Black Sea Bream Sparus Macrocephalus Research Articles

Bacterial diversity in gut of large yellow croaker Larimichthys crocea and black sea bream Sparus macrocephalus reared in an inshore net pen

Bacterial diversity in the foregut, midgut and hindgut of large yellow croaker Larimichthys crocea and black sea bream Sparus macrocephalus reared in an inshore net pen, formulated feed and seawater were analyzed with Illumina MiSeq high-throughput sequencing platforms. A total of 270 operational taxonomic units (OTUs) were identified from fish guts, formulated feed and seawater, which belonged to 17 phyla and 20 genera. Firmicutes and Proteobacteria dominated at the phylum level, while Bacillus, Lactococcus and Oceanobacillus dominated at the genus level, in fish gut. The similarity in bacterial community between the guts of two fish species was higher than that either between fish gut and formulated feed or between fish gut and seawater. This result indicates that bacterial communities in guts of large yellow croaker and black sea bream were independent on those in the formulated feed and seawater. The common OTUs between fish gut and formulated feed were more than that between fish gut and seawater, suggesting that the impact of the formulated feed on intestinal bacteria of large yellow croaker and black sea bream was greater relative to that of seawater in the net pen. Spatial heterogeneity in bacterial composition along the gut of large yellow croaker and black sea bream was also evaluated.

Bioremediation using Gracilaria chouae co-cultured with Sparus macrocephalus to manage the nitrogen and phosphorous balance in an IMTA system in Xiangshan Bay, China

A cage experiment using the red alga Gracilaria chouae co-cultured with the black seabream Sparus macrocephalus in Xiangshan Bay, China was conducted to measure the nutrient flux of the integrated multi-trophic aquaculture (IMTA) system. Results showed that trash fish were the main nutrient input contributor and adult fish were the main nutrient output contributor in the system. Contents of N and P in adult fish accounted for 54.45% and 59.48% of N and P in trash fish and fry, which suggests that 45.55% of N and 40.52% of P generated by fish farming were released into to the water. G. chouae proved to be an efficient bioremediation species in this IMTA system. To balance the excess nutrients generated by the system, 231.09kg of seedlings should be cultured and 5315.07kg of adult seaweed should be harvested.

Dietary l-methionine requirement of juvenile black sea bream (Sparus macrocephalus) at a constant dietary cystine level

An 8-week feeding trial was conducted to determine the effects of dietary methionine level on juvenile black sea bream Sparus macrocephalus. Fish (initial body weight: 14.21 ± 0.24 g) were reared in eighteen 350-L indoors flow-through circular fibreglass tanks (20 fish per tank). Isoenergetic and isonitrogenous diets contained six levels of L-methionine ranging from 7.5 to 23.5 g kg−1 of dry diet in 3.0 g kg−1 increments at a constant dietary cystine level of 3.1 g kg−1. Growth performance and feed utilization were significantly influenced by dietary methionine levels (P 0.05), while total protein level and triacylglycerol concentration kept relatively constant among treatments (P < 0.05). Analysis of dose response with second-order polynomial regression on the basis of either SGR or PPV, the optimum dietary methionine requirements of juvenile black sea bream were estimated to be 17.1 g kg−1 of diet (45.0 g kg−1 methionine of protein) and 17.2 g kg−1 of diet (45.3 g kg−1 methionine of protein) in the presence of 3.1 g kg−1 cystine, respectively.

Optimum arginine requirement of juvenile black sea bream,Sparus macrocephalus

An 8-week feeding trial was conducted to determine the dietary arginine requirement of juvenile black sea bream Sparus macrocephalus in 18 350 L indoors flow-through circular fibreglass tanks. Six isonitrogenous and isoenergetic diets were formulated to contain graded levels of l-arginine (1.85%, 2.23%, 2.51%, 2.86%, 3.20% and 3.46% dry diet) from dietary ingredients and crystalline arginine. Each diet was randomly assigned to triplicate groups of 25 juvenile fish (10.51±0.15 g) twice daily (08:00 and 16:00 hours) to apparent satiation. Results showed that the specific growth rate (SGR) increased with increasing dietary arginine levels up to 2.51% and remained nearly the same thereafter. Feed efficiency ratio, protein efficiency ratio (PER) and protein productive value all showed an increasing tendency and then levelled off. Apparent digestibility coefficients of dry matter, crude protein and gross energy significantly improved up to 2.86% arginine diet and decreased at different extents thereafter. Fish fed 1.85% arginine diet had significantly lower protein content in the whole body and dorsal muscle than those fed diets supplemented with or >2.86% of arginine. Lipid content decreased and lower value occurred at 3.46% of dietary arginine. The dietary essential amino acid composition in the whole body of the black sea bream was significantly influenced by dietary arginine. Arginine retention increased with an increasing dietary arginine level from 1.85% to 3.20%, then declined slightly at 3.46% arginine diet. Serum biochemical parameters were significantly affected by the dietary arginine level except for the cholesterol content. Broken-line regression based on SGR and second-order polynomial regression based on PER indicated that the optimum dietary arginine requirements for juvenile black sea bream were 2.79% and 3.09% diet, corresponding to 7.74% and 8.13% of the dietary protein respectively.

Quantitative l-lysine requirement of juvenile black sea bream (Sparus macrocephalus)

An 8-week feeding experiment was conducted to determine the quantitative l-lysine requirement of juvenile black sea bream Sparus macrocephalus (initial mean weight: 9.13 ± 0.09 g, SD) in eighteen 300-L indoors flow-through circular fibreglass tanks provided with sand-filtered aerated seawater. The experimental diets contained six levels of l-lysine ranging from 20.8 to 40.5 g kg−1 dry diet at about 4 g kg−1 increments. All the experiment diets were formulated to be isoenergetic and isonitrogenous. Each diet was assigned to triplicate groups of 20 fish in a completely randomized design. Weight gain and specific growth rate (SGR) increased with increasing levels of dietary lysine up to 32.5 g kg−1 (P 0.05). All groups showed high survival (above 90%) and no significant differences were observed. The whole body crude protein and crude lipid contents were significantly affected (P 0.05), however, haemoglobin level was significantly influenced by different diets (P < 0.05). Analysis of dose (lysine level)-response (SGR) with second order polynomial regression suggested the dietary lysine requirement of juvenile black sea bream to be 33.2 g kg−1 dry diet or 86.4 g lysine kg−1 protein.