February 15-18, 2009 Washington State Convention Center Seattle ...

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FERTILIZATION OF OVOCYTES OF PIRACANJUBA (Brycon orbignyanus) USING
DIFFERENT VOLUMES OF WATER IN THE ACTIVATION OF THE SPERMATOZOIDS
Luis Murgas, Viviane de Oliveira Felizardo and Gilmara Junqueira M. Pereira
Veterinary Medicine Department
Federal University of Lavras
Lavras-MG, Brasil
lsmurgas@ufla.br
The piracanjuba (Brycon orbignyanus) is species of migratory spawning fish threatened by extinction in South America. The
present experiment was accomplished with the objective of evaluating the effects of the use of different volumes of water as an
activating solution for the spermatozoids on the rates of artificial fertilization of piracanjuba ovocytes. Four couples of selected
piracanjuba from the Itutinga Environmental Station reproducer tanks were used - MG (EAI-CEMIG), in the migratory spawning
period of 2007/2008. The animals received hormonal induction of crude carp hypophysis extract (CHE), for obtaining of
the gametes. The gametes were dry collected, via cranial-caudal massage of the animals. Ovocyte samples of 0.1 g from each
female were fertilized with 10µl of semen, using four different tank water doses (5, 10, 20 and 40 mL) for gamete activation,
doing two repetitions for each sample. After activation the eggs were placed in 1 liter experimental incubators, arranged inside
a 1000 liter tank, with constant water renewal, at an average temperature of 28ºC. After eight hours, the fertilization rate was
analyzed (viable eggs). The experiment was installed according to a random block layout with four treatments and two repetitions.
The averages were compared by the Tukey Test at 5%. The volumes of water tested didn't alter the fertility rates (P>0.05).
The use of 5 ml of water is recommended for activation of the spermatoids, so that there is practicality during the accomplishment
of the process.
ROLE OF SHELTERS ON PRODUCTION OF FRESHWATER PRAWN, Macrobrachium
rosenbergi
Shivananda Murthy, H.,* Kumarswamy, R. Shankar, K M Rajesh and K. J. Palaksha
Department of Aquaculture
Karnataka Veterinary, Animal and Fisheries Sciences University
College of Fisheries
Mangalore-575002, India
hsmurthy05@yahoo.com
Freshwater prawn, Macrobrachium rosenbergii is a commercially important species in India and other Asian countries.
Shelters play an important role in growth and survival of Macrobrachium rosenbergii, since it is aggressive and has territorial
and agonistic behavior. The effect of three types of shelters, namely, Eichhornea plant, used tires and PVC pipes on survival
and growth of Macrobrachium rosenbergii was investigated in soil based and fertilized cement tanks in triplicate. Tanks without
shelters were used as control . Growth of prawns in shelter based tanks was significantly (P < 0.05) higher than that of the
control. Relatively best growth and survival were achieved in tanks supplied with PVC pipes, which was followed by tyres
and Eichhornea plants. The percent increase in growth over that of the control was 168.22, 133.06 and 90.32 for PVC pipes,
tyres and Eichhornea respectively. Overall survival, net production and specific growth rate were superior in the PVC pipe
treatment. Growth and survival of Macrobrachium rosenbergii were increased by the introduction of shelters in culture tanks
and the magnitude of the effect appears to be dependent on the types of substrate. The increased growth and survival in general
in sheltered tanks is attributed to their use for refuge particularly for freshly moulted animals and increase in the surface area,
which reduce frequency of agonistic interactions.