Oogenesis and relevant changes in egg quality of abalone Haliotis discus hannai during a single spawning season     

Hirotatsu Fukazawa  Tomohiko Kawamura  Hideki Takami  Yoshiro Watanabe 《Aquaculture (Amsterdam, Netherlands)》2007,270(1-4):265-275

Oogenesis of abalone Haliotis discus hannai was examined histologically during a single spawning season using broodstock of various maturation conditions, which were controlled by effective accumulative temperature (EAT). The quality of eggs spawned was determined in relation to oogenesis. For histological examinations, three to five females were sacrificed at 300, 600, 850, 1050, and 1150 °C days EAT, without induction of artificial spawning. Other females were successfully induced to spawn at 700 °C days EAT and were reared following spawning. Three of these females were then sacrificed every 200 °C days EAT until 1300 °C days EAT. Gonad histology showed that two oocyte cohorts matured in H. discus hannai ovaries during a single spawning season. One mature oocyte cohort could be spawned in multiple times. The second oocyte cohort started developing after the first oocyte cohort had been spawned or reabsorbed, and became fully mature 400 °C days EAT after the first cohort was depleted. For egg quality measurements, three to five females were successfully induced to spawn at 850, 1050, 1150, 1900, and 2350 °C days EAT (Experiment 1). Three females were induced to spawn twice, at 700 and 1500 °C days EAT, resulting in two batches of eggs from the same individuals (Experiment 2). Total lipid and protein content of eggs were measured and were greater in eggs from the second cohort than in eggs from the first cohort. No carbohydrates were detected in eggs and there was no difference in cytoplasm volume between the two cohorts. In hatcheries producing H. discus hannai, it is important to increase post-larval starvation tolerance by increasing the quality of eggs, to yield higher and more consistent survival. The results of this study suggest that H. discus hannai hatcheries should use eggs from the second oocyte cohort, which are of higher quality, rather than eggs from the first oocyte cohort.  相似文献   

Identification of juvenile abalone <Emphasis Type="Italic">Haliotis diversicolor</Emphasis> based on number of open and sealed respiratory pores     

Toshihiro Onitsuka  Tomohiko Kawamura  Toyomitsu Horii  Masami Hamaguchi  Satoshi Ohashi  Naoyuki Takiguchi  Yoshiro Watanabe 《Fisheries Science》2007,73(5):995-1000

ABSTRACT:   Changes in the number of respiratory pores (open pores) and their imprints (sealed pores) in post-larvae and juveniles were observed and compared for four abalone species Haliotis diversicolor , H. discus discus , H. madaka , and H. gigantea . The first open pore was evident at a shell length (SL) of 1.5 mm in H. diversicolor , 1.9–2.0 mm SL in H. discus discus , and 2.3–2.4 mm SL in H. madaka and H. gigantea . The number of open pores in H. diversicolor gradually increased with growth, with four to five pores at 2.5–18.0 mm SL and five to six pores at 18.0–27.0 mm SL. The other three species maintained four to five open pores after they reached 3.4–4.5 mm SL. The total number of open and sealed pores (TNP) was greater in H. diversicolor than in the other species at the same SL. Juvenile H. diversicolor were identified among field-caught abalone by the difference in the relationship between SL and TNP (SL–TNP relationship) and also by the monoclonal antibody reaction method. The results of the two methods were in perfect agreement, indicating that our method using the SL–TNP relationship is reliable for the identification of H. diversicolor .  相似文献   

Effects of single and repeated heat stress on anxiety-like behavior and locomotor activity in medaka fish     

Otsuka  Airi  Shimomura  Yuki  Sakikubo  Honoka  Miura  Kensuke  Kagawa  Nao 《Fisheries Science》2022,88(1):45-54

In this study, we examined whether a single heat stress incident and long-term repeated heat stress could affect behavioral and neural responses in male medaka fish Oryzias latipes. By using the novel tank diving test, we found that 7-day repeated heat stress led to anxiety-like behaviors and suppressed locomotor activity, whereas fluoxetine treatment during repeated heat stress led to anxiolytic behaviors. Furthermore, a single heat stress incident increased hyper-locomotor activity. A single heat stress incident decreased mRNA expression of tryptophan hydroxylase 2 (tph2), a rate-limiting enzyme in serotonin biosynthesis, while a single heat stress increased mRNA expression of tyrosine hydroxylase 1 (th1) and tyrosine hydroxylase 2 (th2), catalyzing dopamine biosynthesis in the brain. Plasma cortisol concentration increased after a single stress, repeated stress, and fluoxetine treatment during repeated stress. These results suggest that medaka fish are a good model for assessing anxiety-like behavior induced by long-term repeated stress. Moreover, th1, th2, and tph2 in the brain would be key factors in the exploration of the central regulation of behavioral responses to a single and repeated stress in fish.

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Maturation and spawning of <Emphasis Type="Italic">Spratelloides gracilis</Emphasis> Clupeidae in temperate waters off Cape Shionomisaki,central Japan     

Norio Shirafuji  Yoshiro Watanabe  Yasuyuki Takeda  Tomohiko Kawamura 《Fisheries Science》2007,73(3):623-632

ABSTRACT:   The reproductive ecology of Spratelloides gracilis was investigated in the temperate waters off Cape Shionomisaki, central Japan. Cape Shionomisaki is located at the northern margin of the distribution range of this species. Females of S. gracilis with gonadosomatic index (GSI) ≥ 4.0 were defined as mature based on the relationship between GSI and the histological maturity phases of their ovaries. More than 50% of females greater than 60 mm standard length (SL) were mature. Hatch dates of larvae and juveniles collected in the study area were determined by otolith daily ring counts and found to extend from April to November. The size at maturity of females (60 mm SL) and the spawning season of S. gracilis in the temperate waters off Cape Shionomisaki (April–November) was larger and shorter, respectively, than those in tropical waters in the western Pacific. The reproductive traits observed for S. gracilis off Cape Shionomisaki appear to be adaptive to northern temperate waters with seasonal changes in environmental conditions.  相似文献   

Expression and subcellular localization of apical junction proteins in canine duodenal and colonic mucosa     

Ohta H  Yamaguchi T  Rajapakshage BK  Murakami M  Sasaki N  Nakamura K  Hwang SJ  Yamasaki M  Takiguchi M 《American journal of veterinary research》2011,72(8):1046-1051

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Pathologically and serologically different avian nephritis virus isolates implicated in etiology of baby chick nephropathy.     

J Shirai  N Tanimura  K Uramoto  M Narita  K Nakamura  H Kawamura 《Avian diseases》1992,36(2):369-377

Three virus isolates (WG-3, -4, and -5) from chicks affected by baby chick nephropathy were orally inoculated into 1-day-old specific-pathogen-free chicks of lines PDL-1 and 15I. Additional chicks were orally inoculated with avian nephritis virus (ANV) strain G-4260. Chicks inoculated with isolates WG-3, -4, and -5 died between 2 and 6 days postinoculation (PI), with mortality ranging from 0% to 53.3%. Pathological findings in the dead chicks included nephrosis in chicks inoculated with WG-3, -4, and -5, and nephritis and visceral urate deposition in chicks inoculated with G-4260. The stability of the WG-5 isolate, as well as the size of the particles and the nucleic acid type, were also similar to those of the G-4260 strain. All of the examined chicks inoculated with WG-3, -4, and -5 had interstitial nephritis at 14 days PI. Therefore, the three virus isolates were considered to be ANV. However, there was no serological relationship between the isolates and ANV (G-4260 and M-8 strains).  相似文献   

A fatal case in newborn piglets with Getah virus infection: pathogenicity of the isolate     

H Kawamura  K Yago  M Narita  T Imada  T Nishimori  M Haritani 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1987,49(6):1003-1007

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Inhibitory modes of Kunitz and Bowman-Birk soybean trypsin inhibitors to tryptic and chymotryptic proteinases of tiger puffer and yellowtail     

Kenji Takii  Kohji Kawamura  Motoji Nakamura  Hidemi Kumai  Yasuko Yoshizawa 《Fisheries Science》2001,67(1):52-57

SUMMARY: An inhibitory effect of Kunitz and Bowman-Birk soybean trypsin inhibitors (K- and BB-SBTI) was investigated on tryptic and chymotryptic proteinases of a brood of tiger puffer Takifugu rubripes and yellowtail Seriola quinqueradiata . These assist to comprehend the differences in dietary soybean meal (SBM) utility by fish species and to develop low cost SBM diets with low contents of fish meal. The K-SBTI strongly inhibited tryptic proteinase and weakly inhibited chymotryptic proteinase from the hepatopancreas and intestine including pyloric ceca of the fishes. The BB-SBTI strongly inhibited both proteinases of the fishes. The K-SBTI inhibition for tryptic protease and the BB-SBTI inhibition for tryptic and chymotryptic proteases were relatively constant in tiger puffer with growth of 12–199 g bodyweight. In yellowtail with growth of 7–672 g bodyweight, the K-SBTI inhibition for tryptic protease and the BB-SBTI inhibition for chymotryptic protease were also relatively constant. The BB-SBTI inhibition for yellowtail tryptic protease typically fell in the stage from 7 g to 57 g bodyweight, and then decreased slightly or was maintained constantly. These results indicate that there are different inhibitory modes of K- and BB-SBTI and there is inter- and intraspecific diversity of tryptic protease conformation between the two species.  相似文献   

Changes of immunological response after experimentally ozonated autohemoadministration in calves.     

N Terasaki  A Ogata  H Ohtsuka  K Tamura  F Hoshi  M Koiwa  S Kawamura 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2001,63(12):1327-1330

Changes in subsets of peripheral blood mononuclear cells and lymphocyte blastogenesis reaction were observed after ozonated autohemoadministration (OAHA) in calves. Ten healthy calves were used in this study. After OAHA, CD8+ cells, CD14+ cells and WCl+cells increased (p<0.05). The level of lymphocyte blastogenesis stimulated by PHA decreased after OAHA. A significant increase in serum IL-6 activity was observed in OAHA calves. These results suggested that OAHA induced immunological changes in calves.  相似文献   

Observation on kinetes of Babesia ovata in the hemolymph of the vector tick Haemaphysalis longicornis     

S Higuchi  N Itoh  S Kawamura  Y Yasuda 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1987,49(6):1145-1147

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