The effect of digestible lysine levels was evaluated in diets for Nile tilapia fingerlings (Oreochromis niloticus), Thailand lineage, based on the ideal protein concept. Four hundred and thirty two Nile tilapia fingerlings with an initial body weight of 0.98 ± 0.03 g were allotted in a randomized complete design, with six treatments, six replications per treatment and twelve fish per experimental unit. The treatments consisted of six isoenergetic (3.000 kcal of DE/kg feed) and isoproteic (39.14% CP) diets with different […]

This study was carried out to determine and compare the apparent digestibility of dry matter (DM), crude protein (CP), crude fat (CF), gross energy (GE), and the apparent availability of minerals (P, Ca, Mg, Mn, Cu, and Zn) of emergent (leaf and petiole), submerged (root and rhizome) and total biomass meal of water hyacinth for Nile tilapia. Four diets were prepared, containing 0.10% chromic oxide-III, one being the reference diet (purified) and the others containing 30% of each ingredient. The […]

The objective of the present study was to determine the proper insemination dose of dourado (Salminus brasiliensis) oocytes. The oocytes were placed in a randomized complete design and fertilized with one of the spermatozoa.oocytes-1 ratio, 6.0×103, 6.0×104, 6.0×105, 6.0×106, 3.0×107 SPZ:OOC, each one with four replications. An experimental unit was considered to be an incubator with a 2.5L useful volume containing 2.0 mL non-hydrated oocytes. The fertilization rates were measured eight hours after the start of fertilization. In order to […]

Salinity tolerance of Betta splendens was evaluated in a complete randomized design, with six salt concentrations in the water (0; 3; 6; 9; 12 and 15 g common salt/L) with five replications (1 fish/replication). Adult female B. splendens were individually placed in aquariums in an incubation chamber at 26 ± 0.2ºC and 12-hour photoperiod. Fish were fed to satiation, once a day, with commercial diet. Feed intake and survival rate were measured every 12 hours. To evaluate the effect of […]

The objective of this study was to evaluate the enzymatic activity of trypsin in the intestinal content of the Thai tilapia male submitted to four different water temperatures. Fingerlings with 0.835 ± 0.004 g initial body weight were distributed in fishbowls with temperatures of 20, 24, 28 and 32ºC. They were fed the same diet and maintained under these conditions until the 55th day of the experiment. The tilapias were removed from the fishbowls and immediately placed on ice for […]

The experiment was carried out to evaluate the reproductive and animal performance and lipids deposition in the liver tissue of the Nile tilapia female, fed diets containing different levels of digestible energy, obtained by soybean oil inclusion. Three hundred breeding females and 100 breeding males were used, distributed in a completely randomized design with five treatments and four replications. The broods were fed diets containing 35% crude protein and 2,700; 2,950; 3,200; 3,450 and 3,700 kcal energy digestible/kg feed. The […]

The objective of the present study was to investigate crude protein reduction and the methionine+cystine and threonine to lysine ratios in diets for reversed Nile tilapia fingerlings (Oreochromis niloticus), Thai strain. Four hundred and twenty Nile tilapia fingerlings with an average initial weight of 1.83 ± 0.02 g were placed in a completely randomized design, with five treatments, seven replications per treatment and 12 fish per experimental unit, for 37-days. Two crude protein (CP) levels were evaluated (32 and 28%). […]

The objective of this study was to evaluate the effect of weight categories on the relation of the measures of standard length; length of the head; height of the body measured at the front of the 1° ray of pectoral, dorsal, anal and tail fins; width of the body measured at the front of the insertion of 1º ray of pectoral, dorsal and anal fins; perimeter measured at the front of the insertion of the 1° ray of pectoral, dorsal […]

This work presents a conceptual analysis of the main biotechnologies used in Chilean salmoniculture, which is based on the production of Atlantic salmon (Salmo salar, 356.407 t),silver salmon or coho (Oncorhynchus kisutch, 116.481 t), (O. tshawytscha, 2.062 t) and rainbow trout (O. mykiss, 189.178 t).These activities are focused on the photoperiod artificial manipulation to obtain out-of-season spawning, in the use of hormonal therapies which allow synchronizing the final oocyte maturation (FOM) and sexual maturity acceleration or the increase in milt […]

The action of different concentrations of sodium chloride, benzocaine and clove oil in the survival of fingerling and juvenile tilapia (Oreochromis niloticus),chitraladalineage, was tested during 5 hours for transportation. A total of 1350 fingerlings were used ( weight 9.74 ± 0.04 g and length 6.79 ± 0.01 cm) and 270 juveniles (average weight 29.6 ± 0.06 g and length 11.52 ± 0.01 cm). The fish were maintained without food for 24 hours in four 500L asbestos boxes with constant aeration. […]