Effects of dietary α‐lipoic acid on the growth and antioxidative responses of juvenile abalone Haliotis discus hannai Ino

A feeding experiment was conducted to determine the effects of α‐lipoic acid (LA) on the growth and antioxidative responses of juvenile abalone Haliotis discus hannai Ino. Six purified diets supplemented with 0, 200, 400, 800, 1600 and 3200 mg kg^?1 of LA, respectively, were fed to abalone for 16 weeks in a flow‐through water system. The results showed that the weight gain ratio (WGR) increased with the dietary LA levels, and reached the highest value in the group with 800 mg kg^?1 dietary LA supplement. Glutathione peroxidase activity in the 800 mg kg^?1 dietary LA group was significantly higher than that in the dietary LA‐deficient (0 mg kg^?1) group. Superoxide dismutase activities in the 200, 400 and 800 mg kg^?1 groups were significantly increased. Supplements of 200, 400 and 800 mg kg^?1 dietary LA elevated the total antioxidative capacity significantly. The glutathione level in the hepatopancreas increased significantly with the dietary LA supplements in a dose‐dependent manner (except for the 200 mg kg^?1 group). Catalase and malondialdehyde in the hepatopancreas were not significantly affected by dietary LA. In conclusion, dietary LA promoted the growth and stimulated the antioxidative defence capacity of abalone. Based on the data of WGR, the optimal dietary LA supplement for juvenile abalone was found to be 709 mg kg^?1 using piece‐wise linear analysis.     

Triploidy induction in Australian greenlip abalone Haliotis laevigata (Donovan) with cytochalasin B

Triploid induction in Australian greenlip abalone, Haliotis laevigata (Donovan), was conducted by blocking the formation of the second polar body using cytochalasin B (CB). Twenty minutes after fertilization, the zygotes of greenlip abalone were treated with four CB concentrations (0, 0.25, 0.5 and 0.75 mg L⁻¹) for 10, 15 and 20 min. The ploidy of resultant larvae was determined using flow cytometry at 72-h post fertilization. Our study showed that fertilization, hatching, survival and induced triploidy of abalone larvae were significantly affected by the CB concentration and treatment duration. The effective range of CB concentration for triploid induction on greenlip abalone was 0.5–0.75 mg L⁻¹ with an induction duration of 10–15 min. The results indicate that the most effective treatment combination for triploid induction in greenlip abalone is 0.5 mg CB L⁻¹ for 15 min starting at 20-min post fertilization.     

Growth and feeding in juvenile triploid and diploid blacklip abalone, Haliotis rubra (Leach, 1814), at two temperatures

Growth and feeding of juvenile triploid and diploid blacklip abalone Haliotis rubra (Leach, 1814) were investigated at two temperatures of 17 and 21 °C over a 50‐day period. There were no differences in growth between triploid and diploid abalone as measured by shell length and body weight. Both triploid and diploid abalone increased in length but not in weight at 21 °C. Condition indices were similar for triploid abalone maintained at both temperatures; however, those for diploid abalone were significantly higher at 17 °C than at 21 °C. Food intake was significantly greater yet feed conversion efficiency was significantly lower in triploid than in diploid abalone. Both the feeding variables were independent of temperature. On average, diploid abalone were able to convert 1 g of dry food ingested to 0.58 g of body weight, but triploid abalone only 0.44 g.     

Antioxidant Properties and Arsenic Speciation of Ultrafiltration and Nanofiltration Derived Abalone Viscera Hydrolysate Fraction

A fraction with molecular weight of 0.2–1.0 kDa was prepared from abalone viscera hydrolysate by ultrafiltration and nanofiltration. The contents of protein, carbohydrate, and fat in abalone viscera were 45.75%, 18.19%, and 13.60%, respectively. The protein in abalone viscera hydrolysate faction (AVHF) reached up to 75.73%, while carbohydrate and fat fell to 1.80% and 0.20%, respectively. The leucine (Leu) content was the highest in the AVHF. On the other hand, the hydroxyl and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activities and reducing power increased with increased concentration of AVHF. The inhibiting ability of AVHF on lipid peroxidation was higher than that of ascorbic acid. The total content of K, Na, and P in AVHF was 9.78 g/100 g, and total arsenic content reached 16.23 mg/kg. The proportion of arsenobetaine and arsenocholine accounted for more than 96%, while the proportion of arsenate was 0.47%, and arsenite was not detectable. It is concluded that the AVHF from abalone viscera is a safe natural antioxidant.     

Growth performance of disk abalone Haliotis discus hannai in pilot- and commercial-scale recirculating aquaculture systems

The study investigated the growth performance of abalone from juvenile to marketable size in a commercial-scale recirculating aquaculture system. The rearing system consisted of 12 raceways (4.0 × 0.8 × 0.6 m) with a protein skimmer and a submerged biofilter for juveniles and 10 raceways (6.6 × 1.3 × 0.6 m) with a protein skimmer and a trickling biofilter for on-growing. Sea mustard (Undaria pinnatifida) and kelp (Laminaria japonica) were fed to the abalone. The total weight of abalone in the recirculating aquaculture system at the juvenile stage increased from 22.0 kg (average shell length 24.5 mm) to 75.5 kg (average shell length 42.5 mm) after 180 days. Feed conversion ratios increased slightly from 13.7 for the first 90 days to 16.3 thereafter. The shell growth rate of juvenile abalone between 24.5 mm and 34.8 mm was 3.4 mm month⁻¹, while for juveniles between 34.8 mm and 42.5 mm it was 2.6 mm month⁻¹. The total weight of abalone in the recirculating aquaculture system for the on-growing stage increased from 100.0 kg (average shell length 44.0 mm) to 433.3 kg (average shell length 72.7 mm) after 570 days. The feed conversion ratios for the first 173 days, the next 320 days, and the last 570 days were 19.6, 22.1, and 24.8, respectively. The growth rate of the average shell length during the on-growing period was 1.5 mm month⁻¹. Total ammonia nitrogen (TAN) concentrations were stabilized below 0.12 mg l⁻¹ in the juvenile recirculating system and 0.14 mg l⁻¹ in the on-growing recirculating system after conditioning of the biofilters.     

The potential for utilizing fouling macroalgae as feed for abalone Haliotis discus hannai

In order to assess the potential of utilizing fouling macroalgae as feed for abalone Haliotis discus hannai, the species, biomass and total stock of fouling macroalgae attached on the aquaculture facility‐lines were investigated and assessed at Sungo Bay, China, in August 2007. The nutritional value of four fouling macroalgae (Codium fragile, Sargassum muticum, Ulva pertusa and Laminaria japonica) and one cultured macroalgae (Gracilaria lemaneiformis) as the diet of abalone was assessed by analysis of the chemical composition of the macroalgae and by measuring bioavailability and digestibility to abalone H. discus hannai under laboratory conditions in August 2007. The results showed that the biomass of fouling macroalgae at the two sites was 243.61 ± 26.23 and 1078.15 ± 50.28 g m^?1 respectively. The contents of protein of G. lemaneiformis and C. fragile were 18.30% and 17.60%, respectively, which were significantly higher than the others. The five macroalgae were accepted by the abalone, and growth energies (P) and growth efficiency (%) were positive. However, significant differences were found among the different macroalgae. The growth efficiencies of abalone show a negative relationship with the levels of dietary lipid and a positive relationship with the protein contents. These results suggest that fouling macroalgae have a great potential to be used as diets of abalone.     

Influences of dietary antimicrobial peptide APSH‐07 on the growth performance,immune response and vibriosis resistance of abalone Haliotis discus hannai Ino

A 115‐day feeding trial and subsequently a 10‐day challenge test with Vibrio parahaemolyticus were conducted to investigate the effects of dietary antimicrobial peptide APSH‐07 on growth performance, immune response, antioxidative status and vibriosis resistance of abalone Haliotis discus hannai (initial body weight: 2.06 ± 0.01 g; initial shell length: 25.42 ± 0.18 mm). Four artificial diets were designed with 0 (artificial diet control), 7.5, 15.0 and 22.5 mg/kg of APSH‐07, respectively. The brown alga Laminaria japonica was used as the live food control. Results showed that the specific growth rates of abalone in the groups with 7.5 and 15.0 mg/kg dietary APSH‐07 were significantly higher than those in the controls (p < .05). The total haemocyte counts and respiratory burst activity in haemolymph of abalone in the group with 7.5 mg/kg of dietary APSH‐07 were significantly higher than those in the groups with 0 and 22.5 mg/kg of dietary APSH‐07 (p < .05). The gene expression levels of Mn‐superoxide dismutase and thioredoxin peroxidase 2, and the activities of glutathione peroxidase in the group with 7.5 mg/kg of dietary APSH‐07 were significantly higher than those in the other groups (p < .05). Cumulative mortality of abalone after the challenge test was significantly decreased in the group with 7.5 mg/kg of dietary APSH‐07 supplementation. Supplementation of 22.5 mg/kg dietary APSH‐07 significantly increased the cumulative mortality. In conclusion, 7.5 mg/kg of dietary APSH‐07 supplementation had the better growth performance, higher antioxidation, immune and disease resistance capacity of abalone. Excessive supplementation of dietary antimicrobial peptide APSH‐07 (22.5 mg/kg) had significantly negative effects. Further studies are needed to determine the optimal level of dietary APSH‐07 supplementation for abalone.     

Use of thraustochytrid <Emphasis Type="Italic">Schizochytrium</Emphasis> sp. as source of lipid and fatty acid in a formulated diet for abalone <Emphasis Type="Italic">Haliotis asinina</Emphasis> (Linnaeus) juveniles

The effects of using thraustochytrid Schizochytrium sp. as source of lipid and fatty acids in a formulated diet on growth, survival, body composition, and salinity tolerance of juvenile donkey’s ear abalone, Haliotis asinina, were investigated. Treatments consisted of diets either containing a 1:1 ratio of cod liver oil (CLO) and soybean oil (SBO) (Diet 1) or thraustochytrid (Diet 2) as source of lipid and fatty acids at 2 % level. Natural diet Gracilariopsis heteroclada (Diet 3) served as the control. No significant difference in growth was observed in abalone fed Diet 3 (SGR: 5.3 % BW day^?1; DISL: 265 μm day^?1) and Diet 2 (SGR: 5.2 % BW day^?1; DISL: 255 μm day^?1). Survival ranged from 78 to 85 % for all treatments and was not significantly different from each other. A 96-h salinity stress test showed highest survival of 84 % in abalone fed Diet 2 compared with those fed diets 1 and 3 (42 %). The high growth rate of abalone fed Diet 2 and high tolerance to low salinity could be attributed to its high DHA content (8.9 %), which resulted to its high DHA/EPA ratio of 10.5 %. These fatty acids play a significant role in abalone nutrition. The fatty acid profile of abalone meat is a reflective of the fatty acid profile of the oil sources in the diet. The present study suggests that the use of Schizochytrium oil in lieu of CLO and SBO can support good growth of abalone which is comparable with abalone fed the natural seaweeds diet.     

Effect of dietary substitution of sea tangle (ST), Laminaria japonica with rice bran (RB) on growth and body composition of juvenile abalone (Haliotis discus)

Dietary substitution effect of sea tangle (ST) with rice bran (RB) on growth and carcass composition of juvenile abalone (Haliotis discus) was determined. Juvenile abalone was acclimated to the experimental conditions for 4 weeks. Seventy juvenile abalone averaging 0.43 g were randomly distributed into each of the 18, 70 L plastic rectangular containers. The experimental diets were fed to abalone once a day at a satiation level with a little leftover. The feeding trial lasted for 16 weeks. Survival of abalone was not affected by dietary substitution of ST with RB. However, weight gain of abalone fed the RB40 diet was higher than that of abalone fed the all other diets except for the RB0 diet. No significant difference in weight gain was found in abalone fed between the RB0 and RB100 diets. SGR of abalone fed the RB40 diet was higher than that of abalone fed the all other diets. Also SGR of abalone fed the RB0 diet was higher than that of abalone fed the RB100 diet, but not different from that of abalone fed the RB20, RB60 and RB80 diets. Moisture, crude protein and ash content of the soft body of abalone were affected by dietary substitution of ST with RB. In conclusion, the 100% ST could be substituted with RB without a retardation of weight gain of abalone when the 20% ST was included into the experimental diet. However, the best growth performance was obtained in abalone fed the RB40 diet substituting 40% ST with RB.     

Effects of alternate starvation and refeeding cycles on food consumption and compensatory growth of abalone, Haliotis asinina (Linnaeus)

The effects of alternate starvation and refeeding on food consumption and compensatory growth of hatchery‐bred abalone, Haliotis asinina (Linnaeus), were determined. Two groups of abalone juveniles (mean shell length = 29 mm, body weight = 5 g) were alternately starved and refed a macro‐alga, Gracilariopsis bailinae at equal duration (5/5 or 10/10) over 140 days. A control group (FR) was fed the seaweed ad libitum throughout a 200‐day experimental period. Starved and refed abalone showed slower growth rates (DGR, 63 and 70 mg/day in the 5/5 and 10/10 groups respectively), as a result of reduced food intake (DFI 15% and 16% day^?1 respectively), after repeated starvation and refeeding cycles. Percentage weight gains (5/5 = 196%, 10/10 = 177%) were significantly lower than that of the control (397%). When refed continuously over 60 days, the starved groups exhibited increased DFI and fed at the rate of 24% and 25% day^?1, which were not significantly different from that of the control at 26% day^?1. At the end of the experiment, no significant differences were observed among three treatments in terms of shell length (range: 46–48 mm), body weight (range 25–28 g), % weight gain (392–465%) and per cent survival (range 87–98%). The results indicated that H. asinina had a complete compensatory growth following a return to full rations after a series of intermittent starvation and refeeding cycles.     

Factors influencing half‐pearl (mabe) production and quality in the red abalone Haliotis rufescens

The factors influencing half‐pearl (mabe) production in the red abalone Haliotis rufescens were investigated, as a strategy to optimize the technology for the development of a pearling industry in Chile. The effects of abalone size (small, large), implant position (dorsal, central, ventral and their combinations), and number of nuclei (one, two, three) were analysed on the quantity, thickness of the nacre layer and quality (shape, colour, lustre, defects) of the mabe produced. The size of abalone did not exert a clear influence on the quantity and quality of mabe, but the position on the shell (firstly) and number of nuclei (secondly) did. More mabe, with thicker nacre, brighter lustre and fewer defects occurred in small or large abalone implanted with only one nucleus on dorsal position. In contrast, small and large abalone implanted in the ventral position formed less mabe, with thinner nacre, poor lustre and more defects. This likely occurs because mantle tissue folds at the ventral position and does not always cover the nucleus, leaving it partially or totally exposed. Most of the pearls were categories AA in small abalone and A in large abalone; only three AAA gems were produced in large abalone with one nucleus on dorsal position or with three nuclei (DCV). Based on these results, we recommend implanting abalone at 60–100 mm shell length, with only one nucleus on the dorsal position.     

Evaluation of cryodamage in small abalone,Haliotis diversicolor,spermatozoa by using a flow cytometer

We used flow cytometry to determine the quality of small abalone, Haliotis diversicolor, sperm before freezing and after thawing. We investigated the effects of cryopreservation on the characteristics of small abalone semen and determined the motility and fertilization capacity of the pre-freezing and post-thawed sperm. The percentages of motility and fertility were 61 ± 2% and 67 ± 1%, respectively, for the post-thawed sperm and 90 ± 4% and 92 ± 0%, respectively, for the pre-freezing sperm. Sperm cells were stained with specific fluorescent dyes to measure plasma and acrosomal membrane integrity, mitochondrial status, oxidation level, DNA compaction, and viability through flow cytometry. The frozen–thawed sperm exhibited significantly higher mitopotential activity (p < 0.05, damaged mitochondria; 25.01 ± 1.18%) and oxidation value (p < 0.01, free radicals; 63.79 ± 3.93%) compared with the pre-freezing sperm. The oxidation level was the most sensitive signal of the cryopreservation-induced small abalone sperm damage. Flow cytometry is valuable for the objective, accurate, and rapid assessment of pre-freezing and post-thaw small abalone sperm quality.     

The effects of hairtail protein hydrolysate–Fe<Superscript>2+</Superscript> complexes on growth and non-specific immune response of red swamp crayfish (<Emphasis Type="Italic">Procambarus clarkii</Emphasis>)

The experiment was conducted to investigate the effects of prepared hairtail protein hydrolysate–Fe²⁺ (PH–Fe²⁺) complexes on growth and non-specific immune responses of crayfish (Procambarus clarkii). The diets with five different levels of PH–Fe²⁺ (200, 400, 600, 800, and 1000 mg/kg) were fed to crayfish for 60 days. The results indicated that the survival rate, weight gain percentage, specific growth rate, and muscle index of crayfish with 400–1000 mg/kg of PH–Fe²⁺ feeding were significantly higher, 9.94–10.10, 8.55–8.72, 0.24–0.29 %/day, and 2.39–3.05 %, respectively, than the control values after 60 days of feeding. Additionally, after 30 days of feeding, 200–400 mg/kg of PH–Fe²⁺ showed no significant (P > 0.05) improvement effect on activities of superoxide dismutase (SOD), phenoloxidase (PO), lysozyme (LSZ), and acid phosphatase (ACP) in serum or hepatopancreas of crayfish. However, significant improvement effects were observed in 800–1000 mg/kg groups. After 60 days of feeding, 400–600 mg/kg of PH–Fe²⁺ significantly (P < 0.05) improved the activity of SOD and LSZ, but did not affect the activity of PO and ACP significantly (P > 0.05). Moreover, the activities of SOD, PO, LSZ, and ACP in serum and hepatopancreas were all significantly enhanced upon treatment with 800–1000 mg/kg of PH–Fe²⁺. For these reasons, PH–Fe²⁺ can be recommended as a supplement in crayfish feed to increase the growth and immunity.     

Changes in growth characteristics of the small abalone Haliotis diversicolor (Reeve, 1846) after one decade in a closed culture system: a comparison with wild populations

Small abalone Haliotis diversicolor (Reeve, 1846) is one of the smallest commercial abalone in the world. The successful application of artificial propagation and mass seed production techniques since the 1980s have resulted in the establishment of well-developed culture systems for small abalone in Taiwan. In the study reported here, we estimated the growth of a population of small abalone after a decade in a closed culture system and its growth characteristics with those of wild populations reported in previous studies. The von Bertalanffy growth equations of the shell length (L) and body weight (W) of cultured abalone were L _t  = 71.73 (1 ? e^{?0.84 (t?0.16)}) and W _t  = 47.70 (1 ? e^{?0.84 (t?0.16)})^3.180, respectively. The instantaneous rate of change for weight had an inflection point at the age of 1.54 years, indicating that cultured abalones reach their apex of body growth around this age. Compared with the wild populations, the cultured population exhibits a significantly smaller maximal shell length (L _∞) and a significantly larger growth coefficient (k). Based on our results, it appears that the artificial culture of generations of small albalone for one decade or more in a closed system could be one of the major factors causing the observed minimization of size in the cultured abalone; this may be an adaptation in which growth is traded off for the larger k.     

Effect of tremata closures on the oxygen consumption rhythm of ezo abalone Haliotis discus hannai

Cultured adults of ezo abalone, Haliotis discus hannai (shell length, 89.3 ± 6.4 mm and flesh dry weight, 13.0 ± 1.6 g; n = 12) were exposed to different temperatures (10 and 25 °C) to determine whether respiration effects were induced by artificial closure of the second and third tremata (respiratory pores). A respirometer was used to determine the oxygen consumption rates (OCRs) as measures of metabolic activity. The closed tremata were the second and third of the four open tremata anterior to the head of the abalone. The OCRs of starved abalone were measured under constant conditions (CC: constant dark and constant temperature) during a 240-h period, consisting of 120 h before and 120 h after the closure of tremata. The endogenous rhythm of the OCRs in cultured ezo abalone exhibited a dominant circadian rhythm (unimodal rhythm) in the latter half of the experimental period and occasionally showed a weaker but similar circatidal rhythm (bimodal rhythm) in the first half of the experimental period regardless of temperature. The results from the present study indicate that the rhythmicity of the OCRs in starved abalone is not affected by closure of the second and third tremata. This study offers essential physiological information for utilizing tremata in developing a tagging technique in abalone.     

Effects of oxygen supersaturation and temperature on juvenile greenlip, Haliotis laevigata Donovan, and blacklip, Haliotis rubra Leach, abalone

Growth and survival of juvenile greenlip (39.03 (SD 3.80) mm (n=524)) and blacklip (31.92 (SD 4.19) mm (n=531) abalone were investigated at high dissolved oxygen levels (95–120% saturation) between 17 and 19°C. Abalone were fed the same artificial diet and each species was contained in groups of approximately 30 individuals within triplicate tanks for each of six treatments and were exposed to flow through water adjusted to give experimental conditions for up to 75 days. Blacklip abalone held at 16.9°C and 97% oxygen saturation grew in shell length significantly faster than all other treatments of blacklip abalone held at 19°C, and significantly faster than blacklip abalone maintained at 111% oxygen saturation and 17.5°C. Both temperature and oxygen saturation significantly affected the survival of this species. Blacklip abalone held at 19°C had significantly lower survival for both 96% oxygen saturation and 120% oxygen saturation, compared with blacklip abalone maintained at either 110% oxygen saturation and 19°C, or for any 17°C treatment. No significant differences were noted for greenlip abalone within the range tested in terms of growth rate, food consumption rate or survival, indicating that greenlip abalone tolerated these conditions better than did blacklip abalone.     

Ability of salmon growth hormone to accelerate somatic growth of juvenil abalone Haliotis discus hannai

ABSTRACT:   The ability of salmon growth hormone (sGH) to accelerate the somatic growth of juvenile abalone Haliotis discus hannai by immersion was examined. After immersion for one hour into a sGH-rich solution at a concentration of 30 mg/L, the sGH immunoreactivity in the body fluid of abalone was maximal after one day, and levels were still detectable at two days. No immunoreactivity was observed in the control group. Following immersion for one hour at one or two-week intervals for 120 weeks into the sGH-rich solution at 30 mg/L, the sGH-immersed abalone exhibited a significant increase in shell length and body weight. On the other hand, abalone immersed into a salmon prolactin (sPRL)-rich solution at 30 mg/L for one hour showed a lower increase in both shell length and body weight than the sGH-immersed abalone. No increases in shell length and body weight were observed in either the bovine serum albumin-immersed abalone or untreated controls. These results provide evidence that sGH can be transported from ambient water into the circulatory system of abalone, and can subsequently improve the somatic growth of juveniles.     

The growth and carbon allocation of abalone (Haliotis discus hannai) of different sizes at different temperatures based on the abalone‐kelp integrated multitrophic aquaculture model

The integration of shellfish and seaweed is an important and successful IMTA model. The IMTA of abalone and kelp has been well‐practiced in Sanggou Bay, China. In the present study, the growth and carbon allocation of abalone (Haliotis discus hannai) of different sizes (S, small; M, medium; L, large) fed kelp (Laminaria japonica) were investigated at different temperatures (10, 14, 18 and 22°C). A two‐way ANOVA showed that both size and temperature significantly affected the specific growth rate (SGR), food consumption (FC), feed conversion ratio (FCR) and apparent digestion rate (ADR) of abalone (p < 0.05), and significant interactions between the two factors were detected (p < 0.05). Curve estimation showed a significant quadratic relationship between SGR and temperature in each size class (p < 0.05). The two‐way ANOVA also showed that both size and temperature significantly affected all the measures of carbon allocation (p < 0.05) except for the carbon lost in metabolism (p > 0.05). All the measures of carbon allocation increased with the increasing temperature. It was concluded that it was better to culture H. discus hannai with a body weight less than 15 g at 20–22°C, and more than 15 g at 15–20°C to achieve good growth. The growth carbon of kelp around the abalone farm should be more than the metabolic carbon expenditure, which means the growth of kelp around the abalone farm should be more than 23.06%–61.91% of food consumption to maintain a carbon sink IMTA system without any carbon release.     

Supplementary oxygen and temperature management during live transportation of greenlip abalone, Haliotis laevigata (Donovan, 1808)

Live greenlip abalone, Haliotis laevigata , are highly valued in Australian export markets with demand increasingly being met with cultured stock. Live transportation of abalone requires the maintenance of favourable conditions within transport containers for periods exceeding 35 h. We examined the combined effects of temperature regulation (ice provision) and of supplemental oxygen (60% and 100% concentrations) on mortality rates of abalone over 7 days following a 35-h simulated live-transport experiment. We also examined the physiological condition of greenlip abalone (oxygen consumption rate, haemolymph pH and weight) during the simulation experiment. The provision of ice and supplementary oxygen reduced abalone mortalities. Omission of ice and supplementary oxygen during the transport simulation resulted in mortality rates ranging from 70% to 100%. The addition of ice to containers with ambient oxygen concentrations decreased average mortality rates by 50%. While supplementary oxygen further reduced these rates, the provision of both ice and 100% oxygen was by far the most effective combination, reducing mortalities to between 2% and 6%. Supplementary oxygen increased oxygen consumption rates of abalone above those transported at ambient oxygen concentrations. Live-transport decreased haemolymph pH in all treatments but was most pronounced in treatments without ice or supplementary oxygen. On average, abalone lost 7–13% of their weight during the simulation but this loss was independent of transport treatment.     

Effect of fishmeal substitution with various animal and/or plant protein sources in the diet of the abalone Haliotis discus hannai Ino

The effect of dietary substitution of animal and/or plant protein sources for fishmeal on the growth and body composition of juvenile abalone was determined. Nine experimental diets in triplicate were prepared: Con, SM, PM, CM, SPM, MB, SM+CM, SM+SPM and CM+SPM diets. A 350 g kg^?1 fishmeal was included in the Con diet, and the whole fishmeal was substituted with a 580 g kg^?1 soybean meal (SM), 335 g kg^?1 poultry meal (PM), 370 g kg^?1 corn gluten meal (CM), 325 g kg^?1 silkworm pupae meal dehydrated (SPM), 590 g kg^?1 meat and bone meal (MB), the combined 290 g kg^?1 soybean meal and 180 g kg^?1 corn gluten meal (SM+CM), 290 g kg^?1 soybean meal and 160 g kg^?1 silkworm pupae meal dehydrated (SM+SPM) and 180 g kg^?1 corn gluten meal and 170 g kg^?1 silkworm pupae meal dehydrated (CM+SPM) diets respectively. All experimental diets were iso‐nitronic and iso‐lipidic. The survival of abalone fed with the SM and SM+SPM diets was higher than that of abalone fed with the CM, SPM, MB and CM+SPM diets. Weight gain of abalone fed with the SM+SPM diet was higher than that of abalone fed with all the other experimental diets, except for that of abalone fed with the SM+CM diet. The combined soybean meal and corn gluten meal (SM+CM) or silkworm pupae meal (SM+SPM) could be replaced with the whole fishmeal in the diet for abalone and improved its performance.