In order to test the influence of feeding items in the coloration of acara-açus the present study
was carried through two stages. The first one aimed the identification of the main alimentary
groups of Astronotus ocellatus diet through the analysis of the stomachal and intestine research.
Secondly, it aimed to compare the effect caused by the different groups of diet, in an artificial
environment, on the red coloration and the acquisition of corporal mass of the tested individuals.
At the first stage the activities had been developed in the Reserve of Sustainable Development
Mamirauá (RDSM) were 216 individuals. After the preservation of the digestive tracts these were
analyzed qualitatively, under the microscope. The diet items found in the contents had been
classified using broad categories such as: molluscs, crustaceans, insects, fish and vegetables, as
well as unknown material. The length of the first sexual maturation was calculated. The variation
of the water level in the RDSM during the period of the study was obtained from Mamirauá
Institute. The in-dake index for each food item was calculated by the product of the frequency of
relative occurrence and relative weight of each item and the total of products for all itens
identified. The main itens identified were fish, insects and molluscs. Twenty individuals of
Astronotus ocellatus had been captured in Marajó Island in febrary/2006, and placed in fifteen
(15) glass tanks at the aquacultive station of Utinga (Belém, Pará). On the basis of the results
from the first stage and on current literature, five diet treatments were designed for the
experiment: T1 - Commercial formula (control); T2 - Fish; T3 - Molluscs, T4 - Insects; T5 -
Crustaceans. The analysis of the Index of Intensity of Red Coloration was based on the
comparison of the levels of intensity of proportionate color for specific software, and the Index of
Increment of the Red Coloration of oceli and the diffuse lateral coloration were calculated. The
diet treatment with molluscs resulted in the largest increment of the index of intensity of red
coloration in oceli at the end of 20 days. The diet treatment with crustaceans resulted in the
largest increment of index of intensity of the diffuse lateral red coloration at the end of 20 days.
The animals submitted to almost all the treatments had presented an increase in body mass
throughout 40 continous days of experiment, but those fed with molluscs presented a to greater
acquisition of biomass.
|
