Effects of dietary carbohydrates sources on lipids compositions in abalone, Haliotis discus hannai Ino

A study was conducted to evaluate the effects of dietary carbohydrates on triglyceride, cholesterol and fatty acid concentrations in abalone, Haliotis discus hannai Ino. Six semi-purified diets with different carbohydrates (dextrin, heat-treated wheat starch, wheat starch, corn starch, tapioca starch and potato starch, respectively), all containing a carbohydrate level of 33.5%, were fed to abalone (initial shell length: 29.98 mm ± 0.09 mm; initial weight: 3.42 g ± 0.02 g) for 24 weeks in a recirculation system. The results indicate that serum triglyceride concentrations were significantly (P < 0.05) higher in the abalone fed with dextrin, heat-treated wheat starch and wheat starch than those fed with corn starch, and serum cholesterol concentrations were significantly (P < 0.05) higher in the abalone fed with dextrin, heat-treated wheat starch than those fed with corn starch. Fatty acid C20:4n-6 in the foot muscles were significantly (P < 0.05) lower in the abalone fed with dextrin than those fed with wheat starch, corn starch, tapioca starch and potato starch. Fatty acid C20:4n-6 in hepatopancreas was significantly (P < 0.05) lower in abalone fed with heat-treated wheat starch than those fed with corn starch, tapioca starch and potato starch. Fatty acid C22:6n-3 in the foot muscles were significantly (P < 0.05) lower in the abalone fed with dextrin and heat-treated wheat starch than those fed with wheat starch and potato starch.     

Effects of vitamin C deficiency or excess on growth performance,anti-oxidative response and fatty acid composition of juvenile abalone Haliotis discus hannai Ino

Journal of Oceanology and Limnology - A 240-day feeding trial was conducted to investigate the effects of dietary vitamin C on growth performance, anti-oxidative response, and fatty acid...     

Effects of dietary menadione on the activity of antioxidant enzymes in abalone, Haliotis discus hannai Ino

A 240-day growth experiment in a re-circulating water system was conducted to investigate the effects of dietary menadione on the growth and antioxidant responses of abalone Haliotis discus hannai Ino. Triplicate groups of juvenile abalone (initial weight: 1.19 ± 0.01 g; shell length: 19.23 ± 0.01 mm) were fed to satiation with 3 semi-purified diets containing 0, 10, and 1 000 mg menadione sodium bisulfite (MSB)/kg, respectively. Results show that there were no significant differences in the rate of weight gain or in the daily increment in shell length of abalone among different treatments. Activities of superoxide dismutase (SOD), glutathione peroxidase (GPX), glutathione S-transferase (GST) and glutathione reductase (GR) in viscera were significantly decreased with dietary menadione. However, activities of these enzymes except for GPX in muscle were increased. Therefore, antioxidant responses of abalone were increased in muscle and decreased in viscera by dietary menadione.     

Sequences characterization of microsatellite DNA sequences in Pacific abalone (Haliotis discus hannai)

The microsatellite-enriched library was constructed using magnetic bead hybridization selection method, and the microsatellite DNA sequences were analyzed in Pacific abalone Haliotis discus hannai. Three hundred and fifty white colonies were screened using PCR-based technique, and 84 clones were identified to potentially contain microsatellite repeat motif. The 84 clones were sequenced, and 42 microsatellites and 4 minisatellites with a minimum of five repeats were found (13.1% of white colonies screened). Besides the motif of CA contained in the oligoprobe, we also found other 16 types of microsatellite repeats including a dinucleotide repeat, two tetranucleotide repeats, twelve pentanucleotide repeats and a hexanucleotide repeat. According to Weber(1990), the microsatellite sequences obtained could be categorized structurally into perfect repeats (73.3%), imperfect repeats(13.3%), and compound repeats (13.4%). Among the microsatellite repeats, relatively short arrays (＜ 20 repeats) were most abundant,accounting for 75.0%. The largest length of microsatellites was 48 repeats, and the average number of repeats was 13.4. The data on the composition and length distribution of microsatellites obtained in the present study can be useful for choosing the repeat motifs for microsatetlite isolation in other abalone species.     

Heterosis and combining ability: a diallel cross of three geographically isolated populations of Pacific abalone Haliotis discus hannai Ino

We conducted a complete diallel cross among three geographically isolated populations of Pacific abalone Haliotis discus hannai Ino to determine the heterosis and the combining ability of growth traits at the spat stage. The three populations were collected from Qingdao (Q) and Dalian (D) in China, and Miyagi (M) in Japan. We measured the shell length, shell width, and total weight. The magnitude of the general combining ability (GCA) variance was more pronounced than the specific combining ability (SCA) variance, which is evidenced by both the ratio of the genetic component in total variation and the GCA/SCA values. The component variances of GCA and SCA were significant for all three traits (P<0.05), indicating the importance of additive and non-additive genetic effects in determining the expression of these traits. The reciprocal maternal effects (RE) were also significant for these traits (P<0.05). Our results suggest that population D was the best general combiner in breeding programs to improve growth traits. The DM cross had the highest heterosis values for all three traits.     

Effects of Dietary Carbohydrates Sources on Lipids Compositions in Abalone, Haliotis discus hannai Ino

A study was conducted to evaluate the effects of dietary carbohydrates on triglyceride, cholesterol and fatty acid concentrations in abalone, Haliotis discus hannai Ino. Six semi-purified diets with different carbohydrates (dextrin, heat-treated wheat starch, wheat starch, corn starch, tapioca starch and potato starch, respectively), all containing a carbohydrate level of 33.5%, were fed to abalone (initial shell length: 29.98 mm±0.09 mm; initial weight. 3.42 g±0.02 g) for 24 weeks in a recirculation system. The results indicate that serum triglyceride concentrations were significantly (P<0.05) higher in the abalone fed with dextrin, heat-treated wheat starch and wheat starch than those fed with corn starch, and serum cholesterol concentrations were significantly (P<0.05)higher in the abalone fed with dextrin, heat-treated wheat starch than those fed with corn starch. Fatty acid C20:4n-6 in the foot muscles were significantly (P<0.05) lower in the abalone fed with dextrin than those fed with wheat starch, corn starch, tapioca starch and potato starch. Fatty acid C20:4n-6 in hepatopancreas was significantly (P<0.05) lower in abalone fed with heat-treated wheat starch than those fed with corn starch, tapioca starch and potato starch. Fatty acid C22:6n-3 in the foot muscles were significantly (P< 0.05) lower in the abalone fed with dextrin and heat-treated wheat starch than those fed with wheat starch and potato starch.     

AVAILABILITY OF PHOSPHORUS FROM SELECTED INORGANIC PHOSPHATES TO JUVENILE ABALONE, HALIOTIS DISCUS HANNAI INO

The availability of phosphorus to juvenile abalone,Haliotis discus hannai from primary, secondary and tertiary calcium phosphate, primary sodium or potassium phosphate separately or in combination was determined in a 120-day feeding trial. Seven semi-purified diets were formulated to contain relatively constant dietary phosphorus, ranging from 0.78%–0.82%. The concentrations of dietary phosphorus were presumed to be slightly below the requirement for abalone. A brown alga,Laminaria japonica, was used as a control diet. Abalone juveniles of silimar size (average weight 1.18 g; average shell length 18.74 mm) were distributed in a single-pass, flow-through system using a completely randomized design with eight treatments and three replicates each treatment. The survival ranged from 71.1% to 81.1%, and was not significantly (P>0.05) related to dietary treatment. However, the weight gain rate (41.72%–65.02%), daily increment in shell length (36.87–55.07 μm) and muscle RNA-DNA ratio (3.44–4.69) were significantly (P<0.05) affected by dietary treatment. Soft body alkaline phosphatase activity (10.9–19.8 U/g wet tissue) and carcass levels of lipid (7.71%–9.33%) and protein (46.68%–49.35%) were significantly (P<0.05) responsive to available phosphorus of the diets. Dietary treatment had significant effect (P<0.05) on concentrations of phosphorus in the whole body (WB) and soft body (SB). Apparent digestibility coefficients (45%–97%) of phosphorus were also significantly (P<0.05) different between dietary treatments. The results indicated that among these inorganic compounds, primary calcium, potassium and sodium phosphates separately or in combination could be utilized effectively by juvenile abalone as dietary phosphorus sources (availability ranging from 87%–97%). However, secondary and tertiary calcium phosphates were found to be low in availability, the values being 45% and 77%, repectively. Project 39670572 supported by the Natural Science Foundation of China (NSFC).     

Acclimation-dependent expression of heat shock protein 70 in Pacific abalone (Haliotis discus hannai Ino) and its acute response to thermal exposure

Heat shock protein 70 (Hsp70) is one important member of heat shock protein (Hsp) family that is responsible for various stresses, especially thermal stress. Here we examined the response of Hsp70 gene to both chronic and acute thermal exposure in Pacific abalone (Haliotis discus hannai Ino). For the chronic exposure, abalones were maintained at 8, 12, 20, and 30°C for four months and their mRNA levels were measured. The highest mRNA level of Hsp70 gene relative to actin gene was detected in the 30°C-acclimated group, followed by the 8°C-acclimated group and then the 12°C- and 20°C-acclimated groups. After the long-term acclimation, gills from each of the above acclimation groups were dissected and exposed to different temperatures between 8°C and 38°C for 30 min. Hsp70 expression in gills acclimated to different temperatures responded differentially to the same temperature exposure. The incubation temperature that induced maximum Hsp70 mRNA expression was higher in the higher temperature acclimation groups than lower temperature groups. Pacific abalones could alter the expression pattern of Hsp70 gene according to environmental thermal conditions, through which they deal with the stress of thermal variations.     

Sequences Characterization of Microsatellite DNA Sequences in Pacific Abalone(Haliotis discus hannai)

1 Introduction Microsatellites or simple sequence repeats (SSRs) are tandemly repeated motifs of one to six bases found in all prokaryotic and eukaryotic genomes analysed to date (Zane et al., 2002). Due to their hyper-variable and co-dominant nature, relatively high abundance and random distribution in the genome, microsatellites are among the most efficient class of molecular markers. Such repeats display high polymorphism because of variation in repeat length and can be rapidly analysed t…     

Characterization of defensin gene from abalone Haliotis discus hannai and its deduced protein

Defensin is one of preserved ancient host defensive materials formed in biological evolution. As a regulator and effector molecule, it is very important in animals' acquired immune system. This paper reports the defensin gene from the mixed liver and kidney cDNA library of abalone Haliotis discus hannai Ino. Sequence analysis shows that the gene sequence of full-length cDNA encodes 42 mature peptides (including six Cys), molecular weight of 4 323 Da, and pI of 8.02. Amino acid sequence homology analysis shows that the peptides are highly similar (70% in common) to other insects defensin. Because of a typical insect-defensin structural character of mature peptide in the secondary structure, the polypeptide named Haliotis discus defensin (hd-def), a novel of antimicrobial peptides, belongs to insects defensin subfamily. The RT-PCR result of Haliotis discus defensin shows that the gene can be expressed only in the hepatopancreas by Gram-negative and positive bacteria stimulation, which is ascribed to inducible expression. Therefore, it is revealed that the Haliotis discus defensin gene expression was related to the antibacterial infection of Haliotis discus hannai Ino.     

Characterization of genic microsatellite markers derived from expressed sequence tags in Pacific abalone (Haliotis discus hannai)

Simple sequence repeat (SSR) markers were developed from the expressed sequence tags (ESTs) of Pacific abalone (Haliotis discus hannai).Repeat motifs were found in 4.95% of the ESTs at a frequency of one repeat every 10.04 kb of EST sequences,after redundancy elimination.Seventeen polymorphic EST-SSRs were developed.The number of alleles per locus varied from 2-17,with an average of 6.8 alleles per locus.The expected and observed heterozygosities ranged from 0.159 to 0.928 and from 0.132 to 0.922,respective...     

Characterization of genic microsatellite markers derived from expressed sequence tags in Pacific abalone (Haliotis discus hannai)

Simple sequence repeat (SSR) markers were developed from the expressed sequence tags (ESTs) of Pacific abalone (Haliotis discus hannai). Repeat motifs were found in 4.95% of the ESTs at a frequency of one repeat every 10.04 kb of EST sequences, after redundancy elimination. Seventeen polymorphic EST-SSRs were developed. The number of alleles per locus varied from 2–17, with an average of 6.8 alleles per locus. The expected and observed heterozygosities ranged from 0.159 to 0.928 and from 0.132 to 0.922, respectively. Twelve of the 17 loci (70.6%) were successfully amplified in H. diversicolor. Seventeen loci segregated in three families, with three showing the presence of null alleles (17.6%). The adequate level of variability and low frequency of null alleles observed in H. discus hannai, together with the high rate of transportability across Haliotis species, make this set of EST-SSR markers an important tool for comparative mapping, marker-assisted selection, and evolutionary studies, not only in the Pacific abalone, but also in related species.     

An AFLP Genetic Linkage Map of Pacific Abalone （Haliotis discus hannai）

A genetic linkage map of Pacific abalone （Haliotis discus hannai） was constructed using AFLP markers based on a two-way pseudo-testcross strategy in a full-sib family. With 33 primer combinations, a total of 455 markers （225 from the female parent and 230 from the male parent） segregated in a 1 ： 1 ratio, corresponding to DNA polymorphism： heterozygous in one parent and null in the other. The female framework map consisted of 174 markers distributed in 18 linkage groups, equivalent to the H. discus hannai haploid chromosome number, and spanning a total length of 2031.4 cM, with an average interval of 13.0 cM between adjacent markers. The male framework map consisted of 195 markers mapped on 19 linkage groups, spanning a total length of 2273.4cM, with an average spacing of 12.9cM between adjacent markers. The estimated coverage for the framework linkage maps was 81.2% for the female and 82.1% for the male, on the basis of two estimates of genome length. Fifty-two markers （11.4%） remained unlinked. The level of segregation distortion observed in this cross was 20.4%. These linkage maps will serve as a starting point for linkage studies in the Pacific abalone with potential application for marker-assisted selection in breeding programs.     

Comparative transcriptome analysis of abalone Haliotis discus hannai with green and gray egg colors

Journal of Oceanology and Limnology - Haliotis discus hannai is an important marine economic species in China. Its egg color was found to be associated with economic traits, which provides a new...     

Dietary guaiacol improves the growth of juvenile abalone, <Emphasis Type="Italic">Haliotis discus hannai</Emphasis> Ino

We conducted a preliminarily study on the effects of dietary guaiacol on growth performance of abalone, Haliotis discus hannai Ino. Seven semi-purified diets were formulated with graded levels of guaiacol (0, 5, 10, 50, 100, 500, and 1 000 mg kg⁻¹). Abalone (initial weight: 0.29 ± 0.01 g; initial shell length: 8.55 ± 0.27 mm) were fed with these diets in a re-circulated water system for 152 days. Guaiacol significantly improved the specific growth rate (SGR) (P<0.05); excessive dietary guaiacol (1 000 mg kg⁻¹) led to significantly high mortality (P<0.05), and lipid content in the soft body increased significantly after dietary guaiacol (P<0.05). Activities of catalase and phenoloxidase (PO) in the viscera were significantly stimulated by dietary guaiacol (P<0.05). Broken-line analysis based on SGR indicated that the minimum dietary guaiacol for the optimal growth of juvenile abalone is 15.43 mg kg⁻¹.     

Effects of waterborne Cu and Cd on anti-oxidative response,lipid peroxidation and heavy metals accumulation in abalone Haliotis discus hannai ino

The aim of this study was to compare the effects of waterborne copper(Cu) and cadmium(Cd) on survival, anti-oxidative response, lipid peroxidation and metal accumulation in abalone Haliotis discus hannai. Experimental animals(initial weight: 7.49 g ± 0.01 g) were exposed to graded concentrations of waterborne Cu(0.02, 0.04, 0.06, 0.08 mg L-1) or Cd(0.025, 0.05, 0.25, 0.5mg L-1) for 28 days, respectively. Activities of the anti-oxidative enzymes(catalase, CAT; superoxide dismutase, SOD; glutathione peroxidases, GPx; glutathione S-transferase, GST), contents of the reduced glutathione(GSH) and malondiadehyde(MDA) in the hepatopancreas, and metal accumulation in hepatopancreas and muscles were analyzed after 0, 1, 3, 6, 10, 15, 21, 28 days of metal exposure, respectively. Results showed that 0.04 mg L-1, 0.06 mg L-1 and 0.08 mg L-1 Cu caused 100% death of abalone on the 21 st, 10 th and 6th day, respectively. However, no dead abalone was found during the 28-day waterborne Cd exposure at all experimental concentrations. Generally, activities of SOD and GST in hepatopancreas under all Cu concentrations followed a decrease trend as the exposure time prolonged. However, these activities were firstly increased and then decreased to the control level and increased again during Cd exposure. Activities of CAT in all Cu exposure treatments were higher than those in the control. These activities were firstly increased and then decreased to the control level and increased again during Cd exposure. Contents of MDA in hepatopancreas in all Cu treatments significantly increased first and then decreased to the control level. However, the MDA contents in hepatopancreas were not significantly changed during the 28-day Cd exposure. The metals accumulation in both hepatopancreas and muscles of abalone significantly increased with the increase of waterborne metals concentration and exposure time. These results indicated that H. discus hannai has a positive anti-oxidative defense against Cu or Cd. In conclusion, anti-oxidative mechanism in abalone to resist waterborne Cu did not follow the same pattern as that for waterborne Cd.     

Acute toxicity of live and decomposing green alga Ulva (Enteromorpha) prolifera to abalone Haliotis discus hannai

From 2007 to 2009, large-scale blooms of green algae (the so-called “green tides”) occurred every summer in the Yellow Sea, China. In June 2008, huge amounts of floating green algae accumulated along the coast of Qingdao and led to mass mortality of cultured abalone and sea cucumber. However, the mechanism for the mass mortality of cultured animals remains undetermined. This study examined the toxic effects of Ulva (Enteromorpha) prolifera, the causative species of green tides in the Yellow Sea during the last three years. The acute toxicity of fresh culture medium and decomposing algal effluent of U. prolifera to the cultured abalone Haliotis discus hannai were tested. It was found that both fresh culture medium and decomposing algal effluent had toxic effects to abalone, and decomposing algal effluent was more toxic than fresh culture medium. The acute toxicity of decomposing algal effluent could be attributed to the ammonia and sulfide presented in the effluent, as well as the hypoxia caused by the decomposition process.     

Induction of larval settlement and metamorphosis ofHaliotis discus hannai Ino (Gastropoda,Mollusca)

Conspecific foot mucus, excessive [K⁺] and gamma-aminobutyric acid (GABA) showed different metamorphosis-inductive effect on the veliger ofHaliotis discus hannai. The inductive effect of excessive [K⁺] and GABA was developmental stage-dependent and dose-dependent, while that of conspecific foot mucus was only developmental stage-dependent. At 20°C the veliger larvae became competent within 4 days after fertilization.H. discus hannai larvae showed gregarious settlement pattern on the conspecific foot mucus under the conditions of either presence or absence of KCl or GABA. The present studies showed that the effect of conspecific foot mucus on abalone larvae metamorphosis could be dose-independent.