Fatal Streptococcus iniae Infection in a Juvenile Free-Ranging Short-Beaked Common Dolphin (Delphinus delphis)

Streptococcus iniae (S. iniae) is a significant aquatic pathogen of farmed fish species, important zoonotic pathogen, and reported cause of disease in captive Amazon River dolphins (Inia geoffrensis) and a bottlenose dolphin (Tursiops truncatus). Here we report S. iniae as the cause of subcutaneous abscesses, sepsis and mortality in a juvenile free-ranging short-beaked common dolphin (Delphinus delphis) found deceased on a metropolitan Australian beach. Body surfaces were covered by multifocal, depressed, deep, irregular cutaneous ulcerations, which microscopically were characterised by ruptured subcutaneous abscesses with intralesional cocci. Routine microbiological investigations revealed a heavy growth of beta-haemolytic Streptococcus sp. identified as Streptococcus iniae in skin lesions as well as from heart blood, the latter supportive of sepsis. Tissues were negative for cetacean morbillivirus and no other disease processes were identified. S. iniae has not been reported in free-ranging marine mammals, nor in Australian delphinids, previously. More notably a pathogen of captive animals, this case report identifies S. iniae as a pathogen of wild dolphins also. In addition to expanding the host reservoir of a significant zoonotic pathogen, determining the source of infection as well as possible consequences for other marine mammals and wild and intensive fish stocks warrants further investigations.

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Occurrence, distribution and composition of marine mammals in the bight of Bony, Nigeria

International Journal of Biological and Chemical Sciences ◽

10.4314/ijbcs.v15i1.23 ◽

2021 ◽

Vol 15 (1) ◽

pp. 263-272

Author(s):

Gideon Wole Olakunle ◽

Ajuonu Ndubisi

Keyword(s):

Marine Mammals ◽

Bottlenose Dolphins ◽

Atlantic Coast ◽

Primary Objective ◽

Depth Range ◽

Common Dolphin ◽

Coastal Habitat ◽

Oil Companies ◽

Delphinus Delphis ◽

Marine Vessels

Information on the distribution, occurrence and population structure of cetaceans (whales and dolphins) of the Atlantic coast of Nigeria in West Africa remains fairly sparse to date, with few detailed studies being conducted on this valuable marine resource. This paper highlights the abundant cetacean community sighted in the Nigerian coastal waters and the respective importance of this area as a prime coastal habitat for these mammals. The secondary objective was the evaluation of this resource and development of appropriatemanagement policies. Opportunistic data was collected on board six different marine vessels belonging to some international oil companies (IOC) in Nigeria, whose primary objective was to conduct seismic operations. 8,327 hours and 36 minutes of effort was logged during 2 wet and 3 dry seasons respectively, covering almost 880 km2 at a depth range of 10 to 70 m. The total number of individuals recorded was 2199 of which 80% were dolphins and 20% were whales. Out of these, 55.14% was sighted at depth range of 21 – 30 m. This was followed by 30.42% recorded at depth range of 31 - 40 m. The least frequency of 0.75 % was recorded at depth range of 61- 70m. Five hundred and twenty-five (525) individual whales was recorded, out of which 77.14% were adults and 22.86% were juveniles, while 1674 individual dolphins were recorded with 52.63% juveniles and 47.37% adult. Four species of dolphins were identified. The bottlenose dolphins, Tursiops truncatus was the most abundant owing to the large size of the groups observed, followed by common dolphin, Delphinus delphis. All species of dolphins identified occurred throughout the sampling months. Two species of whales were identified with the humpback whale (Megaptera novaeangliae) predominant and killer whales (Orcinus orca) which seem to be present in just a part of a year. Nigerian coastal water is moderately rich in cetacean diversity, which is currently underreported due to limited research.Keywords: Whales, dolphins, species diversity, opportunistic surveys, Nigeria.

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Diversity, Distribution, and Density of Marine Mammals Along the Saudi Waters of the Arabian Gulf: Update From a Multi-Method Approach

Frontiers in Marine Science ◽

10.3389/fmars.2021.687445 ◽

2021 ◽

Vol 8 ◽

Author(s):

Lotfi Rabaoui ◽

Ruben H. Roa-Ureta ◽

Lamia Yacoubi ◽

Yu-Jia Lin ◽

Rommel Maneja ◽

...

Keyword(s):

Marine Mammals ◽

Oil And Gas ◽

Bottlenose Dolphins ◽

Arabian Gulf ◽

Abundant Species ◽

Common Species ◽

Common Dolphin ◽

Cetacean Species ◽

Delphinus Delphis ◽

Multi Method Approach

Despite the important role of marine mammals in marine ecosystems and the imperative for their conservation, there is still a great lack of information on the diversity, distribution, and density of these animals in the Saudi waters of the Arabian Gulf. To fill this gap, an integrative data-collection approach including fishermen’s questionnaires, opportunistic sighting reports, and directed boat-based surveys, was undertaken between 2016 and 2020, leading to the first scientific report of marine mammal diversity, distribution, and density in the region. The results of the different approaches carried out during the study confirmed a high diversity of cetaceans on the west coast of the study area, with bottlenose dolphins (Tursiops aduncus), humpback dolphins (Sousa plumbea) and dugongs (Dugong dugon) as the most common species. While the two dolphin species were found to be widely distributed in both coastal and offshore waters, D. dugon appears to occur exclusively in coastal waters in the southern part of the study area, mainly in the Gulf of Salwah. The presence of both species of dolphins increased during the summer months and in the vicinity of the numerous oil and gas facilities in this region. The distribution of the observed dolphins was found mostly within a 10–20 km radius around each facility. Other cetacean species observed less frequently in the area include Bryde’s whale (Balaenoptera edeni), killer whale (Orcinus orca), common dolphin (Delphinus delphis) and finless porpoise (Neophocaena phocaenoides). Regarding the density of marine mammals in the region, boat-based surveys confirmed the results of fishermen’s questionnaires and reports of opportunistic sightings, with bottlenose and humpback dolphins being the most abundant species. These results provide a baseline for policies oriented to the conservation of mammals in the Saudi waters of the Arabian Gulf.

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Coinfection by Streptococcus phocae and cetacean morbillivirus in a short-beaked common dolphin Delphinus delphis

Diseases of Aquatic Organisms ◽

10.3354/dao03124 ◽

2017 ◽

Vol 124 (3) ◽

pp. 247-252 ◽

Cited By ~ 6

Author(s):

J Díaz-Delgado ◽

E Sierra ◽

AI Vela ◽

M Arbelo ◽

D Zucca ◽

...

Keyword(s):

Common Dolphin ◽

Delphinus Delphis ◽

Cetacean Morbillivirus

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Marine mammals are natural hosts of Oceanivirga salmonicida, a bacterial pathogen of Atlantic salmon

Diseases of Aquatic Organisms ◽

10.3354/dao03478 ◽

2020 ◽

Vol 139 ◽

pp. 161-174

Author(s):

R Palmer ◽

GTA Fleming ◽

S Glaeser ◽

T Semmler ◽

A Flamm ◽

...

Keyword(s):

16S Rrna ◽

Atlantic Salmon ◽

16S Rrna Gene ◽

Marine Mammals ◽

Rrna Gene ◽

Bacterial Disease ◽

Common Dolphin ◽

Stenella Coeruleoalba ◽

Striped Dolphin ◽

Natural Hosts

During 1992 and 1993, a bacterial disease occurred in a seawater Atlantic salmon Salmo salar farm, causing serious mortalities. The causative agent was subsequently named as Oceanivirga salmonicida, a member of the Leptotrichiaceae. Searches of 16S rRNA gene sequence databases have shown sequence similarities between O. salmonicida and uncultured bacterial clones from the digestive tracts of marine mammals. In the current study, oral samples were taken from stranded dolphins (common dolphin Delphinus delphis, striped dolphin Stenella coeruleoalba) and healthy harbour seals Phoca vitulina. A bacterium with growth characteristics consistent with O. salmonicida was isolated from a common dolphin. The isolate was confirmed as O. salmonicida, by comparisons to the type strain, using 16S rRNA gene, gyrB, groEL, and recA sequence analyses, average nucleotide identity analysis, and MALDI-TOF mass spectrometry. Metagenomic analysis indicated that the genus Oceanivirga represented a significant component of the oral bacterial microbiomes of the dolphins and seals. However, sequences consistent with O. salmonicida were only found in the dolphin samples. Analyses of marine mammal microbiome studies in the NCBI databases showed sequences consistent with O. salmonicida from the common dolphin, striped dolphin, bottlenose dolphin Tursiops truncatus, humpback whale Megaptera novaeangliae, and harbour seal. Sequences from marine environmental studies in the NCBI databases showed no sequences consistent with O. salmonicida. The findings suggest that several species of marine mammals are natural hosts of O. salmonicida.

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Expanding protected areas to encompass the conservation of the endangered common dolphin (Delphinus delphis) in the Alboran Sea

Marine Environmental Research ◽

10.1016/j.marenvres.2021.105305 ◽

2021 ◽

Vol 168 ◽

pp. 105305

Author(s):

Joan Giménez ◽

Ana Cañadas ◽

Renaud de Stephanis ◽

Francisco Ramírez

Keyword(s):

Protected Areas ◽

Common Dolphin ◽

Alboran Sea ◽

Delphinus Delphis ◽

Alborán Sea

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Plasma Treatment of Fish Cells: The Importance of Defining Cell Culture Conditions in Comparative Studies

Applied Sciences ◽

10.3390/app11062534 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2534

Author(s):

Henrike Rebl ◽

Claudia Bergemann ◽

Sebastian Rakers ◽

Barbara Nebe ◽

Alexander Rebl

Keyword(s):

Plasma Treatment ◽

Cell Lines ◽

Mammalian Cells ◽

Atmospheric Pressure Plasma ◽

Fish Farming ◽

Skin Lesions ◽

Atmospheric Plasma ◽

Fish Cell ◽

Farmed Fish ◽

Fish Cells

The present study provides the fundamental results for the treatment of marine organisms with cold atmospheric pressure plasma. In farmed fish, skin lesions may occur as a result of intensive fish farming. Cold atmospheric plasma offers promising medical potential in wound healing processes. Since the underlying plasma-mediated mechanisms at the physical and cellular level are yet to be fully understood, we investigated the sensitivity of three fish cell lines to plasma treatment in comparison with mammalian cells. We varied (I) cell density, (II) culture medium, and (III) pyruvate concentration in the medium as experimental parameters. Depending on the experimental setup, the plasma treatment affected the viability of the different cell lines to varying degrees. We conclude that it is mandatory to use similar cell densities and an identical medium, or at least a medium with identical antioxidant capacity, when studying plasma effects on different cell lines. Altogether, fish cells showed a higher sensitivity towards plasma treatment than mammalian cells in most of our setups. These results should increase the understanding of the future treatment of fish.

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Vitamin A physiology in the precocious harbour seal (Phoca vitulina): a tissue-based biomarker approach

Canadian Journal of Zoology ◽

10.1139/z02-152 ◽

2002 ◽

Vol 80 (9) ◽

pp. 1511-1519 ◽

Cited By ~ 19

Author(s):

Lizzy Mos ◽

Peter S Ross

Keyword(s):

Vitamin A ◽

Marine Mammals ◽

Relevant Information ◽

Phoca Vitulina ◽

Retinyl Palmitate ◽

Harbour Seal ◽

Natural Processes ◽

Reproductive Endocrine ◽

Positive Correlations ◽

Free Ranging

Vitamin A is a nutrient essential to all mammals for growth and development, as well as for the maintenance of reproductive, endocrine, and immune systems. Environmental contaminant-related disruption of vitamin A has been observed in many wildlife species and can therefore be used as a biomarker of toxic effects. However, the natural processes regulating vitamin A uptake, storage, and distribution among compartments are poorly understood in marine mammals. In this study, 20 young healthy harbour seals (Phoca vitulina) were captured to establish a compartment-based model providing a foundation for a mechanistic understanding of vitamin A physiology and disruption. Vitamin A (retinol, retinyl palmitate, and (or) retinoic acid) was quantified in blood plasma and in biopsy samples of liver, blubber, and skin. Although the highest concentrations of vitamin A were found in liver, blubber represents a more important storage depot, with an estimated 66% of the total retinoid content of the compartments measured. We suggest that vitamin A physiology in the precocious harbour seal has evolved to deal with high vitamin A availability during a short nursing period and to sustain growth during the postweaning fast. Positive correlations in vitamin A concentrations among liver, blubber, and skin support the use of less invasive biopsy sampling of just blubber or skin, which can provide physiologically relevant information in biomarker studies of free-ranging marine mammals.

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Microplastics in the stomach contents of common dolphin (Delphinus delphis) stranded on the Galician coasts (NW Spain, 2005–2010)

Marine Pollution Bulletin ◽

10.1016/j.marpolbul.2018.10.026 ◽

2018 ◽

Vol 137 ◽

pp. 526-532 ◽

Cited By ~ 30

Author(s):

Alberto Hernandez-Gonzalez ◽

Camilo Saavedra ◽

Jesús Gago ◽

Pablo Covelo ◽

M. Begoña Santos ◽

...

Keyword(s):

Stomach Contents ◽

Common Dolphin ◽

Nw Spain ◽

Delphinus Delphis

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Canine distemper virus infection in a lesser grison (Galictis cuja): first report and virus phylogeny

Pesquisa Veterinária Brasileira ◽

10.1590/s0100-736x2013000200018 ◽

2013 ◽

Vol 33 (2) ◽

pp. 247-250 ◽

Cited By ~ 8

Author(s):

Jane Megid ◽

Carlos R. Teixeira ◽

Adriana Cortez ◽

Marcos B. Heinemann ◽

João M.A.P. Antunes ◽

...

Keyword(s):

Virus Infection ◽

Canine Distemper Virus ◽

Wildlife Conservation ◽

Domestic Animals ◽

Canine Distemper ◽

Habitat Alterations ◽

Source Of Infection ◽

First Case ◽

In Captivity ◽

Free Ranging

Infectious diseases in wild animals have been increasing as a result of their habitat alterations and closer contact with domestic animals. Canine distemper virus (CDV) has been reported in several species of wild carnivores, presenting a threat to wildlife conservation. We described the first case of canine distemper virus infection in lesser grison (Galictis cuja). A free-ranging individual, with no visible clinical sigs, presented sudden death after one day in captivity. Molecular diagnosis for CDV infection was performed using whole blood collected by postmortem intracardiac puncture, which resulted positive. The virus phylogeny indicated that domestic dogs were the probable source of infection.

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