Effect of temperature and feeding rate on the growth and survival of early and mid-stage phyllosomas of the spiny lobster Jasus edwardsii

2000 ◽  
Vol 51 (3) ◽  
pp. 235 ◽  
Author(s):  
Lennard J. Tong ◽  
Graeme A. Moss ◽  
Megan P. Paewai ◽  
Timothy D. Pickering

Stage I J. edwardsii larvae that had hatched from embryos held at one of three temperatures were reared at 12˚C to 24˚C and fed 2–3 mm brine shrimps. Larvae reared at 24˚, 21˚, 18˚, 15˚ and 12˚C moulted to Stage II after 7, 8, 11, 17 and 33 days respectively. Larvae from 18˚ and 15˚C embryos reared at 24˚C had 40% and 100% survival respectively. Larvae reared at 12˚C had 10–15% survival. Stages II, IV, VI and VIII larvae were reared at three temperatures and fed 4, 8, 12, 16, 24 or 36 brine shrimp per day. At optimum feeding levels and at 24˚, 21˚ and 18˚C, Stage II larvae moulted after 6, 8 and 11 days respectively, Stage IV after 9, 10 and 12 days, Stage VI after 12, 14 and 17 days and Stage VIII after 18, 21 and 25 days. Survival was generally >70% but at 24˚C when fed >16 brine shrimp survival was <40%. For all stages, consumption rates increased but total consumption decreased with increasing temperature. For Stages II, IV, VI and VIII the intermoult period increased as the brine shrimp ration reduced. Larvae were successfully reared up to Stage VI ~25% faster at 21˚ than at 18˚C.

2001 ◽  
Vol 52 (8) ◽  
pp. 1459 ◽  
Author(s):  
Graeme A. Moss ◽  
Lennard J. Tong ◽  
Sarah E. Allen

Instar 1, 3, 5, and 7 phyllosomas of the spiny lobsterJasus verreauxi were reared individually at one of four temperatures (18, 21, 24, and 27C) and fed low, medium, or high rations of 2- to 3-mm Artemia salina. An increase in the temperature reduced the intermoult period for all instars tested, but only the instar 5 phyllosomas showed any significant differences in postmoult size with temperature; those at 18C were smaller. Phyllosomas reared at 18C ate fewer Artemia each day than did those at the higher temperatures, but instars 3 and 5 at 18C consumed more in total over the intermoult period. Survival for all instars tested was lowest at 18C. Increasing the food rations affected the growth and survival of instar 5 and 7 phyllosomas; those fed at the lower rations took longer to moult and had a smaller growth increment. For all instars tested, the feeding rate and total consumption increased with food ration.


2011 ◽  
Vol 61 (4) ◽  
pp. 413-425 ◽  
Author(s):  
Mona M. El-Gamal

AbstractThe available studies on oxygen consumption by Artemia related to different salinities reported contradictory results. However, most of these studies have been obtained only for newly hatched nauplii or adults, and have neglected the gradual accommodation that gives a picture about what really happens in nature. In order to face the problems noted above individuals of Artemia franciscana were acclimated to four different salinities (25 g/L, 35 g/L, 70 g/L and 120 g/L) under laboratory conditions. The oxygen consumption under declining oxygen tensions (Po 2) for each of the 19 stages in Artemia life metamorphic developments was examined. The brine shrimp under different salinities is a respiratory regulator over a wide range of Po 2's. Oxygen consumption rates varied across the salinities with a general inverse relationship in uptake rates versus salinity. The brine shrimps' individual weight significantly decreased with increasing salt concentration of the external medium. Generally, regulation of oxygen consumption improved with development. Specimens cultured under high salinities (70 g/L and 120 g/L) started the regulation earlier than low salinities, even before heart and gill formation (in stage 2) and high salinities also accelerated the development of the heart and the gut earlier than those cultured under lower salinities (stage 3 instead of 6). Later developmental stages did not perform osmotical work in the same manner as nauplii did (0-6) and oxygen consumption did not drive the ionic regulation of Artemia franciscana specimens cultured under different salinities.


2021 ◽  
Vol 26 (1) ◽  
pp. 17-23
Author(s):  
Damian P. Rigg ◽  
Robert L. Courtney ◽  
Jamie E, Seymour ◽  
Clive M. Jones

Abstract Modern, intensified aquaculture typically involves three production phases; hatchery, nursery, and grow-out. For redclaw crayfish aquaculture however, such delineation has been ill-defined. Farming of redclaw was initiated based on the putative beneficial physical and biological attributes of the species, which suggested production methods would be relatively simple. The simple approach proved to be inefficient and only partially effective, which hindered industry development. Hatchery technology now exists to supply seed stock for grow-out, but hatchery production is variable, and the performance of hatchery reared juveniles is inconsistent. A nursery phase has been proposed between hatchery production and grow-out of approximately 3 weeks duration, sufficient to allow 2 or more moults. An important primary parameter in the proposed nursery phase is the thermal regime that will support optimum survival and growth. This study quantified the effect of temperature on the growth and survival of redclaw juveniles for a 22-day nursery phase. Temperature had a statistically significant effect on the survival of juveniles, whereby, the high temperatures were associated with high mortality, and the lower temperature treatments were associated with very low mortality. Survival was 98 to 100% for craylings held at temperatures between 18°C and 22°C, and between 0% and 6% for craylings at temperature treatments of 25°C to 32°C. Mortalities within treatments between 25°C and 30°C, primarily occurred from day six to day eleven, corresponding with the initiation of moulting. Change of mass of crayfish was significantly higher with increasing temperature between 18°C and 22°C and at individual weights that suggest they had completed a moult. This study suggests a water temperature of 22°C is optimal for survival and growth in a nursery phase.


2019 ◽  
Vol 65 (5) ◽  
pp. 701-707
Author(s):  
Vitaliy Shubin ◽  
Yuriy Shelygin ◽  
Sergey Achkasov ◽  
Yevgeniy Rybakov ◽  
Aleksey Ponomarenko ◽  
...  

To determine mutations in the plasma KRAS gene in patients with colorectal cancer was the aim of this study. The material was obtained from 44 patients with colorectal cancer of different stages (T1-4N0-2bM0-1c). Plasma for the presence of KRAS gene mutation in circulating tumor DNA was investigated using digital droplet polymerase chain reaction (PCR). KRAS mutations in circulating tumor DNA isolated from 1 ml of plasma were detected in 13 (30%) patients with cancer of different stages. Of these, with stage II, there were 3 patients, with III - 5 and with IV - 5. Patients who did not have mutations in 1 ml of plasma were analyzed for mutations of KRAS in circulating tumor DNA isolated from 3 ml of plasma. Five more patients with KRAS mutations were found with II and III stages. The highest concentrations of circulating tumor DNA with KRAS mutation were found in patients with stage IV. The increase in plasma volume to 3 ml did not lead to the identification of mutations in I stage. This study showed that digital droplet PCR allows identification of circulating tumor DNA with the KRAS mutations in patients with stage II-IV of colon cancer. The results can be used to determine the degree of aggressiveness of the tumor at different stages of the disease, but not the 1st, and it is recommended to use a plasma volume of at least 3 ml.


1966 ◽  
Vol 49 (5) ◽  
pp. 989-1005 ◽  
Author(s):  
Richard Fitzhugh

In the squid giant axon, Sjodin and Mullins (1958), using 1 msec duration pulses, found a decrease of threshold with increasing temperature, while Guttman (1962), using 100 msec pulses, found an increase. Both results are qualitatively predicted by the Hodgkin-Huxley model. The threshold vs. temperature curve varies so much with the assumptions made regarding the temperature-dependence of the membrane ionic conductances that quantitative comparison between theory and experiment is not yet possible. For very short pulses, increasing temperature has two effects. (1) At lower temperatures the decrease of relaxation time of Na activation (m) relative to the electrical (RC) relaxation time favors excitation and decreases threshold. (2) For higher temperatures, effect (1) saturates, but the decreasing relaxation times of Na inactivation (h) and K activation (n) factor accommodation and increased threshold. The result is a U-shaped threshold temperature curve. R. Guttman has obtained such U-shaped curves for 50 µsec pulses. Assuming higher ionic conductances decreases the electrical relaxation time and shifts the curve to the right along the temperature axis. Making the conductances increase with temperature flattens the curve. Using very long pulses favors effect (2) over (1) and makes threshold increase monotonically with temperature.


2020 ◽  
Vol 28 (1) ◽  
pp. 138-151
Author(s):  
Kelly A. Stahl ◽  
Elizabeth J. Olecki ◽  
Matthew E. Dixon ◽  
June S. Peng ◽  
Madeline B. Torres ◽  
...  

Gastric cancer is the third most common cause of cancer deaths worldwide. Despite evidence-based recommendation for treatment, the current treatment patterns for all stages of gastric cancer remain largely unexplored. This study investigates trends in the treatments and survival of gastric cancer. The National Cancer Database was used to identify gastric adenocarcinoma patients from 2004–2016. Chi-square tests were used to examine subgroup differences between disease stages: Stage I, II/III and IV. Multivariate analyses identified factors associated with the receipt of guideline concordant care. The Kaplan–Meier method was used to assess three-year overall survival. The final cohort included 108,150 patients: 23,584 Stage I, 40,216 Stage II/III, and 44,350 Stage IV. Stage specific guideline concordant care was received in only 73% of patients with Stage I disease and 51% of patients with Stage II/III disease. Patients who received guideline consistent care had significantly improved survival compared to those who did not. Overall, we found only moderate improvement in guideline adherence and three-year overall survival during the 13-year study time period. This study showed underutilization of stage specific guideline concordant care for stage I and II/III disease.


2015 ◽  
Vol 34 (2) ◽  
pp. 545-554 ◽  
Author(s):  
Melanie Chiasson ◽  
Gilles Miron ◽  
Dounia Daoud ◽  
Martin D. Mallet

1994 ◽  
Vol 4 (1) ◽  
pp. 66-71
Author(s):  
B. D. Evans ◽  
P. Chapman ◽  
P. Dady ◽  
G. Forgeson ◽  
D. Perez ◽  
...  

Fifty-six patients with ovarian cancer (three stage IC, nine stage II, 33 stage III and II stage IV) were treated with carboplatin 350 mg m−2 i.v. day 1 and chlorambucil orally 0.15 mg kgm−1 days 1–7 inclusive, repeated every 28 days for eight courses. The regimen was well tolerated and was virtually free of nephro- and neurotoxicity. Grade III or IV hematology toxicity occurred in 18 patients but only 31 or 330 courses administered were delayed. Of 40 assessable patients eight achieved a clinical/radiologic complete response and 17 a clinical/radiologic partial response. Actuarial survival at 50 months was 65% for stage II patients, 27% for stage III patients and no stage IV patients survived beyond 20 months. Forty-two per cent of patients with residual disease less 2 cm survived 50 months, compared with 44% of patients with moderate volume (2–5 cm) residual disease and 6% of patients with bulk residual disease. This is an active, well tolerated regimen. However, only patients with small volume residual disease have a significant chance of prolonged survival.


1984 ◽  
Vol 84 (6) ◽  
pp. 845-859 ◽  
Author(s):  
D S Dennison ◽  
W Shropshire

The gravitropism of a mature stage IV Phycomyces sporangiophore has a shorter and more uniform latency if the sporangiophore is exposed horizontally to gravity during its earlier development (stage II and stage III). This early exposure to an altered gravitational orientation causes the sporangiophore to develop a gravireceptor as it matures to stage IV and resumes elongation. A technique has been developed to observe the spatial relationship between the vacuole and the protoplasm of a living sporangiophore and to show the reorganization caused by this exposure to altered gravity. Possible gravireceptor mechanisms are discussed.


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