Effects of Rearing Density on the Stress Response and Growth of Rainbow Trout

Kebus, Myron J.; Collins, Michael T.; Brownfield, Mark S.; Amundson, C. H.; Kayes, Terrence B.; Malison, Jeffrey A.

doi:10.1577/1548-8667(1992)004<0001:eordot>2.3.co;2

Cited by 110 publications

(81 citation statements)

References 14 publications

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“…The present study highlighted the negative effect of high stocking density on growth and feed conversion capacity of labeo and catla as observed in previous studies (Ellis et al, 2002;Kebus et al, 1992;Lupatsch et al (2010); Li et al (2012). At this time fish exposed to a higher density showed significantly lower values in total length and weight as indicated by condition factor.…”

Section: Discussionsupporting

confidence: 83%

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Fatima¹,

Izhar²,

Usman³

et al. 2018

Turk. J. Fish. Aquat. Sci.

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High stocking density is a major problem in extensive aquaculture in Pakistan. Present study investigated its effect of growth, levels of thyroxine (T4) and cortisol in two major carps of Pakistan; labeo (Labeo rohita) and catla (Catla catla). One cohort of labeo (n=30) was kept at high stocking density (HD) (25 g/L). HD cohort was split into two replicates, each containing a total of 15 fish. Second cohort of labeo (n=10) was reared at low stocking density (LD) of 4.4 g/L. LD cohort was divided into two replicates, each containing a total of five fish. Similar protocol was followed for catla. Trial continued for the period of 30 days. At the end of trial, condition factor significantly decreased in HD cohorts of both species. Levels of cortisol in HD cohorts (210±2.00 nmol/L in Catla catla; 425±3.00 nmol/L in Labeo rohita) were significantly higher than those in LD cohorts of both species. Values of T4 in HD cohorts were found to be 1.48±0.20 pmol/L in Catla catla and 1.74±0.10 pmol/L in Labeo rohita at the end of trial which were significantly lower than at the commencement of trial. Suppression of growth, elevation in the levels of cortisol and decrease in profile of T4 in HD cohorts of both species was due to stress induced by high stocking density. Furthermore, present study found that optimum stocking density for extensive farming of both species should be approximately 4.4 g/L.

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Section: Discussionsupporting

confidence: 83%

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Fatima¹,

Izhar²,

Usman³

et al. 2018

Turk. J. Fish. Aquat. Sci.

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“…In studies on stress, Pickering et al (1982) utilizing trout (Salmo trutta) and Ellsaesser & Clem (1986) (Ictalurus punctalus), also showed no significant differences in the number of erythrocytes and other hematological parameters. However, Kebus et al (1992) and Iwama (1993) stated that immunodeficiency resulting from the response to stress was due to a negative correlation of the number of circulating lymphocytes with plasma cortisol level. Pickering et al (1982) observed that the simple stress of handling in two specimens of Salmo trutta caused lymphopenia after 8 h, which required 72 h for recovery of lymphocytes to baseline levels.…”

Section: Resultsmentioning

confidence: 99%

Physiological response of American bullfrog tadpoles to stressor conditions of capture and hypoxia

Rocha¹,

Ferreira²,

Teixeira

et al. 2010

Pesq. Vet. Bras.

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RESUMO.-[Resposta fisiológica de girinos de rã-touro americana submetidos aos mecanismos estressores de captura e hipóxia.] A rã-touro americana (Rana catesbeiana) recentemente denominada Lithobates catesbeianus é criada com propósito comercial em várias regiões do Brasil. Situações estressantes tais como problemas de manejo, criação inadequada e alterações ambientais com consequente redução da imunidade são comuns em produções intensivas. A avaliação destas situações de estresse permitenos detectar estes probemas e diminuir as injurias causadas pelo confinamento. O principal objetivo deste estudo foi utilizar os marcadores biológicos de cortisol, glicemia e dados hematológicos para avaliar a resposta de girinos de rã-touro submetidos aos mecanismos estressores de captura e hipóxia. Os animais foram distribuídosem três tratamentos: estresse por captura individual com puçá; estresse por captura em massa com puçá e estresse por captura por escoamento. Os resultados obtidos demostraram não haver diferenças estatisticamente significativas entre os parametros avaliados quando comparou-se os grupos com e sem exposição ao ar (normoxia e hipoxia). Com base nes- Stressful situations such as problems of management, inadequate facilities and environmental changes with consequent reduction of immunity are common in intensive production. The assessments of these situations of stress allow us detect these problems decreasing the injuries causes by confinement. The main objective of this study was to use the biological markers of plasma cortisol and glucose level and hematological parameters to evaluate the response of bullfrog tadpoles submitted to stressed mechanisms of capture and hypoxia. The animals were subjected to three treatments: stress due to individual capture with a hand net; stress due to batch capture with a hand net; and stress due to capture by emptying. The results obtained demonstrated that there were no statistically significant differences in the parameters tested when comparing the treatments with and without exposure to air (normoxia and hypoxia). Based on these results we can conclude that the stressful stimuli tested were not adequate to alter the biomarker tested. For the cortisol, probably this should have occurred due to the synergistic action between this hormone and thyroxin, which induces metamorphosis in these animals. tes resultados pode-se concluir que os estímulos estressores avaliados não foram adequados para alterar os valores plasmáticos dos marcadores biológicos testados. Para o cortisol, isto ocorreu provavelmente em virtude da ação sinérgica deste hormônio e a tiroxina, que induz a metamorfose nestes animais.

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“…Huang and Chiu (1997), also argued that since tilapia is a territorial and aggressive fish, their density growth effects arises from their competition for territories, as well as from the permanent stress caused by crowding. This leads to inhibitory fish growth as a result of the fish's physiological alterations elicited by stress responses so that adequate energy is mobilized from the consumed diets (Kebus et al, 1992;Ruane et al, 2002;Ruane and Komen, 2003). Therefore, since slight significant growth responses was observed with higher variances occurring in the hapas with the stocking densities of 50 and 100 fry's, indicated that stocking density had effects on the fry's growth.…”

Section: Discussionmentioning

confidence: 99%

Appropriate Stocking and Feeding of Lake Shrimp (Caridina niloticus) Diet to Enhance Nile Tilapia Fry’s Growth in an Intensive Aquaculture System

Oc¹,

Khuting²,

M³

2015

J. of Fisheries and Aquatic Science

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Nile tilapia (Oreochromis niloticus L.) pond culture in Kenya is currently gaining popularity through the governments' economic stimulus programme intervention. However, lack of sufficient fry seeds to stock the ever increasing dug-out ponds is curtailing its expansion. The study therefore aimed to determine the ideal optimal stocking and feeding regimes that would enhance the growth (in <60 days) of fry's fed a locally prepared Lake Shrimp (Caridina niloticus) diet in an intensive aquaculture pond system. Experimental fry's with mean weights 0.06±0.02 g and lengths 13.9±0.7 mm were obtained from the same source and stocked into 1m 2 pond submerged net cages locally known as (hapas) labeled A, B, C and D, respectively. Hapa A with 100 fry's fed five times acted as control whereas Hapa B, with also 100 fry's was only fed twice within the day. Hapas C and D with 50 and 600 fry's, respectively, were both fed five times within the day as used in the farm. All feedings were done at 3% of total mean fry body weights for the entire experimental period. Daily pond water quality parameter values were also recorded and calculated weekly to determine the ideal water culture conditions. Weekly length (mm) and weight sampling values were also used to determine length and weight growths in addition to the fry's Food Conversion Ratios (FCRs). Results indicated that intensively stocked fry's at 100 individuals in 1 m 2 pond area and fed twice daily using the locally prepared Caridina diet had slight significant growths (p = 0.04) with no significant FCRs (p = 0.06) in these intensive stagnant aquaculture ponds.

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Effects of Rearing Density on the Stress Response and Growth of Rainbow Trout

Cited by 110 publications

References 14 publications

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Physiological response of American bullfrog tadpoles to stressor conditions of capture and hypoxia

Appropriate Stocking and Feeding of Lake Shrimp (Caridina niloticus) Diet to Enhance Nile Tilapia Fry’s Growth in an Intensive Aquaculture System

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