Antioxidant and immunomodulatory effects of spermidine and spermine in pearl oysters Pinctada fucata martensii

Aquaculture ◽  
2021 ◽  
pp. 737876
Author(s):  
Yanfei Cao ◽  
Zhixin Li ◽  
Xueru Liang ◽  
Jiayi Chen ◽  
Xinwei Xiong ◽  
...  
Keyword(s):  
Pinctada Fucata ◽  
Immunomodulatory Effects ◽  
Pearl Oysters

scholarly journals Mass mortality of pearl oyster (Pinctada fucata (Gould)) in Japan in 2019 and 2020 is caused by an unidentified infectious agent

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12180
Author(s):  
Tomomasa Matsuyama ◽  
Satoshi Miwa ◽  
Tohru Mekata ◽  
Yuta Matsuura ◽  
Tomokazu Takano ◽  
...  
Keyword(s):  
Infectious Agent ◽  
Serial Passage ◽  
Pearl Oyster ◽  
Mass Mortality ◽  
Pinctada Fucata ◽  
Enveloped Virus ◽  
Pearl Oysters ◽  
Adult Oyster ◽  
Sources Of Infection ◽  
Pathogen Occurrence

Mass mortality of 0-year-old pearl oysters, Pinctada fucata (Gould), and anomalies in adults were observed in Japan’s major pearl farming areas in the summer of 2019 and 2020. Although adult oyster mortality was low, both adult and juvenile oysters underwent atrophy of the soft body, detachment of the mantle from nacre (the shiny inner surface of the valves), deposition of brownish material on the nacre, and loss of nacre luster. Infection trials were conducted to verify the involvement of pathogens in this phenomenon. Healthy adult pearl oysters were obtained from areas where this disease had not occurred to use as the recipients. The sources of infection were either affected adult oysters with atrophied soft bodies or batches of juveniles in which mortality had reached conspicuous levels. Transmission of the disease to the healthy oysters were tested either by cohabitation with affected oysters or by injections of the hemolymph of affected animals. The injection infection test examined the effects of filtration and chloroform exposure on the pathogen. Occurrence of the disease was confirmed by the appearance of brown deposits on the nacre and loss of nacre luster. The abnormalities of nacre were clearly reproduced in recipient shells in three out of four cohabitation trials with affected oysters. The disease was also reproduced in six out of six injection trails either with hemolymph filtered through 100 nm filter or with hemolymph treated with chloroform. In a serial passage with hemolymph injections, the disease was successfully transmitted through eight passages. These results suggest that the etiology of the disease is a non-enveloped virus with a diameter ≤100 nm.

scholarly journals Microbiota Diversity in Pearl Oyster Pinctada fucata martensii Intestine and Its Aquaculture Environment

2021 ◽  
Vol 8 ◽  
Author(s):  
Zhe Zheng ◽  
Yongshan Liao ◽  
Jianming Ye ◽  
Chuangye Yang ◽  
Linda Adzigbli ◽  
...  
Keyword(s):  
Amino Acids ◽  
Intestinal Microbiota ◽  
Bacterial Communities ◽  
Pearl Oyster ◽  
Pinctada Fucata ◽  
Sequencing Data ◽  
Surrounding Water ◽  
Core Microbiome ◽  
Pearl Oysters ◽  
Surrounding Seawater

Environmental microbiota plays a vital role in the intestinal microbiota of aquatic organisms. However, data concerning the association between the intestinal microbiota of pearl oyster Pinctada fucata martensii and the surrounding seawater are limited. The existing bacterial communities in pearl oyster intestine and surrounding water from two sites (D and H, within Liusha Bay in Guangdong, China) were investigated using 16S rRNA-based sequencing to explore the relationship among the two. D located in the inner bay, and H located in the open sea area outside bay. Results revealed the richness and diversity of pearl oyster intestinal microbiota to be less than those of the surrounding water, with 38 phyla and 272 genera observed as a result of the classifiable sequence. The microbiota compositions in the intestine and the surrounding water were diversified at the phylum and genus levels, with the sequencing data being statistically significant. However, the functional prediction of microbiota emphasized the overall similarity in the functional profile of the surrounding seawater and intestinal microbiomes. This profile was associated with metabolism of cofactors and vitamin, carbohydrates metabolism, amino acids metabolism, metabolism of terpenoids, and polyketides, metabolism of other amino acids, lipids metabolism, and energy metabolism. Seven common operational taxonomic units (OTUs), which belonged to phyla Tenericutes, Cyanobacteria, and Planctomycetes, were noted in the intestines of pearl oysters from two different sites. These OTUs may be affiliates to the core microbiome of pearl oyster. Significantly different bacterial taxa in the intestines of pearl oysters from two different sites were found at the phylum and genus levels. This finding suggested that the bacterial communities in pearl oyster intestines may exhibit some plasticity to adapt to changes in the surrounding water-cultured environment. This study generally offers constructive discoveries associated with pearl oyster intestinal microbiota and provides guidance for sustainable aquaculture.

scholarly journals ​Isolation and Characterization of a Vibrio Sp. Strain MA3 Possibly Associated with Mass Mortalities of the Pearl Oyster Pinctada fucata

2021 ◽  
Author(s):  
Akihiro SAKATOKU ◽  
Kaito Hatano ◽  
Shoki Tanaka ◽  
Tadashi Isshiki
Keyword(s):  
Soft Tissues ◽  
Morphological Characteristics ◽  
Pearl Oyster ◽  
Vibrio Alginolyticus ◽  
Pinctada Fucata ◽  
Causative Organism ◽  
Rrna Gene ◽  
Isolation And Characterization ◽  
Pearl Oysters ◽  
Mass Mortalities

Abstract In the summers of 2019 and 2020, a previously undescribed disease occurred in both juvenile and adult shellfish, causing mass mortalities in cultured pearl production, characterized by the major symptom of extreme atrophy of the soft tissues, including the mantle. However, the causative organism was uncertain. We isolated Vibrio sp. strain MA3 from the mantles of diseased pearl oysters Pinctada fucata. Analyses of 16S rRNA gene and DNA gyrase sequence homologies and its biochemical and morphological characteristics suggested that strain MA3 is a new strain of Vibrio alginolyticus. In addition, a hemolysin gene (Vhe1) of strain MA3 was detected as one of the virulence factors, and the complete sequence was determined. BLAST searches showed that Vhe1 shares 99.8% nucleotide sequence identity with Vibrio alginolyticus strain A056 lecithin-dependent hemolysin (ldh) gene, complete cds. Experimental infection of healthy oysters via injection with strain MA3 indicated it could cause high mortalities of the typically affected oysters from which the strain was isolated. These results suggest that the newly isolated Vibrio sp. strain MA3 is a putative causal agent of the recent disease outbreaks in Akoya pearl oysters.

scholarly journals Mass mortalities associated with a virus disease in Japanese pearl oysters Pinctada fucata martensii

1999 ◽  
Vol 37 ◽  
pp. 1-12 ◽  
Author(s):  
T Miyazaki ◽  
K Goto ◽  
T Kobayashi ◽  
T Kageyama ◽  
M Miyata
Keyword(s):  
Virus Disease ◽  
Pinctada Fucata ◽  
Pearl Oysters ◽  
Mass Mortalities
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