Fatty acid composition in sea cucumber Apostichopus japonicus fed with microbially degraded dietary sources

Fatty acids (FAs) in the body walls of sea cucumber, Apostichopus japonicus, reared under diet‐administered conditions were analysed to determine the accumulative status of dietary FAs. Four test diets different in diet source and microbial degradation, that is, a diet composed of powdered pennate diatoms (diet PD), one microbially degraded of diet PD (diet PDM), one composed of brown algae [tangle weed, Saccharina (Laminaria) longissima (Miyabe); diet BA], and one microbially degraded of diet BA (diet BAM), were fed to juvenile A. japonicus, respectively, for 2 months and the FA composition of the juvenile body wall was determined. FAs in body wall were influenced and changed by diet source and microbial degradation of diet. Degradation significantly promoted juvenile's growth and increased iso‐15:0 in the body wall; however, iso‐15:0 was not a growth factor. FA 20:4n6 and 20:5n3 were dominant in all groups despite being a minor dietary constituent, suggesting that these FAs can be readily accumulated or synthesized in the animal.     

Isolation and characterization of bacteria causing mortality in early stage larvae of captive‐bred Japanese eels (Anguilla japonica Temminck & Schlegel)

Bacteria with lethal effect on eel larvae were isolated from moribund captive‐bred eel larvae and their 16S rRNA gene sequences were analysed. Nucleotide sequence of 10 isolates showed highest similarity with Lacinutrix algicola, Crocinitomix catalasitica and Pseudoalteromonas rubra. Age‐dependent changes in the susceptibility of eel larvae were observed in response to challenge by a highly lethal isolate. Compared with 10 and 11 days after hatching (DAH), larval susceptibility to the highly lethal isolate was lower at 18 DAH. We found that the bacterial isolates have lethal effect on the captive‐bred eel larvae, especially at the early developmental stage. These results will be useful to establish appropriate culture practices for eel larvae that will improve the success of mass production of glass eels for aquaculture.     

Moisture Distribution and Diffusion in Cooked Spaghetti Studied by NMR Imaging and Diffusion Model

Moisture diffusion in spaghetti during boiling and holding after boiling was analyzed with a cylinder diffusion model based on moisture content mapped by magnetic resonance imaging. The images showed water penetrating concentrically in the cross section of a cooked spaghetti strand. The moisture profiles calculated from the images refracted near the central part in undercooked spaghetti due to the presence of ungelatinized starch. The moisture profiles of the samples with different holding times intersected around one‐third of the radius from the surface. The slope of the moisture profile decreased along with the holding time while the moisture content at the intersection remained unchanged. The diffusion coefficients were determined statistically for the fully gelatinized region with a cylinder model. The theoretical moisture profiles calculated using such coefficients fitted very well to experimental data. The diffusion coefficients of dried spaghetti were smaller than those of fresh spaghetti at both boiling and holding periods, suggesting that the moisture transport property had been reduced by the drying process during manufacture of spaghetti. The diffusion coefficients decreased with increases in boiling and holding times. The diffusion model with a constant diffusion coefficient is, therefore, valid in a limited boiling or holding time.     

Patchiness structure and mortality of Pacific saury Cololabis saira larvae in the northwestern Pacific

Patchiness structure and mortality rates of Pacific saury Cololabis saira larvae were estimated in the frontal area of the Kuroshio Extension in spring 2000 and 2001. Drogued GPS buoys, which were used as Lagrangian reference points, were deployed to mark dense patches of saury larvae and a series of samplings was conducted using a neuston net around the buoys during the night over a period of several days. A total of 225 tows were conducted and 11 690 specimens were sampled during four buoy tracking. Despite the occurrence of water diffusion, patchiness density, distance between adjacent patches and patch size estimated by geostatistical analysis did not drastically change during the buoy tracking and these parameters were robust for the difference of variogram models and the threshold larval density defining patchiness. Such a stability of the patchiness allowed the estimation of larval mortality from the decrease of larval density for different size classes with respect to individual growth based on the samples taken repeatedly during the buoy tracking. Although low or negative values were obtained for the larvae right after hatching, probably due to continuous hatching, the estimates of mortality then increased and became stable in the range of 23–37% day⁻¹ with a small standard deviation until their knob length reached to 36 mm. In situ information on the patchiness structure and larval mortality provides crucial parameters for simulating the recruitment process of small pelagic fishes in high-resolution hydrodynamic models.     

Structure of Lysophosphatidylglyceryl-Remazolbrilliant Blue (LPG-RBB) from the Surface of Dyed Wheat Starch Granules

Wheat starch granule surface was covalently stained with Remazolbrilliant blue-R dye (RBB) and then extracted with 1% SDS containing 1% 2-mercaptoethanol (2-ME) at room temperature for 14.5 hr. The extracted blue-staining material (A₆₅₀) separated into two fractions. Low molecular weight (LMW) material was further purified by Sephadex G-75 size-exclusion chromatography and thin-layer chromatography. Infrared and nuclear magnetic resonance (¹H-NMR and ¹³C-NMR) spectroscopy indicated that the structure of the purified LMW material was 18-O-(6-lysophosphatidylglyceryl)-RBB.     

Diagnostic imaging of intra-abdominal cyst in heifer using the computed tomography

A 10-month-old Japanese black heifer was diagnosed as having an intra-abdominal cyst using computed tomography (CT). Through a posterior ventral midline incision, the cyst was removed, and the heifer completely recovered after the surgery. CT scans enabled detection of the intra-abdominal cyst and measurements of the diameter of the cyst before the surgery.     

Genetic variation and phylogenetic relationships in East and South Asian melons, Cucumis melo L., based on the analysis of five isozymes

Genetic structure and phylogenetic relationships in East and South Asian melons were analyzed, based on the geographical variation of five isozymes. The analysis of Indian melon accessions showed a continuous variation in seed length, ranging from 4 to 13 mm. Most of the East Asian melons, vars. makuwa and conomon, were classified as the small seed type with seed length shorter than 9 mm. The frequency of the small seed type increased from the west to the east in India. Allelic variation was detected at a total of nine loci of five isozymes among 114 melon accessions. Gene diversity calculated for the nine loci indicated that Indian melon was rich in genetic variation, which decreased from India towards the east. Clear geographical variation was detected in two enzymes, APS and6-PGDH. Pgd-1 ¹ and Ap-3 ¹ were frequent in India and Myanmar, while most of the melons in Laos, China, Korea and Japan carried Pgd-1 ³ and Ap-3 ³, except var. inodorusin China. Among the latter two alleles, the frequency of Ap-3 ³ was more than 50% in the small seed type in north and east India, indicating that vars. makuwa and conomon were related to the small seed type in these areas. It was also suggested that the small seed type with wet tolerance originated in central India and was selected under wet condition in the east. This revised version was published online in August 2006 with corrections to the Cover Date.     

Effects of day-length and temperature on floral structure and fertility restoration in a season-dependent male-sterile Solanum villosum Mill. mutant

Solanum villosum is an important African leafy vegetable whose yield is limited mainly by competition from early and excess fruit-set. Induced male-sterility is a potential tool to reduce this competition and enhance yields. This study was conducted to investigate the influence of photoperiod and temperature on the floral dynamics of a season-dependent male-sterile mutant. The mutant, named T-5, has flowers which are sepaloid, mostly stamenless, indeterminate and partially restored in winter, late-spring, summer and autumn, respectively. Floral organ restoration was found to be largely independent of photoperiod conditions. Day/night temperatures of 25/25 and 30/20°C were found to favour restoration of the floral organ but most flowers were stamenless and infertile. High night temperature favoured the formation of indeterminate flowers both in the growth chamber (30°C) and in the greenhouse (>25°C). On the other hand, low growth chamber (10°C) and greenhouse (<15°C) night temperature favoured the formation of sepaloid flowers. The optimum temperatures for floral structure and fertility restoration were between 20°C and 25°C (day) and 15–20°C (night). Propagation of T-5 mutant can thus be achieved by growing in regions or seasons with such temperature ranges. Under temperatures unfavourable for fruit-set, leaf productivity is expected to be high.     

Anthracnose of salt-wort (<Emphasis Type="Italic">Salsola komarovii</Emphasis>) caused by <Emphasis Type="Italic">Colletotrichum truncatum</Emphasis>

In July 2006, black rot was observed on the leaves of 4-leaf-stage seedlings of salt-wort (Salsola komarovii) in Yamagata Prefecture, Japan. We isolated two single-conidial isolates from the diseased leaves. Although colony appearance of the isolates was different from that of each other, both isolates were identified as Colletotrichum truncatum by morphology and molecular similarity. After inoculation of healthy salt-wort plants with the isolates, the isolates were reisolated from symptomatic plants. We thus propose a new disease, anthracnose of salt-wort.