Quality of Nephrops as food for Atlantic cod (Gadus morhua L.) with possible implications for fisheries management

Abstract Nephrops was found to be of low quality as food for cod. In a laboratory experiment the mean specific growth rate of 1 kg cod was 0.184 and 0.415% d−1 when fed to satiation on Nephrops and capelin, respectively. This large difference in growth rate resulted not only from less intake of Nephrops (1.19 kg cod−1) than capelin (1.55 kg cod−1) but also because more Nephrops (4.6 kg) than capelin (2.2 kg) were required to produce each kilogramme of cod. Higher food conversion ratio was consistent with lower fat content of Nephrops (1.3%) than capelin (9.2%) but the exoskeleton also reduced the digestion rate of Nephrops. In the groups where Nephrops and capelin of equal mean weight were offered simultaneously, 40% of the diet consisted of Nephrops during the first week and 10% during the final seven weeks of the experiment. At the end of the experiment, condition factor, liver index, and gonadosomatic index were significantly lower for cod fed on Nephrops (0.967, 5.7, 7.1, respectively) than for those fed on capelin (1.086, 15.8, 11.2, respectively). These results suggests that predation by cod on Nephrops might be reduced by regular release of capelin or other similar food in the distributional areas of Nephrops.

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Azolla a Boon for the Growth of Gift Tilapia, Oreochromis Niloticus (Linnaeus, 1758)

10.21203/rs.3.rs-692275/v2 ◽

2021 ◽

Author(s):

LEENA GRACE BESLIN ◽

MONISHA RAJAN

Keyword(s):

Growth Rate ◽

Growth Analysis ◽

Specific Growth ◽

Condition Factor ◽

Control Diet ◽

Conversion Ratio ◽

Feed Conversion Ratio ◽

Feed Conversion ◽

Relative Growth ◽

Gift Tilapia

Abstract Appreciative dietary desires and fabrication of fish nourishment is vital to the progress, sustainability of aquaculture and for the advanced feed mill rehearsal. Organizing fish feed includes choosing the exact feed, using an acceptable feeding technique, work out the feed charge and ensuring the cost efficiency of fish farm. The purpose of our present study was to feed the fishes with four different feeds and assessment of growth performance by length weight relationships. The growth analysis was executed by measuring FCR and related indices in gift tilapia oreochromis niloticus. Four feed composition was selected without any chemical contamination. In the present study fishes were collected from the golden farm, Neyyattinkara, Thiruvananthapuram district, South India. Fishes were introduced into four different tanks of well oxygenated good quality water. In each experimental tank, 20 fishes were introduced. For each experimental container a specific feed was fixed from 4 different diets. Every day feed was given to the fishes. They were fed two times for the period of 3 months. They were maintained to assess their growth performance. Four types of feeds used for the present study were control diet, diet 1, diet 2 and diet 3. Length and weight were measured on every 15 days interval for growth estimation. Based on the length-weight data, growth analysis was carried out by calculating relative growth (RG), relative growth rate (RGR), specific growth rate (SGR), feed conversion ratio (FCR) and the Fulton’s condition factor. The results of mean length in diet3proved the highest length of 6.455±0.46cm and diet one contain lowest length of 5.03±0.68cm. Highest weight of 96.8 ± 0.37g was recorded in diet3 and lowest weight obtained for the control diet (3.645 ± 0.306 g). In growth analysis the relative growth of fish was estimated in diet 3 having high relative growth (11.91). Relative growth rate was elevated in diet 3(1.5597). The upper limit of specific growth rate was 1.9146% noticed in diet 3. The feed conversion ratio was maximum in diet 3 (58.06) and minimum in control diet (36). The highest k value in Fulton's condition factor was noticed in diet 3(88.32).All experimental results proved that live Azolla [D3] was a superior feed for the present trials.

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Effects of Intermediate and Low Salinity Conditions on Growth Rate and Food Conversion of Atlantic Cod (Gadus morhua)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f94-155 ◽

1994 ◽

Vol 51 (7) ◽

pp. 1569-1576 ◽

Cited By ~ 101

Author(s):

Yvan Lambert ◽

Jean-Denis Dutil ◽

Jean Munro

Keyword(s):

Growth Rate ◽

Food Intake ◽

Growth Rates ◽

Gadus Morhua ◽

Atlantic Cod ◽

Food Conversion ◽

Coastal Regions ◽

Low Salinity ◽

Feeding Regimes ◽

Food Conversion Efficiency

Growth rates of Atlantic cod (Gadus morhua) were measured under different salinity conditions to test the hypothesis that growth would be best in an isosmotic environment. The results of two experiments (spring and autumn 1991) conducted at three different salinities (7, 14, and 28‰) and two feeding regimes indicate a significant effect of salinity and ration on growth rate. Within each experiment, growth rates were highest for cod maintained in intermediate salinity conditions (14‰). Growth rates in low salinity conditions (7‰) were higher than in seawater (28‰) during the spring, but during the autumn, growth rates of cod held under low salinity conditions and in seawater were similar. Higher growth rates at lower salinities resulted from an increase in food conversion efficiency. They were not associated with an increase in food intake, changes in composition (proteins, lipids, or water), or relative allocation of energy to the tissues (muscle, liver, and gonads) of cod. The results indicate that rearing cod at intermediate salinities, such as would occur in estuaries or coastal regions, could confer an advantage for cod aquaculture.

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Determination of Suitable Water Salinity and Live Food in The Rearing of Eel (Anguilla bicolor) Fry

Jurnal Akuakultur Indonesia ◽

10.19027/jai.7.71-77 ◽

2008 ◽

Vol 7 (1) ◽

pp. 71

Author(s):

. Sutrisno

Keyword(s):

Growth Rate ◽

Survival Rate ◽

Specific Growth Rate ◽

Specific Growth ◽

Conversion Ratio ◽

Live Food ◽

Water Salinity ◽

Food Conversion ◽

Food Conversion Ratio

This study was conducted to determine suitable water salinity and live food in the rearing of eel, Anguilla bicolor fry. Eel fry in weight of 0.15±0.008 g/tail were reared at controlled tank at density of 2 fish liter-1 for 42 days. Experiment was devided into two steps. In the first step of experiment, eel fry were reared at different water salinity, i.e., 0; 5; 10 and 15 ppt. Fish were fed on Tubifex at satiation. The best result from the first experiment was then used in the second step of study to examine proper live food for eel fry. Fish were fed on live food (Tubifex, Artemia, or Spirulina) at 10% body weight. Survival rate, specific growth rate and food conversion ratio were observed. The result of experiment showed that survival rate of eel fry reared in water salinity of 5 ppt (100%), 10 (96%) and 15 ppt (97%) was higher (p<0.05) compared to that of 0 ppt (58%). Specific growth rate was also higher (p<0.05) in fish reared in water salinity of 5 (2.33%), 10 (1.65%) and 15 ppt (1.57%) compared to that of 0 ppt (0.022%). Survival rate and specific growth rate of fish at treatment of 5, 10 and 15 ppt were insignificantly different (p>0.05). The best food conversion ratio was also being obtained at treatment of 5 ppt (3.36), followed repectively by 10 ppt (5.11), 15 ppt (5.70) and 0 ppt (21.11). No different survival rate of eel fry by feeding on different live food was obtained. Higher specific growth rate was achieved at feeding of Artemia (2.82% per day), followed respectively by Tubifex (1.85% per day) and Spirulina (0.15% per day). Food coversion ratio in each treatment was 4.42, 2.77 and 134.33, respectively. Keywords: eel, salinity, live food <h5>ABSTRAK</h5> Penelitian dilakukan dengan tujuan untuk mengetahui salinitas air dan jenis pakan alami yang tepat dalam pemeliharaan benih ikan sidat (Anguilla bicolor). Benih sidat dengan berat rata-rata 0,15±0,008 g/ekor dipelihara selama 42 hari pada wadah terkontrol dengan kepadatan 2 ekor/liter. Penelitian dibagi kedalam dua tahap. Pada tahap pertama benih sidat diperlihara pada media dengan salinitas 0; 5, 10 dan 15 ppt. Pakan alami berupa cacing sutera diberikan secara satiasi. Salinitas terbaik hasil penelitian tahap pertama digunakan pada penelitian tahap kedua untuk mengetahui jenis pakan alami (cacing sutera Tubifex, Artemia, atau Spirulina) yang cocok untuk benih sidat. Pakan diberikan sebanyak 10% bobot tubuh. Paramater yang diamati meliputi sintasan, laju pertumbuhan spesifik dan efisiensi pakan. Hasil penelitian menunjukkan bahwa sintasan benih ikan sidat yang dipelihara pada salinitas 5 (100%), 10 (96%) dan 15 ppt (97%) lebih tinggi (p<0,05) daripada yang dipelihara pada salinitas 0 ppt (58%). Laju pertumbuhan spesifik juga lebih tinggi (p<0,05) pada benih yang dipelihara pada salinitas 5 (2,33%), 10 (1,65%) dan 15 ppt (1,57%) dibandingkan dengan salinitas 0 ppt (0,022%). Sintasan dan laju pertumbuhan spesifik antara perlakuan 5, 10 dan 15 ppt tidak berbeda nyata (p>0,05). Konversi pakan terbaik juga diperoleh pada perlakuan 5 ppt (3,36), diikuti berturut-turut 10 ppt (5,11), 15 ppt (5,70) dan 0 ppt (21,11). Pemberian pakan alami yang berbeda tidak berpengaruh terhadap sintasan benih sidat, tetapi berpengaruh terhadap pertumbuhan. Pemberian Artemia memberikan laju pertumbuhan spesifik tertinggi, yaitu 2,82%/hari, Tubifex (1,85%/hari) dan Spirulina (0,15%/hari). Konversi pakan tiap perlakuan berturut-turut adalah 4,42; 2,77 dan 134,33. Kata kunci: ikan sidat, salinitas, pakan alami

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Size composition and production characteristics of atlantic cod and pollock juveniles of the Zelenetskaya Bay (Eastern Murman) in 2018

Transaction Kola Science Cetnre ◽

10.37614/2307-5252.2021.3.9.002 ◽

2021 ◽

Vol 12 (3-2021) ◽

pp. 13-19

Author(s):

O.V. Bondarev ◽

Keyword(s):

Growth Rate ◽

Gadus Morhua ◽

Specific Growth ◽

Atlantic Cod ◽

Size Composition ◽

Specific Weight ◽

Specific Production ◽

Summer Period ◽

Weight Growth ◽

Production Characteristics

In this article presented data on the growth of the atlantic cod Gadus morhua Linnaeus, 1758 and pollock Pollachius virens (Linnaeus, 1758) juveniles in Zelenetskaya Bay in 2018. The daily specific growth rate and production rate were calculated. The length of atlantic cod juveniles in July–September varied from 3.5 to 7.9 cm, and pollock – from 2.5 to 9.4 cm. The daily specific weight growth rate (qw) of atlantic cod juveniles in Zelenetskaya Bay from July to August was 0.41, and from August to September – 1.08; for pollock juveniles, these indicators are 1.32 and 0.94, respectively. The daily specific production (C) of atlantic cod juveniles in Zelenetskaya Bay over the summer period varied from 0.015 to 0.036, and of pollock juveniles – from 0.011 to 0.042.

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Efek Paparan Subletal Limbah Cair Industri Penyamakan Kulit terhadap Rasio Konversi Pakan dan Laju Pertumbuhan Ikan Nila (Oreochromis niloticus)

Jurnal Teknologi Lingkungan ◽

10.29122/jtl.v22i2.4091 ◽

2021 ◽

Vol 22 (2) ◽

pp. 162-169

Author(s):

Taufiq Ihsan ◽

Tivany Edwin ◽

Vira Elza

Keyword(s):

Growth Rate ◽

Specific Growth Rate ◽

Control Experiment ◽

Specific Growth ◽

Conversion Ratio ◽

Tannery Wastewater ◽

Food Conversion ◽

Food Conversion Ratio ◽

Significant Difference ◽

West Sumatra

ABSTRACT Wastewater from the tanning industry of UPTD XX has entered the waters of Batang Anai River, West Sumatra. This wastewater quality exceeds the established quality standards and can be harmful to tilapia as a river biota. This study aimed to analyze the effect of sublethal tannery wastewater on food conversion ratio (FCR) and the specific growth rate (SGR) of tilapia. This study was conducted in three conditions: zero wastewater exposure (control), 1.85%, and 3.69% wastewater exposure. Each situation was set in triplo and observed for 28 days. We analyzed the correlation between duration exposure to the FCR and SGR by using regression and correlation analysis. Results showed an increase in the FCR value during observation in both wastewater exposure variations of 1.85% and 3.69%, with FCR values consecutively 1.19 and 1.75. At the same time, the control experiment showed a decreasing value of FCR. On the contrary, SGR values were decreased during observation in both wastewater exposure variations of 1.85% and 3.69%, consecutively 3.09% and 3.72%. While increasing SGR value was observed in the control experiment. A reliable correlation was obtained between the FCR and SGR ratio of tilapia to the exposure duration (r = 0.99). Furthermore, multivariate analysis showed a significant difference between the FCR and SGR to the variation and period of direction. It can be concluded that the longer the exposure time and the higher the concentration of exposure, decreasing the food uptake of tilapia and reducing the specific growth rate. Keywords: tilapia, ratio growth rate, tannery wastewater, feed conversion, West Sumatra ABSTRAK Limbah cair dari industri penyamakan UPTD XX, Sumatera Barat telah memasuki perairan Sungai Batang Anai, Sumatra Barat. Kualitas air limbah ini melebihi standar kualitas yang ditetapkan dan dapat berbahaya bagi nila sebagai salah satu biota sungai. Penelitian ini bertujuan untuk menganalisis pengaruh air limbah penyamakan kulit terhadap Rasio Konversi Pakan (Food Conversion Ratio/FCR) dan Laju Pertumbuhan Spesifik (Specific Growth Rate/SGR) pada ikan nila. Penelitian ini dilakukan dalam tiga variasi, yakni tanpa paparan air limbah (uji kontrol), paparan air limbah 1,85% dan 3,69%. Setiap variasi dilakukan secara triplo dan diamati selama 28 hari. Korelasi antara lama paparan dengan rasio FCR serta SGR, dianalisis dengan menggunakan regresi dan analisis korelasi. Selanjutnya analisis multivariat menggunakan ANOVA two-way untuk melihat perbedaan signifikan FCR dan SGR terhadap variasi dan durasi paparan. Hasil penelitian menunjukkan peningkatan nilai FCR di kedua variasi paparan air limbah 1,85% dan 3,69% dengan nilai FCR berturut-turut 1,19 dan 1,75. FCR dalam uji kontrol menunjukkan penurunan nilai FCR. Sebaliknya, nilai SGR cenderung menurun selama pengamatan pada kedua variasi paparan air limbah 1,85% dan 3,69%, dengan nilai SGR berturut-turut 3,09% dan 3,72%, sementara peningkatan nilai SGR terjadi pada uji kontrol. korelasi yang sangat kuat diperoleh dari nilai FCR dan SGR terhadap durasi paparan (r = 0,99). Selanjutnya, uji signifikansi ANOVA menunjukkan perbedaan yang signifikan antara rasio FCR dan SGR dengan variasi dan durasi paparan air limbah. Dapat disimpulkan bahwa semakin lama waktu paparan dan semakin tinggi konsentrasi paparan air limbah, mengurangi serapan pakan ikan nila dan mengurangi tingkat pertumbuhan. Kata kunci: ikan nila, laju pertumbuhan, limbah cair penyamakan kulit, rasio konversi pakan, Sumatra Barat

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Exposure to Atrazine Impairs Behaviour and Growth Performance in African Catfish, Clarias gariepinus (Burchell, 1822) Juveniles

Nigerian Journal of Environmental Sciences and Technology - March 2018 ◽

10.36263/nijest.2021.01.0263 ◽

2021 ◽

Vol 5 (1) ◽

pp. 165-172

Author(s):

P.A. Opute ◽

I.P. Oboh

Keyword(s):

Growth Rate ◽

Growth Performance ◽

Specific Growth ◽

Condition Factor ◽

Clarias Gariepinus ◽

Conversion Ratio ◽

Feed Conversion Ratio ◽

Allometric Growth ◽

Feed Conversion ◽

Relative Growth

Clarias gariepinus juveniles of average weight, 17.57±1.95 g and an average length of 14.26±0.39 cm were exposed to environmentally relevant concentrations of 0 (control), 2.5, 25, 250, and 500 µg L-1 atrazine in a quality-controlled 28-day bioassay. Growth performance was assessed bi-weekly and fish samples were taken from different tanks to determine the relative growth rate, specific growth rate, feed conversion ratio, condition factor and behaviour. At the end of two weeks of exposure, the relative growth rate and the specific growth rate among exposed fish groups was found to reduce significantly (p<0.05) compared to the control, an indication of poor growth performance. The average specific growth rates (SGR) of control fish is 3.86±0.02 %/w at the end of the exposure duration while recording -0.64±0.09 in the 500 µg L-1 group. Feed conversion ratio increased significantly from control to the group with highest atrazine concentration. Condition factor (K) of fish among treatment groups showed significant decrease in values with increasing concentration of atrazine in a dose-dependent pattern. Atrazine exposure resulted in behavioural anomalies including erratic swimming, clinging to the water surface, loss of equilibrium, lethargy, and discolouration. The behavioural responses were found to be concentration-dependent. The length-weight relationships for both control and atrazine exposed fish exhibited positive allometric growth and significant relationships as depicted by the value of R2 (coefficient of determination) except in the fish group exposed to 500 µg L-1 atrazine which exhibited negative allometric growth. Findings from this study indicate interference with normal behaviour and growth performance of C. gariepinus juveniles with ecological implications in water bodies exposed to atrazine even at reduced concentrations.

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Azolla A Boon for the Growth of Gift Tilapia, Oreochromis Niloticus (Linnaeus, 1758)

10.21203/rs.3.rs-692275/v1 ◽

2021 ◽

Author(s):

LEENA GRACE BESLIN ◽

Monisha Rajan

Keyword(s):

Growth Rate ◽

Growth Analysis ◽

Specific Growth ◽

Condition Factor ◽

Control Diet ◽

Conversion Ratio ◽

Fish Feed ◽

Feed Conversion ◽

Relative Growth ◽

Gift Tilapia

Abstract Understanding the nutritional requirements and production of fish feed is essential to the development and sustainability of aquaculture for the matured feed mill practices. Fish feed management includes choosing the right feed, using a correct feeding method, calculating the feeding cost and ensuring the cost effectiveness of fish farm. The purpose of the present study was to feed the fishes with four different feeds and assessment of growth performance by length weight relationships. The growth analysis was executed by measuring FCR and related indices in gift tilapia oreochromis niloticus. Four feed composition was selected without any chemical contamination. In the present study fishes were collected from the golden farm, Neyyattinkara, Thiruvananthapuram district, South India. Fishes were introduced into four different tanks of well oxygenated good quality water. In each experimental tank, 20 fishes were introduced. For each experimental container a specific feed was fixed from 4 different diets. Every day feed was given to the fishes. They were fed two times for the period of 3 months. They were maintained to assess their growth performance. Four types of feeds used for the present study are control diet, diet 1, diet 2 and diet 3. Measurement of length and weight was measured on every 15 days interval. Based on the length-weight data, growth analysis was carried out by calculating relative growth (RG), relative growth rate (RGR), specific growth rate (SGR), feed conversion ratio (FCR) and the Fulton’s condition factor. The results of mean length in diet3proved the highest length of 6.455 ± 0.46cm and diet one contain lowest length of 5.03 ± 0.68cm. Highest weight of 96.8 ± 0.37g was recorded in diet3 and lowest weight obtained for the control diet (3.645 ± 0.306 g). In growth analysis the relative growth of fish was estimated in diet 3 having high relative growth (11.91). Relative growth rate was elevated in diet 3(1.5597). The upper limit of specific growth rate was 1.9146% observed in diet 3. The feed conversion ratio was maximum in diet 3 (58.06) and minimum in control diet (36). The highest k value in Fulton's condition factor was noticed in diet 3(88.32).All experimental results proved that live Azolla [D3] was a superior feed for the present trials.

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Comparison of growth rate among different protein genotypes in Atlantic cod, Gadus morhua, under farmed conditions

ICES Journal of Marine Science ◽

10.1016/j.icesjms.2005.11.005 ◽

2006 ◽

Vol 63 (2) ◽

pp. 235-245 ◽

Cited By ~ 7

Author(s):

K.E. Jørstad ◽

Ø. Karlsen ◽

T. Svåsand ◽

H. Otterå

Keyword(s):

Growth Rate ◽

Gadus Morhua ◽

White Muscle ◽

Specific Growth ◽

Atlantic Cod ◽

The Past ◽

Aquaculture Industry ◽

A New Species ◽

Growth Experiments ◽

Selection Of

Abstract A major aim of the aquaculture industry in Norway is to develop sustainable farming of Atlantic cod, Gadus morhua L. A great deal of research, including farming trials and stock enhancement, has been performed on this species in Norway during the past two decades. The success of domestication of a new species depends on the genetic variability of the wild broodstock and the selection of appropriate genotypes for the farming environment. Growth experiments under farmed conditions, including genetic analyses, were started as early as 1983 after the breakthrough of cod juvenile production in mesocosm systems. At later stages (1988 and 1992 year classes), more detailed studies were conducted under farmed conditions. Based on individual tagging and genotyping (blood and white muscle biopsy sampling), estimates of growth performance (specific growth rate, SGR) of the various genotypes within six polymorphic protein loci were obtained. In general, the SGR in the two experiments varied through the year as a function of temperature and body size. In the 1988 year-class experiment, only a few statistically significant differences (ANOVA) were detected among genotypes, measured as mean weight and SGR. The 1992 year-class experiment included two different cod stocks, Northeast Arctic (NE) and Norwegian coastal (NC) cod, which were reared for about two years in the same net pen. Further, during this experiment, only a few genotypes exhibited significantly different growth within the NE group. No consistency was found in the variation with regard to protein loci investigated, growth periods studied, and relationship with temperature variation.

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