Studies on certain selected Live feed organisms used in Aquaculture with special Reference to rotifers (Family: Brachionidae) (TH 118)

Anitha, P S (2003) Studies on certain selected Live feed organisms used in Aquaculture with special Reference to rotifers (Family: Brachionidae) (TH 118). PhD thesis, Central Institute of Fisheries Education, Mumbai.

[img]
Preview
PDF
66Mb

Abstract

The present study focuses on the taxonomy, ecology and biology of rotifers along the south-west coast of Kerala, India. Species composition, population density and distribution of rotifers in relation to various abiotic and biotic parameters were investigated at three stations in Veli - Aakulam and at two stations in Poonthura estuaries from February 2000 to January 2001 . Based on a review of the history of taxonomy, a comprehensive and systematic study on brachionid family was conducted realizing its importance as potential live feed in aquaculture practices in India. Forty four species of rotifers belonging to 16 genera and 12 families are recorded. Among these, Brachionus dichotomus reductus, B. kostei and B. urceolatis nilsoni are new records for India and B. quadtidentatus mirabilis and B. calyciflorus borgerti are new records for Kerala. The three species under the B. plicatilis complex are taxonomically segregated and redescribed. Similarly, B. havanaensis trahea is recovered and redescribed from India for the first time. Its earlier name was B. forficula keralaiensis from Irinjalakuda (Kerala) as a variety of B. forficula. Many are common and cosmopolitan. Presence of B. dichotomus reductus and B. kostei in Indian waters, considered earlier as endemic Australian species, has thrown new light on the discontinuous distribution as well as the close affinity of the fauna between India and Australia. The impact of physico - chemical parameters and algal blooms on the occurrence, abundance and species composition of rotifers in two estuaries are delineated. Salinity and nutrients significantly correlate with the estuarine abundance while algal blooms appear to be the most important , factor especially in Veli-Aakulam. B. angulatis, B. plicatilis, B. calyciflorus and F. longiseta are the dominants in Veli-Aakulam, whereas B. angulatis, B. calyciflorus, Keratel/a cochleatis and Polyarthra vulgatis in Poonthura. High population density resulted in low species diversity and vice-versa in the study area. The impact of salinity, temperature, feed type and feed concentration on reproductive potential and life table parameters of six brachionid rotifers namely Brachionus angulatis, B. caudatus, B. calyciflorus, B. plicatilis, B. murray and B. rotundiformis are studied. Of these, population dynamic studies on B. angulatis, B. caudatus and B. calyciflorus in India are conducted for the first time. The results suggest that all the variables significantly influenced the reproductive potential, fecundity, lifespan and growth of the species individually and in turn interacted with each other in varying magnitudes. The optimum salinity for the maximum production of B. angulatis, B. caudatus and B. calyciflorus is registered at 0.5 ppt, whereas the same for B. plicatilis, B. murray and B. rotundiformis is at 5 ppt, 10 ppt and 15 ppt respectively. The influence of finfish (Ttichogaster leen) larval age on the rotifers of different sizes illustrated a significant relationship between the larval age and size of the prey. The suitability of rotifers as live feed for the tiger shrimp (Penaeus monodon) larvae is evaluated and the survival is significantly higher in the diet with rotifer group than in the diet without rotifers.

Item Type:Thesis (PhD)
Supervisor(s):George, Rani Mary
Uncontrolled Keywords:Live feed organisms; Aquaculture; rotifers; Brachionidae
Subjects:Aquaculture
Theses
Invertebrata > Rotifer
Marine Fisheries > Feed
Divisions:CMFRI-Cochin > Mariculture
ID Code:7194
Deposited By:Dr. V Mohan
Deposited On:29 Jan 2011 16:02
Last Modified:20 Jan 2014 12:35

Repository Staff Only: item control page