Performance of a new artificial abalone hatchery culture system in terms of settlement of larvae and growth and survival of postlarval Haliotis discus discus (Reeve)

ABSTRACT:   A new abalone postlarval culture system, Stott's abalone postlarval production system (SAPPS), is being developed as an alternative method for settling larvae and on-growing postlarval abalone. SAPPS was tested in trial 1 using two commercially available artificial diets, Adam and Amos (Adam; supplied by Adam and Amos, Mt Barker, SA, Australia) and Cosmo (Cos; supplied by Cosmo, Matsuyama, Japan), against the diatom biofilm method (Diatom). In trial 2, SAPPS was tested against the previous production system (PPS, used by Stott et al. 2002). Larvae were induced to metamorphose and the resulting postlarvae were on-grown in 10-L flow-through tanks for 28 days in their respective treatments. The final survival of postlarvae was significantly higher ( P  < 0.05) in the SAPPS-Cos group (56.7 ± 11.15%) than in the Diatom (9.4 ± 2.7%) and SAPPS-Adam groups (8.5 ± 1.1%). The final length of postlarvae in SAPPS-Cos (1065 ± 73 µm) was significantly higher ( P  < 0.05) than those in the other two treatments (average of 841–883 µm). In trial 2 the metamorphosis rate was improved by using Spirulina platensis. The final length of postlarvae in SAPPS (1449–1471 µm) was significantly higher ( P  < 0.05) than PPS (1065–1075 µm) and Diatom (993 µm). There is potential for SAPPS to be used as an alternative to the current diatom method in the culture of postlarval abalone.     

Using micro particle diets to replace diatoms for feeding postlarval abalone Haliotis discus discus (Reeve.)

Feeding artificial micro diets instead of diatoms may allow a more constant and controlled form of nutrition, and thus results in lower mortality rate and increased growth. A 4-week trial was conducted to determine the growth and survival of postlarval Haliotis discus discus (Reeve.) postlarvae fed three experimental micro particle diets, and naturally occurring diatoms. A completely randomized design was adopted with each diet being replicated three times. All diets varied in terms of particle size and gross composition. Survival rate was significantly lower ( P  < 0.05) in the diatom diet (19.5 ± 2.1%) when compared with the K-1 diet (38.8 ± 8.9%), the K-2 diet (43.7 ± 5.6%) and the MD-Q diet (44.2 ± 14.8%). The size of postlarvae fed the four diets was not significantly different ( P  > 0.05). There was also little difference in the daily growth rate. Based on the results of this work for the preliminary implementation of artificial food as a replacement diet for diatoms, it seems that postlarval H . discus discus readily consumes artificial micro particle diets and has a superior survival rate when compared to that of diatoms.     

Yield and dry matter dynamics of vegetative and reproductive organs in Japanese and US soybean cultivars

ABSTRACT

Recently, US soybean cultivars have exhibited higher yields than Japanese soybean cultivars. To identify the determinants for this yield difference in reference to dry matter dynamics, recently developed US cultivars and Japanese commercial cultivars were cultivated in drained paddy fields in 2012 and 2013. The total dry matter (TDM) of each cultivar was measured at the initial seed-filling stage (R5), at 30 d after R5, and at maturity (R8). From R5 to R8, the DM of abscised leaves and petioles were measured. The actual HI (with abscised leaves and petioles) and apparent HI (without abscised leaves and petioles) were determined at R8. US soybean cultivars showed higher yields and apparent TDM (without abscised leaves and petioles) than did Japanese cultivars at R8. However, the difference in actual TDM (with abscised leaves and petioles) production was not significant between US and Japanese cultivars at R8. On the other hand, the actual HI was higher in US cultivars than in Japanese cultivars. US cultivars exhibited a higher TDM distribution to the pod before R5 and a higher pod growth rate from R5 to 30 d after R5. US cultivars tended to show greater crop growth rates (CGRs) from R5 to 30 d after R5. The higher yield in US cultivars was associated with the higher actual HI, which was considered attributable to a greater TDM productivity during the seed-filling period and higher DM distribution in the pod before R5.     

Systemic resistance induced in Arabidopsis thaliana by Trichoderma asperellum SKT-1, a microbial pesticide of seedborne diseases of rice

BACKGROUND: Trichoderma asperellum SKT-1 is a microbial pesticide of seedborne diseases of rice. To investigate the mechanisms of disease suppression in SKT-1, the ability to induce systemic resistance by SKT-1, or its cell-free culture filtrate (CF), was tested using Arabidopsis thaliana Col-0 plants. RESULTS: Both SKT-1 and its CF elicit an induced systemic resistance against the bacterial leaf speck pathogen Pseudomonas syringae pv. tomato DC3000 in Col-0 plants. Involvement of plant hormones in the induced resistance by SKT-1 and CF was assessed using Arabidopsis genotypes such as the jasmonic acid (JA)-resistant mutant jar1, the ethylene (ET)-resistant mutant etr1, the plant impaired in salicylic acid (SA) signalling transgenic NahG and the mutant npr1 impaired in NPR1 activity. In soil experiments using SKT-1, no significant disease suppression effect was observed in NahG transgenic plants or npr1 mutant plants. Expression levels of SA-inducible genes such as PR-1, PR-2 and PR-5 increased substantially in the leaves of Col-0 plants. Expression levels of JA/ET-induced genes such as PDF1.2a, PR-3, PR-4 and AtVsp1 were also induced, but the levels were not as high as for SA-inducible genes. In a hydroponic experiment using CF from SKT-1, all Arabidopsis genotypes showed an induced systemic resistance by CF and increased expression levels of JA/ET- and SA-inducible genes in leaves of CF-treated plants. CONCLUSION: The SA signalling pathway is important in inducing systemic resistance to colonisation by SKT-1, and both SA and JA/ET signalling pathways combine in the signalling of induced resistance by CF. These results indicate that the response of A. thaliana is different from that found in root treatments with barley grain inoculum and CF from SKT-1. Copyright © 2011 Society of Chemical Industry     

Porencephaly in a cynomolgus monkey ( macaca fascicularis )

Porencephaly was observed in a female cynomolgus monkey (Macaca fascicularis) aged 5 years and 7 months. The cerebral hemisphere exhibited diffuse brownish excavation with partial defects of the full thickness of the hemispheric wall, and it constituted open channels between the lateral ventricular system and arachnoid space. In addition, the bilateral occipital lobe was slightly atrophied. Histopathologically, fibrous gliosis was spread out around the excavation area and its periphery. In the roof tissue over the cavity, small round cells were arranged in the laminae. They seemed to be neural or glial precursor cells because they were positive for Musashi 1 and negative for NeuN and GFAP. In the area of fibrous gliosis, hemosiderin or lipofuscin were deposited in the macrophages, and activated astroglias were observed extensively around the excavation area.     

A novel vitamin K1 2,3-epoxide reductase (VKOR) inhibitor, 3-acetyl-5-methyltetronic acid, reduces experimental glomerulonephritis

Excessive proliferation of mesangial cells is observed in various types of glomerular disease including glomerulonephritis (GN), which is progressive in nature and eventually results in end-stage renal disease (ESRD). Vitamin K(1) 2,3-epoxide reductase (VKOR) and the vitamin K-dependent growth arrest-specific gene 6/Axl pathway play a key role in mesangial cell proliferation in GN. In the present study, we indicate the potential of a VKOR inhibitor, 3-acetyl-5-methyltetronic acid (AMT), to prevent the proliferation of glomerular mesangial cells and suppress the progression of GN. AMT was administered intravenously to rats once daily for 12 days and a mouse anti-Thy1 monoclonal antibody was injected intravenously after the AMT treatment on Day 6. Creatinine clearance (CCr) significantly increased and the albumin-to-creatinine ratio (ACR) significantly decreased in the AMT-treated group of the Thy-1 GN rats. In addition, glomerular and tubular damage was improved histopathologically in the AMT-treated group. AMT did not affect blood coagulation due to its unique pharmacokinetic properties. The concentration of AMT reached the IC(50) for VKOR in kidney, but not in liver. A novel VKOR inhibitor, AMT, reduced renal mesangial cell proliferation and could be a supportive treatment for GN.     

Babesia microti-like parasites detected in feral raccoons (Procyon lotor) captured in Hokkaido, Japan

Raccoons (Procyon lotor), which have recently become feral in Japan, were examined for the presence of Babesia microti-like parasites. Out of 372 raccoons captured in the west-central part of Hokkaido, 24 animals with splenomegaly were selected and tested by nested PCR targeting the babesial 18S rRNA gene. B. microti-like parasites were detected in two of the 24 individuals, and their DNA sequences were identical to that of the B. microti-like parasite reported from raccoons in the United States, suggesting that the parasites were probably imported into Japan and that the life cycle of the parasite has already been established in the country. The potential risk of this B. microti-like parasite spreading among dogs and foxes in Japan will need to be carefully monitored, as parasitization by phylogenetically very close parasites has been reported from such animals.     

Changes in peripheral leukocyte subsets in dairy cows with inflammatory diseases after calving

To clarify the cellular immune system in dairy cows with inflammatory diseases after calving, the leukocyte subsets were examined in Holstein dairy cows. Twenty Holstein cows reared in one herd, were used in this study. Nine cows (Group 1) experienced onset of mastitis or puerperal fever within 2 weeks after calving, and the other eleven cows remained healthy (Group 2) after calving. The numbers of CD3(+), CD4(+) and CD8(+) cells tended to be lower in Group 1 than in Group 2 from the day of calving through week 1. These results suggested that the cows with inflammatory diseases might have experienced a decline in T cells by the day of calving, before the onset of disease.