Effect of
salinity on growth, survival and oxygen consumption of juvenile brown
shrimp, Farfantepenaeus californiensis (Holmes)
H. Villarreal, A. Hernandez-Llamas, R.
Hewitt-2003
Aquaculture
Research, 34(2): 187-196
Abstract:
The brown shrimp, Farfantepenaeus
californiensis (Holmes), is a species native to north-west Mexico, where
its culture potential is presently being addressed. Because of the climatic
conditions prevailing in the region, salinities over 40 g L
-1
is a commonly encountered problem. In the present study, the effect of
salinity on the growth and mortality of juvenile F. californiensis is
described. The change in short-term routine metabolism at different
salinities was also evaluated in order to define the adaptive capacity of
the shrimp and to provide insight into the changes in the pathways of energy
distribution. Groups of shrimp were exposed to increasing salinity (25, 35,
45 and 55 g L
-1),
and growth and survival rates after 75 days were determined in
duplicate 1.8-m3 tanks for each salinity level. Significant
differences were found in final weight, growth rate and mortality of shrimp
as a result of salinity level. Final mean shrimp weights at increasing
salinity levels were 10.0, 9.4, 8.6 and 7.8 g. Corresponding
mortality was 24.4%, 15.1%, 33.6% and 55.7%. Oxygen consumption was found to
depend significantly on salinity and was equivalent to 0.0027, 0.0037,
0.0043 and 0.0053 mg g-1 min
-1
respectively for the increasing salinities. The increased rate of oxygen
consumption at high salinities reflects the response of the organism to
osmoregulatory and ionic imbalances. Increased energy requirements to fulfil
basic metabolic function as salinity increased resulted in a reduction in
the energy that could be diverted to growth. Consequently, the culture of
the brown shrimp at salinities over 35 g L
-1
would probably result in reduced yields.
(Centro de Investigaciones Biológicas del Noroeste SC, AP 128, La Paz
BCS, Mexico 23000. E-mail: humberto@cibnor.mx)