Effects of short-term continuous and intermittent feeding regimes on food consumption, growth, gonad production and quality of sea urchin Strongylocentrotus intermedius fed a formulated feed

2016 ◽  
Vol 97 (2) ◽  
pp. 359-367 ◽  
Author(s):  
Jing Wei ◽  
Chong Zhao ◽  
Lisheng Zhang ◽  
Limeng Yang ◽  
Rantao Zuo ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Test Diameter ◽  
Short Term ◽  
Consumption Growth ◽  
Feeding Regime ◽  
Intermittent Feeding ◽  
Feeding Regimes ◽  
Gonad Production ◽  
Formulated Feed

Feeding regime is an important concern for sea urchin aquaculture. However, optimal feed regimes have not been established for land-based sea urchin ventures using a formulated feed. In this study, we investigated the effects of short-term continuous and intermittent feeding regimes on food consumption, growth, gonad production and quality of the sea urchin Strongylocentrotus intermedius (54.90 ± 2.28 mm of test diameter) fed a formulated feed. The results showed that (1) compared with initial conditions, all involved traits except a* (test diameter, test height, body weight, gonad weight, gonad index, gonad moisture, L* and b*) showed significant increase at the end of the experiments; (2) only the longest term feed regime tested in this trial (S2) significantly negatively affected growth and gonad production of S. intermedius fed a formulated feed; (3) there was a trend but this was not significant for inhibiting gonad development of S. intermedius in intermittent feeding regimes and there was no change in the gonad colour and sweetness; (4) S0.5 (fasting half day and then feeding half day) is the optimal intermittent feeding regime for S. intermedius fed a formulated feed. To our knowledge, the present study is the first report of finding an effective intermittent feeding regime for land-based cultured sea urchins of relatively large size, and thus has direct application potential in the field of aquaculture.

Effects of temperature and feeding regime on food consumption, growth, gonad production and quality of the sea urchin Strongylocentrotus intermedius

2015 ◽  
Vol 96 (1) ◽  
pp. 185-195 ◽  
Author(s):  
Chong Zhao ◽  
Wenping Feng ◽  
Jing Wei ◽  
Lisheng Zhang ◽  
Ping Sun ◽  
...  
Keyword(s):  
Water Temperature ◽  
Food Consumption ◽  
Sea Urchins ◽  
High Water ◽  
High Water Temperature ◽  
Consumption Growth ◽  
Feeding Regime ◽  
Gonad Production ◽  
Formulated Feed

Water temperature is one of the most important factors greatly affecting the aquaculture of sea urchins. However, no information is available on how to improve commercial traits of sea urchins reared at high water temperature. Here, we investigated the effects of water temperature and feeding regime on food consumption, growth, gonad production, gametogenesis and gonad quality of the sea urchin Strongylocentrotus intermedius. We found that high water temperature (22°C) significantly decreased dried food consumption and gonad production of S. intermedius, but not the somatic growth. The feeding regime of formulated feed and kelp has direct application potential in S. intermedius aquaculture, especially at field temperature. Feeding kelp alone is not effective in supporting growth and gonad production for S. intermedius cultured at high water temperature. This finding greatly challenges the current commonly used feeding regime (feeding macroalgae only) for S. intermedius cultured at high water temperature. Based on the current results, we suggest the feeding regimes of formulated feed and kelp or formulated feed alone for S. intermedius aquaculture at high water temperature. The present study provides new information for aquaculture of S. intermedius at high temperature and for production out of season.

scholarly journals Video surveillance methods to evaluate individual feeding response in rainbow trout (Oncorhynchus mykiss, Walbaum)—implications for feeding regime optimisation

2021 ◽  
Author(s):  
Philip Niclas Just ◽  
Bernd Köllner ◽  
Matthew James Slater
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Video Surveillance ◽  
Average Weight ◽  
Short Term ◽  
Feeding Regime ◽  
Daily Feeding ◽  
Juvenile Rainbow Trout ◽  
Feeding Regimes ◽  
The Impact

AbstractPrecisely analysing and optimising feeding regimes is central to salmonid growth performance and delivery of special diets. The current study developed novel video surveillance methods and analysis techniques to assess individual feed intake and minimum pellet intake (MPI) in individually identified juvenile rainbow trout, Oncorhynchus mykiss. Three trials were conducted to test the impact of short-term starvation (N=112 [16 tanks, 7 fish per tank], average weight=27.1±3.4g, age= 119 days), portion numbers per feeding (N=105 [15 tanks, 7 fish per tank], average weight=22.8±2.1g, age= 99 days) and varied numbers of daily feeding events (N=84 [12 tanks, 7 fish per tank], average weight=32.4±3.3g, age= 133 days). All trails were carried out in a recirculating aquaculture system with 20 tanks held at 15 ± 0.5°C. All individuals were code-tagged and high quality video images were taken and analysed to identify all feeding interactions. Individual trout feeding activity under different feeding regimes could be precisely analysed with the video methods developed. Moving from one to two daily feeding events doubled pellet intake per fish from 27.4 ± 5.8 to 52.8 ± 11.5 pellets. Pellet intake (58.8 ± 24.2 pellets) did not increase at three daily feeding events but became more variable across fish. MPI nearly doubled to 30 pellets in fish receiving two daily feeding events (MPI30: chi-squared = 8.74, df = 2, p = 0.01). Short-term starvation had no influence on intake (28 ± 8 pellets/fish) or MPI. Increasing portion number from one (27.8 ± 7.4 pellets fish−1) to two (31.1 ± 7.4 pellets fish−1) or more did not significantly increase the number of ingested pellets. Adjusting the feeding regime by increasing daily feeding events to two, possibly combined with multiple portions, can increase pellet intake and reduce the heteroscedasticity of pellet intake. The methods presented in this study are viable for analysing feeding regimes for juvenile rainbow trout and controlled feedstock/supplement delivery. Implications for analyses with other species and for vaccination optimisation are discussed.

scholarly journals Reproduction of the sea urchin Tripneustes depressus (Camarodonta: Toxopneustidae) in Bahía de La Paz, Baja California Sur, Mexico

2021 ◽  
Vol 69 (Suppl.1) ◽  
pp. 202-218
Author(s):  
Ailet Vives ◽  
Tamara Rubilar ◽  
María-Dinorah Herrero-Pérezrul ◽  
Bertha-Patricia Ceballos-Vázquez
Keyword(s):  
Sea Urchin ◽  
Baja California ◽  
Gonad Development ◽  
Reproductive Season ◽  
Baja California Sur ◽  
Test Diameter ◽  
La Paz ◽  
Wet Weight

Introduction: Sea urchin gonads (roe or uni) are considered a culinary delicacy worldwide. However, only a few species are considered edible and commercialized. The sea urchin Tripneustes depressus has generated the interest of producers in Baja California Sur, Mexico, due to the quality of its gonads. A biological basis for designing a management strategy is key to consider its commercial exploitation. Objective: To determine the reproductive season of T. depressus through description of the gonad stages and reproductive cycle, and to establish its relationship with environmental factors. Methods: We collected monthly samples (October 2016-September 2017), recording in-situ temperature and photoperiod. We evaluated a sample of 1 055 specimens for demographic characteristics, using total weight (g) and test diameter (cm). We also did a histological analysis of gonads from 178 individuals. Results: Average test diameter was 9.70 ± 0.03 cm (5-12.50 cm). Based on the proportion into the gonad of sexual (gametes) and somatic (nutritive phagocytes) cells, we propose five gonad stages (growing, premature, mature, spawning, and intergametic) for both sexes. There were two times of the year when gonads were heaviest and closely corresponded to the growing stage, coinciding with the highest proportions of nutritive phagocytes. Gonad development (growing and premature stages) peaks in the months with the longest daylight periods, with spawning in the shortest daylight periods. Conclusions: Gonad wet weight and adjusted gonad weight are good indicators of the reproductive season of T. depressus. The lowest gonad wet weights were matched the spawning peak in the shortest daylight period (January and March).

Cathartic Effect of Suicide Attempts Not Limited to Depression

Crisis ◽  
2003 ◽  
Vol 24 (2) ◽  
pp. 73-78 ◽  
Author(s):  
Yves Sarfati ◽  
Blandine Bouchaud ◽  
Marie-Christine Hardy-Baylé
Keyword(s):  
Quality Of Life ◽  
Depressive Symptoms ◽  
Personality Traits ◽  
Rating Scales ◽  
Suicide Attempts ◽  
World Health ◽  
Life Questionnaire ◽  
Short Term

Summary: The cathartic effect of suicide is traditionally defined as the existence of a rapid, significant, and spontaneous decrease in the depressive symptoms of suicide attempters after the act. This study was designed to investigate short-term variations, following a suicide attempt by self-poisoning, of a number of other variables identified as suicidal risk factors: hopelessness, impulsivity, personality traits, and quality of life. Patients hospitalized less than 24 hours after a deliberate (moderate) overdose were presented with the Montgomery-Asberg Depression and Impulsivity Rating Scales, Hopelessness scale, MMPI and World Health Organization's Quality of Life questionnaire (abbreviated versions). They were also asked to complete the same scales and questionnaires 8 days after discharge. The study involved 39 patients, the average interval between initial and follow-up assessment being 13.5 days. All the scores improved significantly, with the exception of quality of life and three out of the eight personality traits. This finding emphasizes the fact that improvement is not limited to depressive symptoms and enables us to identify the relative importance of each studied variable as a risk factor for attempted suicide. The limitations of the study are discussed as well as in particular the nongeneralizability of the sample and setting.

On Being Precarious

2020 ◽  
Vol 50 (1) ◽  
pp. 51-54
Author(s):  
Deirdre Flynn
Keyword(s):  
Quality Of Life ◽  
Short Term ◽  
Teaching Research ◽  
Part Time

In this essay, I reflect on my experience of part-time, fixed term, zero-hour, short-term, and unpaid contracts in academia. Precarious contracts are one of the biggest challenges facing our industry as neo-liberal values rule our institutions, impacting our teaching, research, and quality of life.

Bioactive Peptides Sensitize Cells to Anticancer Effects of Oxaliplatin in Human Colorectal Cancer Xenografts in Nude Mice

2019 ◽  
Vol 26 (7) ◽  
pp. 512-522
Author(s):  
Xian Li ◽  
Long Xia ◽  
Xiaohui Ouyang ◽  
Qimuge Suyila ◽  
Liya Su ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Colorectal Cancer ◽  
Nude Mice ◽  
Low Dose ◽  
Bioactive Peptides ◽  
Human Colorectal Cancer ◽  
Short Term ◽  
Hct 116

<P>Background: Despite new agent development and short-term benefits in patients with Colorectal Cancer (CRC), metastatic CRC cure rates have not improved due to high rates of oxaliplatin resistance and toxicity. There is an urgent need for effective tools to prevent and treat CRC and reduce morbidity and mortality of CRC patients. Exploring the effects of bioactive peptides on the antitumor to CRC was of vital importance to the clinical application. </P><P> Objective: This study aimed to investigate the therapeutic impact of Anticancer Bioactive Peptides (ACBP) on anticancer effect of oxaliplatin (LOHP) in human colorectal cancer xenografts models in nude mice. </P><P> Methods: HCT-116 cells were cultured in vitro via CCK-8 assays and the absorbance was measured at 450 nm. Apoptosis and cell cycle were assessed by Flow Cytometry (FCM) in vitro. HCT-116 human colorectal cancer cells inoculated subcutaneously in nude mice of treatment with PBS (GG), ACBP, LOHP, ACBP+LOHP (A+L) in vivo. The quality of life was assessed by dietary amount of nude mice, the weight of nude mice, inhibition rates, tumor weight and tumor volume. Immunohistochemistry and RT-qPCR method was conducted to determine the levels of apoptosisregulating proteins/genes in transplanted tumors. </P><P> Results: ACBP induced substantial reductions in viable cell numbers and apoptosis of HCT116 cells in combined with LOHP in vitro. Compared with the control GG group, ACBP combined low dose oxaliplatin (U) group demonstrated significantly different tumor volume, the rate of apoptosis, the expression levels of Cyt-C, caspase-3,8,9 proteins and corresponding RNAs (P<0.05). The expression of pro-apoptotic proteins in the cytoplasm around the nucleus was significantly enhanced by ACBP. Short term intermittent use of ACBP alone indicted a certain inhibitory effect on tumor growth, and improve the quality of life of tumor bearing nude mice. </P><P> Conclusion: ACBP significantly increased the anti-cancer responses of low dose oxaliplatin (L-LOHP), thus, significantly improving the quality of life of tumor-bearing nude mice.</P>

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