Japanese Abalone Haliotis Discus Hannai Research Articles

Evaluation of lipid profile in different tissues of Japanese abalone Haliotis discus hannai Ino with UPLC-ESI-Q-TOF-MS-based lipidomic study

Abalone has been farmed commercially for the last few decades, and the breeding and economic value of abalone have gained extensive attention. In this study, the lipid profile of the foot muscles, viscera, and gonads of male and female Japanese abalone Haliotis discus hannai Ino was explored using ultra performance liquid chromatography-electrospray ionization-quadrupole time-of-flight mass spectrometry (UPLC-ESI-Q-TOF-MS), to discuss the effect of lipid composition on its nutritional value. Thirty-four species from ten lipid classes including phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylglycerol, phosphatidic acid, lysophosphatidic acid, triacylglycerol, steroids, terpenoids and fatty acids were annotated by MS-DIAL to obtain all fragment ions for precursors. Glycerophospholipids (GPLs) enriched in unsaturated fatty acids were the major components, which accounted for 52–57% of total lipids. Considering the high-level of GPLs, and their importance in maintaining the integrity and functionality of cell membranes, further utilization of inexpensive tissues, such as viscera and gonads is warranted.

Isolation and characterisation of Vibrio harveyi as etiological agent of foot pustule disease in the abalone Haliotis discus hannai Ino 1953

Foot pustule disease is an important disease affecting abalones. In the present study, microbiological and histopathological investigations were carried out in the Japanese abalone Haliotis discus hannai, affected by foot pustule disease. Diseased abalones became lethargic, weak, and eventually died. The remarkable symptoms were apparent foot pustules and atrophy of the foot muscle. A predominant bacterium designated as BV2 was isolated from the pustules of diseased abalones. Experimental infection by immersion challenge showed that BV2 was virulent to abalones and caused symptoms of foot pustule disease with median lethal dose value of ≈7.76×105 cfu ml-1. BV2 was infectious to all tested abalones with high mortality. Histopathological investigations showed degeneration and collapse of foot muscles as well as connective tissues. Tissues in round pustules were necrotic and disorganised. The BV2 bacterium was identified as Vibrio harveyi based on the results of phenotypic and biochemical tests as well as 16S rRNA gene sequence analysis.. The bacterium was found resistant to kanamycin and clindamycin, and sensitive to other 11 antibiotics tested.

Differential susceptibility to the Withering Syndrome agent and renal coccidia in juvenile Haliotis rufescens, Haliotis discus hannai and the interspecific hybrid

Withering Syndrome (WS) is a pathogenic chronic disease caused by the intracellular rickettsial-like bacterium “Candidatus Xenohaliotis californiensis” (WS-RLOs), which affects many abalone species. The renal coccidium (Margolisiella haliotis) has often been observed concurrent with WS infection. The red abalone Haliotis rufescens is a very susceptible species to WS and is also infected by the coccidium M. haliotis. In contrast, the Japanese abalone Haliotis discus hannai is not infected by these parasites. Interspecific hybridization is a method for improving important traits in animal husbandry. The objective of this study was to determine susceptibility to WS-RLO and M. haliotis infection in the hybrid generated from a cross between red and Japanese abalones. Juveniles from both species and the interspecific hybrid were challenged by exposure to effluent from red abalone adults infected with both parasites. The animals were analyzed by histology at 130days post-challenge. A 33% prevalence WS-RLOs was observed in the red abalone H. rufescens, whereas a 20% prevalence was observed in the hybrid. Infections were graded on a scale of 0–3. Of these red abalones infected, 53% presented grade 1 infection intensity, 10% had grade 2 infections, and 50% had grade 3 infections. However, the hybrids only presented intensities at the extremes of the scale; of those infected 33% showed grade 1 infections and 66% had grade 3 infections. The coccidium prevalence was 7% in red abalone individuals and 13% in the hybrid abalone. In contrast, the Japanese abalone did not present infections with either parasite. As with the prevalence, the infection intensities for the coccidium were higher in the hybrid abalone; of those infected 25% had grade 2 infections, and 75% had grade 3 infections, but the red abalone presented only grade 2 infection intensities. Therefore, the hybrid did not inherited non-susceptibility or resistance characteristics of the parental H. discus hannai and possessed biological conditions that could foster development of both parasites. Development of a culture based on this hybrid abalone should consider its susceptibility to infection by coccidian, WS-RLOs and the potential for developing the WS disease.

Hybridization betweenHaliotis rufescensandHaliotis discus hannai: evaluation of fertilization, larval development, growth and thermal tolerance

Two introduced abalone species are currently produced in Chile, red abalone Haliotis rufescens and Japanese abalone Haliotis discus hannai. However, red abalone accounts for 99% of total production, while the Japanese abalone has not adapted well to Chilean coastal waters. This study reports the hatching, growth and thermal tolerance performance in interspecific hybrids produced between red (R) and Japanese (J) abalone. Our results show that egg age and sperm concentration were critical factors to produce hybrids. The cross R♀ 9 J♂ showed a fertilization rate of 55.3 ± 3.5% using 20-min-old eggs and sperm concentrations of 14 9 10 6 cells mL 1 , while the reciprocal cross (J♀ 9 R♂) was not successful. Further, larval development stages were similar in RR, JJ and RJ hybrid abalones. Among the experimental trials, settlement rate varied from 12.3% to 18.6% and final survival from 20.1% to 31.7%, being the RJ hybrid rates intermediate between parental species. The final shell lengths were similar between RR and RJ hybrids, but significantly higher in JJ abalones. In addition, thermal tolerance was ascertained due its pivotal role for the abalone physiology. Thus, RJ hybrids showed the highest HSP70 gene expression and offers new possibilities to expand Chilean abalone production in warm waters zones.

Inhibitory Effect of 2,4-Dibromophenol and 2,4,6-Tribromophenol on Settlement and Survival of Larvae of the Japanese AbaloneHaliotis Discus HannaiIno

We examined the inhibitory effects of 2,4-dibromophenol (DBP) and 2,4,6-tribromophenol (TBP), which are released by the large perennial brown algae Eisenia bicyclis and Ecklonia kurome, on settlement and survival of veliger larvae of the Japanese abalone Haliotis discus hannai. The proportion of larvae attached to a polycarbonate chip coated with pregrazed diatom films and abalone trail mucus reached 70% by 2 h, and the proportion of larvae that underwent metamorphosis rose gradually to 65% at 8 h and 85% at 24 h. DBP and TBP at 1 ppm had no effect on larval health or settlement. However, in the presence of 10 ppm DBP, the proportions of larvae attached and metamorphosed were reduced to less than 15% and less than 2%, respectively, and those of overturned and dead larvae were increased to 50% and 41% at 24 h, respectively. In the presence of 10 ppm TBP, the proportion of metamorphosed larvae was reduced to 53% and that of overturned larvae increased to 30% at 24 h. All larvae exposed to 50 ppm DBP or TBP died after 2 h or 8 h, respectively. These findings suggest that DBP and TBP strongly inhibit attachment, metamorphosis, or both at 10 ppm, and that DBP is more toxic than TBP. DBP and TBP may explain low recruitment levels of abalone in kelp forests.

EFFECT OF THREE PHOTOPERIOD REGIMES ON THE GROWTH AND MORTALITY OF THE JAPANESE ABALONE HALIOTIS DISCUS HANNAI INO

Feeding activity of the Japanese abalone Haliotis discus hannai is clearly diurnal, with an increase in feeding between the onset of darkness and midnight. The feeding rate increases slowly in the afternoon, approaching sunset and becomes constant between sunset and midnight. The abalone remain within shaded refuges during the day, and only emerge from them at night. The present study evaluated some effects of varying the photoperiod on a group of these abalone to determine its potential effects on their feeding behavior. Three groups of juvenile abalone with an initial mean length near 14 mm were maintained in raceway cage culture systems with a continuous flow of fresh seawater and abundant food where each group was exposed to different photoperiods. Growth of the abalone in these systems was monitored for a period of 106 days. Treatment A, considered “natural,” included 12 h of light and 12 h of darkness. In Treatment B, the abalone were maintained in complete darkness, and Treatment C included four h of light and 20 h of darkness. The results showed that juveniles cultured in total darkness demonstrated some retardation in growth early in the experiment compared with abalone in a natural light regimen, and those with a partial light regimen. After 43 days, the abalone in the partial light regimen reached and surpassed sizes of the abalone maintained in the natural light regimen and in total darkness, although their feeding activity and growth patterns were erratic compared with abalone in the normal light and total darkness regimes. The results of the experiment were inconclusive as to which light regimen was most favorable when considering the growth patterns and comparative mortality rates within the systems.

EVALUATION OF GROWTH AND SURVIVAL OF JUVENILES OF THE JAPANESE ABALONE HALIOTIS DISCUS HANNAI IN TWO CULTURE SYSTEMS SUSPENDED IN TANKS

Growth and survival of the Japanese abalone Haliotis discus hannai were studied over a six-month period at the Center for Abalone Production, Universidad Catolica del Norte, Coquimbo, Chile. Cultures were carried out in lantern and basket nets suspended in seawater tanks having a constant flow of fresh seawater from La Herradura Bay. A total of 900 juveniles were observed, starting with individuals having an average length of 20 mm. The abalone juveniles were fed with two species of macroalgae, half of which was Gracilaria chilensis, and the other was half Ulva sp (mass basis), fed ad libitum. Artificial pelletized food was fed as a supplement, at a rate of 2% of the body mass of the abalones daily. Water quality in the cultures was monitored twice daily, included water temperature, pH, dissolved oxygen, and water flow rate. The average survival of the abalones at the termination of the experimental period was 96.2% in the lantern nets, and 94.6% in the culture baskets, although these differences were not statistically significant (P > 0.05; nested ANOVA). The highest mean specific growth rates were obtained in the lantern net systems with rates of 0.34% per day in length and 1.02% per day in weight; comparative values for the basket systems were 0.31% per day and 0.86% per day. Higher growth rates for weight and length of the shell were obtained in the lantern systems than in the basket culture systems. An analysis of covariance of values for growth in weight and length of the abalones showed significant differences between results from the lantern and basket systems (P < 0.05). Based on the results of the study, the lantern systems should be considered as an interesting alternative for the culture of Haliotis discus hannai both in land-based cultures, and at sea, because they have a larger carrying capacity for abalones compared with the baskets in the culture tanks and only occupy one third of the water column space. The lantern nets not only provided the best growth, but were also more economical, and easier to handle than the baskets.

Mass Mortality of Japanese Abalone Haliotis discus hannai Caused by Vibrio harveyi Infection

Sixty thousand of deaths among cultured Ezo abalone Haliotis discus hannai occurred within a few days at an abalone farm in Japan in the middle of August, 2002. Dead animals were characterized by a hemolymphatic edema around the major circulatory system. Vibrios showing swarming motility dominated in the edema. The pathogenic vibrios were identified as Vibrio harveyi based on a phylogenetic analysis and a phenotypic characterization. In both immersion and injection experiments, the swarming vibrios fulfilled Koch's postulates as a pathogen for Ezo abalone. Using a GFP-tagged V. harveyi S20, a clump of bacterium was detected on the gills of the abalone within 48 hours after contact with the bacterium. This is the first report of V. harveyi infection in Ezo abalone Haliotis discus hannai.

Interactions between the Japanese abalone Haliotis discus hannai (Ino 1953) and Chilean species: Consumption, competition, and predation

The Japanese abalone, Haliotis discus hannai (Ino, 1953) is produced in Land-based culture on the coast of Chile. The high costs involved in such culture systems generated the interest to evaluate the possibility to culture the abalone confined to cages in the sea. Introduction of this species into the natural environment may pose risks to local flora and fauna, particularly the establishment of populations arising from escaped specimens or larval settlement. Laboratory experiments were carried out to evaluate interactions between this abalone and local species in order to determine rates of consumption of local algae by these molluscs, competition with other organisms occupying the same feeding niche, and predation on the abalone by some local carnivores. The experiments demonstrated consumption of all offered algae by the abalone, particularly Rhodymenia howeana at rates of 1.3% to 5% of their body weight per day. In competition with other species of herbivores it was observed that with some there was a decline in consumption rate both by the abalone and the competitors when they were together, suggesting occurrence of competitive interference. The abalone readily attracted and were consumed by a variety of predators, particularly Meyenaster gelatinosus and Cancer setosus. It was concluded that if H. discus hannai escapes from the cages or produces larvae which settle on rocky reefs, this species might become established as an additional component of the natural communities. However, due to competitive interactions, predation pressure, and an opportunistic fishery, the development of substantial populations, let alone population explosions, with serious negative environmental impacts is improbable.

Pacific dulse (Palmaria mollis) as a food and biofilter in recirculated, land-based abalone culture systems

Palmaria mollis (Pacific dulse) is increasingly being used as an in situ biofilter and feed in land-based abalone culture. This work reviews physical and nutrient requirements for P. mollis culture and its nutritional value for three abalone species, the Japanese abalone Haliotis discus hannai, the red abalone Haliotis rufescens, and the U.S. Federally endangered white abalone Haliotis sorenseni.P. mollis growth was positively correlated with light over specific light densities (SLD) ranging from 0.0048 to 0.036molphotonsg−1fresh weightd−1, under tumble culture conditions. Under low light conditions, growth was greatest at a temperature of 12°C (SGR=8.69±0.29%d−1), while under high light conditions growth was greatest at a temperature of 14–18°C (SGR=10.5±0.12%d−1). Addition of Guillard's f nutrient medium [Guillard, R.R.L., Ryther, J.H., 1962. Studies on marine plankton diatoms. I. Cyclothella nana Huntedt and Detonula confercacae (Cleve). Gran. Can. J. Microbiol. 8, 229–239] significantly increased Pacific dulse growth in cultures receiving one seawater exchange per day; furthermore, growth was significantly improved by addition of trace metals. The use of NaNO3 as an N source in the f medium resulted in better growth compared with NH4NO3. The use of phosphorus additions above 83.3μMPd−1 depressed P. mollis growth rates. P. mollis growth was positively correlated with concentrations of dissolved inorganic carbon, including HCO3−. Growth rates were not significantly different over a pH range of 8.3–8.9.There were no significant toxic effects on Japanese abalone, H. discus hannai cultured in seawater supplemented with (0.75f+1.37μM Zn) trace metals d−1. H. discus hannai showed the highest growth rates when fed on P. mollis fertilized with f medium and nitrate (NO3−-N) loads ranging from 1176 to 2353μMd−1 while red abalone, H. rufescens, grew best when fed on P. mollis fertilized with f medium and nitrate loads of 2353–2942μMd−1. Both abalone species grew better on P. mollis fertilized with (0.75f+1.37μM Zn) d−1 trace metal solution compared with P. mollis without trace metal additions. H. sorenseni, grew well when fed on P. mollis, showing higher linear shell growth rates and higher survival rates compared with those of abalone fed on commercially harvested and abundant giant kelp, Macrocystis pyrifera.