Browsing by Author "Pham, Thanh Liem"

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    Breeding performance and traits inheritance of hybrid catfish, Clarias macrocephalus and Clarias gariepinus
    (Institut Akuakultur Tropika, 2008-09) Pham, Thanh Liem
    Interspecific hybridization between Clarias macrocephalus (CM) and Clarias gariepinus (CG) has been conducted to produce hybrid with specific desirable traits. To evaluate its potential application in aquaculture, fertility and performance of desirable traits (e.g. growth, external morphology, flesh quality, disease resistance) were examined on reciprocal Fi and backcross hybrids. Reciprocal hybrids were partially fertile with various abnormalities in gonad development that resulted in low gamete production. Abnormalities observed in gonad development of all hybrid genotypes included a single ovary or testis, tumor-like and adipose-like tissues in ovaries, ovotestis, and retarded gonad. Reciprocal hybrid males had problems with spermatogenesis that was likely due to genetic incompatibility since treatment with hormones did not improve spermatogenesis.
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    Studies on the early development and larval rearing of Oxyeleotris marmoratus (bleeker)
    (Fakulti Sains dan Teknologi, 2001-03) Pham, Thanh Liem
    Some aspects on the early development and larval rearing of Oxyeleotris marmoratus were studied. The pattern of food selection by the larvae was analysed using Ivlev's electivity index. The larvae commenced feeding on phytoplankton on day 2 after hatching with the slight selection for Chlorella and Closterium. The Brachionus and nauplii of copepods were preferred by larvae from day 3 to day 10 after hatching and subsequently replaced by bigger size prey such as Cyclops and Moina thereafter. Cyclops was found to be the most preferred food during the larval stage. The prey selectivity by the larvae could be attributed to change in mouth size, mobility of the larvae and the prey, its size and type.