste, by investigating the skin secretions and microbial flora. In our study, both the skin flora and mucus contents of the discarded species Dasyatis pastinaca (Linnaeus,1758), Myliobatis aquila (Linnaeus, 1758), and Raja clavata(Linnaeus, 1758) caught in the Sea of Marmara were investigated to determine their potential antimicrobial activities. A total of 164 bacteria were isolated from the epidermal mucus of the three batoid species. Antibacterial activity was observed from three isolated bacteria against Escherichia coli, Vancomycin-resistant Enterococcus faecium, E. faecalis, and Bacillus subtilis. Additionally, the highest antibacterial activity was observed for skin mucus of R. clavata. Mouse fibroblast cell viability was challenged with mucus secretions. M. aquila and R. clavata mucus secretions exhibited no observable change after 24 and 48 hours. The assays indicated that both the isolates and the skin mucushave potential antimicrobial activity against opportunistic pathogens.

2

Ontogenetic development of storied ray pattern in cambium of Hippophae rhamnoides L.

86%

Myskow E. , Zagorska-Marek B.

Acta Societatis Botanicorum Poloniae

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2004

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tom 73

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nr 2

EN

Storied pattern, in the arrangement of both fusiform initials and the rays in cambium of Hippophae rhamnoides, develops in ontogeny relatively quickly and becomes clearly visible in terminal parenchyma of third and fourth annual ring. At first, anticlinal longitudinal divisions and restricted intrusive growth of fusiform initials lead to the formation of their characteristic horizontal tiers. Then, initiation of secondary rays, taking place rather within such tiers, not between them, makes possible the formation of storied ray pattern. New secondary rays originate most frequently from fusiform initials by their segmentation. This makes the appearance of ray tiers rather quick. However, the high order in the structure of cambium of Hippophae rhamnoides is also due to another, very curious and not known until now mechanism. It operates through limited in its range, thus highly controlled, vertical migration of rays on the cambial surface. This applies to asymmetrically positioned rays either primary, which are often originally sited "out of order" or secondary, initiated off-centre within the existing tiers. Excessively asymmetric rays, lying accidentally on the border between two neighbouring storeys, often undergo splitting and then the derivative rays move toward the centres of the storeys. Ray displacement is due to elimination of one or two of ray initial cells on one edge of the ray and simultaneous, multiple divisions adding new ray cells on the opposite edge.

3

Late Oligocene sharks and rays from the Chandler Bridge Formation, Dorchester County, South Carolina, USA

72%

Cicimurri D. J. , Knight J. L.

Acta Palaeontologica Polonica

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2009

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tom 54

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nr 4

EN

A diverse vertebrate fauna, dominated by elasmobranch taxa, was collected from the upper Oligocene (Chattian) Chandler Bridge Formation in Summerville, Dorchester County, South Carolina. Nearly 3,500 teeth and dermal denticles are assigned to 29 species of sharks and rays, and our sample includes the oldest known occurrence of the whale shark, Rhincodon, as well as a new skate, Raja mccollumi sp. nov. The Chandler Bridge elasmobranch assemblage is comparable in species diversity to Chattian assemblages of Virginia and North Carolina, USA, and Germany. Notable absences from Germany include Rhincodon, Hemipristis, and Sphyrna zygaena, likely reflecting the influence of colder water on the North Sea Basin during the Chattian. Squaloids, pristiophoroids, and hexanchoids are known from Chattian deposits of the Albemarle Embayment (North Carolina), Salisbury Embayment (Virginia), and North Sea Basin, but these taxa are absent from the Chandler Bridge assemblage, perhaps because of shallow, warm water (20 to 25°C) conditions within the more southerly Charleston Embayment.

4

Two thousand parasites on a single ray: An infection with two species of skin monogeneans on a blotched fantail ray kept in an aquarium

72%

Justine J. L. , Grugeaud A. , Keller F. , Leblanc P.

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tom 55

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nr 3

286-290

EN

A blotched fantail ray, Taeniurops meyeni (Müller et Henle, 1841), was captured in New Caledonia, South Pacific, and kept in a tank for quarantine before exhibition at the Nouméa public aquarium. After 24 days, the ray exhibited a heavy infection with two species of skin monogeneans. A freshwater bath allowed the collection of 1,914 monogeneans, including 1,453 capsalids, Neoentobdella taiwanensis Whittington et Kearn, 2009, on the ventral surface, and 461 monocotylids, Dendromonocotyle pipinna Chisholm et Whittington, 2004, on the dorsal surface. More than 300 monogeneans were prepared on slides to allow precise measurements. Capsalids and monocotylids occupied about 6% and 0.2% of the total ventral and dorsal ray surfaces, respectively.

FR

Une raie, Taeniurops meyeni (Müller et Henle, 1841), a été capturée en Nouvelle-Calédonie, Pacifique Sud, et gardée dans un bac en quarantaine avant exposition à l’Aquarium de Nouméa. Après 24 jours, la raie a montré une forte infection par deux espèces de monogènes de la peau. Un bain d’eau douce a permis la récolte de 1914 monogènes, dont 1453 Capsalidae, Neoentobdella taiwanensis Whittington et Kearn, 2009 sur la surface ventrale, et 461 Monocotylidae, Dendromonocotyle pipinna Chisholm et Whittington, 2004 sur la surface dorsale. Plus de 300 monogènes ont été montés en lames pour permettre des mesures précises. Les Capsalidae et les Monocotylidae occupaient approximativement 6% et 0,2% des surfaces ventrale et dorsale de la raie, respectivement.

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The effect of gamma irradiation dose on cucumber [Cucumis sativus L.] haploid embryo production

72%

Faris N. M. , Nikolova V. , Niemirowicz-Szczytt K.

Acta Physiologiae Plantarum

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1999

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tom 21

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nr 4

6

On open mappings of compactifications of the ray onto an arc

58%

Charatonik J. J. , Charatonik W. J. , Pyrih P.

Bulletin of the Polish Academy of Sciences. Mathematics

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2002

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tom Vol. 50, no 1

11-20

EN

The existence of an open mapping from a compactification of a ray onto the closed unit interval [0, 1] is investigated. The main theorem says that such an open mapping does exist if and only if there is a confluent mapping of the remainder onto [0, 1].