Food selectivity of pond reared and wild Etroplus suratensis (Bloch) and effect of supplementary feeding on its growth
| dc.contributor.advisor | Susheela, Jose | |
| dc.contributor.author | Sathiavathy, C R | |
| dc.contributor.author | KAU | |
| dc.date.accessioned | 2018-11-30T10:49:18Z | |
| dc.date.available | 2018-11-30T10:49:18Z | |
| dc.date.issued | 1989 | |
| dc.description.abstract | Food and feeding habits of E.suratenis during fry (30-49 mm), fingerlings (50-69) mm, subadult (70-89 mm) and adult (90-120mm) stages in the captive environment of a culture pond and wild environment viz. Cochin backwater were studied. The study was conducted from October 1986 to March 1987. A culture pond in the College of Fisheries, Panangad was stocked with E. suratensis of the above four length groups in 1:1:1:1 ratio, at a stocking density of 5600 Nos/ha, after preliminary preparations. Samples were collected from both these environments form the end of first month onwards. Each month, the numbers that were removed from the culture pond were restocked with same numbers of specimens of various length groups. Salient ecological parameters viz, temperature, PH, salinity, alkalinity,dissolved oxygen,phytoplankton primary productivity, zooplankton and zoobenthos of the culture pond and the backwaters were analysed at monthly intervals . The feeding intensity of the specimens in the captive and wild environment, relative lengths of gut during different stages, food items consumed in the culture pond and in the backwaters and selectivity index of various food items were studied. A feeding experiment was also conducted with fingerlings of E. suratensis where five feeds were used in duplicate. The feeds used were (I) conventional feed made of groundnut oil cake and rice bran (1:1) having 31.50% crude protein (II) 50% conventional feed + 50% fresh hydrilla verticillata having 24.55% crude protein (III) Fresh Hydrilla verticillata alone having 17.60% crude protein (IV) 50% conventional feed + 50% fresh Enteromorpha intestinalis having 23.30% crude protein (V) fresh Enteromorpha Intestinalis alone having 15.1% crude protein. Analyses of the physio-chemical parameters of the captive and wild environments show that their range was tolerable for the normal life activities of fishes and did not affect the food intake of the species. The feeding intensity of E.suratensis was found to increase from the first length group to the fourth length group in both the environments. The feeding indices of the four different length groups in the brackish water culture pond were 13.89, 19.45, 33.33 and 44.44 while the corresponding values in the backwaters were 55.56, 66.67, 72.72 and 77.78. Feeding intensity of E.suratensis was higher in the backwaters than in the culture pond. The RLG of E.suratensis from first to fourth length groups in the culture pond were 2.911, 3.111, 3.850 and 4.420 while the corresponding values for the fishes form the backwaters were 3.011,3.331, 4.010 and 4.535. The food items in general of the four length groups in culture pond were detritus, diatoms, filamentous algae, rotifers, copepods, other crustaceans, insect larvae and gastropods, with some variations in their order of preference among different length groups. In the backwaters the major food items in general were diatoms, higher aquatic plants, detritus , rotifers, copepods, other crustaceans and insect larvae. Selectivity index of the important food items in the culture pond and backwaters during October 1986 and March 1987 were studied for all the length groups. Selectivity index values were obtained for diatoms, filamentous algae, rotifers, copepods, other crustaceans and insect larvae for all the for length groups in pond and backwater. The selectivity index of detritus was +1 for all the four length groups in culture pond and backwaters, during both the months under study. For the higher aquatic plants, the selectivity index was +1 for the length groups II, III and IV in the backwater. But for the length group I in the backwaters and for all the four length groups in culture pond, no selectivity index exist for higher aquatic plants. In the feeding experiment, maximum values for average specific growth rate expressed as percentage wet body weight d-1 (0.455), average monthly increment (39), percentage gain in the body weight (14.634%) and best food conversion factor (18) were obtained for feed V, viz; fresh Enteromorpha intestinalis alone. Statistical analysis using analysis of variance technique showed that there was significant variation due to the effect of feeds. Analysis of least square method indicate that these five feeds can be grouped into two. In the first group, with feeds I and II, there was no significant difference between the feeds. In the second group with feeds III, IV and V , no significant difference were seen among themselves, but all these feeds show significant difference with the feeds I and II. The growth performance obtained by these feeds in the second group were superior that the feeds I and II. | en_US |
| dc.identifier.uri | http://krishikosh.egranth.ac.in/handle/1/5810084902 | |
| dc.keywords | Aquaculture | en_US |
| dc.language.iso | en | en_US |
| dc.publisher | Department of Aquaculture, College of Fisheries, Panangad | en_US |
| dc.sub | Aquaculture | en_US |
| dc.subject | null | en_US |
| dc.theme | Food selectivity and effect of supplementary feeding | en_US |
| dc.these.type | M.Sc | en_US |
| dc.title | Food selectivity of pond reared and wild Etroplus suratensis (Bloch) and effect of supplementary feeding on its growth | en_US |
| dc.type | Thesis | en_US |