The effects of salinity and
added substrates on growth and survival of Metapenaeus monoceros
(Decapoda: Penaeidae) post-larvae
M. Kumlu, O.T. Eroldogan, B. Saglamtimur-2001
Aquaculture, 196(1-2): 177-188
Abstract:
This study was carried out to determine the optimal
culture salinity and to investigate the effects of added substrate on growth
and survival of Metapenaeus monoceros during its nursery culture in
two separate experiments.
In experiment 1, at the end of a 50-day culture
period, post-larvae (PLs) reared at 5, 10, 20, 30, 35, 40 and 50 ppt
displayed 8, 11, 48, 49, 52, 59 and 36% survival, respectively. Daily growth
rates at salinities above 30 ppt (0.266-0.320 mm day -1) were
about 5-fold higher than those obtained at salinities below 10 ppt
(0.035-0.056 mm day -1) (P<0.05). Total lengths (TL) at
30, 35, 40 and 50 ppt were 19.09, 18.97, 19.09 and 18.89 mm, respectively (P>0.05).
Mean wet weights acquired at 30-40 ppt (63-71 mg) were 7-8 times higher than
those at 5 and 10 ppt (8.12-9 mg) (P<0.05). A rise in salinity
resulted in a drastic increase in biomass (over 50-fold) from 0.018 g at 5
ppt to 0.927 g at 40 ppt. Hence, optimum salinity for the nursery culture of
M. monoceros PLs appeared to be between 30 and 40 ppt at 28°C.
In experiment 2, Group A received no additional
substrate while the other two groups had added substrates consisting of
wooden frame with vertical (Group B) or horizontal (Group C) plastic mesh.
Additional substrate increased habitable surface area approximately 330%.
Percentage survivals in Group A, B and C were 71, 70 and 63%, respectively.
TL was significantly lower in Group C (15.65 mm) than in either Group A
(17.71 mm) or Group B (17.23 mm) (P<0.05). The PLs in Group A
attained a significantly greater mean final weight (62 mg) than those
(40-55.14 mg) in both treatments containing artificial substrates. The PLs
in Group B and C had 12% and 40% lower biomass than that in Group A. The
current results demonstrated that the use of either vertically and
horizontally placed substrates do not provide any advantage during the
nursery culture of M. monoceros.
(Faculty of Fisheries, Cukurova University, 01330
Balcali, Adana, Turkey, Tel.: +90-322-338-6893; fax: +90-322-338-6439,
E-mail: mkumlu@mail.cu.edu.tr)