• Title/Summary/Keyword: salinity effects

Search Result 512, Processing Time 0.024 seconds

The Effect of Dissolved Oxygen and Salinity on Oxygen Consumption and Ammonia Excretion in the Mysid, Neomysis awatschensis (곤쟁이 (Neomysis awatschensis)의 산소소비와 질소배설에 미치는 염분 및 용존산소의 영향)

  • SHIN Yun Kyung;LEE Jung Ah;CHIN Pyung
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.33 no.2
    • /
    • pp.110-114
    • /
    • 2000
  • Effects of the combinations of six oxygen concentrations ($control, 0.6, 1.0, 2.0, 3.4 and 7.4 mg DO/l$) and two salinity levels ($20{\%_{\circ}} and 32{\%_{\circ}}$) on the rates of oxygen consumption, ammonia excretion and mortality of the mysid, Neomysis awatschensis were tested at $20{\circ}C$. The lethal level ($96 hr-LC-(50)$) of dissolved oxygen for mysid at $20{\%_{\circ}} and 32{\%_{\circ}} were 2,20 mg DO/l and 1.60 mg DO/l$ respectively, and all mysids died within $24hr at 0.6 mg DO/l$. Oxygen consumption rate of mysid was increased with dissolved oxygen increase at $20{\%_{\circ}} and 32{\%_{\circ}}$, but ammonia excretion rate was high af $1.0 mg DO/l$ during 96h exposure to DO concentration, and significantly greater in $20{\%_{\circ}} than 32{\%_{\circ}}$. $O:N$ ratio of mysid exposed during 96hr with salinity anil dissolved oxygen was below $10 at 20{\%_{\circ}} and 1,0{\~}2.0 mg DO/l, and was 4.4 at 32{\%_{\circ}} and 1.0 mg DO/l$. These results indicated that mysids were capable of changing their energy substrate in response to salinity and DO changes, and obtaining energy from proteins.

  • PDF

Effect of Food and Salinity on Larval Growth and Survival of the River Puffer, Takifugu obscurus (황복, Takifugu obscurus의 초기 발달 동안 성장 및 생존에 있어 먹이와 염분의 효과)

  • 강희웅;강덕영;조기채;이진호;박광재;김종화
    • Journal of Aquaculture
    • /
    • v.17 no.3
    • /
    • pp.221-227
    • /
    • 2004
  • In the present study, we investigated the effects of food and salinity on growth and survival of river puffer, Takifugu obscurus offsprings in indoor land-based tank during the early development. In the food experiment, the river puffer larvae (TL 8.7$\pm$0.1 mm, BW 20.0$\pm$3.2 mg) were fed with tubificid, Limnodrilus gotoi, water flea, Daphnia carinata, mysid, Neomysis awatschensis, Manila clam, Ruditapes philippinarum and artificial food together Artemia nauplii for 30 days, and the growth and the survival of larvae were investigated. In the salinity experiment, the river puffer larvae and juvenile at three stages (Stage I: TL 5.8$\pm$0.4 mm; Stage II: TL 12.0$\pm$0.2 mm, Stage III: TL 44.5$\pm$0.7 mm) were supplied with Artemia nauplii, water flea and/or artificial food and were reared in 0, 10, 20 and 30 psu at respective stages. The results shows that the growth rates of larvae feeding with artificial food and tubificid together Artemia nauplii were higher than those of larvae in other groups, but the survival rates of larvae feeding with water flea and mysid together Artemia nauplii were higher than those of larvae in other groups. In salinity, the results shows that the growth and survival rates of offsprings were significantly higher in 10∼20 psu than those in 0 and 30 psu at Stage I and n. At Stage III, the growth and the survival rates were the highest in 20 psu, but the lowest in 0 psu. However, it should be noted that the rates in 0 and 30 psu were significantly enhanced at Stage III in comparison with those at Stage I and II. Therefore, it is concluded that river puffer, T. obscurus is euryhaline marine species, which can normally grow and live at salinities from 0 to 30 psu, and that a combinative supplement with Artemia nauplii and water flea, D. carinata may confer an advantage on growth and survival of the river puffer offsprings in indoor land-based tank.

Fermentation Characteristics of Low-Salt Kimchi with Starters on Fermentation Temperature and Salt Concentration (종균이 첨가된 저염김치의 발효온도 및 소금 농도에 따른 발효 특성)

  • Moon, Sung-Won;Park, Sun-Hyun;Kang, Byung-Sun;Lee, Myung-Ki
    • The Korean Journal of Food And Nutrition
    • /
    • v.27 no.5
    • /
    • pp.785-795
    • /
    • 2014
  • This study was conducted to develop low-salinity Kimchi with acetic acid, starters and fruits added for health and taste. The quality characteristics of the developed Kimchi by storage period and salt concentrations were investigated herein. The effects of salinity and fermentation temperature ($0^{\circ}C$, $5^{\circ}C$) on the quality characteristics of low-salinity Kimchi were investigated through physicochemical and microbiological analysis. The sensory characteristics are shown in the results below. The pH and acidity were quickly changed by higher temperature over longer storage periods, with gradual decrease in the pH accompanied with an increase in acidity. The microbiological analysis revealed increase in the total cell number regardless of the concentration and strain added during the storage period. Finally, test of the overall acceptability with regard to sensory characteristics according to the different strain sets in low-salinity Kimchi showed the average score for smell, salty taste and overall acceptability were highest in the hetero-fermentation strain group.

Effect of salinity and used medium on the induction of sexual reproduction in the rotifer Brachionus rotundiformis (해수산 rotifer Brachionus rotundiformis의 유성생식유도에 관한 염분 및 기사용 배양수의 효과)

  • Lee, Kyun-Woo;Sim, So-Myung
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.17 no.4
    • /
    • pp.692-697
    • /
    • 2016
  • This study examined the effects of salinity and medium used on the induction of sexual reproduction for the mass production of the resting eggs in the marine rotifer Brachionus rotundiformis for 9 days. After exposure to various salinities, the mixis rate in all treatments began to increase on the third day and decreased after the 4th or 5th day. The resting eggs appeared on the 4th day at 10‰, 15‰, 20‰, 25‰. In particular, the fertilization rates with 33.3% and 31.3% at 20‰ and 25‰ on day 6 were higher than those of the others, respectively. Mean mixis rate for 9 day at 0‰ and 20‰ were the highest with 25.3% and 20.2%, respectively, and the fertilization rate (14.0%) at 25‰ was the highest. In the medium experiment used, the mixis rate in all treatments were similar to the results of the salinity experiment. The resting eggs were only found at 0% and 25% of the used medium treatments. While there were no significant differences in the mean fertilization rate of all treatments, the mean mixis rate (22.3%) in the 25% treatment was higher than that of the control (0% treatment). As a result, salt stress was more effective than using the used medium to induce sexual reproduction in B. rotundiformis. The optimal salinity was considered to be 20-25‰, which caused a high mixis and fertilization rate in the rotifer. These results provide basic data for the mass production of rotifer resting eggs.

Stratification Variation of Summer and Winter in the South Sea of Korea (한국 남해의 여름과 겨울철 성층 변동)

  • Lee, Chung-Il;Koo, Do-Hyung;Yun, Jong-Hwui;Kim, Dong-Sun
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.13 no.2 s.29
    • /
    • pp.119-125
    • /
    • 2007
  • In order to illustrate the variation cf stratification and to know the effects of the temperature and the salinity on the stratification in the South Sea of Korea, the stratification parameter defined as potential energy anomaly (PEA, $V(J/m^3)$) introduced by Simpson and Hunter (1974) was used. The oceanographic data were obtained in August 1999 and February 2000 by National Fisheries Research and Development Institute (NFRDI). V in August is generally high in offshore and low in near shore. However, in February, V in the near shore is higher than that cf the offshore due to the vertical temperature gradient between surface and bottom layer caused by the expansion of South Korean Coastal Waters (SKCW). In summer, the increase of the atmospheric heating acts on the stratification as the buoyancy forcing. In most cases, the effect cf the temperature on the stratification is stronger than that of the salinity. The temperature effect is predominantly due to the extent of the intrusion of Tsushima Warm Current into the study area. However, at stations where V is high the effect of the salinity is also significant. In winter, V is very low due to the decrease cf the buoyancy forcing, but some stations show the relatively high V due to the expansion of SKCW and salinity in winter unlike that in summer makes the stratification weak.

  • PDF

The Effect of Water Temperature and Salinity on Settlement of Pacific Oyster, Crassostrea gigas Pediveliger Larvae (굴 Crassostrea gigas 부착기 유생의 부착에 미치는 수온 및 염분의 영향)

  • Jeon, Chang-Young;Hur, Young-Baek;Cho, Kee-Chae
    • The Korean Journal of Malacology
    • /
    • v.28 no.1
    • /
    • pp.21-28
    • /
    • 2012
  • The combined effects of water temperature and salinity on the settlement rate and density (spats/$cm^2$) of Crassostrea gigas pediveliger larvae were studied under the hatchery conditions. Four water temperatures (20.0, 23.0, 26.0 and $29.0^{\circ}C$) were tested at three salinities (20.0, 30.0 and 40.0). The optimum water temperature by salinity conditions were $29.0^{\circ}C$ and 20.0, 30.0 which significantly (P < 0.05) the highest mean (${\pm}S.D$) larval settlement rate of $43.1{\pm}0.1%$, $42.1{\pm}0.1%$, respectively. But the combination of water temperatures and salinities for settlement density was not effected, but each factor as water temperature ($29.0^{\circ}C$), salinity (40.0) was shown significantly high and low settlement density, respectively (P < 0.05). The statistics result of settlement density frequency was appeared: mode ($1.2-2.3spats/cm^2$), Mean ($1.9-2.4spats/cm^2$), Range ($3.0-5.8spats/cm^2$) and the lowest variance was obtained 0.4 at water temperature $20.0^{\circ}C$ by salinity 30.0, but $29.0^{\circ}C$ by 20.0 was the highest (1.1). The best condition at this results for the larvae setting under the artificial seed collection of C. gigas was $29.0^{\circ}C$ and 20.0-30.0.

Effect of Feeding on Postlarvae of Pacific White Shrimp, Litopenaeus vannamei during the Acclimation Process to Low Salinities in Seawater (해수 저염분 순치과정에서 먹이섭취가 흰다리새우, Litopenaeus vannamei 유생에 미치는 영향)

  • Kim, Su Kyoung;Shim, Na Young;Cho, Ji-Hyun;Kim, Jong Hyun;Kim, Su-Kyoung
    • Korean Journal of Environmental Biology
    • /
    • v.36 no.3
    • /
    • pp.377-384
    • /
    • 2018
  • This study focused on the effects of feeding on postlarvae of shrimp, Litopenaeus vannamei, during the identified acclimation time to low salinity. A total of 5 different salinity groups with or without feeding (32, 24, 16, 8, and 2 psu, 1 liter, triplicates) were prepared, and 30 shrimp were settled at PL21 (postlarvae) and placed in each group. After 24 hours of the experimentation process, the survival rate of the fed and starved groups was observed to be lower in the 2 psu group compared to other salinity groups, with the rate of 86.6% and 81.1%, respectively. The condition index of glucose and triglyceride, which are important factors for osmoregulation and as energy sources, was 4.2-7.6 times and 2.7-3.4 times higher in the fed groups than the starved groups at all the levels of salinities. The creatine level increased by 1.1-1.5 times in the starved groups as compared to the fed groups. Likewise, the activity of all the digestive enzymes like, lipase, ${\alpha}$-amylase, trypsin, and alkaline protease were clearly higher in the fed groups (ANOVA, p<0.05). Apparently, it was observed that feeding is effective for the postlarvae of shrimp, which shows a characteristic fast metabolism and larval development, during the acclimation period to low salinity.

Effects of Temperature and Salinity on the Growth and Paralytic Shellfish Toxin (PST) Production by Toxic Dinoflagellate Alexandrium pacificum (유독 와편모조류 Alexandrium pacificum의 생장과 마비성 패독 생산에 미치는 수온과 염분의 영향)

  • Li, PeiJin;Oh, Seok Jin;Kim, Seok-Yun
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.28 no.6
    • /
    • pp.866-873
    • /
    • 2022
  • Growth rate and production of the paralytic shellfish poisoning toxin (PST) of a toxic dinoflagellate Alexandrium pacificum (LIMS-PS-2611) isolated from the southern sea of Korea, were examined under various temperatures and salinity conditions. The maximum growth rate (0.28 day-1) was observed under 25℃ and 30 psu. Optimal growth (≥ 70% of maximum growth rate) was obtained between 20~25℃ and 25~35 psu. Among the PSTs of A. pacificum, the principal toxins were C1+2 and GTX5 in N-sulfocarbamoyl toxin group, and minor components were characterized as neoSTXs in the carbamate toxin group. Maximum toxin content was observed under 20℃ and 30 psu, and the toxin content increased with the increase of salinity. Low toxin contents were measured under the temperature and salinity conditions of the maximum growth rate. Therefore, the PSP of bivalve, which occurs at a temperature range of 20-25℃ in June, might have been derived from A. pacificum.

Suspended Particulate Matter of the Surface Water in Relation to the Hydrography in the South Sea of Korea in Early Winter (한국 남해의 초겨울 해황과 관련한 표층 부유물질의 분포)

  • Choi Yong-Kyu
    • Journal of Environmental Science International
    • /
    • v.14 no.11
    • /
    • pp.1063-1069
    • /
    • 2005
  • In order to investigate the distribution of suspended particulate matter of the surface water in the South Sea of Korea in early winter, the cruise results during 2 to 8 December 2004 were analyzed in relation to the hydrography. The front was formed along the line connecting between Tsushima and Cheju Islands, which divided the water into two water masses; the coastal water with for temperature and for salinity, and the Tsushima Warm Current Water with high temperature and high salinity. In the coastal water the suspended particulte matter was 5.0-6.5 mg/l, while in the oceanic water suspended particulate matter was 4.5-5.0 mg/l. The coastal water showed higher mixing effects, compared to the oceanic area where vertical stratification was clearly formed. These indicate that the distribution of suspended particulate matter was affected by the stratification or mixing of the water column. Also it is suggested that the mixing effects of sea surface cooling and rind play an important role on the distribution of suspended particulate matter in the South Sea of Korea in winter time.

Influence of Probiotics-Friendly Pig Production on Meat Quality and Physicochemical Characteristics

  • Chang, Sung Yong;Belal, Shah Ahmed;Kang, Da Rae;Choi, Yang Il;Kim, Young Hoon;Choe, Ho Sung;Heo, Jae Young;Shim, Kawn Seob
    • Food Science of Animal Resources
    • /
    • v.38 no.2
    • /
    • pp.403-416
    • /
    • 2018
  • In this study, the dietary effects of probiotics with a liquid application system on meat quality and physicochemical characteristics of pigs were evaluated. A total of 80 Landrace${\times}$Yorkshire${\times}$Duroc (LYD) 3-way crossbred pigs (average age $175{\pm}5d$) were assigned to a conventional farm and a probiotics farm equipped with a liquid probiotics application system (40 pigs in each farm). The two treatments were: CON (diet without probiotics) and PRO (diet with probiotics). Dietary probiotics decreased shear force in the longissimus muscle compared to the control group (p<0.05). The treatment diet did not affect backfat thickness, carcass weight, meat color, cooking loss, water holding capacity (WHC), and drip loss. Dietary probiotics significantly reduced ash, salinity, and pH (at 5 and 15 d) (p<0.05). There was no significant effect on thiobarbituric acid reactive substance (TBARS) values. Polyunsaturated fatty acid (PUFA) and omega fatty acids (${\omega}3$ and ${\omega}6$) were significantly (p<0.05) higher in the PRO group, whereas monounsaturated fatty acid (MUFA) was decreased. The free amino acid composition, serine, lysine, histidine, and arginine levels were significantly lower in the PRO than in the control group. The treatment group exhibited higher nucleotide compounds (hypoxanthine, inosine, GMP, IMP) than the controls. Also, levels of ascorbic acid and thiamin were significantly different (p<0.05), while minerals were not significantly different between the groups. In conclusion, feeding of probiotics had effects on shear force, ash, salinity, pH, PUFA, and some amino acids which related to taste and flavor without any negative effects on the pigs' carcass traits.