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1.
Seawater sampling from three abalone farms in New Zealand showed average ambient concentrations of dissolved inorganic phosphate (Pi) varying between 2.36 and 238 μM. The Pi concentration within each system appeared to be directly linked to the percentage of water that was replaced each day. An experiment was conducted over 5 months to examine the effect of elevated Pi concentrations on the growth of two juvenile abalone (Haliotis iris) size classes (small: average shell length=23.9 ± 0.1 and large: average shell length=61.9 ± 0.1 mm). Abalone from each size class were exposed to Pi concentrations of; (a) natural incoming seawater (average 0.12 ± 0.12 μM), (b) 10.7 ± 1.3 μM, (c) 60.9 ± 5.8 μM and (d) 113.1 ± 5.6 μM. The results suggest that over the course of the 5‐month period of this experiment there was a significant negative impact on growth (shell length and wet weight) when the smaller size class of abalone were exposed to Pi concentrations greater than 10.7 μM and for the large size class of abalone when exposed to greater than 60.9 μM Pi. However, elevated Pi concentrations did not significantly impact on abalone survival during the course of the experiment.  相似文献   

2.
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.  相似文献   

3.
Reduced seawater pH and elevated pCO2 are important considerations in tank‐based abalone aquaculture, while sea‐based farms may be at risk to ocean acidification reductions in pH. Juvenile Haliotis iris (5–13 and 30–40 mm shell length) were reared in two, 100‐day experiments at ambient pHnbs (~ 8.1, 450 μatm CO2), pH 7.8 (~1000 μatm CO2) and pH 7.6 (~1600 μatm CO2). Seawater pH was measured and adjusted automatically by bubbling CO2 into water in replicated flow through tanks. Two separate trials were run, in winter (8.8°C) and summer (16.5°C). Survival and growth were monitored every 30 days, and post experiment measurements of morphometrics and respiration rate undertaken. Growth of shell length and wet weight were negatively affected by reduced pH, with a 2 to 3‐fold reduction in growth of both size classes between ambient and pH 7.6 treatments in the summer experiment. For small juveniles, growth reductions were in conjunction with decreases to shell weight, while large juveniles showed greater resilience in shell production. No changes to respiration rate occurred, suggesting that juveniles may maintain physiological functioning while tolerating dissolution pressure or that they are unable to upregulate metabolism to compensate for pH effects. These data show that CO2 driven reductions in pH can impact growth, metabolism and biomineralization of abalone, and indicate that water quality and ocean acidification are of importance in aquaculture of the species.  相似文献   

4.
The thermoregulatory behaviour of green abalone Haliotis fulgens and pink abalone H. corrugata was investigated. Haliotis fulgens juveniles ranging in wet weight from 3.0 to 3.3 g and from 28.7 to 30.5 mm shell length and of H. corrugata 2.0 g and 25.7 mm in shell length were exposed to 19°C for 30 days in a flow‐through water system. Temperature preference was determined in a horizontal thermal gradient and was found to be 25.4°C for green abalone and 25.0°C for pink abalone. Displacement velocity was 4.3 cm h−1 for H. fulgens and 12.8 cm h−1 for H. corrugata. The optimum temperature for growth calculated for both abalone species was 24.6 and 24.5°C respectively. The critical thermal maxima (CTMax) of H. fulgens and H. corrugata were determined as a measure of thermal tolerance. Abalones were subjected to increasing water temperatures at a rate of 1°C on 30 min until they detached from the substrate. The CTMax at 50% were 33.6 and 32.0°C for green and pink abalone respectively. The results are discussed in relation to site selection and commercial rearing.  相似文献   

5.
Temperature effects vary throughout the ontogeny, but are proportionally more variable during the early life stages than in older fish. The larvae of a few species have been studied but contrasting trajectories were observed, thereby making it difficult to predict how temperature impacts on the growth, survival and size heterogeneity in a particular species. This study examined these interactions in young [0.9 mg–1 g wet mass (WM)] Pangasianodon hypophthalmus, one of the most extensively cultured tropical fish. Fish were raised at five temperatures from 23 to 33 °C in a recirculated water system, fed in excess with a high‐energy feed (Artemia then a formulated feed, >50% protein), and examined at 1‐day (first feeding days) or 4‐day intervals (older fish). The temperature that produced the fastest growth (T°opt) was 31 °C at the start of exogenous feeding (0.9 mg); it increased to 32.7 °C at 8 mg then decreased by 0.7 °C for each 10‐fold increase of WM. Size heterogeneity was lower and survival was higher (70–85% from 0.9 mg to 1 g) when the temperature was close to T°opt. Comparisons with other species suggest that the slope of the relationship between T°opt and fish size has a strong latitudinal component, and may also reflect the fish sensitivity to oxygen.  相似文献   

6.
The protein requirements for optimal growth and health of juvenile New Zealand black‐footed abalone (Haliotis iris) under different water temperatures were investigated. Six diets with different crude protein amounts (0, 10, 20, 30, 40 and 45%) and two temperature regimes (13–21 and 8–16 °C) were used to culture juvenile abalone over a 4‐month period. Growth (shell lengths and animal weights) and health (survival, activity and mucous production) parameters were recorded for animals within all protein and temperature combinations. Proximate analyses and amino acid profiles were also performed on the diets, soft bodies (including gonad), and shells to evaluate the overall nutrient contents (diet and animal) and requirements (animal). The results indicate that the protein requirements for juvenile H. iris are higher when the environmental temperatures are low. Thus, increasing the dietary protein level results in better growth [i.e. increase in soft body (including gonad) crude protein and mean protein gain] and health (i.e. more goblet cells and thicker epithelial layers). Results from amino acid profiles in abalone soft bodies (including gonad) and shells show that these parameters did not change considerably with different dietary protein levels, but temperature did affect the concentration of several amino acids in both soft bodies (including gonad) and shells.  相似文献   

7.
Formulated abalone feeds used by the culture industry are believed to be unsuitable for use at elevated water temperatures (>20 °C). The aim of this study was to develop a feed that could safely be fed to abalone cultured at elevated water temperatures by optimizing dietary protein/energy levels. Abalone (54.90 ± 0.08 mm; 28.99 ± 0.16 g) were cultured at either 18, 22 or 24 °C, and fed diets containing graded levels of protein (18–26%) and energy (11.6–16.2 MJ kg?1). Abalone growth was temperature dependent, declining from 4.33 g month?1 at 18 °C to 0.77 g month?1 at 24 °C. Shell length and weight gain were independent of dietary protein, provided that the digestible energy content of the diet was not lower than 13.5 MJ kg?1. Dietary energy levels below 13.5MJ kg‐1 resulted in significant reductions in shell growth, weight gain and increased mortality from 5% to 27%. Feed consumption of the 22% and 26% protein diets with 11.6 MJ kg?1 was significantly higher (0.53 ± 0.04 and 0.55 ± 0.04% bd. wt. day?1 respectively) compared with abalone fed the 16.2 MJ kg?1 diets at the same protein levels (combined mean of 0.45 ± 0.04% bd. wt. day?1) indicating that consumption was linked to energy requirement. The growth and mortality results suggest that abalone cultured at these temperatures have a dietary digestible energy requirement of at least 13.5 MJ kg?1.  相似文献   

8.
The preferred temperature and critical thermal maximum of Australian blacklip abalone, Haliotis rubra (Leach), and greenlip abalone, Haliotis laevigata (Leach), were found to differ only slightly; the blacklip abalone exhibited lower temperature tolerance and preference, as expected from its habitat distribution. Preferred temperatures were 16.9 and 18.9°C, and 50% critical thermal maxima were 26.9 and 2 7.5°C for blacklip and greenlip abalone, respectively. The optimum temperatures for growth calculated from each of these indices and averaged were 17.0 and 18.3°C, respectively.  相似文献   

9.
Live transport of hatchery‐produced juvenile donkey's ear abalone Haliotis asinina Linne was examined to evaluate the effect of transportation on the survival of juvenile abalone. Simulated transport experiments were conducted to determine the appropriate temperature using 5, 10 and 20 g L?1 of ice to air volume for 8 h and the appropriate size using two size groups (Size A, 15–20 mm, 0.5–1.3 g, and Size B, 30–35 mm, 5.3–8.5 g) up to 24‐h out‐of‐water live transport. Survival was significantly higher (P<0.001) when 10 g L?1 of ice was used to decrease the temperature to the range of 17–23 °C. At this temperature, both size groups subjected to simulated transport for 8 and 10 h had 100% survival after 48 h, while mortality occurred in abalones subjected to 16 and 24 h of simulated transport. The Size B abalone subjected to 24 h of transport had significantly higher survival (64.4 ± 2.9%) (P<0.001) than the Size A abalone (5.5 ± 1.6%) after 48 h. Live juvenile abalone were successfully transported to the field applying the protocols developed in the lab experiment. This study serves as a guide for handling and shipping live juvenile abalone.  相似文献   

10.
Feasibility of offshore co‐culture of abalone and sea cucumber was investigated in Northern China. Survival and growth of abalone, Haliotis discus hannai Ino, and sea cucumber, Apostichopus japonicus, co‐cultured in abalone cages from suspended longlines, in the offshore area, were examined. Abalone and sea cucumbers were co‐cultured at density ratios of both 3:1 and 6:1 for 1 yr. Abalone were fed with fresh kelp and no additional feed was given to sea cucumbers. Survival of abalone and sea cucumber was 100% for all treatments. Abalone and sea cucumber grew well; the body weight (BW) of abalone and sea cucumber was nearly doubled and had reached a commercial size. There were no significant differences in the growth rates for both abalone and sea cucumber between the two density treatments. The specific growth rate of BW of abalone (SGRbw) was highest in June, with a value of 0.536%/d. Growth rate of sea cucumber (SGRsc) was highest in December, reached 1.84%/d, with an annual average SGRsc of 0.182%/d. Results suggested that the offshore co‐culture of abalone and sea cucumber was feasible offshore. The co‐culture of abalone with sea cucumbers may provide an additional valuable crop without additional financial input.  相似文献   

11.
The growth of juvenile abalone in aquaculture is known to be affected by density as a result of competition for food and decreases in water quality. Our results suggest that behaviour is also affected by density and this also has a significant impact on the growth of individual abalone. 1800 juveniles of Haliotis rubra were individually tagged and reared for 5 months in 12 gravity-fed tanks at two levels of density. The experimental design allowed the differentiation of the direct from the indirect effects of density. The abalone growth and distribution was monitored monthly along with the water quality. The distribution of abalone during daytime was closely related to the availability of preferred shelter space. The percentage of abalone stacked on the top of others increased with density. Preferred shelter space was characterized by low light intensity and a corner or edge for the abalone to rest against. Hides at the ends of the tanks were not occupied as much as others. Abalone were found crawling on the side of the tank during daytime when tanks were shaded. Abalone juveniles of 15–60 mm showed fidelity to their resting shelter during daytime but this fidelity was significantly reduced at the higher density. Shading of the tanks totally changed the distribution of the abalone and their daytime behaviour. Competition for shelter space reduced growth more than water quality. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

12.
The critical thermal maximum of juvenile spotted seatrout (SL range 18–33 mm) was determined using a temperature increase of +0.26°C per hour. The critical thermal maximum (water temperature that was lethal to 50% of the test fish [LT50]) for trial 1 was LT50 = 38.8°C, LT50 = 39.4°C for trial 2, and LT50 = 38.9°C for trial 3. Critical thermal maximums differed significantly (P < 0.05) between trials 2 and 3, whereas trial 1 did not differ among trials. This difference correlated with body size, where fish in trial 2 were significantly larger (P < 0.05) (mean = 27.6 ± 2.0 mm in SL) (mean ± SE) than the fish of trials 1 (mean = 23.1 ± 0.5 mm in SL) and 3 (mean = 21.5 ± 0.7 mm in SL), suggesting positive size dependence in the critical thermal maximum.  相似文献   

13.
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14.
The experiment was conducted to assess the growth of juvenile greenlip abalone Haliotis laevigata fed a range of Ulva rigida diets with different nitrogen contents and an artificial pelleted diet. The minimal nutrient concentration resulting in significant enrichment of U. rigida was 2.25 mg N l?1. The maximum nitrogen content obtained by U. rigida in this study was 6.099%, which resulted from an inorganic nutrient concentration of 7 mg N l?1. However, no further significant increase in enrichment occurred from nutrient concentrations of 10 and 15 mg N l?1. Abalone specific growth rate in shell length (SGRL) and wet weight (SGRW) and foot muscle yield were significantly higher for abalone fed the artificial diet compared to those fed any U. rigida diet. Abalone fed U. rigida enriched in less than 15 mg N l?1 had similar growth rates compared to abalone fed unenriched U. rigida. Abalone fed the artificial diet contributed a higher percentage of weight gain into the valuable foot muscle. The foot muscle moisture content of abalone fed the artificial diet was significantly lower than that of abalone fed any U. rigida diet. The conclusions reached by this study should assist Australian abalone producers in assessing the potential benefits of using U. rigida as an effluent biofilter and subsequent food source for the commercially important juvenile greenlip abalone.  相似文献   

15.
Although abalone fisheries in South Africa have existed since 1949, cultivation started by successful spawning of captured specimens in 1981 to produce spat and juveniles. Twelve abalone farms, with an estimated investment of US$12 million, have since been established on the coast of South Africa, with a projected production of 500–800 tons. While Haliotis midae could reach a maximum size of about 200 mm shell length at an age of over 30 years in the wild, farm production is concentrating on an average size of 100 mm after 5 years. Growth rates of 0.08–4.5% body weight day ?1 for abalone of 10–17 mm shell length have been found under stimulated farming conditions on formulated diets, while the corresponding feed conversion ratio (FCR) was 0.9–2.4. Growth rate, FCR and protein efficiency ratio decline at water temperatures above 20 °C. Anaesthetics, for example magnesium sulphate, are used to prevent injury during removal from tanks. Prostrate diatoms, such as Cocconeis sublittoralis (Hendey), Amphora proteoides (Hustedt) and Achnanthes brevipes (Agardh) are preferred after the larval stage (5–7 days, depending on temperature) are finished. South Africa abalone growers prefer formulated feeds in pellet form, which is convenience and cost favourable to farm operations and management. Although fish meal has been found to be the most suitable protein source for inclusion in formulated diets, plant proteins such as soy bean meal, cottonseed meal and sunflower meal presented good growth and apparent protein digestibility. The parasite sabellid polychaete, Terebrasabella heterouncinata, recently named by Australian and American researchers, is indigenous to a variety of South African intertidal molluscs and impedes growth by causing irritation beneath the mantle in abalone. Prevention to some degree is possible by high standards of hygiene and husbandry of abalone in the tanks, but new techniques to control large infestations now include ultrasound. In spite of a reputation for toughness, abalone meat frozen immediately after shucking is tender relative to red meat. The success of abalone farming in South Africa has been as a result of a high degree of cooperation between the private sector and government‐backed research institutions, and it is anticipated that this collaboration will continue.  相似文献   

16.
ABSTRACT

To determine the minimum age/size at which Southern Flounder, Paralichthys lethostigma, can safely be moved to outdoor rearing facilities in Texas, we examined survival of simulated temperature drops in two distinct life stages: premetamorphic larvae and two size classes of postmetamorphic juveniles (small = 9.8 ± 0.3 mm in TL; large = 19.7 ± 0.6 mm). Temperature was lowered by ?0.33°C/h to 4°C, 7°C, or 10°C, held for 48 h and then raised at +0.33°C/h back to normal rearing temperature. Fish were monitored daily for survival. Larger postmetamorphic flounder had high survival for all temperature treatments (89%–100% survival), whereas both premetamorphic larvae and smaller postmetamorphic juveniles had low survival (<30%) for all temperature treatments.  相似文献   

17.
The neutral red retention (NRR) assay was used to evaluate the effects of air exposure on lysosomal membrane integrity in the haemolymph of blacklip abalone, Haliotis rubra, and its subsequent recovery in water. After acclimation in 16°C water for 7 days, abalone were exposed to an air temperature of 7, 16 or 23°C for 12 h in the air exposure experiment or to these three air temperatures, e.g., for 12, 24 or 36 h, followed by re‐immersion in 16°C water in the lysosomal membrane stability recovery experiment. Statistical analyses of the air exposure experiment showed that when abalone were exposed to different air temperatures (7, 16 or 23°C), the lysosomal membrane stability was significantly affected by the air temperature, the exposure duration and their interaction. Air temperature similar to the acclimation temperature had a significantly lower impact on the lysosomal membrane stability within the initial 4.5 h in comparison with the other two temperatures in the same period. The lysosomal membrane stability recovery experiment showed that after air exposure durations of 12, 24 or 36 h, the re‐stabilization of the lysosomal membrane was faster in the animals exposed to lower temperatures than those exposed to higher temperatures. The recovery of the lysosomal membrane stability in abalone exposed to lower 7°C air temperature was not significantly affected (F2, 66=0.251, P=0.779) by the exposure durations (12, 24 and 36 h) used in this study. Alternatively, the lysosomal membrane stability in abalone exposed to higher air temperatures of 16 or 23°C recovered at a faster rate when subjected to shorter durations of air exposure (F2, 66=3.663, P=0.031 and F1, 44=17.057, P<0.001 for 16 and 23°C respectively).  相似文献   

18.
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.  相似文献   

19.
Effect of feeding regime on compensatory growth of juvenile abalone (Haliotis discus hannai) fed on the dry sea tangle (Laminaria japonica) was determined. Thirty juvenile abalone averaging 15.7 g were randomly stocked into 18 50‐L plastic rectangular containers each. Six treatments were prepared in triplicate: Abalone were fed the dry sea tangle once a day at a satiation level with a little leftover for 16 wk as the control (Con) and other abalone were fed the dry sea tangle once a day at a satiation level with a little leftover for 15 wk after 1‐wk starvation (S1 treatment), 14 wk after 2‐wk starvation (S2 treatment), 13 wk after 3‐wk starvation (S3 treatment), 12 wk after 4‐wk starvation (S4 treatment), and 10 wk after 6‐wk starvation (S6 treatment), respectively. A linear relationship between weight change of abalone and wk of starvation was observed: Y (Weight of abalone) = ?0.17X (Wk of starvation) + 15.89 (R 2 = 0.9462) (P < 0.0001). The highest survival of abalone was achieved in the S2 treatment, but not different from that of abalone in the Con, S1 and S3 treatments. Weight gain of abalone in the Con treatment was higher than that of abalone in the S4 and S6 treatments. Abalone fed on the dry sea tangle seemed to be able to achieve full compensatory growth up to 3‐wk starvation.  相似文献   

20.
Effects of feed type and temperature on growth and body composition of juvenile abalone, Haliotis discus hannai Ino, were determined. A 2 (feed types: formulated diet and dry sea tangle) × 3 (temperature conditions: 20, 23 and 26 C) factorial design with triplicate was used. Seventy juvenile abalone averaging 4.7 g were randomly distributed into each of 18, 50‐L plastic rectangular containers. Six containers were placed into each temperature condition of three 1.3 ton concrete flow‐through raceway systems. Abalone were daily fed with either the formulated diet or dry sea tangle once a day to satiation level. Survival was affected by feed type, but not by temperature. Weight gain of abalone was affected by both feed type and temperature. Regardless of temperature, weight gain of abalone fed the formulated diet was better than that of abalone fed the dry sea tangle. Shell length and width were affected by feed type, but not by temperature. In conclusion, weight gain of abalone was affected by both feed type and temperature, but feed type had a stronger effect than temperature. The formulated diet achieved better growth of abalone than the dry sea tangle regardless of temperature and 20 C seemed to be recommendable for abalone among temperature tested.  相似文献   

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