Growth

Growth and Physiological responses of Juvenile African Catfish (Clarias gariepinus) Fed with Dietary Supplementation of Garlic-Ginger Mixture (Published)

A-84-days study was conducted to evaluate the growth and physiological responses of juvenile Clarias gariepinus fed diets supplemented with garlic-ginger mixture. The garlic-ginger mixture was included in a base diet at 0%, 1%, 2%, and 3%; corresponding to treatments D0 or control, D1, D2 and D3. A total of 120 juveniles (46.55±3.66g) were randomly distributed in triplicate to 12 plastic tanks and fed three times daily with biweekly intermediate sampling. The results indicate that D2 fed fish had the most impressive weight gain (WG) of 218.74±6.42g and feed conversion ratio (FCR) of 1.55±0.05, compared to the control (WG=99.53±0.03g, FCR=2.45±0.18). Furthermore, D2 treatment induced significant improvements in whole body bromatological composition, nutrient retention, organosomatic indexes, and serum biochemical profile in fish compared to control. The growth improvement observed could be due to the combined action of the bioactive components of ginger and garlic to enhance the functioning of the organs of the digestive system as well as the homeostasis balance of the body. Therefore, garlic and ginger can be used as a feed additive to enhance the production of African catfish.

Keywords: Clarias Gariepinus, Garlic, Growth, Physiological responses, ginger

Food and feeding biology of a Near Threatened freshwater ornamental fish Nobel Gourami, Ctenops nobilis McClelland, 1845 (Published)

Noble gourami, Ctenops nobilis McClelland, 1845 is one of the most valuable freshwater indigenous ornamental fish currently depends only on natural collection for its trade. In order to decline the population of fish, suppliers cannot meet the market demand so breeding and large scale seed production of C. nobilis is an urgent need. The knowledge of food and feeding habit of fish has been profitably utilised in culture operation. The gut content analysis showed the maximum amount of zooplankton with 31% and tiny crustacean with 27%. The length of alimentary canal and the RLG value (1.06-2.18) implies that the fish is carnivorous in nature. Seasonal changes in RLG and monthly changes in GaSI value recorded for the fish. The values of GaSI have been observed to become high during March to May with the peak being in March. Tubifex and Daphnia gave the higher rate growth with 1.63 FCR.

Keywords: Growth, Nobel gourami, alimentary canal, feeding habit

Growth and Haematological Responses of Clarias gariepinus Juveniles fed diets containing varying digestible lipids of Plant origin (Published)

This study was conducted to evaluate the growth and hematological responses of Clarias gariepinus juveniles fed diets containing different digestible lipids of plant origin. One hundred and eighty (180) juveniles (4.78±0.37g) were stocked using four treatments in three replicates. The experiment lasted for 10 weeks. Fish were fed at 5% body weight with four isonitrogenous diets (40% crude protein), with control diet without lipid supplement (D₁). Diets (D₂-D₄) contained Soya oil, palm kernel oil and groundnut oil respectively. Weight gain (WG), feed conversion ratio (FCR), protein efficiency ratio (PER) and specific growth rate (SGR) showed significant difference (p<0.05) among treatments. However, the highest WG was recorded in D₄ (10.69±0.97g) and lowest in fish fed D₁ (9.91±0.35g). FCR ranged between 1.69±0.17 in D₂ and 1.52±0.67 in D₄ respectively. Protein utilization showed no significant difference (P>0.05) in all treatments. There were significant differences (P<0.05) among hematological parameters analyzed such as PCV, WBC, RBC, Hb, MCHC, MCH, MCV. The highest cholesterol level was recorded in fish fed D₄ (1.67±0.81), while the lowest value was recorded in D₁ (1.10±0.80). Triglyceride was highest in D₃ (1.40±0.45) while the lowest value was recorded in the control D₁ (1.20±0.45) with no lipid inclusion. There was no significant difference (P>0.05) in the HDL and LDL value in all treatments. Hence, all hematological indices fall in the required range for Clarias gariepinus.

Keywords: Clarias Gariepinus, Growth, Juveniles, digestible lipids, haematological responses, plant origin.

Population dynamics and assessment of Golden Trevally, Gnathonodon speciosus (Forsskål, 1775), in the Southern Arabian Gulf off the United Arab Emirates (Published)

The population dynamics of Gnathonodon speciosus from the southern Arabian Gulf off the United Arab Emirates was investigated based on direct and indirect methods to validate the age. The average growth parameters based on the methods were estimated as L_∞=84.52cm TL, K=0.28 and t_o=-0.45years_.  The fitted Von Bertalnaffy’s growth equation for G.speciosus was L_t=84.52*[1–exp-0.28*(t+0.45)]. The estimated growth performance index Ø was 3.30 while the estimated life spans close to 11.0 years. The instantaneous coefficient rates of total mortality Z estimated by length converted catch curve was 1.01yr^-1. Natural mortality M estimated by pauly, Rikhter&Efanov and Hoeing methods were 0.62, 1.02 and 0.41yr^-1 respectively with average 0.68yr^-1 for further analysis. Peaks in spawning occurred during March, April and May. Yield per recruit Y/R and biomass per recruit B/R were estimated as 171.7&520.3g respectively at current F=0.33year^-1 and T_c=1.59 year. Estimates of relative yield per recruit and relative biomass per recruit were E_0.1=0.62, E_0.5=0.35 and E_max=0.74 indicates the stock of G.speciosus is under-exploited.

Keywords: Gnathonodon speciosus, Growth, Mortality, spawning season, yield per recruit

The Growth and Survival of Clarias Gariepinus Fry Fed Various Dry Feeds (Baker’s Yeast, Fishmeal, Egg Yolk, Artemia And Combination of Artemia And Fishmeal) With Cod Liver Oil as Supplement for Test Starter Diet (Published)

1. gariepinus (0.02g) of 1 week old were subjected to five diets consisting of baker’s yeast, fishmeal, chicken egg yolk, Artemia and the combinations of Artemia and fishmeal with a drop of cod liver oil as supplement to each treatment. The fry were fed to satiation daily and the study lasted for 5 weeks. At the end of the study, the respective treatments were compared on the basis of percentage weight gain, body length, survival rate, and condition factor. Fry fed on Artemia and fishmeal with a drop of cod liver oil were significantly higher (5.01cm and 2.8g for length and weight respectively and 95% survival of the fish fry) than those fed on other diets. This present research recommends that at larval to fry age C. gariepinus requires the combinations of Artemia and fishmeal with a drop of cod liver oil.

Keywords: Diets, Growth, survival and Clarias gariepinus

Population Dynamics and Assessment of Golden Trevally, Gnathonodon Speciosus (Forsskål, 1775), in the Southern Arabian Gulf off the United Arab Emirates (Published)

The population dynamics of Gnathonodon speciosus from the southern Arabian Gulf off the United Arab Emirates was investigated based on direct and indirect methods to validate the age. The average growth parameters based on the methods were estimated as L_∞=84.52cm TL, K=0.28 and t_o=-0.45years_.  The fitted Von Bertalnaffy’s growth equation for G.speciosus was L_t=84.52*[1–exp-0.28*(t+0.45)]. The estimated growth performance index Ø was 3.30 while the estimated life spans close to 11.0 years. The instantaneous coefficient rates of total mortality Z estimated by length converted catch curve was 1.01yr^-1. Natural mortality M estimated by pauly, Rikhter&Efanov and Hoeing methods were 0.62, 1.02 and 0.41yr^-1 respectively with average 0.68yr^-1 for further analysis. Peaks in spawning occurred during March, April and May. Yield per recruit Y/R and biomass per recruit B/R were estimated as 171.7&520.3g respectively at current F=0.33year^-1 and T_c=1.59 year. Estimates of relative yield per recruit and relative biomass per recruit were E_0.1=0.62, E_0.5=0.35 and E_max=0.74 indicates the stock of G.speciosus is under-exploited.

Keywords: Gnathonodon speciosus, Growth, Mortality, yield per recruit and spawning season