Sea lice (Lepeophtheirus salmonis [Kr & oslash;yer, 1838]) are a key issue for salmon aquaculture, contributing to increased mortality for both wild and farmed salmon if no action is taken. Using cleaner fish can be an effective, drug-free treatment method, and ballan wrasse (Labrus bergylta) is a hardy wrasse species that displays cleaning behavior. With concerns about the overharvest of wild ballan wrasse, many companies farm this species, but the optimal ranges of a wide variety of rearing parameters are still unknown. This study investigated the effect of 6-week exposure to four dissolved oxygen (DO) levels (125%, 100%, 85%, and 75% DO saturation as the percentage of air) on ballan wrasse. Survival; growth (specific growth rate, SGR); condition factor (CF); and primary (cortisol), secondary (glucose, lactate, magnesium), and tertiary stress indicators (swimming performance) were investigated. There were no differences in SGR, CF, survival, or cortisol level among the groups at the end of the 6 weeks. There was variation in the magnitude of the cortisol response to an acute stressor at the end of the 6-week period, with the 75% DO treatment exhibiting a 3.3-fold increase in cortisol compared to a 5.2-fold increase in the control group (100%), which could suggest chronic stress. Relative critical swimming speed (RUcrit) was measured to investigate swimming performance once all groups were returned to 100% DO saturation. The 75% RUcrit was lower than the 100% treatment (1.7 +/- 0.18 body length [BL]/s compared to 2.5 +/- 0.16 BL/s). Overall, these results suggest that DO levels of 75% trigger physiological changes and therefore may negatively affect welfare.

Atlantic salmon aquaculture relies on continuous supply of high quality eggs. Broodfish nutrition and manipulation of ovulation time (photoperiod and temperature) are key factors. The optimum feeding period with broodfish diet has not been investigated before. The present study examined how feeding period with broodfish diet (9 vs. 17 months) interacted with manipulation of ovulation time (early (Nov), normal (Dec), late (Feb)) on broodstock egg production capacity and egg quality in two-sea-winter female Atlantic salmon (similar to 12 kg). All groups were fed until June 2021 when they were transferred to tanks and starved until ovulation.There were no measurable main or interaction effects of feeding period. Manipulation of ovulation gave several significant effects compared to normal ovulating females: 1. Early ovulating females had higher viscerosomatic index, smaller eggs with higher swelling rate (early 1.36, normal 1.27, late 1.23), and lower egg quality shown as reduced survival from fertilization to the eyed egg stage (mortality: early 11%, normal 5%, late 14%). 2.Late ovulating females: ( i ) were emaciated as shown by low condition factor calculated on gutted weight, and hepatosomatic and viscera indexes; ( ii ) had larger gonads caused by larger eggs; ( iii ) had reduced egg quality measured as elevated mortality from fertilization to first-feeding (eyed egg - first feeding: early 11%, normal 8%, late 23%). 3. All groups spawned a similar number of eggs per female. The current results show that the feeding period with broodstock diet may be set to 9 months. This would make Atlantic salmon egg production more economical and environmentally sustainable. The results also show that manipulation of ovulation time reduce egg quality but not fecundity. Further research should investigate feeding periods with broodstock diet shorter than 9 months and determine the threshold for jeopardized fish welfare with respect to starvation time for manipulated late ovulating females.

Atlantic halibut go through a period with reduced or no feed intake during their spawning period. This study with male Atlantic halibut aimed to assess the effect of a two-month starvation period corresponding to the naturally occurring spawning induced starvation. The actual loss of nutrients compared to initial body burden, was estimated to 25% for gross energy, 32% for total lipid, 14% for crude protein, and 40% and 44% respectively, for the essential fatty acids EPA (C20:5 n-3) and DHA (C22:6 n-3). This indicates that lipid is the preferred energy source during starvation related to spawning, and the n-3 fatty acids are used to a larger extent than other fatty acids, although mono-unsaturated fatty acids (MUFAs) comprised the largest energy reserve. The difference in relative amount of energy and nutrients used should be considered when formulating diets for re-feeding broodstock of annual spawners like the Atlantic halibut.

Cleaner fish species have gained great importance in the control of sea lice, among them, lumpfish (Cyclopterus lumpus) has become one of the most popular. Lumpfish life cycle has been closed, and hatchery reproduction is now possible, however, current production is reliant on wild caught broodstock to meet the increasing demand. Selective breeding practices are called to play an important role in the successful breeding of most aquaculture species, including lumpfish. In this study we analysed a lumpfish population for the identification of genomic markers linked to production traits. Sequencing of RAD libraries allowed us to identify, 7193 informative markers within the sampled individuals. Genome wide association analysis for sex, weight, condition factor and standard length was performed. One single major QTL region was identified for sex, while nine QTL regions were detected for weight, and three QTL regions for standard length. A total of 177 SNP markers of interest (from QTL regions) and 399 high Fst SNP markers were combined in a low-density panel, useful to obtain relevant genetic information from lumpfish populations. Moreover, a robust combined subset of 29 SNP markers (10 associated to sex, 14 to weight and 18 to standard length) provided over 90% accuracy in predicting the animal's phenotype by machine learning. Overall, our findings provide significant insights into the genetic control of important traits in lumpfish and deliver important genomic resources that will facilitate the establishment of selective breeding programmes in lumpfish.

Lumpfish (Cyclopterus lumpus) aquaculture has expanded greatly in recent years due to demands for sea lice cleanerfish from the salmon industry. There are knowledge gaps in lumpfish digestive physiology, nutrient requirement and implications of nutrition for health and disease susceptibility. The present study, conducted to follow up our recent screening trials for estimation of optimal balance of protein, lipid and carbohydrate in diets for lumpfish, involved challenging the fish with Aeromonas salmonicida after a feeding period with diets varying in lipid composition. Three experimental diets were formulated to have similar content of digestible protein and carbohydrate but varying in content of lipid from 6.7 to 18%. Lumpfish with average body weight at start of 1.7 +/- 0.03 g were fed the experimental diets in triplicate tanks each (110 fish per tank, in total 990 fish in 9 tanks) for a period of 90 days. After termination of the feeding trial and subsequent collection of biological samples, remaining fish were challenged with atypical A. salmonicida. No significant effects of diet were observed for growth performance. Carcass composition showed increasing content of lipid, protein, and energy with increasing dietary lipid level. Increasing dietary lipid also increased hepatic dry matter, lipid and energy levels, while crude protein decreased. Blood plasma nutrient levels and biomarkers of liver function showed few significant effects of diet, but dietary lipid level increased plasma cholesterol. Intestinal trypsin activity increased with increasing dietary lipid, whereas activity of other digestive enzymes and digesta bile salt levels were unaffected by diet. Increasing lipid level also increased lipid accumulation in the proximal and mid intestine. Expression profiling of genes related to digestive and immune function showed few effects of diet, but the nutrient transporters fabp2 and slc15a1, as well as the immune genes MHCII, igm, and nfkb showed increases with dietary lipid levels, whereas the cholesterol transporter npc1l1 was suppressed. Diet composition did not affect the lumpfish' resistance against A. salmonicida. To conclude, the variation in macronutrient composition induced modulations in metabolic, digestive and some immune functions. Modulations seemed however to be within normal ranges and did not produce clear compromises in immune responses to bacterial infection.

ABSTRACT Cleaner fish species have gained great importance in the control of sea lice, among them, lumpfish ( Cyclopterus lumpus ) has become one of the most popular. Lumpfish life cycle has been closed, and hatchery reproduction is now possible, however, current production is reliant on wild caught broodstock to meet the increasing demand. Selective breeding practices are called to play an important role in the successful breeding of most aquaculture species, including lumpfish. In this study we analysed a lumpfish population for the identification of genomic markers linked to production traits. Sequencing of RAD libraries allowed us to identify, 7,193 informative markers within the sampled individuals. Genome wide association analysis for sex, weight, condition factor and standard length was performed. One single major QTL region was identified for sex determination, while nine QTL regions were detected for weight, and three QTL regions for standard length. A total of 177 SNP markers of interest (from QTL regions) and 399 top F st SNP markers were combined in a low-density panel, useful to obtain relevant genetic information from lumpfish populations. Moreover, a robust combined subset of 29 SNP markers (10 associated to sex, 14 to weight and 18 to standard length) provided over 90% accuracy in predicting the animal’s phenotype. Overall, our findings provide significant insights into the genetic control of important traits in lumpfish and deliver important genomic resources that will facilitate the establishment of selective breeding programs in lumpfish.

Concerns have long been raised about the welfare of ballan wrasse (Labrus bergylta) used for the biological control of sea lice in Atlantic salmon (Salmo salar) aquaculture. This study assessed the effect of increased dietary eicosapentaenoic acid (EPA) levels and initial condition factor (CF) on the subsequent performance and welfare of ballan wrasse farmed in high and low water temperatures. Fish were fed a diet with either commercial or high EPA levels for 3 months at 15 degrees C. Subsequently, fish were tagged with a passive integrated transponder, measured for their CF and divided into two groups consisting of fish from both treatments and reared for 4.5 months at either 15 or 6 degrees C fed a commercial diet. Each fish was categorized as high (>= 2.7) or low CF (<2.7) fish based on the calculated average CF of the population. Dietary composition influenced the fatty acid (FA) profile of the stored lipids without affecting the growth or welfare of ballan wrasse. Fish reared at 15 degrees C showed higher growth, more fat and energy reserves and less ash content. Fish reared at 6 degrees C lost weight, using up their body lipids at the end of the temperature trial. Gene expression analyses showed upregulation of the positive growth marker (GHra) and two genes involved in the synthesis and oxidation of FAs (elovl5, cpt1) and downregulation of the negative growth marker (mstn) in fish reared at 15 degrees C compared to those reared at 6 degrees C. Fish reared at 6 degrees C showed upregulated levels of il-6 compared to those reared at 15 degrees C, suggesting an enhanced immune reaction in response to low temperature. Fish with high CF showed better survival, growth and performance compared to those with low CF. External welfare scoring showed higher prevalence and severity in emaciation, scale loss and the sum index score (of all measured welfare parameters) in fish reared at 6 degrees C compared to those reared at 15 degrees C and better welfare in fish with high CF compared to those with low CF. Histological examination of the skin showed that fish reared at 6 degrees C had decreased epidermal thickness, a lower overall number of mucous cells in the inner and outer epidermis and a different organization of mucous cells compared to fish reared at 15 degrees C, indicating stress in fish reared at 6 degrees C. Overall, low water temperatures had profound effects on the performance and external and internal welfare parameters of ballan wrasse and can be considered a stressor likely affecting the delousing efficacy. These findings support the seasonal use of different cleaner fish species. High CF, but not increased dietary EPA levels, appeared to help fish cope better with low water temperatures and should thus be assessed and considered before deploying them in salmon cages.

Abstract A 5-week feeding trial was conducted in the cleaner fish Ballan wrasse (Labrus bergylta) for a better understanding of the basic biology of the intestinal functions and health in this stomach less species. During the trial, Ballan wrasse was fed either a reference diet, the reference diet supplemented with (i) a commercial prebiotic (Aquate™ SG, 0·4 %) expected to have beneficial effects, (ii) soya saponins (0·7 %) expected to induce inflammation or (iii) a combination of the prebiotics and the soya saponins to find a remedy for gut inflammation. Blood, intestinal tissue and gut content from four consecutive intestinal segments (IN1 – IN4) were collected. No significant differences in fish growth were observed between the four dietary groups. Saponin supplementation, both alone and in combination with prebiotics, increased weight index of IN2 and IN3 and decreased blood plasma glucose, cholesterol and total protein. Dry matter of intestinal content and activity of digestive enzymes were not affected by diet. Histomorphological analyses revealed a progressing inflammation with increased infiltration by immune cells particularly into the distal parts of the intestine in fish fed diets with saponins, both alone and in combination with prebiotics. Gene expression profiles obtained by RNA sequencing and quantitative PCR mirrored the histological and biochemical changes induced by the saponin load. The study demonstrated that Ballan wrasse gut health and digestive function may be markedly affected by feed ingredients containing antinutrients.

Lumpfish males usually release small amounts of milt and are therefore often sacrificed for surgical harvesting of gonads. To optimize the utilization of sperm obtained by dissection of the gonads, a series of small-scale fertilization experiments was carried out in petri dishes. Sperm extracted from homogenized gonads were diluted 1:1 with a commercial extender solution before use (AquaBoost (R) SpermCoat). Fertilization success was evaluated as percentage eyed eggs similar to 120 day-degrees post fertilization. Firstly, the effect of chilled storage (3 degrees C) of diluted milt were evaluated by fertilizing eggs (2.27 x 10(5) sperm/egg) from two freshly stripped females every 2nd or 3rd day over a 14-day period. Storage time did not affect the fertilization rates which were high throughout the 14-days trial period (89.1-99.8%). Secondly, the effect of sperm to egg ratio of cryopreserved and chilled stored sperm (3 degrees C for 3 days) on fertilization rate was investigated and compared by fertilizing eggs from three separate females with six different sperm to egg ratios (1.25 x 10(5) to 2 x 10(9)). For both storage methods, only the lowest sperm to egg ratio (1.25 x 10(5)) resulted in a significant lower but still high fertilization rate (80.7%). Using freshly extracted sperm at lower sperm to egg ratios (1.25 x 10(5) to 3.1 x 10(4)) to fertilize eggs from three females revealed, however, no relationship between sperm to egg ratio and fertilization rates as they were high for all ratios (91.2-93.4%). Two additional experiments were undertaken at a real scale to validate the petri dish results at higher egg numbers and volumes. A fixed volume of 40 ml eggs (similar to 4800 eggs) was fertilized with four sperm to egg ratios ranging from 3.1 x 10(4) to 5 x 10(5). All sperm to egg ratios resulted in high fertilization rates ranging from 93.7 to 99%. In the second real scale experiment increasing volumes of eggs (1 up to 160 ml) were fertilized with a fixed sperm to egg ratio (2.5 x 10(5)). The fertilization success (95.9-97.5%) was not affected by egg volume. In conclusion, the current study showed that lumpfish sperm can be chilled stored at 3-4 degrees C for 14 days and can be cryopreserved and thawed without any significant reduction in fertilization success under the conditions used in this study. Compared to other marine teleosts, lumpfish require a low sperm to egg ratio for successful fertilization, but the critical low ratio to obtain high fertilization was not revealed in this study.

Cultivation of lumpfish (Cyclopterus lumpus) as lice cleaner fish for salmon is now expanding. For successful cultivation of a new species, understanding the basic biology of digestive functions is vital to facilitate and optimize diet formulation. This paper presents results from two experiments conducted to deepen our knowledge on lumpfish intestine physiology. Experiment 1 was a 42-day feeding trial in which lumpfish were fed twelve different diets in the following ranges of macronutrients: Protein 43-68%, lipid 4-17%, and carbohydrate 6-17%. Intestinal tissue, gut content and liver were sampled from 6 fish per tank. The results showed that with increasing lipid level and corresponding decrease in protein level, there was a linear decrease in several of the observed biomarkers, including activity of brush border membrane digestive enzymes, expression of genes related to nutrient digestion and transport, ion exchange, immune regulation, and cell remodeling. Increased intracellular accumulation of lipid (steatosis) was observed in gut and liver with increasing dietary lipid level. Fewer effects were observed for increased dietary carbohydrate and corresponding decreased protein level. Experiment 2 was a two-week feeding trial for estimation of macronutrient digestibility in which lumpfish were fed three diets, all containing 55% crude protein, with lipid to carbohydrate ratio of the low lipid diet of 7.5%/18.3%, the medium lipid diet of 13.8%/14.6%, and high lipid diet of 18.1%/9.5%. Fecal samples were collected as pooled samples per tank. These results showed that fatty acid digestibility’s increased as dietary lipid level increased. Of note, starch digestibility decreased greatly as starch level increased, whereas protein digestibility did not change as lipid or starch level varied. Taken together, the present studies indicated that increasing lipid level in the diet with corresponding decrease in protein level affects digestion, absorption, and immune responses in the lumpfish intestine. Variation in dietary carbohydrate to protein level showed less effects, possibly due to low starch digestibility which makes the variation in available carbohydrates much less than the variation in the analysed level of dietary carbohydrates.

The production of lumpfish (Cyclopterus lumpus) is increasing rapidly due to their use as a cleaner fish for sea lice infections in Atlantic salmon farming. The sustainable development of captive broodstocks is reliant on good egg quality however this remains unknown. The present study assessed the hatching success and nutritional composition of eggs collected from two wild groups, at the start and end of the Norwegian fishing season (2018–2019), and one captive broodstock population (2019). Eggs from the farmed broodstock, used in this study, showed significantly lower fertilisation rates, eyeing rates and survival to hatching than eggs from wild broodstock. There was significantly less overall lipid content in the captive eggs when compared to the wild group as well as significantly lower levels of lipid fractions such as total N-3 PUFAs, minerals such as sodium and phosphorus and overall egg pigment levels. A principal component analysis of all 139 measured nutritional components within fatty acids, minerals and pigments was conducted to identify those associated with egg quality in lumpfish. A total of 51 components was identified as being positively (31) and negatively (20) correlated with hatching rate including essential fatty acids such as EPA, DHA and ARA, total pigment levels and calcium levels. Overall, this study clearly showed a reduction in egg quality from captive broodstock and suggested nutritional deficiencies in the current broodstock diets. As such, this study provides a foundation for further work into the optimisation of lumpfish broodstock management with a number of nutritional factors to be further investigated.

The aim of this study was to investigate how the dietary balance between protein, lipid, and carbohydrate affects growth, welfare, and health with focus on immune responses, in lumpfish of body weight ranges 1.7-10 g and 15-50 g. A three-component mixture design, with simultaneous variation of the three macronutrients was applied. Growth, tissue and plasma nutrient composition, welfare, cataract frequency, and immune responses in leukocytes isolated from the fish head kidney were studied. Most responses were linear and driven by dietary lipid level, with minor effects of carbohydrate and protein. The growth in 1.7-10 g fish followed a special cubic model with no clear optimum. The fastest growth in the 15-50 g fish was obtained with the diet containing 55% protein, 17% fat, and 6% carbohydrate. The high dietary levels of lipid also gave high lipid levels in the tissues and a trend of improved welfare score, but there were no effects on cataract. The diets with minimum and maximum protein gave suboptimal immune responses in isolated head kidney cells of the 15-50 g fish, while the fastest growing fish showed normal immune responses. We propose that diets for lumpfish from 10-50 g body weight should contain approximately 55% protein, minimum 10% lipid, and maximum 10% carbohydrate. These diets will also be suitable for lumpfish of 1.7-10 g.

Lumpfish (Cyclopterus lumpus) serves an important role as cleaner fish for removing salmon lice in salmon aquaculture. For this use, cultivated lumpfish are preferred over wild-caught fish to avoid overexploitation of natural stocks and provide a stable production of good quality eggs and larvae. To support this, high quality eggs containing the necessary building blocks to support high fertilization success, development into a normal embryo and high hatching success is needed. Ova from wild-caught and captive lumpfish females were collected and assessed to identify how wild and domesticated lumpfish differ in terms of ova lipid profiles, egg and larvae quality. Wild-caught lumpfish displayed higher fertilization and hatching success compared to captive lumpfish, whereas other biological variables like egg size, egg/larvae dry weight and respiration, and larval morphometry, were not significantly different between wild and captive lumpfish. Ova lipid profiles (total lipid, lipid classes, fatty acid composition and lipidomics) can separate egg batches based on their geographic origin of wild-caught females and composition of diets used for captive broodstock (lipid and carbohydrate content). Multivariate statistics were applied to identify lipid markers that can be used to predict the quality of lumpfish ova. Lumpfish ova lipidomic profiles covaried with several biological parameters, indicating that the former can be used to predict the latter. Lumpfish eggs were mostly composed of triacylglycerides (TAGs) with some phosphatidylethanolamines (PEs) and phosphatidylcholines (PCs), and their lipid profiles were more sensitive to the different origins, mother weight/size and fertilization success than variables such as eggs size or larvae morphometric measures. PC and PE content of lumpfish eggs were positively correlated to both hatching success and fertilization rates, thus the lipidomic profiles, with some key highlighted lipid species were putative predictors of egg quality.

Farmed ballan wrasse (Labrus bergylta) is an efficient cleaner fish used for non-medicinal delicing of Atlantic salmon in sea cages replacing to an increasing degree wild wrasse due to considerations for biodiversity and risk of overfishing local wrasse populations. Farming of ballan wrasse has been hampered by low growth rates, high prevalence of skeletal deformities and other welfare related pathologies. In this study we investigated how diets identical in composition but differing in their technical characteristics, by being prepared using different feed production technologies, affect fish performance, mineralization, bone development and gut health of the ballan wrasse larvae and juveniles. The different production technologies include the commonly used ‘high temperature’ extrusion, cold extrusion, and agglomeration, resulting in feed pellets with distinctive physicochemical properties. The results revealed that prolonged feeding periods with extruded pellets during ballan wrasse larvae weaning result in low body mineralization and the development of severe skeletal deformities. In juvenile ballan wrasse, the extruded pellet treatment resulted in higher mortality rates, fish with larger livers, indication for increased serum TAG and cholesterol in a similar manner, and increased activity of the digestive enzymes LAP and maltase, most probably as a compensatory mechanism to the assumed reduced availability of protein and carbohydrates of extruded pellets for this fish species. Smaller dietary effects were identified in terms of intestinal morphology and gene transcription rates.

There is increased commercial interest in the production of Lumpfish (Cyclopterus lumpus, Linnaeus, 1758) as a biological control for sea lice infections in Atlantic salmon farming. To ensure sustainability, reliable captive breeding is required however, optimal husbandry conditions for broodstock performance remain unknown. The present study investigated the effects of holding temperature on spawning productivity and gamete quality in captivity reared lumpfish. Sexually mature lumpfish (15 month old) were held on three temperature regimes (6 degrees C, 9 degrees C and 14 degrees C) from the onset of first spawning. Holding mature lumpfish at high temperatures (14 degrees C) resulted in a notable reduction in spawning activity with a significant reduction in sperm density (50% reduction compared to pre-treatment levels) and furthermore resulted in the production of non-viable oocytes (0% to eyeing rate). Holding lumpfish at 9 degrees C and 6 degrees C did not have a similar negative impact on gamete quality, however the spawning season for the 6 degrees C treatment was twice as long as the 9 degrees C treatment. These results indicate that holding temperature for lumpfish broodstock should not reach the 14 degrees C degree threshold, with a possible thermal optimum below 10 degrees C. The current findings are the first step in identifying optimal rearing conditions for captive Lumpfish broodstock.

Little is known about the digestion of nutrients in stomachless (agastric) fishes with short intestines, such as wrasse. This study describes the digestion, absorption and evacuation rates in ballan wrasse (Labrus bergylta) fed either dry or pre-soaked diets. Ballan wrasse juveniles received either dry or pre-soaked diets containing inert markers to determine intestinal evacuation rates over a 4 to 14 h period after ingestion. The digestive tract evacuation was completed in 12 - 14 h, and was not affected by dietary moisture level. Within the different segments of the intestine, 90 % of the digesta moved from the foregut to the midgut after 4 - 8 h, and over 7 % of the digesta had arrived in the hindgut 4 h after feeding. The foregut was a major site of digestion, where 86 % of carbohydrates, 74 % of proteins, and 50 % of lipids, were absorbed from the diet. The absorption of carbohydrates and lipids increased until the hindgut (98 and 80 %, respectively). Protein absorption continued along the length of the intestine reaching 90 % absorption at the hindgut. Protein and carbohydrate absorption was slightly higher in the foregut for fish fed dry versus moist diets, but this difference disappeared in the midgut. The moisture levels of diet had no effect on the digesta moisture levels, expression of metabolic genes, the levels of nutrients in plasma, or intestinal health. Nine aquaporins were found to be expressed in the wrasse intestinal tissue. Vertebrate aquaporins are involved in water transport from the intestinal lumen into the body and may play a role in maintaining stable moisture level of the digesta in the intestine of ballan wrasse regardless of the initial dietary moisture levels.

Varenkamp Digital devices are a part of most peoples lives today. Using digital devices leaves traces. These traces can be urgent to solve a criminal case. Knowing this, forensic work has the goal to get as much...

Early maturation has been one of the biological bottlenecks of commercializing Atlantic cod culture. To overcome the bottleneck, production of sterile fish through triploidy and other molecular techniques have been suggested and attempted. Although studies have been carried out on triploid performance of Atlantic cod, no studies have been conducted to see the performance of triploid fish at family level. We produced 29 triploid sibling families using standard hydrostatic pressure technique of newly fertilized eggs with parallel, untreated diploid families. Larvae were reared in separate tanks using standard rearing protocols until reaching 20 g and were PIT tagged. PIT tagged juveniles were transferred to sea cages in duplicate. At 34 months post-hatch, all the fish were sampled and body weight, liver weight and gonadal weight were recorded. Results showed that significant family differences exist between diploid and triploid families in gonadal development, especially for the females. Fish from triploid families had significantly smaller gonadosomatic index than fish from diploid families, but diploid families were heavier than the triploid families. Our result highlight the need for considering a parallel strategy for triploid family selection within the conventional diploid breeding program to exploit the existing variation in triploid performance.