Green Abalone Research Articles

GROWTH OF CULTURED ABALONE, HALIOTIS FULGENS, USING NATURAL ALGAL DIETS

Pérez‐Estrada, C. J.1,2, Serviere‐Zaragoza, E.1, Mazariegos‐Villareal, A.1, Reynoso‐Granados, T.1 & Monsalvo‐Spencer, P.1 1Centro de Investigaciones Biológicas del Noroeste (CIBNOR). P.O. Box 128, La Paz, Baja California Sur. 23000. México; 2Universidad Autónoma de Baja California Sur. Carretera al Sur km. 5.5 o 23080 o La Paz, B. C. S.Algal diets have been evaluated and used extensively for the aquaculture of abalone, especially in Japan. In other areas little is known about the nutritional value of the algae that the local abalone consume. In Mexico, regional hatcheries use Macrocystis pyrifera as a main source of natural food. Kelp availability, year round, has not generally been a problem for abalone aquaculturists. Most difficulties occur during severe storms, which may prevent access to kelp beds. El Niño also caused widespread destruction of M. pyrifera. In this study, growth rates of juvenile green abalone Haliotis fulgens, 31.7 " 1.5 mm shell length and 2.5 " 0.2 g body weight were evaluated during 136 days. Juveniles were fed with some of the algae used in regional hatcheries, Macrocystis pyrifera, Egregia menziesii, Eisenia arborea, Porphyra sp. and Ulva sp. Shell length growth rates varied between 2 mm day‐1 for Ulva sp. and 18 mm day‐1 for M. pyrifera. Body weight rates ranged from no growth for Ulva sp. to 14 mg day‐1for E. menziesii. The percent of survival was between 46 and 75 %. Ulva sp. showed the lowest protein content followed by E. menziesii, E. arborea, M. pyrifera and Porphyra sp.

MAD phasing with krypton.

Experiments demonstrating the feasibility of Kr-edge MAD on frozen crystals as a routine method for structure determination are reported. Approximately 50% of protein crystals can be successfully derivatized by pressurization with the noble gases xenon or krypton. While Xe has produced many useful derivatives for MIR phasing over the last several years, the Xe edges (K edge = 34.6 keV, L(I) = 5.5 keV) are not easily accessible for MAD studies. As the Kr K edge (14.3 keV) is accessible on most MAD beamlines, Kr derivatization provides the additional opportunity to conduct a MAD experiment and obtain phases using only a single crystal. This paper describes the phasing of two proteins using Kr MAD: the 17 kDa Fe protein myoglobin (Mb) from sperm whale (Physeter catodon) and an 18 kDa protein (SP18) from green abalone (Haliotis fulgens). Three-wavelength data were collected at SSRL beamline 9-2 from crystals of Mb and SP18 incubated in 2.76 MPa of Kr gas for 2 min, depressurized and then flash-frozen in a stream of nitrogen gas at 100 K. MAD phases were calculated using the program SHARP and the resulting density improved with wARP. The final maps for both Mb and SP18 were of excellent quality.

Evaluation of the green abalone haliotis fulgens fishery in bahía asunción, baja california sur, mexico

The fishery of green abalone in Bahía Asunción, Baja California Sur (Mexico), was analyzed with an age-structured simulation model using data on catch, effort, abundance estimates, natural mortality and the population growth parameters (k, L∞, to, a and b of the length-weight relationship, age at first capture and longevity). The parent-recruit relationship can be established from the correspondence between the adult stock and the one-year-old juveniles and was analyzed as a random variable with normal distribution; it shows anomalies with a sinusoid pattern. Estimates of potential yield show that current yields are below the biologic maximum sustainable yield and economic maximum sustainable yield levels.

The high resolution crystal structure of green abalone sperm lysin: implications for species-specific binding of the egg receptor

Abalone sperm lysin is a 16 kDa acrosomal protein used by sperm to create a hole in the egg vitelline envelope. Lysins from seven California abalone exhibit species-specificity in binding to their egg receptor, and range in sequence identity from 63 % to 90 %. The crystal structure of the sperm lysin dimer from Haliotis fulgens (green abalone) has been determined to 1.71 Å by multiple isomorphous replacement. Comparisons with the structure of the lysin dimer from Haliotis rufescens (red abalone) reveal a similar overall fold and conservation of features contributing to lysin’s amphipathic character. The two structures do, however, exhibit differences in surface residues and electrostatics. A large clustering of non-conserved surface residues around the waist and clefts of the dimer, and differences in charged residues around these regions, indicate areas of the molecule which may be involved in species-specific egg recognition.

Digestive proteases in juvenile Mexican green abalone, Haliotis fulgens

In this study, proteolytic and specific substrate activities were measured in viscera (VIS) and hepatopancreas (HP) extracts from juvenile green abalone, Haliotis fulgens. The soluble protein was more abundant in the hepatopancreas than viscera. The HP proteolytic activity was higher than VIS. Proteolytic activity assayed with 1% azocasein and 2% haemoglobin at different pHs showed that juvenile digestive enzymes have activity peaks at acid pH. In alkaline pH, both activities decreased. Regardless of the size of the organism and diet, extracts from hepatopancreas and viscera hydrolysed trypsin, chymotrypsin, and acid phosphatase-specific substrates, but not carboxypeptidase A and B substrates. Specific substrate activities in HP were higher than VIS activity in all groups, except in juveniles fed diatoms in which the VIS trypsin and chymotrypsin activity was higher than the HP activity.

The occurrence and possible significance of diacylglyceryl ether lipids in abalone.

Gonadal and foot tissues of the green abalone, Haliotis fulgens, farm-raised on macroalgal [corrected] diets, were analyzed for lipids using thin-layer chromatography/flame-ionization detection and gas chromatography-mass spectrometry (GC-MS). Diacylglyceryl ether (DAGE) was 0.7% of total lipids in the gonad. The major alkyl constituents of the glyceryl ether diols in the gonad (as % of total diols) were 16:0 (38%) and 18:1 (36%). While levels of DAGE in the abalone foot were below flame-ionization detection limits, glyceryl ether diols from them were detected using the more sensitive GC-MS procedure. The major diol components in the foot were 18:0 (39%) and 18:1 (32%). To our knowledge, this is the first report of DAGE in abalone tissues. Although the precise role of DAGE in abalone remains to be determined, a possible structural role may exist.

Southern California Abalones: Can Stocks Be Rebuilt Using Marine Harvest Refugia?

Recovery of the isolated Palos Verdes Peninsula (PVP) kelp forest community after severe disturbance offers important implications for the design of marine harvest refugia. In 1977, part of the Southern California mainland coast was closed to abalone fishing to promote natural recovery. Pink (Haliotis corrugata) and green (Haliotis fulgens) abalones, historically the more abundant haliotids at PVP, did not respond. Nearby islands had substantial stocks, but the short planktonic period of green abalone larvae suggested that dispersal between isolated beds was uncommon. A drift tube study supported this hypothesis and stressed the importance of local brood stock. An experimental transplant of green abalone brood stock into sites where the drift tube data suggested high probability of larval retention led to a dramatic increase in juvenile abundance, a pattern not seen at distant controls. Other taxa with different distributions and larval periods further support the importance of dispersal potential to the natural recovery of depleted stocks. Thus, refugia design must consider the life history of target species, the oceanographic regime and distances from source areas, as well as the feasibility of enforcement.

Comparative Disposition and Biotransformation of Pentachlorophenol in the Oyster ( Crassostrea gigas) and Abalone ( Haliotis fulgens)

In order to elucidate possible detoxication mechanisms, the disposition and biotransformation of pentachlorophenol (PCP, a general biocide) were compared in two marine molluscs: a bivalve, the Pacific oyster ( Crassostrea gigas), and a gastropod, the green abalone ( Haliotis fulgens). In a flowthrough exposure system, oysters and abalones ( n = 6 each) were individually exposed to 800 and 500 μg liter of PCP in seawater, respectively, for 5 hr to determine bioconcentration and tissue distribution after short-term exposure; three individuals of each species were removed for analysis, while remaining animals were exposed to clean seawater for an additional 13 hr to allow depuration of retained residues. Retained residues were quantified by tissue digestion and liquid scintillation counting (LSC), and excreted residues were collected on XAD-4 resin and identified by high-pressure liquid cochromatography, fraction collection, and LSC. The 5-hr total concentration factor (similar to a bioconcentration factor but including both PCP and any metabolites) ranged from 25.1 to 44.5 in the oyster and from 44.5 to 63.2 in the abalone. Highest PCP tissue concentrations were 109.3 nmol g −1 in oyster viscera and 141.6 nmol g −1 in abalone gill; tissues retaining the greatest PCP mass were oyster viscera (41.5%) and abalone foot muscle (39.0%). During recovery, oysters depurated 95.2% of retained residues, while abalones depurated only 23.3%, with concentrations in all individual tissues of both species declining. Finally, PCP biotransformation was limited in both species, with oysters depurating only PCP (88.8%) and pentachlorophenylsulfate (11.2%), while abalones produced pentachlorophenyl-β-D-glucoside (14.7%), tetrachloro- p-hydroquinone (7.3%), and pentachlorophenylsulfate (5.5%). During short-term exposure, Pacific oysters limit the accumulation of PCP, possibly by closing their shells, and efficiently depurate retained residues to limit toxic effects. In contrast, green abalones rely more on biotransformation to detoxify residues since they can neither limit PCP accumulation nor depurate retained residues as effectively.

Drift-tube study of the dispersal potential of green abalone (Haliotis fulgens) larvae in the southern California Bight: implications for recovery of depleted populations

Drift-tube study of the dispersal potential of green abalone (Haliotis fulgens) larvae in the southern California Bight: implications for recovery of depleted populations

Experimental hybridization in abalones

Homologous and hybrid zygotes, larvae and juveniles were produced from induced spawnings among four abalone species native to the California coast: the Red, Haliotis rufescens, the Pink, H. corrugata, the Green, H. fulgens, and the White, H. sorenseni, abalones. The sperm concentration for optimal fertilization and subsequent development was 106/ml in homologous combinations and 107/ml in heterologous crosses. The best success was achieved in heterologous fertilizations when sperms were added to ova within 15 min after the ova were spawned. Highest fertilization rates in homologous combinations, 80–100%, were obtained even three hours after egg expulsion. Except for crosses between White females and Red males (which averaged 96%), fertilization rates for heterologous crosses averaged 10–36%. Viable larvae were obtained from all crosses. Back-cross combinations produced juveniles separable by phenotype in the ratio 1:1. Hybrid Red × Green abalone proved fertile, yielding F2 progeny in ratios also suggesting simple Mendelian inheritance. Hybrid Red × White and Red × Green juveniles displayed growth rates better than one or both parental forms. Red × Pink progeny were characterized by survival far superior to that for homologous Pink abalones in culture. This heterosis may be of special value to aquaculture and to fishery enhancement programs.

ACCELERATION OF DEVELOPMENT AND GROWTH IN YOUNG GREEN ABALONE (Haliotis fulgens) USING WARMED EFFLUENT SEAWATER

AbstractLarvae and juveniles of the green abalone grow and survive well at temperatures in the range 20–28°C. A program of hatchery research with this species utilizing thermal effluent has been in progress since 1979 at the Redondo Beach Electric Power Facility, Southern California Edison Company. All life stages may be cultured in the effluent seawater with temperature regulation by admixture of ambient seawater when required. Using thermal effluent, growth rates of juveniles are increased by a factor of 1.5–2.0 over those reared at ambient temperatures (14–20°C) characteristic of southern California. The time to harvest for seed 1–2 cm is reduced from about one year to six months.While optimal temperatures for larvae and postlarvae fall in the range 20–24°C, juveniles are more broadly tolerant of heat and exhibit a growth optimum in the range 24–28°C. The upper lethal limit for juveniles is 31.5°C (LD50, 48 hours). Postlarvae, juveniles and adults have exhibited no indications of unfavorable conditions in power plant effluent.Young adults at 1.5 years (4–5 cm) became reproductively mature and yielded viable larvae. Both hatchery‐reared and wild‐caught adult green abalone were conditioned to spawning readiness during winter months (natural period, spring‐fall) when held in a mixture of effluent and ambient seawater at 20–24°C.Progeny from this research were provided to the California Department of Fish and Game for release in experimental plants. Approximately 30,000 juveniles were produced in 1980–81.

A FLOATING LABORATORY APPLIED TO CULTURE OF ABALONE AND ROCK SCALLOPS IN MISSION BAY, CALIFORNIA

ABSTRACTApplication of the floating laboratory concept to hatchery culture of abalones and rock scallops was tested in 1975–76 using a mono‐hull pleasure craft. Successful experiments prompted construction of a larger vessel consisting of a deck and laboratory superstructure supported by pontoons. The facility has been in operation since early 1978, moored in a marina cove near the entrance to Mission Bay. Seawater is delivered to tanks in the laboratory when currents and tides bring offshore water into the cove. Use is made of inexpensive materials and equipment wherever possible.This paper describes the laboratory, relates successes in spawning and rearing young of the green abalone (Haliotis fulgens) and the purplehinge rock scallop (Hinnites multirugosus), and compares culture conditions and success with those at the nearby La Jolla laboratory of the National Marine Fisheries Service.

Echinocephalus pseudouncinatus n. sp., a Nematode Parasite of the Abalone

The writer has examined thirty specimens of the pink abalone (Haliotis corrugata) of Southern California and found them to be heavily infected with a larval nematode parasite belonging to the superfamily SPIRUROIDEA, the family GNATrOSTOMIDAE, and the genus Echinocephalus. Only old abalones were found to harbor the worms; these encyst in the ventral portion of the foot producing a blister-like effect on the outside of this structure. This vesicatory effect and the burrowing of the larvae through the foot prior to encystment, apparently weakens the muscle and decreases the efficacy of this structure as a hold-fast organ. These two salient characteristics of an infected abalone, the appearance of the foot and the ease with which the animal may be removed from the rocks, enable the commercial divers to distinguish between the healthy and the infected animals. Aside from the above mentioned effects the host seems to suffer no other ill effects from the parasite. A few specimens of the southern green abalone (H. fulgens) were also examined, but were found to be free from this parasite. However, reliable reports from the divers and the processing plants indicate that the green abalone is as susceptible to this parasite as is the pink abalone, an indication that the parasite is not host specific.