الفهرس 
REVIEW OF LITERATUREOnly 14 pages are availabe for public view
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Abstract
Egypt marine aquaculture still in the beginning due to lack of two major keys, marine hatcheries and larvae aquafeeds development and bad policies. European Sea bass (D. labrax) is one of the most valuable cultured species in Mediterranean countries but yet still not well developed in Egypt. Several challenges facing Egypt marine aquaculture development to be sustainable industry or just begin to be an industry, the lack of fry and fingerlings with good quality considered the most important declining factor. Marine hatcheries around the world become seed factories but Egypt marine hatcheries still less developed, this is not only because of facilities and equipments shortage and misplaced but also due to less developed protocols and management under Egypt conditions. Thus the present work aimed to study some factors affecting European seabass larvae production from marine hatcheries as small step on the way to marine fish reproduction and larvae rearing development using marine probiotic and synbiotic.
Several experiments had been studied as following:
Experiment 1. Impacts of female broodstock European seabass (Dicentrarchus labrax) weight on reproductive and fry growth performances under NIOF marine hatchery conditions.
The relationship between weight of female broodstock (1200 and 1500 gm) and reproductive performance parameters showed that No. of fertile ova per female were recorded no significant differences. Relative fecundity and No. of fertile ova per kg of females showed no significant differences. The Hatching %, No. of hatching larvae per female, No. of hatching larvae per kg female and No. of hatching larvae per gm female showed the best significant (P < 0.05) resulted newly hatched fry resulted by the 1500 gm female broodstock weight. The results showed the interaction effect between weight of female broodstock and final weight in gm, weight gain in gm, weight average daily gain in mg and weight gain % of resulting offspring fries according to ages in 80 and 90 DPH. The group of fry at 90 dph which resulted from the 1200 gm female broodstock weight showed the best significant (P < 0.05) resulted fry weight gains. The weight specific growth rate % of the group of fry at 80 dph which resulted from the 1200 gm female broodstock weight showed the best significant (P < 0.05) resulted fry weight specific growth rate %. The results showed the interaction effect between weight of female broodstock and final length in cm, length gain in cm, length average daily gain in mm, length specific growth rate length gain % and condition factor (K) of the resulted offspring fries according to ages in 80 and 90 dph recorded that the group of fry at 90 dph which resulted from the 1200 gm weight of female broodstock showed the best significant (P < 0.05) resulted fry final length gains and K.
Experiment 2. Methods for identification of ripe European seabass (Dicentrarchus labrax) broodstock (female and male) gonads.
Histological and fine structure observations of (D. labrax) germ cell development showed that the testis of European seabass is tubular in shape and the germ cells are arranged in cysts or clusters within the seminiferous lobules. Spermatogenesis occurs in several places along the length of each lobule and the testis structure could be described as the spermatogonial testicular type. Based on histological characteristics and the development of the egg in (D. labrax) ripe ovaries is divided into six stages as follows: oogonia or presynaptic oocyte, cytoplasmic growth, early and late vacuolized oocyte, the yolk deposition stages, the spawning stage and the spent stage. Fatty acids composition of total lipids from (D. labrax) female ripe ovaries in the spawning season showed that the fatty acids with high concentration in percentages were achieved by Euric acid C22:1 with 19.977%, Olic acid C18:1 with 14.506%, Palmitic acid C16:0 with 11.161%, Linoleic acid C18:2 with 9.333%, Palmitoleic acid C16:1 with 8.083% and Eicosapentanoic acid (EPA) C20:5 with 6.571% of the total detected fatty acids concentration.
Experiment 3. Some factors affecting European seabass larvae production in the marine hatcheries
3. 1. Potential bioactivity effects of marine probiotic, synbiotic contents supernatants and ethanolic extract of synbiotic contents against Vibrio damsela, Staphylococcus aureus and Aeromonas hydrophila.,
The effects of marine probiotics (MP), synbiotic contents supernatants (S) and ethanolic extract of synbiotic contents (ES) were examined to determine their ability to produce compounds with antimicrobial activities against V. damsela, S. aureus and A. hydrophila. Thus, in this experiment, all treatment showed no antimicrobial activity against V. damsela, S showed no antimicrobial activity against all the 3 reference bacteria. Quantitative evaluation of the antagonistic effect of the treatments was further estimated by measuring clear zones formed using the well-cut diffusion technique. The ES and MP exhibited the highest significant (P < 0.05) of absolute unit against the bacteria S. aureus and the bacteria A. hydrophila.
3. 2. Effects of marine probiotic and synbiotic on rotifers (Brachionus plicatilis) culture and enrichment.
The rotifers (B. plactilis) culture and production performances using two feeding treatments: the 1st feeding treatment was using Nanochlorapsis salina algal (RN) feeding protocol (Egypt Marine hatcheries feeding treatment) and the 2nd feeding treatment was using N. salina and Tetrasalmis chuii algal and Sacharomysis cerviesiea baker yeast (RNTY) feeding treatments (Egypt Marine hatcheries new feeding treatment). The rotifers productivity in ml and 500 liter tank productivity showed that rotifers harvest in 24 hours post culture (hpc), harvest in 48 hpc, Final harvest in 72 hpc, final gain, specific growth rate % and final gain % with the highest significant (P < 0.05) production results were achieved by the 2nd treatment (RNTY) while the smallest significant (P < 0.05) production results were resulted by the 1st treatment (RN). The fatty acids composition of total lipids from the harvested, cleaned and (FMW, GMW, GMW+MP and GMW+S) enriched rotifers cultured using the new feeding treatment showed that the total n-6 HUFA showed no significant differences and the highest resulted by (FMW), LA C18:2 FA showed no significant differences and the highest detected by (GMW+MP), Eicosadienoic acid C20:2, showed no significant differences and the highest showed by (FMW), Mead acid C20:3 showed no significant differences and the highest resulted by (GMW), ARA acid C20:4 and Docosadienoic acid C22:2 showed no significant differences and the highest indicated by (FMW). The total n-3 HUFA showed no significant differences and the highest detected by (GMW), ALA C18:3 FA showed the highest significant (P < 0.05) determined by (FMW), EPA acid C20:5, showed no significant differences and the highest achieved by (FMW) and DHA acid C22:6 showed no significant differences and the high hest detected by (GMW). The total bacterial counts (TCB) were determined in the four (FMW, GMW, GMW+MP and GMW+S) treatments on rotifers (B. plactilais) showed that the TBC in the rotifers enriched for 4 hours (RE4h) showed no significant differences, while the highest TBC was achieved by (GMW). The Aeromonas counts (ABC) were determined in four treatments on rotifers indicated that there was no ABC detected in all treatments. The Staphylococcus counts (SBC) were determined in the four treatments on rotifers showed that the SBC in RE4h showed the highest significant TBC achieved by (FMW). The Vibrio counts (VBC) were determined in the four treatments on rotifers in RE4h showed no significant differences, while the highest VBC was achieved by (GMW). The Bacillus counts (SBC) were determined in four treatments on rotifers in RE4h showed that the highest significant BBC achieved by (GMW+MP).
3. 3. Effects of marine probiotic and greenwater plus synbiotic on artemia (Artemia fransiscana) hatching and enrichment.
Comparative study on artemia cysts decapsulations protocols, the 1st protocol was the traditional decapsulation protocol of Egypt hatcheries using (Bruggeman et al., 1980) protocol and the 2nd protocol was the newest decapsulation protocol in the world using (Delbos and Schwarz, 2009) protocol. The results presented that hatching efficiency and hatching % of the new 2nd protocol were significantly (P < 0.05) higher than the 1st protocol. The fatty acids composition of total lipids from the harvested, cleaned and (FMW, GMW, GMW+MP and GMW+S) enriched artemia (A. fransiscana) decapsulated using the new decapsulation protocol showed that the total n-6 HUFA and LA C18:2 showed no significant differences and the highest indicated by (GMW+S), Eicosadienoic acid C20:2 and Mead acid C20:3showed no significant differences and the highest resulted by (GMW), ARA C20:4 showed no significant differences and the highest achieved by (FMW) and Docosadienoic acid C22:2 showed the highest significant (P < 0.05) indicated by (GMW+S). The total n-3 HUFA showed the highest significant (P < 0.05) detected by (GMW), ALA acid C18:3 FA showed no significant differences and the highest achieved by (GMW+S), EPA C20:5, showed no significant differences and the highest indicated by (FMW), DHA C22:6 showed no significant differences and the highest achieved by (GMW). The total bacterial counts (TCB) were determined in the four (FMW, GMW, GMW+MP and GMW+S) treatments on A. fransiscana. Results presented that the TBC in the 6 hours enriched artemia nauplii (AE6h) showed no significant difference, while the highest TBC was achieved by (FMW). The Aeromones counts (ABC) were determined in the four treatments indicated that there was no ABC detected in all treatments. The Staphylococcus counts (SBC) were determined in the four treatments on AE6h exhibited that the highest significant (P < 0.05) SBC was achieved by (FMW). The Vibrio counts (VBC) were determined in four treatments on AE6h showed that the highest significant (P < 0.05) VBC was achieved by (GMW+S). The Bacillus counts (BBC) were determined in four treatments on AE6h showed that the highest significant (P < 0.05) BBC was achieved by (GMW+MP).
3. 4. Effects of marine probiotic and synbiotic on fertilized eggs embryonic and newly hatched yolk sac larvae stages development of European seabass (D labrax).
The effect of using (FMW, GMW, GMW+MP and GMW+S) treatments on the total length in mm of dph, 3dph, 5dph and 7dph larvae showed that the 1dph showed no significant differences in the larvae total length while the best results showed by (GMW). The 3dph showed the best significant (P < 0.05) total length achieved by (GMW+S). The 5dph showed no significant differences in the larvae total length while the best results showed by (GMW+MP). The 7dph showed no significant differences in the larvae total length while the best results showed by (GMW+MP). The 1dph showed that the biggest significant (P < 0.05) yolk sac volume mm3 recorded by (GMW+MP). The 3dph showed no significant differences while the biggest yolk sac volume achieved by (FMW). The 5dph showed no significant differences in the larvae yolk sac volume while the biggest yolk sac volume recorded by (GMW+MP). The 7dph showed that the biggest significant (P < 0.05) in larvae yolk sac volume resulted by (GMW). The length gains between 1dph initial and 7dph final lengths (total length (TL) and yolk sac volume (YV) gain, ADG, SGR % and G %) were determined. The TL gain in mm, TLADG in mm, TLSGR % and TLG % showed no significant differences while the best recorded by (FMW). The YV gain showed the biggest significant (P < 0.05) resulted by (GMW). The YVADG and YVSGR % showed the biggest significant (P < 0.05) detected by (FMW). The YVG % showed the biggest significant (P < 0.05) recorded by (GMW). The effect of treatments on newly hatched 1dph yolk sac larvae, on newly hatched 7dph yolk sac larvae at the end of yolk sac consumption showed that the newly hatched 1dph yolk sac larvae showed the best significant (P < 0.05) detected in (GMW+MP). The 7dph yolk sac larvae at the end of yolk sac consumption showed the best significant (P < 0.05) recorded by (GMW+MP), (GMW) and (GMW+S). The newly hatched yolk sac larvae hatching%, survival rate% of the stocked eggs and survival rate% at the end of yolk sac consumption showed that the hatching% showed the best significant (P < 0.05) detected in (GMW+MP). The survival rate% of the stocked eggs showed the best significant (P < 0.05) recorded by (GMW+MP), (GMW) and (GMW+S). The survival rate% in the end of yolk sac consumption showed the best significant (P < 0.05) detected by (GMW+MP), (GMW) and (GMW+S).
The dissolved oxygen % (DO %) (1dph and 7dph) were determined, the 7dph larvae tanks with the best significant (P < 0.05) DO% resulted by (GMW+MP) and (GMW+S). The dissolved oxygen in mg/l (DO) in the 7dph larvae tanks showed no significant differences while the best DO recorded by (GMW+S). The pH in the 7dph larvae tanks showed no significant differences while the best pH recorded by (GMW), (GMW+MP) and (GMW+S). Salinity in mg/l (Sppt), the conductivity (Cond.), the total dissolved solids (TDS) and temperature (Temp.) showed in the 7dph larvae tanks showed the biggest significant (P < 0.05) results recorded by (FMW). The total bacterial counts (TBC) were determined in the four treatments on (2dpf eggs, 1dph, 5dph and 7dph larvae) tanks, the 7dph larvae tanks showed the highest significant TBC resulted by (GMW). The Aeromones counts (ABC) were determined in four treatments indicated that there was no ABC detected in all treatments. The Staphylococcus counts (SBC) were determined in the four treatments in the 7dph larvae tanks showed the highest significant SBC exhibited by (FMW). The Vibrio counts (VBC) were determined in four treatments in the 7dph larvae tanks showed no significant difference while the highest VBC recorded by (GMW+S). The Bacillus counts (BBC) were determined in four treatments presented that the 7dph larvae tanks showed the highest significant BBC was resulted by (GMW+MP).
3. 5. Effects of marine probiotic and synbiotice enriched artemia (A. fransiscana) and rotifers (B. plicatilis) on European seabass (D. labrax) larvae early weaning.
The aim of this experiment was to evaluate the effect of using GMW, GMW+MP and GMW+S treatments on newly hatched larvae early weaning, growth performances, fatty acids, amino acids and quality development using green water rearing environments. The negative control treatment using FMW in this experiment had an aquarium of the treatment duplicated aquarium with 100% mortality in the 10dph larvae, although its negative results for the clear water treatment but also it was positive result for green water environment for larvae rearing under the present study conditions. So the treatments became 3 treatments in the enriched rotifers and artemia experiment reaching to the early weaned larvae. The effect of treatments on newly hatched larvae growth parameters as total length (TL) in mm. The TL of 7dph larvae showed no significant differences while the best TL achieved by (GMW+MP). The TL of 14dph showed that the best significant (P < 0.05) TL resulted by (GMW+MP). The TL of 21dph showed no significant differences while the best TL exhibited by (GMW+S). The TL of 25 and 35dph showed that the best significant (P < 0.05) TL recorded by (GMW+MP) and (GMW+S). The length gains between 7dph as initial and 40dph as final lengths of TLG, TLADG, TLSGR % and TLG % were determined that the best significant (P < 0.05) achieved by (GMW+MP). The effect of treatments on newly hatched larvae weight growth parameters as (final weight in mg (FW), condition factor (K), (weight gain in mg (WG), weight average daily gain in mg (WADG), weight specific growth rate% (WSGR%) and weight gain% (WG%) between 7dph as initial and 40dph as final weights)) showed that the FW, WG, WADG and WSGR% showed no significant differences while the best FW achieved by (GMW+S). The condition factor (K) and WG showed no significant differences while the biggest indicated by (GMW). The effect of treatments showed that the 40dph larvae FS% on 7dph as initial stocking density showed that the best significant (P < 0.05) noticed by (GMW+S) and (GMW+MP).
Amino acids composition of the 40dph early weaned sea bass larvae fed on enriched rotifers and artemia using (GMW, GMW+MP and GMW+S) showed that the EAA as total EAA, Histidine Arginine, Phenyl Alanine, Methionine and isoleucine showed no significant differences and the highest achieved by (GMW+MP), Lysine showed no significant differences and the highest indicated by (GMW), Threonine showed no significant differences and the highest achieved by (S), Valine showed no significant differences and the highest exhibited by (GMW), and Leucine showed the highest significant indicated by (GMW+S). The NEAA as total NEAA, Serine, Glycine, Aspartic acid and Cystine showed no significant differences and the highest achieved by (GMW), Proline showed the highest significant (P < 0.05) resulted by (GMW+MP), Alanine showed no significant differences and the highest indicated by (GMW+MP) and Glumatic acid showed the highest significant (P < 0.05) by (GMW+S). Fatty acids composition of total lipids from the 40dph early weaned sea bass larvae fed on enriched rotifers and artemia showed that the total n-3 HUFA and ALA C18:3 FA showed no significant differences and the highest achieved by (GMW+S), EPA C20:5, showed no significant differences and the highest indicated by (GMW+MP), DHA C22:6 showed no significant differences and the highest achieved by (GMW). The effect of treatments on European sea bass (D. labrax) showed that the DO% and DO mg/l in the 40dph larvae tanks showed no significant DO% differences while the best results achieved by (GMW+MP). The pH in the 40dph larvae tanks showed no significant pH differences while the best pH indicated by (GMW+MP) and (GMW). The Sppt, TDS, Temp. and The Cond. in the 40dph larvae tanks showed no significant differences while the best results indicated by (GMW). Total bacterial counts (TBC) were determined in three treatments on newly hatched larvae water in the 40dph larvae tanks showed that the highest significant TBC resulted by (GMW+S) and (GMW+MP). The Aeromonas counts (ABC) were determined and indicated that there was no ABC detected in all treatments. The Staphylococcus counts (SBC) were determined in the 40dph larvae tanks showed that the highest significant SBC achieved by (GMW+S) and (GMW). The Vibrio counts (VBC) were determined in three treatments in the 40dph larvae tanks showed that the highest significant VBC exhibited by (GMW). The Bacillus (BBC) was determined in the 40dph