Growth response of Heterobranchus longifilis (Valenciennes, 1840) fingerlings fed raw and boiled Mucuna cochinchinensis seed meal

Feeding trial was conducted in static water to assess the growth of H. longifilis fingerlings fed different I inclusion levels of mucuna seed meal (MSM). Raw and boiled MSM were used in the diets at 10%, 20%, 30% and 40% inclusion levels and the performance of fish fed these diets was compared with fish fed a fishmeal-based diet which contained 40% protein. All diets were prepared to be isonitrogenous and isocaloric A two by five factorial experiment with three replicates using ten fish of average initial weight 1 .46g was carried out. Daily fish ration of five percent body weight was administered two times for eight weeks. The specific growth rate in diets 1 (control) and 6(10% boiled MSM) were similar and significantly (P<0.05) higher than the other dietary groups. The significantly lower growth performance of fish fed diets containing higher inclusion levels of both raw and boiled MSM might be due to incomplete elimination of the antinutritional factors present in MSM by boiling. Other methods of processing MSM to improve its nutritive value should be investigated. (7 page document)

Nutrient digestibility and growth response of rainbow trout (Salmo gairdneri ) fed different carbohydrate types

Seven groups of fingerling rainbow trout (S. gairdneri ) were fed for 10 weeks on 0%, 10%, 20% and 30% of cassava or rice in isonitrogenous diets. Optimum growth and food utilization was at 20% dietary cassava. High fiber content of the control diet did not suppress protein digestibility in this group. Rather, at all levels, protein digestibility was good and remained between 84.4% and 90.1%. However, in the control group, carbohydrate digestibility was very poor. The cassava diets which had the highest digestible energy as carbohydrate produced the best growth performance, food utilization and protein sparing. At the levels studied, the dietary carbohydrates produced no hyperglycamic effect on the fish

Growth response of Clarias gariepinus fry to organic and inorganic fertilizers

The growth response of Clarias gariepinus was investigated in various types of fertilizers. Fertilizer type was found to influence plankton abundance which in turn determine the growth and well being of C. gariepinus. The best weight increase recorded was in cow dung /NPK (1.37~c1.01g) followed by poultry (0.49~c0.31g), NPK/poultry (0.05~c0.25g) and NPK(0.03~c0.57g) The survival rate in these treatments were cow dung/NPK (100%), poultry (100%), NPK/cow/poultry (33%) and NPK (8%)

Growth response, feed conversion rate and cost benefits of hybrid catfish fed maggot meal based diets in outdoor tanks

The growth response, feed conversion ratio and cost benefits of hybrid catfish, Heterobranchus longifilis x Clarias gariepinus fed five maggot meal based diets were evaluated for 56 days in outdoor concrete tanks. Twenty-five fingerlings of the hybrid fish were stocked in ten outdoor concrete tanks of dimension 1.2mx0.13mx0.18m and code MM sub(1)-MM sub(5) in relation to their diet name. Five isonitrogenous and isocaloric maggot meal based diets namely MM sub(1)-0% maggot meal, MM sub(2)-25% maggot meal, MM sub(3)-50% maggot meal, MM sub(4-)75% maggot meal and MM sub(5-) 100% maggot meal were used for the experiment. The higher the proportion of maggot in the meal, the higher the ether extract and crude fiber. No significance difference P>0.05 exists between ash content of the experimental diets. Diet MM sub(2) had the best growth performance and highest MGR with a significant difference P<0.05 with other diets fed fish. No significance differences P>0.05 exists between the growth parameters for diets MM sub(1), MM sub(3), and MM sub(4). A positive correlation (r=1.0) exists (P<0.05, 0.25) between the growth parameters for the different experimental diets. Highest correlation r super(2)=0.9981 exists P<0.05 between MGR within the treatments. However, there no significant (P>0.05) difference in expenditure but there is between the profit indices and incidence of cost between the trials. MM sub(2) has the best yield cost and net profit. Without any reservation, inclusion of maggot based meal diet is recommended as feed of hybrid catfish to 75% inclusion for growth and profit incidence

Growth response and survival of F1 hybrid fry of Heterobranchus longifilis and Clarias gariepinus reared in glass aquaria and plastic basins

The growth response of F1 hybrid fry of female Heterobranchus longifilis and male Clarias gariepinus were investigated under laboratory conditions in glass aquaria glass tanks and plastic basins. The larvae were produced artificially after inducement with Ovarptim. The hatching percentage was very high. Weekly mean length and weight were monitored for 6 weeks. The average length increase was higher in aquaria glass tanks than in plastic basins. However, there were depressed and irregular weight increases in both types of rearing troughs while significant weight increase (P<0.05) was recorded at week 6 in the plastic basin. Generally, the growth rate and survival in both containers were not significantly different

Growth response of Heterobranchus longifilis fingerlings fed with varying levels of dietary freshwater mussel (Aspatharia sinuata)

A common bivalve: Freshwater mussel, Aspatharia sinuate was evaluated as a dietary protein supplement in the production diet for Heterobranchus longifilis fingerlings with mean body weight 8.34 plus or minus 10g reared in aquaria tanks. Four diets containing fishmeal protein at a rate of 25%, 50% and 75% along with the freshwater mussel flesh were formulated. The diet without the freshwater mussel served as the control. The fish fingerlings were fed at 5% body weight per day for 56 days. It was revealed at the end of the experiment that freshwater mussel was most suitable as a protein supplement when incorporated at 25% replacement. The body weight gain, specific growth rate and feed conversion ration values of 6.83g, 1.06% day and 0.62 respectively were highest in diet with 25% replacement closely followed by diet with 50% replacement. Beyond 75% inclusion level there was no significant growth (P>0.05). However, complete replacement of fishmeal by freshwater mussel decreases growth rates and should not be used in Heterobranchus longifilis diets

The relationship between smolt and postsmolt growth for Atlantic salmon (Salmo salar) in the Gulf of St. Lawrence

The interaction of ocean climate and growth conditions during the postsmolt phase is emerging as the primary hypothesis to explain patterns of adult recruitment for individual stocks and stock complexes of Atlantic salmon (Salmo salar). Friedland et al. (1993) first reported that contrast in sea surface temperature (SST) conditions during spring appeared to be related to recruitment of the European stock complex. This hypothesis was further supported by the relationship between cohort specific patterns of recruitment for two index stocks and regional scale SST (Friedland et al., 1998). One of the index stocks, the North Esk of Scotland, was shown to have a pattern of postsmolt growth that was positively correlated with survival, indicating that growth during the postsmolt year controls survival and recruitment (Friedland et al., 2000). A similar scenario is emerging for the North American stock complex where contrast in ocean conditions during spring in the postsmolt migration corridors was associated with the recruitment pattern of the stock complex (Friedland et al., 2003a, 2003b). The accumulation of additional data on the postsmolt growth response of both stock complexes will contribute to a better understanding of the recruitment process in Atlantic salmon.

Individual growth rates and movement of juvenile white shrimp (Litopenaeus setiferus) in a tidal marsh nursery

We measured growth and movements of individually marked free-ranging juvenile white shrimp (Litopenaeus setiferus) in tidal creek subsystems of the Duplin River, Sapelo Island, Georgia. Over a period of two years, 15,974 juvenile shrimp (40−80 mm TL) were marked internally with uniquely coded microwire tags and released in the shallow upper reaches of four salt marsh tidal creeks. Subsequent samples were taken every 3−6 days from channel segments arranged at 200-m intervals along transects extending from the upper to lower reach of each tidal creek. These collections included 201,384 juvenile shrimp, of which 184 were marked recaptures. Recaptured shrimp were at large an average of 3−4 weeks (range: 2−99 days) and were recovered a mean distance of <0.4 km from where they were initially marked. Mean residence times in the creek subsystems ranged from 15.2 to 25.5 days and were estimated from exponential decay functions describing the proportions of marked individuals recaptured with increasing days at large. Residence time was not significantly correlated with creek length (Pearson=−0.316, P=0.684 ), but there was suggestive evidence of positive associations with either intertidal (Pearson r=0.867, P=0.133) or subtidal (Pearson r=0.946, P=0.054) drainage area. Daily mean specific growth rates averaged 0.009 to 0.013 among creeks; mean absolute growth rates ranged from 0.56−0.84 mm/d, and were lower than those previously reported for juvenile penaeids in estuaries of the southeastern United States. Mean individual growth rates were not significantly different between years (t-test, P>0.30) but varied significantly during the season, tending to be greater in July than November. Growth rates were size-dependent, and temporal changes in size distributions rather than temporal variation in physical environmental factors may have accounted for seasonal differences in growth. Growth rates differed between creeks in 1999 (t-test, P<0.015), but not in 1998 (t-test, P>0.5). We suggest that spatial variation in landscape structure associated with access to intertidal resources may have accounted for this apparent interannual difference in growth response.

Effect of feeding frequency on the growth of common carp (Cyprinus carpio L.) fry

A laboratory-feeding trail was conducted for 45 days with fry of common carp Cyprinus carpio L. (0.45±0.03g) in aquaria in a static indoor fish rearing system. The fry were fed on a pelleted diet containing 33% crude protein having fishmeal as major protein source. The fish fry in five treatments A, B, C, D, and E, each with two replicates were fed on 5% daily ration divided into different feeding frequencies of 2, 3, 4, 5 and 6 times a day respectively in order to observe the growth performance. Each replicate contained 15 fry having total initial weight of 6.87±0.31g. At the end of the feeding trial, significantly different and higher (p<0.05) growth response was observed in treatment C having a feeding frequencies of 4 times a day. Significantly the highest and the lowest percent growth of 334.30 and 218.91% were observed in fish fed on the diet (Treatment C) with 4 times and (Treatment A) 2 times feeding frequencies per day, respectively. Food conversion ratio (FCR) of 1.78 was significantly higher (pgrowth parameters viz, specific growth rate (SGR), apparent protein digestibility (ADP) were also higher in treatment C than the other treatments. The results of the present study demonstrated that the growth performance of C. carpio was the best at 4 times feeding in a day using 33% dietary protein containing fish meal as major protein source.

Aquaculture Asia, Vol.14, No.4, pp.1-52, October - December 2009

Sustainable aquaculture Peter Edwards writes on rural aquaculture Edwards, P. Mussel farming initiatives in North Kerala, India: A case of successful adoption of technology leading to rural livelihood transformation Laxmilatha, P., Thomas, S., Asokan, P.K., Surendranathan, V.G., Sivadasan, M.P., and Ramachandran, N.P. Selective study on the availability in indigenous fish species having ornamental value in some districts of West Bengal Panigrahi, A.K., Dutta, S. and Ghosh, I. Aquaculture livelihoods service centres in Aceh, Indonesia: A novel approach to improving the livelihoods of small scale fish farmers Ravikumar, B. and Yamamoto, K. Research and farming techniques e-Sagu Aqua - an innovative information and communication technology model for transfer of technology for aquaculture Vimala, D. D., Ravisankar, T., Mahalakshmi, P., and Kumaran, M. Freshwater pearl crop: an emerging enterprise in the Indian subcontinent Misra, G., Jena, J. and Kumar, K. Genetics and biodiversity Preliminary risk assessment of Pacific white leg shrimp (P. vannamei) introduced to Thailand for aquaculture Senanan, W., Panutrakul, S., Barnette, P., Chavanich, S., Mantachitr, V., Tangkrock-Olan, N., and Viyakarn, V. Farmer profile Aquatic animal health Asian fish health experts visit Australia Olsen, L. and Ingram, B. (Fisheries Victoria) Black gill disease of cage-cultured ornate rock lobster Panulirus ornatus in central Vietnam caused by Fusarium species Nha, V.V., Hoa, D.T. and Khoa, L.V. Marine Finfish Aquaculture Network Effects of the partial substitution fish oil by soybean oil in the diets on muscle fatty acid composition of juvenile cobia (Rachycentron canadum) Hung, P.D. and Mao, N.D. Growth response of cobia Rachycentron canadum (Pisces: Rachycentridae) under the hypersaline conditions of the Emirate of Abu Dhabi Yousif, O.M.*, Kumar, K.K. and Abdul-Rahman, A.F.A. NACA Newsletter

Selectivity of three aquatic weeds as diet for Nile tilapia (Oreochromis niloticus)

A total of sixty juvenile Oreochromis niloticus (Nile tilapia) were fed three species of aquatic weed, namely Azolla filiculoides (water fern), Elodea sp. and Pistia stratiotes (water lettuce) to determine which of the weeds will be selectively consumed, and preferred of all. A control group of twenty Nile tilapia was fed compounded feed. The selectivity of the weeds was observed based on their utilization as food source, and Azolla filiculoides was found to be highly utilized, followed by Elodea sp. and the roots of Pistia stratiotes. The growth response of the fish to the diets was found to be highest for fish fed compounded feed followed by Azolla filiculoides and Elodea sp., while Pistia stratiotes produced a negative growth trend. It is therefore postulated that Azolla filiculoides and Pista sp. are good feedstuffs for O. niloticus especially when used together with other feedstuffs

Larval rearing and fry raising of Pangasius sutchi(Fowler)

Pangasius sutchi were artificially bred for determining the hatching success and larval growth response to live food in relation to varying stocking densities. The fertilized eggs were hatched out with successful hatching rates ranging between 60 and 63%. Newly hatched larvae of 4.4 mm average length were reared using Tubifex as live food in metallic trays with water temperature of 27 to 29.5°C and dissolved oxygen level of 3.88 to 6.22 mg/1 for 6-day with an average survival rate of75.56±13.25%. The P. sutchifry of9- day old were further reared using Tubifex in the polythene covered metallic trays at the stocking densities of 2-7 fry per litre of water for a period of 14 day. P. sutchi fry raising at 4 individual per litre of water for 14 day gives better results in terms of survival and growth.

Comparative Response of Two Hydrilla Strains to Fluridone

Experiments were conducted in a controlled-environmental growth chamber to evaluate the response of two strains of the invasive submersed plant Hydrilla verticillata (L.f.) Royle to fluridone (1-methyl-3-phenyl-5-[3-trifluoromethyl)phenyl]- 4(1H)-pyridinone). (PDF has 6 pages.)

Population response of triploid grass carp to declining levels of hydrilla in the Santee Cooper Reservoirs, South Carolina

Approximately 768,500 triploid grass carp ( Ctenopharyngodon idella Valenciennes) were stocked into the Santee Cooper reservoirs, South Carolina between 1989 and 1996 to control hydrilla ( Hydrilla verticillata (L.f.) Royle). Hydrilla coverage was reduced from a high of 17,272 ha during 1994 to a few ha by 1998. During 1997, 1998 and 1999, at least 98 triploid grass carp were collected yearly for population monitoring. Estimates of age, growth, and mortality, as well as population models, were used in the study to monitor triploid grass carp and predict population trends. Condition declined from that measured during a previous study in 1994. The annual mortality rate was estimated at 28% in 1997, 32% in 1998 and 39% in 1999; however, only the 1999 mortality rate was significantly different. Few (2 out of 98) of the triploid grass carp collected during 1999 were older than age 9. We expect increased mortality due to an aging population and sparse hydrilla coverage. During 1999, we estimated about 63,000 triploid grass carp system wide and project less than 3,000 fish by 2004, assuming no future stocking. management, population size Ctenopharyngodon idella, Hydrilla

Effects of fermented fluted pumpkin leaf (Telfaria occidentalis) on the growth and nutrient utilization of Clarias (Clarias gariepinus)

Clarias (Clarias gariepinus) (Burshell, 1821) fingerlings were fed isonitrogenous diets (38.9% crude protein) with fermented fluted pumpkin leaves (FFPL) replacing different proportion (0,50,75,100%) of extruded soybean meal (ESM) for 8 weeks. Growth responses at the different substitution levels measured. Increasing FFPL intake resulted in better weight gains and higher specific growth rates (SGR) of 0.29, 0.36 and 0.38% per day respectively. The increase in growth from feeding diets containing 75% and 100% of the ESM replaced with FFPL were significantly higher (P<0.05) than those of other diets. Further more fish tissue protein deposition consistently increased with increasing level of FFPL concentration in their diets. Fish fed diets where whole ESM was replace 100% FFPL gave the best overall response in terms of their weight gain, food conversion ratio, protein efficiency ratio, and specific growth rate. Economic considerations indicate the replacement of ESM with FFPL, which is a cheaper ingredient in feeds for Clarias