Quantitative genetic parameter estimates for size and growth rate traits in Pacific white shrimp, Penaeus vannamei (Boone 1931) when reared indoors

Heritabilities of size traits and growth rate traits, as well as genetic, phenotypic and environmental correlations were estimated at three ages for a captive population of Pacific white shrimp (Penaeus vannamei) grown indoors. A covariate, mean size or mean growth rate during early growth in individual tanks before tagging and mixing, was introduced in the analyses to reduce the error caused by unique previous growth conditions on variance components. Heritabilities of size traits increased with age, with the h² for TL, AL, TWt and Wi1AS being 0.15, 0.20, 0.20 and 0.22, respectively, at 17 weeks, increasing to 0.28, 0.33, 0.34 and 0.35 at 29 weeks of age. Heritabilities of growth rate traits estimated between consecutive growth periods decreased from the first (h² for ΔTL 0.65, ΔAL 0.71, ΔTWt 0.63 and ΔWi1AS 0.84) to the second period (h² for ΔTL 0.34, ΔAL 0.50, ΔTWt 0.54 and ΔWi1AS 0.52). Phenotypic correlations were always larger than genetic correlations for both, size and growth rate traits. Genetic correlations between size traits within age were high (r_G >0.95), but those between the same size trait at different ages decreased as the age difference increased in spite of a consistently high environmental correlation (r_E 0.80–0.85) between the same trait at different ages. Phenotypic and genetic correlation's between the same growth rate trait at the two different growth periods evaluated were negative or zero (r_G TL –0.26, AL –0.24, Wi1AS 0.00) with the exception of total weight (r_G TW 0.35) and the environmental correlations between growth periods were also low (r_E 0.13–0.32).     

Family growth response to different laboratory culture environments shows genotype–environment interaction in the sea urchin Strongylocentrotus intermedius

This study investigated the genetic variation and genotype–environment interaction (GEI) in the early growth stage among seven full‐sib families of the sea urchin Strongylocentrotus intermedius. From each of the seven families, 180 or 270 sea urchins of the same size were exposed to three laboratory environments (E₁, E₂ and E₃). These environments were commonly used in breeding programs for S. intermedius. After a 102 days trial, test height, test diameter, body weight and the coefficient of variation of body weight were determined. The results revealed significant family effects on most growth traits in all the three environments (except for test diameter in environment E₂), and significant environmental effects on growth in several families (family 1, 5, 6, 7). The study also revealed that the coefficient of variation in body weight varied significantly among the families (P < 0.01) but not among the environments. Highly significant GEI effects were also recorded for all growth traits (P ≤ 0.001), except for the coefficient of variation in body weight (P > 0.05). Variances of GEI accounted for about 0–2.742% of phenotypic variances for the investigated traits. Significant GEI caused a certain degree family ranking inversions for the growth traits. The present study provides evidence for the existence of GEI in the family selection of sea urchin S. intermedius. More attention should be paid to the GEI to obtain satisfactory genetic gain in S. intermedius.     

三角帆蚌紫色选育系1龄阶段内壳色及生长性状的遗传参数估计

采用群体选育辅助种内群体间杂交选育的方法,以内壳色、体质量作为选育性状,经过连续4代的选育获得了紫色选育系F4。本实验以F4为亲本进行繁殖,利用6对微卫星标记,对15个同批繁育的F4母蚌的1龄后代进行亲子鉴定,鉴别出了来自12个父本、15个母本的42个全同胞家系,使用ASREML软件的约束极大似然法对三角帆蚌内壳色及生长性状进行了遗传参数分析。结果显示,内壳色颜色参数L*、a*、b*、dE*的遗传力分别为0.31±0.22、0.11±0.08、0.36±0.18、0.29±0.19,L*、a*、b*之间的遗传相关和表型相关均较低,范围为0.08~0.47和0.04~0.32,L*与dE*相关性最大,遗传相关为-0.94±0.06,表型相关为-0.96±0.01;生长性状壳长、壳高、壳宽、体质量和壳重的遗传力分别为0.24±0.19、0.37±0.27、0.26±0.16、0.26±0.17、0.31±0.19,各性状间遗传相关和表型相关均为正相关,分别为0.71~0.92、0.66~0.94;颜色参数与生长性状的遗传相关和表型相关均很低,为0.02~0.18。三角帆蚌紫色选育系1龄阶段内壳色和生长性状的遗传力多为中高水平,对其继续进行遗传改良预期能够获得良好遗传进展。内壳色与生长性状的相关度很低,无法实现相互选择,体质量与其他生长性状相关均较紧密,表明将内壳色、体质量作为目标性状进行同步选育的方法合理,可实现同时改良壳色及生长性能的目的。     

Estimates of heritability and genetic correlations for growth‐related traits in the tiger prawn Penaeus monodon

Heritabilities and genetic and phenotypic correlations were estimated for body weight (BW), body length (BL), carapace length (CL), carapace width (CW) and carapace height (CH) of the Penaeus monodon from measurements on progeny at 6 months of age resulting from a nested mating design. Estimation was made on data from 41 full‐sib and 10 half‐sib families. The estimated heritabilities for these traits were 0.13–0.24, and the significantly phenotypic and genetic correlations were 0.81–0.94 and 0.88–1.00, respectively. The present results indicate that genetic improvement through selective breeding conducted on P. monodon might be feasible and would be an efficient method to obtain a positive response to selection.     

Heritability and phenotypic correlations of gonad sweetness in the sea urchin Strongylocentrotus intermedius

Gonad is the only edible part of sea urchins. Thus, a number of studies have been focusing on how to improve both quantity and quality of their gonads. However, as far as our knowledge, the genetic basis of gonad flavor remains totally unknown in sea urchins. In the present study, we found that the heritability of gonad sweetness was at a high level of 0.56, clearly indicating that it is, to a large extent, under genetic control. Gonad sweetness was significantly positively correlated with gonad weight (P < 0.05), a* (P < 0.01) and b* (P < 0.01), while significantly negative correlated with L* (P < 0.01), ΔE ₁ (P < 0.01) and ΔE ₂ (P < 0.01). The present study provides valuable information into the genetic basis of gonad sweetness and evidences that gonad sweetness is potential to be improved in sea urchin genetic breeding programs.     

Estimates of Heritabilities and Genetic Correlations for Growth and Gonad Traits in Blunt Snout Bream,Megalobrama amblycephala

Blunt snout bream, Megalobrama amblycephala, is an herbivorous freshwater fish and has been recognized as a main aquaculture species in the Chinese freshwater polyculture system. The objective of the study is to estimate the genetic parameters for growth, body shape, and gonad traits for M. amblycephala at 1 yr of age. The phenotypic analysis showed that coefficients of variation for gonad traits had large variation relative to the other traits analyzed, and there was no sexual dimorphism by comparing growth and body shape in M. amblycephala. Based on restricted maximum likelihood and Markov chain Monte Carlo Bayesian methods using the animal model, the heritabilities of body weight (0.423–0.504), body length (0.309–0.678), body height (0.408–0.599), and dressed weight (0.359–0.643) were moderate and high, while the other traits, including conditional factor (0.029–0.199), body shape coefficient (0.095–0.405), edible ratio (0.073–0.207), gonad weight (0.018–0.170), and gonadosomatic index (0.050–0.222), had moderate or low heritabilities. High genetic and phenotypic correlations were found among growth traits, but not between growth traits and body shape or gonad traits except dressed weight. Based on our results, it could be efficient to combine the selection on body weight for fast growth and nonearly sexual maturity varieties of M. amblycephala breeding.     

The development of a formulated feed containing Ulva (Chlorophyta) to promote rapid growth and enhanced production of high quality roe in the sea urchin Tripneustes gratilla (Linnaeus)

This study investigated growth and gonad production of Tripneustes gratilla fed four protein‐rich artificial diets supplemented with varying amounts (0%, 5%, 15% and 20% weight/weight (w/w); designated 0, 5, 15 and 20U, respectively) of the macroalga Ulva over a 12‐week period. Gonad size, texture, colour and a number of production performance parameters were quantified and compared with urchins fed fresh Ulva (FU) and a combination of FU and artificial feed (FB). All artificial diets significantly (P ≤ 0.05) increased gonad somatic indices (GSI) compared with the FU treatment. The 20U treatment increased GSI by 205% by week 9, compared with a 57% increase in the GSI of urchins fed FU. Gonad colour was calculated using three colour parameters, namely L* (lightness), a* (redness) and b* (yellowness). Whereas L* and a* values did not differ significantly between treatments, b* values for all treatments, with the exception of the 20U and FB treatments, were significantly (P ≤ 0.05) lower or less yellow than the FU treatment by week 12. These results show that we have successfully formulated a feed (20U) which can produce commercially acceptable gonads in terms of both size and colour, indicating the potential for this artificial feed to support commercial echinoculture.     

Long-term effects of stocking density on survival,growth performance and marketable production of the sea urchin <Emphasis Type="Italic">Strongylocentrotus intermedius</Emphasis>

Sea urchins were stocked at a density of 15 (D15), 30 (D30), 45 (D45) and 60 (D60) urchins/cage (0.3 m long × 0.2 m wide × 0.4 m high) in a laboratory culture environment for 16 months. The wet body weight (BW) and test diameter growth were monitored at 2-month intervals during the experiment. At the conclusion of the experiment, the surviving sea urchins were counted and the gonad wet weight (GW) and gonad color were measured. Specific growth rate (SGR) of body weight, survival rate (SR), gonad index (GI), gonad color difference (ΔE ₀₀), coefficients of variation (CV) of BW, GW, GI and ΔE ₀₀, total biomass yield (TY) and total gonad yield (TGY) per cage were calculated. Two marketable yield variables, graded according to gonad index, i.e., marketable biomass yield (MY) and marketable gonad yield (MGY), were also calculated. Coefficient of variation of final body weight (FW) and final test diameter (FTD) of sea urchins increased as the stocking density increased, indicating the existence of adverse social interactions. These adverse social interactions detrimentally affected FW, FTD, SGR, GW and GI (P < 0.01). Although SR decreased with the increasing densities, no statistical significant difference was detected. Sea urchins at D15 had the lowest gonad color difference (ΔE ₀₀) (P < 0.05). However, statistically equal CV of ΔE ₀₀ indicates this density effect was not a result of adverse social interactions. TY and TGY increased with increased density and can be described by the following equations: TY = 84.18X ^0.64, R ² = 0.999 and TGY = 24.16X ^0.38, R ² = 0.979. However, the MY and MGY were not significantly different among stocking densities. The results of this study demonstrate that in intensive culture S. intermedius at low stocking density can achieve high growth rate, gonad index and desirable color without decreasing the marketable yield. Farmers should choose to culture S. intermedius at low stocking densities.     

Changes of heritability and genetic correlations in production traits over time in red abalone (Haliotis rufescens) under culture

Red abalone Haliotis rufescens is one of the most valuable mollusks in the international market, but it has a low growth rate. A breeding program is being developed to increase its growth rate in Chile. We estimated the changes in direct heritability (h²), maternal/common environments heritability (m²) and genetic correlations (r_G) of growth traits (shell length and width, total mass, flesh mass and foot protein as an indicator of meat quality) measured during 2 years (every 4 months) from the juvenile stage (27 months) to the adult harvesting age (51 months), in 60 full‐sib red abalone families. Heritabilities for growth traits measured in juveniles and young adults (27–35 months of age), were low (0.07–0.17) and not significant. Initial low h² were associated with significant amounts of maternal/common environmental effects (m² = 0.4). In young adults and abalone near the harvest age (39–51 months of age) h² were much higher (0.32–0.75). These results emphasize the importance of multiple estimations of h² over time. Among meat quality traits, only the h² for the flesh mass for adults at harvesting age was significant (0.15). We observed strong positive r_G (>0.9) between shell sizes (easy to measure) and total and flesh masses (trait more related to market value than shell sizes but harder to measure) for adults at harvesting age. Thus, if the 5% largest 51 month old abalone were selected from the population as broodstock we expect a positively correlated response on flesh mass of 23.4%.     

Genetic parameter estimates for growth‐related traits of blunt snout bream (Megalobrama amblycephala) using microsatellite‐based pedigree

Blunt snout bream (Megalobrama amblycephala) is an herbivorous freshwater fish species native to China and has been recognized as a main aquaculture species in the Chinese freshwater polyculture system with high economic value. The genetic parameter estimates for important economic traits are needed for its selective breeding. The aim of this study was to estimate the heritabilities for its growth‐related traits and explore the genetic and phenotypic correlations among the traits using microsatellite‐based pedigree approach. Offspring from a mass‐spawning of 92 broodstocks (42 sires and 50 dams) were reared in a communal pond and nine microsatellites were used to identify the parents of each sampled offspring. Of 749 offspring randomly selected, 708 (94.53%) could be assigned directly to a single parental pair, which was used for heritability estimates. Data were analysed using the method of restricted maximum likelihood (REML) using animal model and the results showed that the heritabilities of body weight, body length, total length and body height were 0.65, 0.53, 0.53 and 0.50, respectively. High genetic correlations were found among these four traits. According to these results, selection for growth seems to be feasible in M. amblycephala and the other growth traits will be heightened accordingly with the selection based on body length.     

Effects of continuous and diel intermittent feeding regimes on food consumption, growth and gonad production of the sea urchin Strongylocentrotus intermedius of different size classes

We investigated effects of a continuous and three diel feeding regimes on food consumption, growth and gonad production of cultured Strongylocentrotus intermedius of three size classes. There was no significant difference of food consumption, body weight and gonad production between nocturnal and diurnal feeding regimes of S. intermedius of all size classes, greatly challenging the old paradigm on the diel feeding preference of cultured S. intermedius. The continuous and three diel intermittent feeding regimes did not significantly affect body weight of sea urchins of all size classes. However, sea urchins in the large and small size classes which were fed continuously had significantly higher gonad wet weight and gonad index than those fed intermittently. Gonad of sea urchins in the medium size class did not change with feeding regime. The present study increases our understanding of the feeding behavior of cultured S. intermedius, with a potential of direct application in aquaculture.     

Estimates of genetic parameters for growth-related traits of the red swamp crayfish,Procambarus clarkii

In this study, technologies of family construction and grow-out culture in the same pond were studied for red swamp crayfish. A total of 77, 110 and 78 families were constructed in 2011, 2012 and 2013, respectively. Heritability, genetic and phenotypic correlations were estimated for body weight, body length and carapace length through performance testing in progeny of 2012 at 5 and 10 months of age, resulting from a nested mating design. At 5 months of age, none of the estimated heritabilities were significant (0) based on sire components (h _s ² ) for these traits, the genotypic correlations, either; only the phenotypic correlations were significant (0.8561–0.9420). At 10 months of age, the estimated heritabilities (h _s ² ) were low for the three traits (0.1429–0.1632); the phenotypic and genetic correlations were significant, 0.8148–0.9052 and 0.9981–0.9993, respectively. It was concluded that genetic improvement through selective breeding conducted on red swamp crayfish might be feasible and would be an efficient method to obtain a positive response to selection for the 10-month-old red swamp crayfish.     

Increased gonad growth of the purple sea urchin (Strongylocentrotus purpuratus) fed the giant kelp (Macrocystis pyrifera) and the sea lettuce (Ulva lactuca) enriched with nutrients

Adult (Strongylocentrotus purpuratus) purple sea urchins were fed giant kelp (Macrocystis pyrifera) and sea lettuce (Ulva lactuca) macroalgae that were unenriched and enriched with nutrients. Urchins were fed over 10 weeks (5% body weight per day) under laboratory conditions to determine the effect of macroalgae species and treatment (enriched and unenriched) on growth, gonad index and gonad quality. Significant differences were observed when urchins were fed enriched Macrocystis pyrifera (MPE). Gonad weight increased from 0.7 ± 0.1 g (mean ± SD) to 5.9 ± 1 g, and gonad index increase from 3.5 ± 1.5% to 14.9 ± 2.3% over 10 weeks. Significant differences were also noted in gonad quality, and gonad colour and firmness were better in urchins that were fed unenriched M. pyrifera (MPUE) and MPE – whereas texture did not differ between M. pyrifera treatments and unenriched U. lactuca (ULUE). With regard to taste, gonads were sweeter in MPE‐fed individuals. Enriched U. lactuca (ULE) failed to grow gonads significantly; as a result, their quality was unacceptable for the market. These results suggest that S. purpuratus experience increased gonad production and quality in short periods when fed nutrient‐enriched M. pyrifera.     

壳白长牡蛎品系生长和壳色性状遗传参数估计

以经过连续4代家系选育获得的壳白长牡蛎(Crassostrea gigas)选育系为亲本,通过巢氏平衡设计建立了30个全同胞家系混合养殖,采用微卫星多重PCR技术进行家系鉴定,基于REML法估算24月龄壳白长牡蛎的生长性状和壳色性状的遗传参数。结果表明,壳白长牡蛎品系壳高、壳长、总重、壳重、L~*(明度)、a~*(红绿轴色品指数)和b~*(黄蓝轴色品指数)的遗传力为中高等水平,依次为0.35±0.13、0.18±0.09、0.20±0.09、0.16±0.08、0.16±0.08、0.27±0.11和0.19±0.08,壳宽、肉重、出肉率、壳型指数A和壳型指数B的遗传力为低等水平,依次是0.07±0.02、0.11±0.06、0.02±0.03、0.08±0.06和0.11±0.06。壳高、壳长、壳宽、总重、壳重和肉重之间的遗传相关和表型相关均为正相关,其中,壳高、壳宽和总重与其他生长性状的相关性较高,分别为0.40±0.65~0.90±0.14、0.39±0.55~0.97±0.24和0.50±0.66~0.99±0.02。壳型指数A和壳型指数B与壳高均为较高的负相关,分别为–0.94±0.16和–0.77±0.19,表明仅以壳高性状为选育目标时,可能不会对长牡蛎壳型改良产生作用。壳白长牡蛎壳色参数与生长性状之间的遗传相关范围为–0.09±0.42~0.91±0.74,不同性状间的遗传相关差异很大,其中L~*与生长参数遗传相关较高,为0.49±0.29~0.91±0.74,表明以壳高、壳长、总重和L~*任一个为选育目标时,其他生长性状都可以获得提高。壳色参数间L~*与a~*负的相关性最高,为–0.96±0.04,L~*与b~*和a~*与b~*相关性较低,分别为–0.08±0.36和0.21±0.31,表明以L~*为选育目标时,可间接降低a~*值。本研究为合理制定壳白长牡蛎新品系育种方案和选择反应预测提供了参考依据。     

Effects of dietary β‐carotene levels on growth and liver vitamin A concentrations of the soft‐shelled turtle,Pelodiscus sinensis (Wiegmann)

A feeding trial was conducted to evaluate the effect of dietary β‐carotene level on the growth and liver vitamin A concentrations in soft‐shelled turtles, Pelodiscus sinensis, fed a vitamin A‐free diet. Soft‐shelled turtles were fed diets containing 0, 14.5, 26.5, 47.5, 87.3, 112.8 and 163.8 mg β‐carotene kg^?1 for 10 weeks. Although it was not statistically significant due to high deviation within each group, mean weight gain of soft‐shelled turtles fed the diet without β‐carotene supplementation was the lowest among all test groups. Vitamin A concentrations in liver of turtles significantly (P<0.05) increased when dietary β‐carotene level reached 47.5 mg kg^?1 indicating that soft‐shelled turtles were capable of converting β‐carotene to vitamin A. Analysed by regression modelling, dietary β‐carotene levels for optimal growth and maximal liver vitamin A contents of juvenile soft‐shelled turtles fed the vitamin A‐free diets were 49.1 and 88.7 mg kg^?1 respectively.     

Fat or lean? The quantitative genetic basis for selection strategies of muscle and body composition traits in breeding schemes of rainbow trout (Oncorhynchus mykiss)

Quantitative genetic analyses of fish composition have been strongly biased towards lipid deposition, rather than protein deposition. This is partly at odds with desires of the modern aquaculture industry, to improve the efficiency of lean growth. Using a quantitative genetic approach, we examined the selection potential in both protein and lipid components of wet weight growth in rainbow trout over a two-year growth period. Two diet treatments were applied to test the hypothesis that an experimental, high protein, low lipid diet (HP) would enhance selection potential compared to the current modern, normal protein, high lipid diet (NP). We found that lipid traits (lipid body weight, percent muscle and body lipid; h² = 0.40) were more heritable than corresponding protein traits (protein body weight, percent muscle and body protein; h² = 0.18), indicating a higher selection potential for lipid traits. The results revealed further that breeding for improved lipid composition over the whole growth period is easier than for protein composition. This was shown by the high favourable genetic correlations between differently aged fish for lipid traits. In contrast, the respective correlations for protein traits were low or even negative. Similarly, the genetic correlations between muscle and body composition were higher for lipid than for protein, enhancing selection efforts to change lipid traits. Heritabilities increased with age, implying that selection practiced on old (> 800 g) rather than young (< 60 g) fish should be more effective in achieving a compositional response. Although the diet had a significant effect on the composition traits, there was no general trend for diet differences in heritabilities of either protein or lipid traits. Thus, the hypothesis of increased selection potential on HP diet was not supported. In conclusion, lipid traits are both more variable and exhibit more favourable genetic architecture for selection compared to protein traits.     

The effect of fresh seaweed and a formulated diet supplemented with seaweed on the growth and gonad quality of the collector sea urchin,Tripneustes gratilla,under farm conditions

This gonad enhancement study investigates the effect of different fresh and formulated feeds and feeding regimes on the growth and gonad quality of wild‐collected adult sea urchin, Tripneustes gratilla, under farm conditions for over 18 weeks. In the first 12 weeks (phase 1), urchins were fed fresh Ulva rigida (U); a 50:50 mixture of fresh U. rigida and Gracilaria gracilis (UG); fresh G. gracilis (G) and a formulated diet 20U (containing 20% U. rigida), and in the final 6 weeks (phase 2) of the study, diet was changed to a formulated feed (20U diet). By the end of phase 1, urchins fed the 20U diet produced gonads (50.72 ± 5.4 g) that were significantly heavier (p < .001) than the gonads of urchins fed the fresh seaweed diets (U, UG & G). By the end of phase 2, gonad weight of urchins in treatment groups UG‐20U and G‐20U were similar to those fed the 20U‐20U diet. Gonad colour of urchins in the G‐20U treatment became significantly lighter (ANOVA, p = .029) and poorer quality, compared with urchins in the U‐20U group. This gonad enhancement study, conducted on wild‐collected adult T. gratilla, has shown that a formulated feed (20U diet) can enhance gonad growth and produce commercially acceptable gonads. This farm‐based study supports previous findings from aquarium‐based studies by our group and indicates that short‐term sea urchin gonad enhancement can be carried out under farm conditions in South Africa.     

Estimates of genetic and phenotypic parameters for length and weight of marine net-pen reared coho salmon (Oncorhynchus kisutch Walbaum)

Heritabilities and genetic and phenotypic correlations were estimated for length and weight of two brood years (BY 1977 and BY 1978) of coho salmon [Oncorhynchus kisutch (Walbaum)] during the marine net-pen phase of rearing. The estimates were calculated from length and weight measurements on progeny resulting from a nested mating design and measurements at approximately 4 and 7 months after entering sea water. Point estimate for heritabilities based on the sire component for BY 1977 were low to moderate (0.02–0.19) and did not differ significantly from zero. On the other hand, BY 1978 estimates ranged from 0.31 to 0.62 and, with two exceptions, were significantly different from zero. The latter estimates may have been inflated by inclusion of variances from non-additive sources, but still indicated that differences in the genetic potential for increased growth between the two year classes may be substantial. Genetic correlations between length and weight within sampling periods were consistently high (0.95–1.00), indicating that pleiotropic gene action or close linkage among genes affects length and weight. Genetic correlations between body size traits (length and weight) between sampling periods varied considerably but suggested a potential for indirect selection gains. Genetic correlation approximations derived using family means or ranks appeared to provide reliable estimates and may be useful when environmental influences cause a significant deviation from normality.     

Effect of Arthrospira supplementation on Oreochromis niloticus gut microbiota and flesh quality

Supplementing fish feed with Arthrospira platensis has several beneficial effects, such as improved growth, survival and feed conversion, but little is known about how it affects gut microbiota or flesh quality. In this trial, feed with 3% A. platensis was given to Oreochromis niloticus (SPR, spirulina supplemented) over a period of 50 days and their gut microbiota and flesh quality were compared with controls (CTRs, no supplementation). Average daily growth was higher in SPR fish (p < 0.05). Regarding microbiota, a total of 5,470,272 readings (individuals) were obtained from 16 gut samples (n = 8 CTR, n = 8 SPR), with a gamma diversity of 1,563 species but no significant differences were found between treatments. Among the high inter‐individual variability found, some individual microbiota were dominated by Proteobacteria (36.6%) and Fusobacteria (32.9%) and others more by Actinobacteria (37%). Regarding flesh quality, significant differences were observed in flesh colour post‐mortem (a*, b* and chroma) (p < 0.05), with higher reflectance in the range of 470–500 and 620–670 nm in SPR tilapia, which corresponds with the reflectance range of β‐carotene and phycocyanin. However, rigor mortis was resolved earlier in SPR fish (p < 0.05), which suggests a shorter shelf life. Adding 3% of A. platensis in O. niloticus diet can improve growth and flesh colour and does not appear to modify intestinal microbiota.