Long-term shifts in the growth and maturation size of Miyabe charr <Emphasis Type="Italic">Salvelinus malma miyabei</Emphasis>     

Yuki Yamamoto  Taku Yoshiyama  Keitaro Kajiwara  Toshikuni Nakatani  Takashi Matsuishi 《Fisheries Science》2018,84(3):425-433

Overfishing can affect life history traits, resulting in population collapse and oftentimes a decrease in length-at-age and maturation size in fish populations. However, little is known about the recovery mechanisms and time scales of these traits in exploited wild populations. In the study reported here, we documented long-term shifts in growth and mature size in Miyabe charr Salvelinus malma miyabei associated with a history of recreational fishing in Lake Shikaribetsu for approximately 80 years. Downsizing in the charr was observed when the charr population collapsed due to intensive recreational fishing. However, subsequent moratoriums and the introduction of fishing regulations, especially the implementation of a catch-and-release policy, during the following 10–30 years facilitated the recovery of population size, length-at-age and mature fish size. This study provides important insights into the biological changes and required recovery time scales of a heavily harvested population and supports management and conservation strategies.  相似文献   

Effect of supplemented sericin on the development,cell number,cryosurvival and number of lipid droplets in cultured bovine embryos          下载免费PDF全文

Misa Hosoe  Yasushi Inaba  Yutaka Hashiyada  Kei Imai  Kenji Kajitani  Yuichi Hasegawa  Mamoru Irie  Hidetoshi Teramoto  Toru Takahashi  Sueo Niimura 《Animal Science Journal》2017,88(2):241-247

Sericin was investigated as an alternative to fetal bovine serum (FBS) for bovine embryo culture. In vitro matured oocytes were developed using 0.05%, 0.1% or 0.15% sericin. The developmental rate, cryosurvival rate and blastulation time of these embryos were compared with those of embryos developed using 5% FBS. The number of lipid droplets was compared among the blastocysts developed using 5% FBS, using 0.05% sericin and in vivo. The rate of cleavage and blastocyst formation was similar among all groups. Blastulation occurred significantly earlier in the embryos developed using 5% FBS than in those developed using sericin at any concentration (P < 0.05). At 72 h after thawing, the cryosurvival rate of the blastocysts developed using 5% FBS and 0.05% sericin were significantly higher compared with those developed using 0.1% and 0.15% sericin (P < 0.05). The blastocysts developed using 0.05% sericin and in vivo produced a significantly fewer number of medium and large lipid droplets than those developed using 5% FBS. These results suggest that the blastocysts developed using 0.05% sericin show characteristics similar to those of the blastocysts developed in vivo and that the use of sericin as an alternative to FBS is feasible.  相似文献   

Effects of mycoplasmal pneumonia of swine (MPS) lung lesion‐selected Landrace pigs on MPS resistance and immune competence in three‐way crossbred pigs          下载免费PDF全文

Liushiqi Borjigin  Tomoyuki Shimazu  Yuki Katayama  Kouichi Watanabe  Haruki Kitazawa  Sang‐gun Roh  Hisashi Aso  Kazuo Katoh  Masahiro Satoh  Yoshihito Suda  Akiko Sakuma  Mituru Nakajo  Keiichi Suzuki 《Animal Science Journal》2017,88(4):575-585

To clarify the genetic influence of mycoplasmal pneumonia of swine (MPS) lesion‐selected Landrace (La) on MPS resistance and immune characteristics in three‐way crossbred pigs (LaWaDa), the LaWaDa pigs were compared with the non‐selected crossbred (LbWbDb) and purebred (La) pigs. The MPS lesion score in the three lines was as follows: La line < LaWaDa line < LbWbDb line, with significant differences among the lines. The proportions of myeloid cells and T cells were lower and higher, respectively, in the LaWaDa pigs compared with those in the other two lines. Messenger RNA (mRNA) expression of interleukin (IL)‐6, IL‐10, transforming growth factor‐β, and interferon‐γ in peripheral blood was significantly increased after vaccination in the La and LaWaDa lines. IL‐4 mRNA expression in the LaWaDa line was intermediate to the La and LbWbDb lines. Furthermore, principal component analysis for immune traits and MPS lesions was executed to clarify the characteristics of each pig line. These findings suggest that the immune responses in the three pig lines are genetically distinct and that MPS resistance and some immunity characteristics from the La line were transmitted to the three‐way crossbred pigs.  相似文献   

Comparison of Survival Times for Dogs with Pituitary‐Dependent Hyperadrenocorticism in a Primary‐Care Hospital: Treated with Trilostane versus Untreated          下载免费PDF全文

N. Nagata  K. Kojima  M. Yuki 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2017,31(1):22-28

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Starch Characteristics of the Rice Mutant du2‐2 Taichung 65 Highly Affected by Environmental Temperatures During Seed Development     

Yasuhiro Suzuki  Yoshio Sano  Tetsuya Ishikawa  Tomoko Sasaki  Ushio Matsukura  Hiro‐Yuki Hirano 《Cereal Chemistry》2003,80(2):184-187

The effects of environmental temperature (21 vs. 28°C) during rice seed development on the starch characteristics (apparent amylose content, amylopectin chain length distribution, and gelatinization properties) of nonwaxy Taichung 65 (T65), waxy Taichung (T65wx), du2‐2 mutated low‐amylose strain Taichung (76‐3/T65), and Koshihikari were studied. Amylose contents increased with decreasing environmental temperatures. Analysis of the amylopectin chain length distribution showed that the relative amounts of long chains with degree of polymerization (DP) > 25 in all starches decreased if maturation occurred at 21°C. Gelatinization onset, peak, and conclusion temperatures and enthalpies decreased with decreasing environmental temperatures. Of all starches studied, the du2‐2 mutated low‐amylose Taichung (76‐3/T65) was most affected by maturation temperatures. These results indicate that the du2‐2 mutated low‐amylose Taichung (76‐3/T65) may be a useful strain in understanding biochemical and genetic starch biosynthesis response to slight changes in temperature.  相似文献   

The use of machine learning to predict acute hepatopancreatic necrosis disease (AHPND) in shrimp farmed on the east coast of the Mekong Delta of Vietnam     

Khiem  Nguyen Minh  Takahashi  Yuki  Oanh  Dang Thi Hoang  Hai  Tran Ngoc  Yasuma  Hiroki  Kimura  Nobuo 《Fisheries Science》2020,86(4):673-683

Fisheries Science - Predicting the outbreak of disease is essential when managing shrimp farms. Acute hepatopancreatic necrosis disease (AHPND) caused by Vibrio parahaemolyticus is a serious...  相似文献   

Distribution of Flavobacterium psychrophilum and its gyrA genotypes in a river     

Fujiwara-Nagata  Erina  Shindoh  Yuki  Yamamoto  Michitaka  Okamura  Takashi  Takegami  Kentaro  Eguchi  Mitsuru 《Fisheries Science》2019,85(6):913-923

Fisheries Science - Flavobacterium psychrophilum can be divided into three genotypes, G-C type (ayu type), A-C type (multi-fish type), and A-T type (salmon-trout type), by two single-nucleotide...  相似文献   

Clistobothrium sp. (Cestoda: Tetraphyllidea) in oarfish (Regalecus russelii) stranded on the coast of Akita Prefecture, Japan     

Haruyuki HIRATA  Yuki MIBE  Koji ONO  Satsuki SHIZUNO  Kazuyuki SUZUKI  Mitsuhiko ASAKAWA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(10):1590

Oarfish (Regalecus russelii Cuvier) are mesopelagic fish with little known about their life history. Oarfish live in deep water, making it difficult for researchers to collect specimens; thus, records of their parasitic helminths are limited. Two plerocercoids were found for the first time in an oarfish stranded on the coast of Akita Prefecture, Japan. These plerocercoids were identified as Clistobothrium sp. RR-1 using morphological and molecular analyses. It was revealed that oarfish represent one of the intermediate hosts of the genus Clistobothrium, and large sharks are the definitive hosts for these parasites.  相似文献   

Detection of Bemisia tabaci Mediterranean cryptic species on soybean in São Paulo and Paraná States (Brazil) and interaction of cowpea mild mottle virus with whiteflies     

Vinicius Henrique Bello  Felipe Barreto da Silva  Luís Fernando Maranho Watanabe  Eduardo Vicentin  Cristiane Muller  Regiane Cristina Oliveira de Freitas Bueno  Jessica Costa Santos  Bruno Rossitto De Marchi  Angélica Maria Nogueira  Valdir Atsushi Yuki  Julio Massaharu Marubayashi  Maria Márcia Pereira Sartori  Marcelo Agenor Pavan  Murad Ghanim  Renate Krause-Sakate 《Plant pathology》2021,70(6):1508-1520

Since the detection of Bemisia tabaci Middle East-Asia Minor 1 (MEAM1) species in Brazil in the early 1990s, this whitefly has been the predominant species and the main viral vector in the country. In this work, whiteflies were collected from commercial soybean fields near and far from greenhouses where Mediterranean (MED) species had previously been detected infesting vegetable crops. Results indicated that MEAM1 was the predominant whitefly species in soybean in most sampling sites, while MED was found colonizing soybean plants in open field conditions alone and/or with MEAM1 in several places. Among the tested insects, MED species was mostly detected harbouring the facultative endosymbiont Hamiltonella. We also detected cowpea mild mottle virus (CPMMV) infecting soybean plants. Transmission assays demonstrated that MED species was more efficient transmitting CPMMV from beans to beans and from soybean to soybean plants than MEAM1, while MEAM1 was more efficient in transmitting the virus from soybean to bean than MED. Performance assays indicated that adult emergence of both species on CPMMV-infected soybean plants was higher when compared with the emergence on healthy plants. Moreover, nonviruliferous MED and MEAM1 adults preferred to settle more often on healthy plants, while viruliferous adults settled more often on CPMMV-infected soybean plants. As MED has already been found in soybean open fields in São Paulo and Paraná States, Brazil, and it is a good vector of CPMMV, we anticipate problems related to whitefly management and to increase in the incidence of the virus in soybean.  相似文献   

Development of nuclear DNA markers to characterize genetically diverse groups of <Emphasis Type="Italic">Misgurnus anguillicaudatus</Emphasis> and its closely related species     

Takafumi Fujimoto  Aya Yamada  Yukihiro Kodo  Kohei Nakaya  Michiko Okubo-Murata  Taiju Saito  Kazuto Ninomiya  Michiko Inaba  Masamichi Kuroda  Katsutoshi Arai  Masaru Murakami 《Fisheries Science》2017,83(5):743-756

Repetitive DNA sequences, ManDra and ManBgl, were isolated from the DraI and BglII digests of the genomic DNA of Misgurnus anguillicaudatus, respectively. A primer set of ManDra distinguished two genetically different groups (A and B) of M. anguillicaudatus by specific electrophoretograms. A primer set of ManBgl amplified the DNA of M. anguillicaudatus and M. mizolepis. The individuals of M. anguillicaudatus were divided into two groups depending on the fragment sizes, in which the groups A and B (B-1 and B-2) showed 400 and 460 bp, respectively. M. mizolepis was distinguished by a different pattern (400-, 460-, and 510-bp fragments). PCR–RFLP analyses of recombination activating gene 1 gave a clear difference between A or B-2 (443-bp fragment) and B-1 groups (296- and 147-bp fragments). Clonal lineages and hybrids between B-1 and B-2 groups could be identified by appearance of three fragments (443, 296, and 147 bp). The combined analyses using the above three nuclear markers discriminated among nuclear genomes of genetic groups (A, B-1 and B-2) of M. anguillicaudatus and M. mizolepis. In several localities, natural hybridizations between the group B-1 and B-2 loaches and introgressions of clonal mitochondrial genomes into the group B-1 loaches were detected.  相似文献