Printer Friendly
The Free Library
22,741,889 articles and books

Effect of two stocking densities on the growth and mortality of the pink abalone Haliotis corrugata in recirculating and flow-through systems.



ABSTRACT Traditional abalone abalone (ăbəlō`nē), popular name in the United States for a univalve gastropod mollusk of the genus Haliotis, members of which are also called ear shells, or sea ears, as their shape resembles the human ear.  culture is carried out in flow-through systems with water exchange rates between 200 and 2,400% of the total tank volume per day. These high volumes of water associated with abalone culture represents a constraint for the growth of this industry, and recirculating systems can become a viable alternative, because the water exchange rates are less than 10% of the total volume. The objective of this experiment was to evaluate the water quality parameters and the growth rate and mortality of the pink abalone cultured at two different densities, 10% (D1) and 30% (D2) in a flow-through system (S1) and two closed recirculating systems (S2 and S3). A total of 2,400 juvenile abalone (7.11 [+ or -] 2.0 g and 37.01 [+ or -] 3.4 mm) were distributed among the three experimental systems. The experiment lasted for 127 days. Weight and length of all the abalone were measured at the beginning and end of the experiment. Average water quality parameters for each system (S1, S2, and S3) were respectively: temperature (18.2 [+ or -] 1.4, 18.4 [+ or -] 1.9, and 18.1 [+ or -] 2.0[degrees]C); salinity (33.8 [+ or -] 1.0, 34.5 [+ or -] 1.2, and 34.2 [+ or -] 1.5[per thousand]); alkalinity al·ka·lin·i·ty
n.
The alkali concentration or alkaline quality of a substance that contains alkali.



alkalinity

1. the quality of being alkaline.

2.
 (127 [+ or -] 13.2, 135 [+ or -] 13.7 and 131 = 14.1 mg of CaC[O.sub.3]/L), total ammonia nitrogen (0.006 [+ or -] 0.02, 0.03 [+ or -] 0.07, and 0.02 [+ or -] 0.08 mg TAN/L) and nitrite nitrite

Any salt or ester of nitrous acid (HNO2). The salts are inorganic compounds with ionic bonds, containing the nitrite ion (NO2) and any cation.
 (0 [+ or -] 0.00, 0.08 [+ or -] 0.07, and 0.07 [+ or -] 0.05 mg N[O.sub.2]/L). Growth rates Growth Rates

The compounded annualized rate of growth of a company's revenues, earnings, dividends, or other figures.

Notes:
Remember, historically high growth rates don't always mean a high rate of growth looking into the future.
 in weight (g/d) were for S1D1 (0.027 [+ or -] 0.007), S1D2 (0.018 [+ or -] 0.001), S2D S2D Seek to Destroy 1 (0.007 [+ or -] 0.001), S2D3 (0.005 [+ or -] 0.000), S3D S3D Scorched 3D (game) 1 (0.007 [+ or -] 0.000) and S3S2 (0.009 [+ or -] 0.003), and growth rates in length (mm/d) were for S1D1 (0.038 [+ or -] 0.004), S1D2 (0.031 [+ or -] 0.002), S2D1 (0.013 [+ or -] 0.001), S2D3 (0.013 [+ or -] 0.000), S3D1 (0.002 [+ or -] 0.000), and S3D2 (0.024 [+ or -] 0.001) respectively. In flow through systems growth in length and width was density dependent. Mortality was higher in S3D2 than in any other treatment. A lower water exchange rate in closed systems could adversely affect growth and mortality. Abalone culture in closed recirculating systems could become another alternative for this industry, but more research is required.

KEY WORDS: abalone, Haliotis corrugata, recirculating system, growth, mortality

INTRODUCTION

Abalone (Haliotis spp.) fishery has been one of the most important in the northwest part of Mexico over the past 40 y. Several factors such as overfishing Overfishing occurs when fishing activities reduce fish stocks below an acceptable level. This can occur in any body of water from a pond to the oceans. More precise biological and bioeconomic terms define 'acceptable level'.  and diseases have had a toll on landings, which have decreased dramatically from 3,000 mt in the 1970s, to less than 300 mt nowadays (Salas-Garza & Searcy-Bernal 1992, Anonymous 2000). This drastic reduction in abalone capture increased the interest in their aquaculture aquaculture, the raising and harvesting of fresh- and saltwater plants and animals. The most economically important form of aquaculture is fish farming, an industry that accounts for an ever increasing share of world fisheries production. . Abalone culture officially began in Mexico in the 1990s, and currently all farms are land-based. In these farms, abalone culture is characterized by high water flow rates to keep optimum water quality parameters within levels recommended for grow-out conditions. The rate of water exchange in an abalone culture tank normally ranges from 200% to 2,400% per day. The cost associated with the maintenance of this high rate of exchange accounts for between 15% to 30% of the production costs in an abalone farm. One way to decrease the cost of production associated with constantly pumping water through the abalone grow-out tanks, can be by the use of recirculation Noun 1. recirculation - circulation again
circulation - the spread or transmission of something (as news or money) to a wider group or area
 technology. Recirculating systems have been successfully used elsewhere to grow tilapia tilapia (təlä`pēə) or St. Peter's fish, a spiny-finned freshwater fish of the family Cichlidae, native chiefly to Africa and the Middle East. , turbot turbot: see flatfish.
turbot

Species (Scophthalmus maximus, family Scophthalmidae or Bothidae) of broad-bodied European flatfish, a highly valued food fish. It lives along sand and gravel shores.
, artic artic
Noun

Brit informal an articulated lorry
 char, and northern quahog quahog: see clam.
quahog

Thick-shelled edible clam of the U.S. The northern quahog (Mercenaria mercenaria), also known as the cherrystone, littleneck, or hard-shell clam, is 3–5 in. (8–13 cm) long.
 among others species (Pfeiffer et al. 1999, Timmons et al. 2002, Labatut & Olivares 2004, Summerfelt et al. 2004). Biofiltration, solids removal, circulation, aeration aeration /aer·a·tion/ (ar-a´shun)
1. the exchange of carbon dioxide for oxygen by the blood in the lungs.

2. the charging of a liquid with air or gas.


aer·a·tion
n.
, and degasification are the five most important characteristics for the efficient operation of any recirculating system. In abalone culture, recirculation has been used for broodstock maintenance and conditioning, and grow-out experiments with species such as H. discus hannai and H. tuberculata (Park et al. 1995, Nie et al. 1996, Mgaya & Mercer 1995, Sawa 2000). Haliotis discus hannai has also been cocultured in recirculating systems with the red algae red algae: see seaweed; Rhodophyta.  Palmaria mollis with the benefit of maximizing biofilter function and reducing the amount of nutrients to the effluents (Demetropoulos & Langdon 2004). So far, no studies have been conducted with H. corrugata in recirculating systems. The results obtained from this experiment might set the road for the transformation of the way abalone is cultured in Mexico.

MATERIALS AND METHODS

Abalone Stock and Culture Systems

Juvenile pink abalone Haliotis corrugata were obtained from B.C. Abalone and Productores Marinos Baja (2,400, 7.2 [+ or -] 2.0 g, 37.01 [+ or -] 3.4 mm), Ejido ejido (āhē`thō) [Span.,=common land], in Mexico, agricultural land expropriated from large private holdings and redistributed to communal farms.  Erendira, Baja California Baja California, state, Mexico
Baja California (Span.: bä`hä kälēfōr`nyä), state (1990 pop. 1,660,855), 27,628 sq mi (71,576 sq km), NW Mexico, on the Baja California peninsula. Mexicali is the capital.
, Mexico. At their arrival to CICESE CICESE Centro de Investigacion Cientifica y de Educacion Superior de Ensenada (Spanish) , Aquaculture Department, the abalone were placed in plastic cages in a flow-through system, and the juvenile abalone were acclimated for 42 days at 20[degrees]C. During this period, abalone were fed ad libitum ad libitum

without restraint.


ad libitum feeding
food available at all times with the quantity and frequency of consumption being the free choice of the animal.
 with macroalgae Macrocystis pyrifera and exposed to natural photoperiod photoperiod /pho·to·pe·ri·od/ (fo´to-per?e-od) the period of time per day that an organism is exposed to daylight (or to artificial light).photoperiod´ic

pho·to·pe·ri·od
n.
.

One flow-through system and two recirculating systems were used in the growth trial. The flow-through system (S1) consisted of six black round flat bottom tanks (280-L capacity). The water used in this experiment was pumped from the ocean, filtered to 70 [micro]m and UV-irradiated before reaching the tanks. A flow rate of 0.5 L/min was provided to each one of the six tanks for a daily rate of water exchange of 290%. Each of the two recirculating systems used in this experiment (S2 and S3) consisted of three round flat bottom tanks (280 L capacity) connected to a 180 L sump. A bubble-washed, bead filter (0.056 [m.sup.3] polyethylene beads) was used to provide biofiltration and clarification to each system. Both bead filters were acclimated for 48 days at 20[degrees]C prior to the experiment as recommended by Simonel et al. (2002). In each system, water was recirculated with a 1/6 HP centrifugal pump centrifugal pump

Machine for moving liquids and gases. Its two major parts are the impeller (a wheel with vanes) and the circular pump casing around it. In the most common type, called the volute centrifugal pump, fluid enters the pump at high speed near the centre of the
. Flow rate to each tank was 3 L/min. For the flow-through and the recirculating system, air was provided by air-stones connected to an electric blower. Water temperature was maintained using 250 W titanium heaters for each tank in the flow-through system, and 800 W heaters in each of the two recirculating system.

In each tank, four plastic cages (0.25 m x 0.25 m x 0.3 m, 0.012 m square mesh size) were placed, and within each cage, two polyvinyl chloride polyvinyl chloride (PVC), thermoplastic that is a polymer of vinyl chloride. Resins of polyvinyl chloride are hard, but with the addition of plasticizers a flexible, elastic plastic can be made.  gutters (0.24 m x 0.26 m) were used to provide for available area for the abalone (0.1248 [m.sup.2]). All abalones used in the experiment were fed with M. pyrifera at a rate of 15% body weight/day and leftover macroalgae were regularly removed from the tanks. During the experiment, temperature and salinity were measured daily (conventional thermometer and refractometer refractometer /re·frac·tom·e·ter/ (re?frak-tom´e-ter)
1. an instrument for measuring the refractive power of the eye.

2.
). Total ammonia-nitrogen (TAN), nitrate, and alkalinity were measured twice a week (HACH HACH Housing Authority of the City of Houston (Texas)  FF3 tests). Alkalinity was maintained in both recirculating systems by placing abalone shells in the sump as recommended for volatile, low-density systems (Malone & Burden 1988, Malone et al. 1996, Malone & Beecher 2000, Timmons et al. 2002).

The experiment was conducted from December 2004 to March 2005 and data were averaged for each month.

Experimental Design

Two stocking densities were evaluated in the flow-through and recirculating systems. The densities used in this experiment were 10% (D1) and 30% (D2) of available surface area, 26 and 74 abalone per cage (104 and 297 abalone per tank). In S1, a total of 6 tanks (3 tanks-D1, and 3 tanks-D2), were used. For S2 and S3, both densities were distributed as follows: S2, two tanks D1, and one tank D2, and S3, one tank D1, and two tanks D2. Because of logistic problems, densities could not be equally replicated in these recirculating systems. All abalone were dislodged manually in each cage, blot dried, weighted to the nearest 0.1 g body weight, and shell length and width was measured to 0.1 mm with a digital caliper caliper

Instrument that consists of two adjustable legs or jaws for measuring the dimensions of material parts. Spring calipers have an adjusting screw and nut; firm-joint calipers use friction at the joint to hold the legs unmoving.
 at the beginning of the experiment (day 0) and at the end of the experiment (day 127). At the time of feeding, mortality was removed from each cage and quantified.

Abalone growth rate (AGR AGR advanced gas-cooled reactor ) (growth [rate.day.sup.-1]) was calculated for body weight, shell length, and width by the following equation:

Growth rate = (final - initial)/time (days)

Statistical Analyses

After all data were analyzed for normality and homogeneity, all water quality parameters and mortality were analyzed with a one-way ANOVA anova

see analysis of variance.

ANOVA Analysis of variance, see there
 to determine if significant differences existed among S1, S2, and S3 in the different months evaluated. When significant differences were indicated, treatment means were separated with a Tukey HSD HSD Human Services Department
HSD High Speed Data
HSD Hillsboro School District (Hillsboro, OR)
HSD Hybrid Synergy Drive (Toyota/Lexus)
HSD High School Diploma
HSD Historical Society of Delaware
 test at a level of significance of 0.05.

A two-factor ANOVA was used to detect differences among systems (S1, S2, and S3) and densities (D1 and D2) in growth rates in total weight, shell length, and width When significant differences were indicated, orthogonal contrasts tests were conducted between treatment means at a level of significance of 0.05 (SAS (1) (SAS Institute Inc., Cary, NC, www.sas.com) A software company that specializes in data warehousing and decision support software based on the SAS System. Founded in 1976, SAS is one of the world's largest privately held software companies. See SAS System.  1985).

RESULTS

Water Quality

The salinity means ([+ or -] SD) throughout the experiment for S1, S2, and S3 were 33.76 [+ or =] 0.97[per thousand], 34.47 = 1.2[per thousand], and 34.24 [+ or -] 1.53[per thousand] respectively. Significant differences in salinity were detected in January between S1 and S2, and S3 was similar to both (F = 4.76, P = 0.0219). No significant differences were detected in the other months (Fig. 1). Temperature means ([+ or -]SD) were 18.2 [+ or -] 1.4, 18.4 1.9, and 18.1 [+ or -] 2.0[degrees]C, for S1, S2, and S3, respectively. A power outage Noun 1. power outage - equipment failure resulting when the supply of power fails; "the ice storm caused a power outage"
power failure

equipment failure, breakdown - a cessation of normal operation; "there was a power breakdown"
 at the 13th day of experiment and a malfunction in the heaters at the 30th day caused a temperature fluctuation in the first month of the growth trial in both recirculating systems (22.6[degrees]C to 13. 1[degrees]C in S2, and 23[degrees]C to 13.5[degrees]C in S3). Significant differences in temperature were detected in February where S2 was different from S1 and S3 (F = 5.85, P = 0.0096). In March, S1 was significantly different from S3, and S2 was similar to both (F = 4.60, P = 0.0166) (Fig. 2). Ammonia means ([+ or -]SD) for S1, S2, and S3 respectively, were 0.006 [+ or -] 0.02, 0.03 [+ or -] 0.07, and 0.02 [+ or -] 0.08 mg TAN/L. No significant differences in TAN were detected among the three systems throughout the experiment (Fig. 3). However, in the first month (December) the closed systems showed higher concentrations of TAN (up to 0.3 mg/L). Nitrite means ([+ or -]SD) were 0 [+ or -] 0.00, 0.08 [+ or -] 0.07, and 0.07 [+ or -] 0.05 mg N[O.sub.2]/L, for S1, S2, and S3, respectively. Significant differences in nitrites were detected in December, where S1 was significantly different from S2 and S3 (F = 19.05, P = 0.0001). Significant differences were also detected in February where S1 was significantly different from S2 and S3 (F = 6.09, P = 0.0149) (Fig. 4). Alkalinity means ([+ or -]SD) were 127 [+ or -] 13.2, 135 [+ or -] 13.7, and 131 [+ or -] 14.1 mg of CaC[O.sub.3]/L, for S1, S2, and S3 respectively. No significant differences in alkalinity were detected between the three systems in all the culture periods (Fig. 5). A volume of 720 L/day of water was required for each tank in S1, 91,440 L per tank for the whole experiment, and a total of 548,640 L for S1 for all six tanks. Each of the closed systems used a total volume of 6,375 L in for the experiment, including 430 L of freshwater used to replenish water lost by evaporation. Water exchange rates are shown in Table 1.

[FIGURE 1 OMITTED]

[FIGURE 2 OMITTED]

[FIGURE 3 OMITTED]

[FIGURE 4 OMITTED]

Abalone Growth and Mortality

The two-way ANOVA in growth rate in weight (GRW GRW Graciosa Island, Azores, Portugal (airport code)
GRW Giant Ragweed
GRW Gang Rod Withdrawal
) was significant among systems (F = 19.31, P = 0.0024) but no differences caused by densities or interactions were detected (F = 1.57, P = 0.2564 and F = 1.30, P = 0.3395, respectively). The contrasts tests showed that weight in the open system (S1) was significantly higher than in the closed systems (S2 and S3) (F = 38.31, P = 0.0008) (Fig. 6).

Growth rate in shell length (GRL GRL Girl
GRL Greenland (ISO Country code)
GRL Geophysical Research Letters
GRL Air Greenland (ICAO code)
GRL global reach laydown (US DoD)
GRL Grain Length
) was significantly different among systems (F = 45.27, P = 0.0002) but not between densities (F = 1.44, P = 0.2753), although a significant interaction was also detected (F = 8.12, P = 0.0196). The contrasts tests showed that GRL was significantly higher in S1 than in S2-S3 (F = 89.61, P = 0.0001), but did not differ between S2 and S3 (F = 0.94, P = 0.3705). The significant interaction may be explained by the lower GRL for D2 compared with D1 in S1, contrasting with the higher values in the closed systems, especially in S3 (Fig. 7).

[FIGURE 5 OMITTED]

Growth rate in shell width (GRWd) was significantly different among systems (F = 39.51, P = 0.0004), but no densities or interaction effects were detected (F = 4.39, P = 0.0810 and F = 2.78, P = 0.1399, respectively). The contrast tests showed that shell width in the open system was significantly higher in S1 than in S2 and S3 (F = 78.49, P = 0.0001) (Fig. 8).

The total mortality rate during the growth trial was 16.67% (400 abalone).The mortality rates for D1 and D2, were 15.22% (95 abalone) and 17.17% (305 abalone), respectively. The mortality rates for S1, S2, and S3 were 10.25% (123 abalone), 15.87% (80 abalone) and 28.3% (197 abalone), respectively. The highest mortality rates were observed in the first month of the experiment, 70, 34, and 118 abalones for S1, S2, and S3; which were equivalent to 56.9%, 42.5%, and 59.8% of the total mortality. In the analysis of mortality for treatment combinations, S3D2 was significantly higher (F = 13.92, P = 0.0001) from the other treatments (Table 2).

[FIGURE 6 OMITTED]

[FIGURE 7 OMITTED]

[FIGURE 8 OMITTED]

DISCUSSION

Recommended concentrations of salinity varies for different abalone species for example as follows: H. discus hannai from 25-44[per thousand], H. rufescens, 32[per thousand] ([+ or -] 0.02), H. tuberculata 34[per thousand] ([+ or -]1), H. laevigata 34[per thousand], H. diversicolor supertexta and H. fulgens, 35[per thousand], H. varia var·i·a  
n.
A miscellany, especially of literary works.



[Latin, from neuter pl. of varius, various.]
 32[per thousand] ([+ or -]2), and H. asinina from 30[per thousand] to 34[per thousand] (Hahn 1989, Basuyaux & Mathieu 1999, Harris et al. 1999, Capinpin et al. 1999, Medina-Romo 2002, Steinarsson & Imsland 2003, Cheng et al. 2004, Najmudeen & Victor 2004). For pink abalone, the recommended salinity is 35[per thousand] (Re-Araujo 2003) and in our experiment, salinity ranged between 32.37[per thousand] to 36.72[per thousand]. In January, we experienced an unusual amount of rain, the water we used for the flow-through system was directly pumped from the shallow ocean waters and the runoff probably affected salinity.

The temperature range reported for the optimal growth of H. corrugata is between 15[degrees]C and 23[degrees]C (Spencer 2002). Re-Araujo (2003) reported that the preferred temperature for H. corrugata was 24.5[degrees]C.

Gastropod gastropod, member of the class Gastropoda, the largest and most successful class of mollusks (phylum Mollusca), containing over 35,000 living species and 15,000 fossil forms.  excretion is mostly composed of nitrogenous nitrogenous /ni·trog·e·nous/ (ni-troj´e-nus) containing nitrogen.

ni·trog·e·nous
adj.
Relating to or containing nitrogen.



nitrogenous

containing nitrogen.
 compounds, largely ammonia, whereas feces constitute only a marginal source of ammonia (Kinne 1976, Spotte 1979). Ammonia is a toxic and a stressor in aquaculture (Harris et al. 1998, Basuyaux & Mathieu, 1999). Abalone tolerance to TAN varies among the different species, H. tuberculata shows toxicity symptoms when TAN is [greater than or equal to] 10 mg/L and the recommended concentration should be less than 1 mg/L (Basuyaux & Mathieu 1999). The higher concentration of TAN in the closed systems in the first month was caused by an increase in the backwash frequency of the bubble bead filters. An increase in frequency and intensity of the backwash harvested a higher amount of biofilm Biofilm

An adhesive substance, the glycocalyx, and the bacterial community which it envelops at the interface of a liquid and a surface. When a liquid is in contact with an inert surface, any bacteria within the liquid are attracted to the surface and adhere
 from the plastic beads or filter media, and thus decreased the ability of the biofilter to nitrify ni·tri·fy  
tr.v. ni·tri·fied, ni·tri·fy·ing, ni·tri·fies
1. To oxidize (an ammonia compound) into nitric acid, nitrous acid, or any nitrate or nitrite, especially by the action of nitrobacteria.

2.
 (Goltz et al. 1999, Sastry et al. 1999, Malone & Beecher 2000, Sandu et al. 2002). During the rest of the experiment, ammonia remained undetected or extremely low in all systems.

Nitrite has been shown to adversely affect growth or food consumption in several aquatic species; however, at least two different dose response patterns have been reported (Harris et al. 1997). A decrease in 50% in growth can be observed for the shrimp Penaeus indicus when exposed to 6.4 mg of N[O.sub.2]/L, however, as nitrite concentration increased further, growth inhibition Growth inhibition (GI) is a medical term pertaining to cancer therapy and the specific reduction in growth of tumors and oncogene cells by a chemical compound, mechanical therapy (e.g.  is not necessarily exacerbated, reaching a dose response plateau pattern (Wickins 1976, Chen & Chen 1992). In the abalone H. tuberculata (7-12 g), weight decreased up to 30% when 2 mg/L of N[O.sub.2] were present, and growth drastically decreased when nitrite concentration was higher than 5 mg/L (Basuyaux & Mathieu 1999). In our experiment, both closed systems S2 and S3, experienced a significantly higher nitrite concentration than S1 because they experienced a lower water exchange rate and the solids produced by abalone feeding activity on the macroalgae Macrocystis pyrifera were more difficult to remove. In January and March nitrite concentrations were detectable in both recirculating systems, whereas ammonia was not detected. This might be because of a decrease in the alkalinity values in these months, because nitrifying bacteria nitrifying bacteria: see nitrogen cycle.
nitrifying bacteria

Small group of oxygen-requiring bacteria that use nitrogen as an energy source.
 are especially sensitive to disturbances away from optimal alkaline conditions (Hagopian & Riley 1998). Probably if nitrates were measured, then more elements would be available to explain this discrepancy.

In early studies with the red abalone The red abalone, Haliotis rufescens, is a large brick colored mollusk that feeds on kelp and other algae along the coast of Oregon to Baja California. Being the largest, and most common abalone in the state it is the only species of abalone still commonly harvested in  H. rufescens in a flow-through system, the reported alkalinity values were 95-140 mg/L CaC[O.sub.3] and 100 165 mg CaC[O.sub.3] in a closed recirculating system (Vivanco-Aranda 2004). In our experiment, the highest values for alkalinity in S1 were detected in the first two months (130 and 132 mg/L CaC[O.sub.3], respectively). For S2 and S3, although there was no significant difference throughout the experiment, the lowest values were detected in the first month.

One alternative to decrease the production costs associated with the pumping of high volumes of water is the use of recirculating systems. It is well known that a closed system must have less than 10% of water exchange per day of the total volume of the system (Losordo et al. 1992a, Malone et al. 1996, Masser et al. 1998). Several factors such as species cultured, density and management practices among others, will determine the optimum water exchange rate per day in a recirculating system (Timmons et al. 2002). In our experiment, the water exchange for S2 and S3 was less than 5% of the total volume and the only water replaced was that lost by evaporation and biofilter backflushes. One of the reasons we suspect abalone growth rates were significantly lower in S2 and S3, was because of the low water exchange and the presence of diverse metabolic wastes in the water (solids and N[O.sub.2]) (Hahn 1989). An increase in the water exchange rate and better tank design would increase solid removal, improve growth rate and survival of H. corrugata in a closed recirculating system (Losordo et al. 1992b, Leonard et al. 2002, Pfeiffer 2004).

Growth rate in weight, shell length, and width in S1 was density dependent, D1 showed a higher growth rate than D2. For abalone cultured in flow-through systems, growth is inversely related to density (Mgaya & Mercer 1995, Capinpin et al. 1999, Valdes-Urriolagoitia 2000). Our results from SI were similar to those obtained by other researchers that reported a reduction in growth ranging from 14-52% caused by 2--to 60-fold increase in density (Huchette et al. 2003). For H. rufescens, growth rate varies with density; 37.8 [micro]m/day on 0.19 abalone/[cm.sup.2], 33.3 [micro]m/day on 0.29 abalone/[cm.sup.2] and 19.44 [micro]/day on 0.41 abalone/[cm.sup.2] (Valdes-Urriolagoitia 2000). The abalone H. discus hannai grown in sea cages at high densities (3,000 abalone/[m.sup.2]), showed a lower growth rate (70.2 [micro]m/day and 11.11 mg/day) than abalone stocked at a lower density (1,000 abalone/[m.sup.2])(83.9 [micro]m/day and 15 mg/day) and in each case, growth rate was independent from water temperature (Jee et al. 1988). Growth rate in weight, and shell length and width in both systems, S2 and S3 were lower than those obtained in S1, and showed not a clear trend in the effect of density on growth rates. In all systems and densities, (D1S1, D2S D2S Distortion 2 Static (television program) 1, D2S1, D2S2, D1S3, D2S3) growth rates were higher than the 0.3 mm/month (0.0098 mm/d) reported for this species (Spencer 2002). Several factors can affect growth in juvenile abalone such as water flow and water quality variables like salinity, temperature, nitrogen wastes, and tank design (Wickins 1981, Hindrum et al. 1995, Fleming at al. 1997, Harris et al. 1998, Higham et al. 1998). Even when food was not a limiting factor A factor or condition that, either temporarily or permanently, impedes mission accomplishment. Illustrative examples are transportation network deficiencies, lack of in-place facilities, malpositioned forces or materiel, extreme climatic conditions, distance, transit or overflight rights,  in any of the three holding systems, the solids generated by leftover macroalgae were difficult to remove and tended to accumulate in the tanks S2 and S3. In coldwater fish such as rainbow trout rainbow trout

Species (Oncorhynchus mykiss) of fish in the salmon family (Salmonidae) noted for spectacular leaps and hard fighting when hooked. It has been introduced from western North America to many other countries.
, the presence of suspended solids Suspended solids refers to small solid particles which remain in suspension in water as a colloid or due to the motion of the water. It is used as one indicator of water quality.  in water results in poor growth and stress (Timmons et al. 2002). Nitrite and temperature were the only two water quality parameters that greatly differed between the flow-through and recirculating systems. Nitrite chronic exposure probably affected growth rate of H. corrugata in both recirculating systems, S2 and S3. As the concentration of nitrite increase, an apparent decline in oxygen consumption can compromise respiratory efficiency (Harris et al. 1997). In another study on the carp Cyprinus carpio Cyprinus carpio

farmed finfish in family Cyprinidae. Called also common carp. See Table 23.
, a chronic exposure to nitrite increases the levels of methemoglobin methemoglobin /met·he·mo·glo·bin/ (met-he´mo-glo?bin) a hematogenous pigment formed from hemoglobin by oxidation of the iron atom from the ferrous to the ferric state. , decreasing the levels of arterial oxygen (Jensen et al. 1987, Williams et al. 1992). Harris et al. (1997) suggested that nitrite can depress growth by increasing protein catabolism Protein catabolism is the breakdown of proteins into amino acids and simple derivative compounds, for transport into the cell through the plasma membrane and ultimately for the polymerisation into new proteins via the use of ribonucleic acids (RNA) and ribosomes. , as indicated by a higher ammonia excretion. The greenlip H. laevigata is more sensitive to nitrite than other aquatic species, suggesting that other abalones species such as H. corrugata could show the same metabolic response (Harris et al. 1997).

The highest mortality rates were observed at the beginning of the experiment, probably caused by stress from manipulation, water temperature variation, and higher nitrite concentration (Edwards et al. 2000, Ragg et al. 2000, Spencer 2002). Similar results were observed for the abalone H. discus hannai cultured in a recirculation system, where the highest mortality rate was observed in the first 70 days (Nie et al. 1996). On several days we experienced temperatures equal or higher than 20[degrees]C, which caused mortality on the abalones. Re-Araujo (2003) reported a 100% survival of H. corrugata at 24.5[degrees]C, but in our experiment abalone showed a better growth rate and higher survival rate when temperature was around 17[degrees]C. The survival rate reported for this species is of 74% in a flow-through system (Spencer 2002). In our experiment, the lowest survival rate (71.7%) was in the recirculating system S3 with an average water exchange rate of less than 3%. In another experiment using two different biofiltration systems with the abalone H. discus hannai a survival was 66%, and 63.4% was attained (Nie et al. 1996). The effects of manipulation at the beginning of the experiment and water quality management were the factors that have a profound effect of growth and survival of H. corrugata. In the abalone H. laevigata, low ammonia affected shell growth more than weight, whereas in high ammonia concentrations, an inverse effect was observed (Harris et al. 1997). In our experiment body weight was more affected than shell growth. Similar effects in length gain/weight gain because of nitrite exposure were reported by Liu & Avault (1996).

The data obtained in this experiment showed that it is possible to grow pink abalone in recirculating systems. However the tank design and water inlets and outlets did not allow an efficient solid removal and the water exchange rates were probably too low. These factors probably produced lower growth rates than in the flow through system. More research is required to address these issues.

ACKNOWLEDGMENTS

This paper was adapted from the M. Sc. thesis by L.M. Badillo-Sotelo submitted to the Department of Graduate Studies of CICESE. This research was partially funded by CICESE's internal project 623148. The authors thank the Consejo Nacional de Ciencia y Tecnologia CONACyT for the M.Sc. scholarship for the first author; Patricia Ascencio, Norberto Flores Flores, town, Guatemala
Flores (flōrəs), town (1990 est. pop. 2,200), capital of Petén department, N Guatemala. Flores was built on an island in the southern part of Lake Petén Itzá and on the site of the
, and Francisco Valenzuela for technical assistance: B.C. Abalone and Productores Marinos Baja for providing the abalone used in this study, and the anonymous reviewers for the comments on the manuscript.

LITERATURE CITED

Anonymous. 2000. Anuario estadistico de pesca 2000. Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion. Mexico. 268 pp.

Basuyaux, O. & M. Mathieu. 1999. Inorganic nitrogen and its effect on growth of the abalone Haliotis tuberculum Linnaeus and the sea urchin sea urchin, spherical-shaped echinoderm with movable spines covering the body. The body wall is a firm, globose shell, or test, made of fused skeletal plates and marked by regularly arranged tubercles to which the movable spines are attached.  Paracentrotus lividus Lamarck. Aquaculture 174:95-107.

Capinpin, E. C., J. D. Toledo, V. C. Encena & M. Doi. 1999. Density dependent growth of the tropical abalone Haliotis asinina in cage culture. Aquaculture 171:227-235.

Chen, J.-C. & S. F. Chen. 1992. Effects of nitrite on growth and molting molting, periodical shedding and renewal of the outer skin, exoskeleton, fur, or feathers of an animal. In most animals the process is triggered by secretions of the thyroid and pituitary glands.  of Penaeus monodon Penaeus monodon (common names include giant tiger prawn, black tiger prawn, leader prawn, sugpo and grass prawn) is a marine crustacean that is widely reared for food.  juveniles. Comp. Biochem. Physiol. 101C:453-458.

Cheng, W. Ch. H., S. Liu, Y. Cheng & J. C. Chen. 2004. Effect of dissolved oxygen on the acid-base balance acid-base balance
n.
The state that exists when acidic and basic ions in solution neutralize each other.


Acid-base balance 
 and ion concentration of Taiwan abalone Haliotis diversicolor supertexta. Aquaculture 231:573-586.

Demetropoulos, C. & C. Langdon. 2004. Pacific dulse (Palmaria mollis) as a food and biofilter in recirculated, land-based abalone culture systems. Aquacultural Eng. 32:57-75.

Edwards, S., C. Burke, S. Hindrum & D. Johns. 2000. Recovery and growth effects of anesthetic and mechanical removal on greenlip (Haliotis laevigata) and blacklip (Haliotis rubra) abalone. Fourth International Abalone Symposium Abstracts. February 2003. Cape Town Cape Town or Capetown, city (1991 pop. 854,616), legislative capital of South Africa and capital of Western Cape, a port on the Atlantic Ocean. It was the capital of Cape Province before that province's subdivision in 1994. , South Africa South Africa, Afrikaans Suid-Afrika, officially Republic of South Africa, republic (2005 est. pop. 44,344,000), 471,442 sq mi (1,221,037 sq km), S Africa. . pp. 16-17.

Fleming, A., P. Hone & J. Highham. 1997. The effect of water velocity on consumption and growth of greenlip abalone in tanks. In: P. W. Hone & A. Fleming, editors. Proceedings of the 4th annual abalone culture workshop, Port Fairy, Victoria Port Fairy is a coastal town in the Moyne Shire of Victoria, Australia. It is located on the Princes Highway 28 km west of Warrnambool and 290 km west of Melbourne, where the Moyne River enters the Southern Ocean. , FRDC FRDC Fisheries Research and Development Corporation (Australia)
FRDC Food Research and Development Centre (Saint-Hyacinthe, Québec, Canada)
FRDC Florida Research and Development Center
, Canberra. Australia. pp. 16-23.

Goltz, W. J., K. A. Rusch & R. F. Malone. 1999. Modeling the major limitations on nitrification nitrification /ni·tri·fi·ca·tion/ (ni?tri-fi-ka´shun) the bacterial oxidation of ammonia to nitrite and then to nitrate in the soil.

ni·tri·fi·ca·tion
n.
1.
 in floating-bead filters. Aquaeultural Eng. 20:43-61.

Hagopian, D. S. & J. G. Riley. 1998. A closer look to the bacteriology bacteriology

Study of bacteria. Modern understanding of bacterial forms dates from Ferdinand Cohn's classifications. Other researchers, such as Louis Pasteur, established the connection between bacteria and fermentation and disease.
 of nitrification. Aquacultural Eng. 18:223-244.

Hahn, K. O. 1989. Handbook of culture of abalone and other marine gastropods. Boca Raton Boca Raton (bō`kə rətōn`), city (1990 pop. 61,492), Palm Beach co., SE Fla., on the Atlantic; inc. 1925. Boca Raton is a popular resort and retirement community that experienced significant industrial development in the 1970s and 80s. , FL: CRC (Cyclical Redundancy Checking) An error checking technique used to ensure the accuracy of transmitting digital data. The transmitted messages are divided into predetermined lengths which, used as dividends, are divided by a fixed divisor.  Press. 348 pp.

Harris, J. O., G. B. Maguire, S. J. Edwards & S. M. Hindrum. 1997. Effect of nitrite on growth and oxygen consumption for juvenile greenlip abalone, Haliotis laevigata Donovan. J. Shellfish Res. 16:395-401.

Harris, J. O., G. B. Maguire, S. J. Edwards & S. M. Hindrum. 1998. Effect of ammonia on growth rate and oxygen consumption of the juvenile greenlip abalone, Haliotis laevigata Donovan. Aquaculture 160:259-272.

Harris, J. O., G. B. Maguire, S. J. Edwards & D. R. Johns. 1999. Low dissolved oxygen reduces growth rate and oxygen consumption rate of juvenile greenlip abalone, Haliotis laevigata Donovan. Aquaculture 174:265-278.

Higham, J. O., P. Hone, S. Clarke, R. Baudinette & M. Geddes. 1998. The effect of flow on growth on the juvenile greenlip abalone, Haliotis laevigata (Donovan). In: P. W. Hone, editor. Proceedings of the 5th annual abalone aquaculture workshop. Canberra, Australia: Hobart. FRDC. pp. 115-122.

Hindrum, S. M. M. Cropp & G.B. Maguire. 1995. Evolution of abalone growout tank design at Marine Shellfish Hatcheries, Bicheno, Tasmania Bicheno is a town on the east coast of Tasmania, Australia, 185 km north-east of Hobart on the Tasman Highway, with a population of 771 <ref name="population" />. It is part of the municipality of Glamorgan/Spring Bay. . Proceedings of the 2nd annual FDRC/CRC workshop on abalone culture, CSIRO CSIRO Commonwealth Scientific & Industrial Research Organization (Australia)  Marine Laboratories. Canberra, Australia Hobart. FRDC. pp 78-91.

Huchette, S. M. H., C. S. Koh & W. D. Day. 2003. Growth of juvenile blacklip abalone (Haliotis rubra) in aquaculture tanks: effects of density and ammonia. Aquaculture 219:457-470.

Jee, Y. J., S. K. Yoo, S. Rho & S. H. Kim. 1988. The stocking density and growth of young abalone Haliotis discus hannai lno cultured in hanging net cage. Bull. Nat. Fish. Res. Dev. Agency 42:59-69.

Jensen, F. B., N. A. Anderson & N. Heisler. 1987. Effects of nitrite exposure on blood respiratory properties, acid-base and electrolyte regulation in the carp (Cyprinus carpio). J. Comp. Physiol. 157B:533-541.

Kinne, O. editor. 1976. Marine Ecology Marine ecology

An integrative science that studies the basic structural and functional relationships within and among living populations and their physical-chemical environments in marine ecosystems.
, Vol. 3. London: Wiley. 1239 pp.

Labatut, R. A. & J. F. Olivares. 2004. Culture of turbot (Scohthalmus maximus) juveniles using shallow raceways tanks and recirculation. Aquacultural Eng. 32:113-127.

Leonard, N., J. P. Guiraud, E. Gasset, J. P. Cailleres & J. P. Blancheton. 2002. Bacteria and nutrients-nitrogen and carbon-in a recirculating system for sea bass production. Aquaculture 26:111-127.

Liu, H. & J. W. Avault. 1996. Effect of nitrite on growth of juvenile red swamp crawfish red swamp crawfish

see procambarus clarkii.
, Procambarus clarkii Procambarus clarkii

farmed crustacean in family Astacidae; called also red swamp crawfish. See Table 23.
. J. Shellfish Res. 15:759-761.

Losordo, T. M., M. Masser & J. Rakocy. 1992a. Recirculating aquaculture tank production systems. An overview of critical consideration. Southern Regional Aquaculture Center Publication No. 451.6 pp.

Losordo, T. M., J. Rakocy & M. Masser. 1992b. Recirculating aquaculture tank production systems. Component options. Southern Regional Aquaculture Center Publication No. 453. 11 pp.

Malone, R. F. & D. G. Burden. 1988. Design of recirculating blue crab blue crab, common name for a crustacean, Callinectes sapidus, found on the S Atlantic and Gulf coasts of North America. The blue crab is a member of the family of swimming crabs known as the Portunidae and is characterized by a broad, semitriangular carapace  shedding systems. Louisiana Sea Grant College sea grant college
n.
A college or university that receives government grants for oceanographic research.
 Program. Louisiana State University Louisiana State University and Agricultural and Mechanical College, generally known as Louisiana State University or LSU, is a public, coeducational university located in Baton Rouge, Louisiana and the main campus of the Louisiana State University System. . August 1988. Baton Rouge Baton Rouge (băt`ən rzh) [Fr.,=red stick], city (1990 pop. 219,531), state capital and seat of East Baton Rouge parish, SE La. , LA. pp. 8-21.

Malone, R. F., K. A. Rush & J. M. Christensen. 1996. Design of recirculating crawfish crawfish: see crayfish.  system employing expandable granular biofilters. In: Aquacultural Engineering Society Proceedings II. Successes and failures in commercial recirculating aquaculture. Roanoke, Virginia Roanoke is an independent city located in the Commonwealth of Virginia. The city of Roanoke is adjacent to the city of Salem and the town of Vinton and is otherwise surrounded by, but politically separate from, Roanoke County. . pp. 467-480.

Malone, R. F. & L. E. Beecher. 2000. Use of floating bead filters to recondition re·con·di·tion  
tr.v. re·con·di·tioned, re·con·di·tion·ing, re·con·di·tions
To restore to good condition, especially by repairing, renovating, or rebuilding.
 recirculating waters in warm water aquaculture production systems. Aquacultural Eng. 22:57-73.

Masser, M. P., J. Rakocy & T. M. Losordo. 1998. Recirculating aquaculture tank production systems. Southern Regional Aquaculture Center Publication No. 452. 11 pp.

Medina-Romo, E. Z. 2002. Temperatura oprima de cultivo y temperatura critica maxima del abulon azul Haliotis fulgens. Licenciatura Thesis. Facultad de Ciencias Marinas. Universidad Autonoma de Baja California. Ensenada, Baja California
For other uses see Ensenada (disambiguation)


Ensenada is the third-largest city in the Mexican state of Baja California. It is located 116 km (about 70 miles) south of Tijuana, at .
. Mexico. 62 pp.

Mgaya, Y. D. & J. P. Mercer. 1995. The effects of size grading and stocking density on growth performance of juvenile abalone, Haliotis tuberculata Linnaeus. Aquaculture 136:297-312.

Najmudeen, T. M. & A. C. C. Victor. 2004. Seed production and juvenile rearing of tropical abalone Haliotis varia Linnaeus 1758. Aquaculture 234:277-292.

Nie, Z. Q., M. F. Ji & J. P. Yan. 1996. Preliminary studies on increased survival and accelerated growth of overwintering o·ver·win·ter·ing
n.
The persistence of an infectious agent in its vector for an extended period, as in the cooler winter months, during which the vector has no opportunity to be reinfected or to infect another host.
 juvenile abalone, Haliotis discus hannai Ino. Aquaculture 140:177-186.

Park, M. E., S. Rho & C. B. Song. 1995. Density effect on the growth of juvenile abalones (Haliotis discus hannai) reared in the closed recirculating water system. Bull. Mar. Res. Int. Cheju. Natl. Univ. 19:93-102.

Pfeiffer, T. 2004. System design: parallel or series flow. Aquaculture Magazine Aquacultural Engineering Society. March/April. pp. 51-52.

Pfeiffer, T., T. B. Lawson & K. A. Rusch. 1999. Northern quahog, Mercenaria mercenaria, seed clam waste characterization study: precursor to a recirculating culture system design. Aquacultural Eng. 20:149-161.

Ragg, N. L., H. H. Taylor & J. Behrens. 2000. Stress and weight loss associated with handling in the blackfoot abalone, Haliotis iris. Fourth International Abalone Symposium Abstracts. February 2003. Cape Town, South Africa. pp. 42.

Re-Araujo, C. G. 2003. Temperatura preferida y critica maxima con dos niveles de salinidad en el abuldn rosa Haliotis corrugata. Licenciatura Thesis. Universidad Autonoma de Baja California. Ensenada, Baja California. Mexico. 40 pp.

Salas-Garza, A. E. & R. Searcy-Bernal. 1992. Desarrollo y estado actual del cultivo del abuldn en Mexico. In: S. A. Shephered, M. J. Tegner & S. A. Guzman del Proo, editors. Abalone of the world, biology, fisheries and culture. Oxford: Fishing New Books pp. 538-546.

Sandu, S. I., G. D. Boardman, B. J. Watten & B. L. Brazil. 2002. Factors influencing the nitrification efficiency of fluidized bed filter with a plastic bead medium. Aquacultural Eng. 26:41-59.

SAS. 1985. SAS/STAT Guide for personal computers. Version 6. Cary, NC: SAS Institute. 378 pp.

Sastry, B. N., A. A. De los Reyes, K. A. Rusch & R. F. Malone. 1999. Nitrification performance of a bubble-washed bead filter for combined solid removal and biological filtration in a recirculating aquaculture system. Aquacultural Eng. 19:105-117.

Sawa, N. 2000. A recirculating system for reproductive conditioning of abalone broodstock. Proceeding of 7th annual abalone aquaculture workshop. NSW NSW New South Wales

Noun 1. NSW - the agency that provides units to conduct unconventional and counter-guerilla warfare
Naval Special Warfare
, Australia. pp. 31-32.

Simonel, I., G. D. Boardman, B. J. Watten & B. L. Brazil. 2002. Factors influencing the nitrification efficiency of fluidized bed filter with a plastic bead medium. Aquacultural Eng. 26:41-59.

Spencer, B. E. 2002. Molluskan mol·lus·kan  
adj. & n.
Variant of molluscan.
 shellfish farming, 1st edition. Oxford, UK: Blackwell. 274 pp.

Spotte, S. editor. 1979. Fish and invertebrate invertebrate (ĭn'vûr`təbrət, –brāt'), any animal lacking a backbone. The invertebrates include the tunicates and lancelets of phylum Chordata, as well as all animal phyla other than Chordata.  culture, water management in closed system. 2nd edition. New York New York, state, United States
New York, Middle Atlantic state of the United States. It is bordered by Vermont, Massachusetts, Connecticut, and the Atlantic Ocean (E), New Jersey and Pennsylvania (S), Lakes Erie and Ontario and the Canadian province of
: Wiley. 179 pp.

Steinarsson, A. & A. K. Imsland. 2003. Size dependent variation in optimum growth temperature of red abalone (Haliotis rufescens). Aquaculture 224:353-362.

Summerfelt, S. T., G. Wilton, D. Roberts, T. Rimmer & K. Fonkalsrud. 2004. Developments in recirculating systems for Artic char culture in North America. Aquacultural Eng. 30:31-71.

Timmons, M. B., J. Ebeling, F. Wheaton, S. Summmerfelt & B. Vinci. 2002. Recirculating aquaculture systems, 2nd edition. Ithaca NY: Northeastern Regional Aquaculture Center. Publication No. 01-002. 769 pp.

Valdes-Urriolagoitia, A. A. 2000. Efecto de tres densidades de cultivo en la sobrevivencia y crecimiento de juveniles de abulon rojo Haliotis rufescens en un laboratorio comercial. Licenciatura Thesis. Facultad de Ciencias Marinas. Universidad Autonoma de Baja California. Ensenada, Baja California. Mexico. 52 pp.

Vivanco-Aranda, M. 2004. Relacion entre el crecimiento y caracteristicas geneticas del abuldn en dos sistemas de cultivo. M.Sc. Thesis. Centro de Investigacion Cientifica y de Educacidn Superior de Ensenada. Ensenada Baja California, Mexico. 143 pp.

Wickins, J. F. 1976. The tolerance of warmwater prawn prawn: see shrimp.  to recirculated water. Aquaculture 9:19-37.

Wickins, J. F. 1981. Water quality requirements for intensive aquaculture: a review. In: E. Tiews, editor. Proceedings world symposium on aquaculture in heated effluents and recirculation systems, Stavanger, Norway. pp. 17-37.

Williams, E. M., M. L. Glass & N. Heisler. 1992. Blood oxygen tension and content in carp, Cyprinus carpio L., during hypoxia hypoxia

Condition in which tissues are starved of oxygen. The extreme is anoxia (absence of oxygen). There are four types: hypoxemic, from low blood oxygen content (e.g., in altitude sickness); anemic, from low blood oxygen-carrying capacity (e.g.
 and methaemoglobinaemia. Aquacult. Fish. Mgmt. 23:679-690.

L. BADILLO, (1) M. SEGOVIA (1) * AND RICARDO SEARCY-BERNAL (2)

(1) Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, Division de Oceanologia, Depto. de Acuicultura, Diseno y Desarrollo de Tecnologia Acuicola. Km. 107 Carretera Tijuana-Ensenada, Ensenada, B.C., C.P. 22860 Mexico; (2) Universidad Autonoma de Baja California, Instituto de Investigaciones Oceanologicas, P.O. Box 453, Ensenada, B.C. 22860, Mexico

* Corresponding author. E-mail: msegovia@cicese.mx
TABLE 1.
Average water exchange rate per day throughout the experiment
in the three systems (S1, S2, and S3).

                         Time (days)

         December    January    February    March

S1           289%       289%        289%     289%
S2          4.92%      2.66%       2.41%    1.98%
S3          4.92%      2.66%       2.41%    1.98%

TABLE 2.
Pink abalone H. corrugata total mortality rate by system
and density. Values with the same letter are not significantly
different (P > 0.05).

System and    Stocking Density     Total Mortality         Total
Density       (% Surface area)   (Number of abalone)   Mortality (%)

S1D1                 10                  33              10.58 (b)
S1D2                 30                  90              10.14 (b)
S2D1                 10                  41              19.71 (b)
S2D2                 30                  39              13.18 (b)
S3D1                 10                  21              20.19 (b)
S3D2                 30                 176              29.73 (a)
Total                                   400              16.67
COPYRIGHT 2007 National Shellfisheries Association, Inc.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2007, Gale Group. All rights reserved.

 Reader Opinion

Title:

Comment:



 

Article Details
Printer friendly Cite/link Email Feedback
Author:Badillo, L.; Segovia, M.; Searcy-Bernal Ricardo
Publication:Journal of Shellfish Research
Geographic Code:1MEX
Date:Sep 1, 2007
Words:5928
Previous Article:Effects of antibiotics on the concentration of bacteria in biofilms and on the growth of Haliotis rufescens postlarvae.
Next Article:Effects of vitamin E on antioxidant enzyme activities and fatty acid compositions in juvenile abalone Haliotis discus hannai Ino.
Topics:



Related Articles
Experimental abalone ranching on artificial reef in Port Phillip Bay, Victoria.
Viability of abalone (Haliotis iris) stock enhancement by release of hatchery-reared seed in Marlborough, New Zealand.
Modeling growth and mortality of red abalone (Haliotis rufescens) in Northern California.
Comparisons of rearing systems based on algae or formulated feed for juvenile greenlip abalone (Haliotis laevigata).
Investigation of optimal temperature and light conditions for three benthic diatoms and their suitability to commercial scale nursery culture of...
Effect of three photoperiod regimes on the growth and mortality of the Japanese abalone Haliotis discus hannai Ino.
Evaluation of growth and survival of juveniles of the Japanese abalone Haliotis discus hannai in two culture systems suspended in tanks.
Metamorphosis and postlarval growth of abalone Haliotis rufescens in a Mexican commercial hatchery.
Effect of darkness and water flow rate on survival, grazing and growth rates of abalone Haliotis rufescens postlarvae.
Effects of antibiotics on the concentration of bacteria in biofilms and on the growth of Haliotis rufescens postlarvae.

Terms of use | Copyright © 2014 Farlex, Inc. | Feedback | For webmasters