Demographic and competition studies on Brachionus ibericus and Proales similis in relation to salinity and algal (Nannochloropsis oculata) density

Autor: Uriel Arreguin Rebolledo, José Cristóbal Román Reyes, S. Nandini, Gustavo A. Rodríguez-Montes de Oca, S. S. S. Sarma
Rok vydání: 2018
Předmět:
Zdroj: Aquaculture International. 26:629-644
ISSN: 1573-143X
0967-6120
DOI: 10.1007/s10499-017-0233-z
Popis: We isolated the rotifers Brachionus ibericus and Proales similis from the sediment of shrimp tanks and studied their individual demographic characters and competition between them at two food levels (0.25 × 106, 1.00 × 106 cells ml−1 of Nannochloropsis oculata at 25 °C) and salinities ranging from 10 to 30‰. Our hypothesis was that growth rates would be higher with increasing food levels and salinities. Observations were taken twice a day for life table studies and daily once for population growth experiments. Using survivorship and fecundity data, we derived various life history variables. Although the average life span (7.6 ± 0.4 days) and gross reproductive rate (33.8 ± 2.9 neonate female−1 day−1) of B. ibericus were higher than those of P. similis (average life span 5.4 ± 0.6 days and gross reproductive rate 13.0 ± 0.6 neonate female−1 day−1), the population growth experiments showed that P. similis had higher r values (0.32 ± 0.005 day−1) than B. ibericus (0.23 ± 0.002 day−1) at 1.0 × 106 cells ml−1 of N. oculata. The rotifer P. similis was more adversely affected due to the presence of B. ibericus than vice versa. The data are important for developing techniques for a large-scale culture of these rotifers as food in aquaculture.
Databáze: OpenAIRE
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