Search

The objective of this study was to evaluate how the tank colours may change the effects of extreme temperature on the survival, growth, and quality of juvenile golden trevally (Gnathanodon speciosus). The experiment was set up with fifteen treatments of five tank colours (blue, red, yellow, grey, and white) and three temperatures (30°C, 32°C, 34°C) with three replications. Fish performance was assessed for four weeks. The results showed that tank colours and elevated temperatures affected the quality of golden trevally juveniles. The survival and growth rate of fish tend to decrease gradually, but the deformation rate of fish tended to increase in the order of tank colours: red, yellow > grey, blue, and white. The growth and survival rate of fish gradually decreased when the rearing temperature increased from 30°C to 34°C and this effect was independent of tank colors. Importantly, the deformation rate increased under elevated temperature, particularly in blue and white tanks with potential long-term effects. It is, therefore, not recommended to use blue and white tanks for rearing the golden trevally juveniles, particularly during extremely high temperatures from heatwave events.

Snubnose pompano (Trachinotus blochii) are widely cultured in the world. Light colours are among factors affecting fish performance in captivity. Snubnose pompano larvae often reared under white light. However, no study supports its choice or informs the extent of its effect or its constituent colour. The study investigated the influence of green, blue, yellow, purple, and white lights on growth, survival, cortisol, body composition, and digestive enzymes activities of one-day post-hatch Snubnose pompano larvae reared in light magenta tanks under a photoperiod of 24 Light:0 Dark hours for 25 days. Overall, the best growth performance of snubnose pompano larvae was in purple and white, and green lights during early and late larval stages, respectively. White light promoted survival rate while that of green light reduced. Larvae were less stressed and had enhanced body contents under white and purple light environments. Purple and yellow lights influenced low trypsin and pepsin activities. The study reports for the first time the effect of the light colour environment on the digestive enzyme activities and body composition of the finfish larvae. Generally, the study provides novel insights on optimal light colour in the larval rearing protocol of this species. Through this study, the use of white light during the first feeding (zero to four days post-hatch) and purple light in later stages (five days post-hatch until metamorphosis) is encouraged while discourages green and yellow lights in the larval rearing of Snubnose pompano.

The mineralization of collagen scaffolds can improve their mechanical properties and biocompatibility, thereby providing an appropriate microenvironment for bone regeneration. The primary purpose of the present study is to fabricate a synergistically intra- and extrafibrillar mineralized collagen scaffold, which has many advantages in terms of biocompatibility, biomechanical properties, and further osteogenic potential. In this study, mineralized collagen scaffolds were fabricated using a traditional mineralization method (ie, immersed in simulated body fluid) as a control group and using a biomimetic method based on the polymer-induced liquid precursor process as an experimental group. In the polymer-induced liquid precursor process, a negatively charged polymer, carboxymethyl chitosan (CMC), was used to stabilize amorphous calcium phosphate (ACP) to form nanocomplexes of CMC/ACP. Collagen scaffolds mineralized based on the polymer-induced liquid precursor process were in gel form such that nanocomplexes of CMC/ACP can easily be drawn into the interstices of the collagen fibrils. Scanning electron microscopy and transmission electron microscopy were used to examine the porous micromorphology and synergistic mineralization pattern of the collagen scaffolds. Compared with simulated body fluid, nanocomplexes of CMC/ACP significantly increased the modulus of the collagen scaffolds. The results of in vitro experiments showed that the cell count and differentiated degrees in the experimental group were higher than those in the control group. Histological staining and micro-computed tomography showed that the amount of new bone regenerated in the experimental group was larger than that in the control group. The biomimetic mineralization will assist us in fabricating a novel collagen scaffold for clinical applications.