Papers by Ricardo Searcy Bernal
Scientific Reports, Jan 9, 2024
Marine reserves (MRs) are implemented worldwide to protect, restore, and manage marine ecosystems... more Marine reserves (MRs) are implemented worldwide to protect, restore, and manage marine ecosystems and species. However, it is important to document the positive effects those marine reserves have on slow-growth, temperate invertebrates such as abalone. Abalone, Haliotis spp., are marine gastropods of high economic value extracted worldwide for decades, which has led to fisheries-driven population decreases. In this work, we focused on a case study and assessed the short-term (1-2 years) effects of marine reserves established and managed by a local fishing cooperative at Guadalupe Island, Mexico. We evaluated the population status of green abalone, H. fulgens, by conducting (1) an assessment of the green abalone population around Guadalupe Island through subtidal monitoring and (2) an evaluation of the effect of two recently established marine reserves on population parameters such as the increase in density (individuals•m 2 ), biomass, number of aggregated abalone, egg production, and proportion of individuals bigger than 150 mm (minimum harvest size) compared to fished areas. To assess the population around Guadalupe Island, we surveyed 11,160 m 2 during 2020 and 2021. We recorded 2327 green abalones with a mean ± SE shell length of 135.978 ± 0.83 mm and a mean density of 0.21 ± 0.02 individuals•m 2 . All variables were statistically higher at the MRs except for shell length in 2021. In this work, we report for the first time the green abalone population status at Guadalupe Island and a positive short-term biological response to community-based marine reserves. This study suggests that a network of MRs combined with good management could help abalone populations in the short term in Guadalupe Island, potentially leading to more sustainable fishing practices and social-ecological resilience. Marine reserve CONANP Comisión Nacional de Áreas Protegidas PROSEMAR Proyectos y Servicios Marinos Marine protected areas or marine reserves (MR) have the potential to rebuild depleted populations 1 , increase fisheries yields through adult 2 and larvae spillover 3,4 , protect biodiversity 5 , empower local communities 6 , and assure the continuing flow of ecosystem services 7 . In addition, establishing MRs is a well-documented approach for reducing local disturbance of selective fishing and stock collapses from overexploitation 8-10 .
Ciencias Marinas, 2020
In recent decades, global abalone aquaculture has significantly increased, while wild abalone fis... more In recent decades, global abalone aquaculture has significantly increased, while wild abalone fishery landings have decreased drastically, shifting production from fishing to farming. In California (USA) and Baja California (Mexico), overfishing and climate changelinked diseases are thought to be responsible for mass mortalities and significant declines in abalone fisheries landings. Conservation aquaculture is an option for enhancing abalone populations through captive propagation and cage mariculture with subsequent restockings into the wild. To test, inform, and promote innovative sustainable seafood production strategies in the Northeastern Pacific, we designed an experimental mariculture system at San Jeronimo Island, Baja California. We explored the feasibility of rearing juvenile red abalone, Haliotis rufescens, in a near-shore mariculture cage-based production system to supply individuals for local restoration programs. We tested the effects of 2 different depths, surface an...
Ciencias Marinas, 2009
Four-day-old postlarvae of the abalone Haliotis corrugata were exposed to different diatom densit... more Four-day-old postlarvae of the abalone Haliotis corrugata were exposed to different diatom densities (Navicula incerta, 0 to 8000 cells mm–2) under two illumination conditions: constant light (19–21 µmol quanta m–2 s–1) and darkness. The effect of these two factors on postlarval grazing rate, survival, and growth was evaluated. The experiment was conducted for 14 days in 10-mL sterile wells following a split-plot experimental design with three replicates per treatment. The highest grazing rate was observed in the 2000 cells mm–2 density treatment and it was higher in darkness (196 ± 67 cells pl–1 h–1) than in constant light (139 ± 36 cells pl–1 h–1). Mean survival was also higher in darkness (59%) than under constant light (44%), as was mean growth rate (20 and 14 µm d–1, respectively). Growth rate at the end of the experimental period tended to decrease with the increase in diatom density. Higher grazing and growth rates in darkness reinforce the hypothesis that the nocturnal habit...
Journal of Shellfish Research, 2016
The effects of different diets on the survival, growth, food consumption, and conversion factor o... more The effects of different diets on the survival, growth, food consumption, and conversion factor of juvenile red abalone (Haliotis rufescens) under tank culture conditions were investigated. The algae Macrocystis pyrifera, Gracilaria chilensis, and Sarcothalia crispata were administered as mixed diets, mono diets, or in rotation changing weekly. Additionally, an artificial pellet feed (ABfeed) was administered alone using a feeder or as part of a mixed diet. The experiment lasted 10 mo. The 100% S. crispata diet was suspended after 4 mo due to low survival rates (92.1% ± 3.4%). Treatments had significant effects (P < 0.05) on survival, growth, food consumption, and conversion factor. The lowest survival rate was obtained using the artificial feed with a feeder (94.2% ± 4.3%) and the highest with a mix of M. pyrifera and artificial feed (99.0% ± 0.8%). The highest growth rates were obtained with the mix of M. pyrifera, G. chilensis, and artificial feed (0.044 ± 0.007 mm/day per 0.054 ± 0.005 g/day) and with 100% M. pyrifera (0.043 ± 0.002 mm/day per 0.054 ± 0.01 g/day). The lowest growth rates were obtained with 100% G. chilensis (0.026 ± 0.01 mm/day per 0.021 ± 0.01 g/day). Food conversion factor was highest with the mixed M. pyrifera (16.0) and G. chilensis (12.7) diet, whereas the lowest food conversions rates were obtained using artificial feed with a feeder (1.4) and artificial feed without a feeder (1.6). In this study, the M. pyrifera mono diet produced the highest growth rates in H. rufescens juveniles. Given that it is also the most abundant alga in terms of biomass and is easily managed during the feeding process, this would appear to be the best option for the culturing red abalone in southern Chile.
Regional Studies in Marine Science, 2017
• Isostichopus fuscus asexual reproduction was induced by fission and body parts regenerated in 9... more • Isostichopus fuscus asexual reproduction was induced by fission and body parts regenerated in 90 days. • A high protein diet with brown macroalgae powder produced a rapid growth of posterior body parts. • This technique might be used for restoring wild populations of sea cucumbers.
Journal of Shellfish Research, 2016
The evaluation of abalone (Haliotis spp.) restocking programs might be improved by the use of mic... more The evaluation of abalone (Haliotis spp.) restocking programs might be improved by the use of microchips attached to seeds ]. Preliminary studies were conducted to standardize this methodology and to assess tag retention and the potential impacts of tagging red abalone (Haliotis rufescens) seeds (initial averages: 26 mm SL, 2.5 g total weight) with passive integrated transponder (PIT) tags (932 mm, Biomark, HPR Plus Reader). Tags were placed in previously made grooves in the shells and glued with a cyanoacrylate adhesive fast cured with sodium bicarbonate. Laboratory trials showed that metabolic rate increased in tagged seeds compared with untagged controls (t ¼ 4.74, P ¼ 0.009) immediately after the tagging procedure, but this effect was not significant after 3 h (t ¼ 1.43, P ¼ 0.23). Food (Macrocystis pyrifera) consumption after 24 h was similar by seeds marked with PIT tags, plastic tags, both tags, and untagged controls (F ¼ 0.12, P ¼ 0.94). Tag retention and survival was 100% after 108 days in all treatments and no effects were detected on growth rates in length (range ¼ 0.92-1.11 mm/mo, F ¼ 0.72, P ¼ 0.57) or weight (range ¼ 0.30-0.44 g/mo, F ¼ 2.44, P ¼ 0.16). Results from a small-scale field experiment in tide pools, suggest that the detection of planted abalone seeds can be significantly improved when these are marked with PIT tags, compared with those marked with conventional plastic tags. Improvements should, however, be made regarding antenna design and reading distance to optimize the use of this technology to evaluate restocking programs.
Journal of Shellfish Research, 2007
Metamorphosis induction and postlarval growth of the red abalone (Haliotis rufescens) were evalua... more Metamorphosis induction and postlarval growth of the red abalone (Haliotis rufescens) were evaluated in a commercial farm of Baja California, Me´xico. This hatchery settles larvae with gamma-aminobutyric acid (GABA, 1-mM final concentration) and culture postlarvae in 250-L tanks placed in a four-story structure inside a building with artificial illumination. Eight tanks (four at the top and four at the bottom of a culture structure) were sampled during four months after settlement. Upper tanks received more light than the lower tanks (means of 727 and 217 lux, respectively) and had a higher mean water temperature (14.9°C and 14.4°C, respectively). Estimates of metamorphosis induction were highly variable (37% to 99%) and mean values were higher in lower (76%) than in higher (54%) tanks. Potential causes of this unexpected variability are discussed. There was a significant positive linear relationship between metamorphosis induction and early (7-day) postlarval survival. Average postlarval growth rates were also highly variable among tanks (37-63 mm/day) and slightly higher in upper than in lower tanks (60 and 52 mm/day, respectively). During the sampling period, growth variability was positively associated with water temperature changes, especially after the formation of the first respiratory pore when growth increased abruptly.
Journal of Shellfish Research, 2007
Traditional abalone culture is carried out in flow-through systems with water exchange rates betw... more Traditional abalone 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 ± 2.0 g and 37.01 ± 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:
Journal of Shellfish Research, 2007
The effect of two light conditions (light at 10-13-mmol quanta/m 2 /s and darkness) in three wate... more The effect of two light conditions (light at 10-13-mmol quanta/m 2 /s and darkness) in three water flow rates (0, 200, and 600 mL/min) on the survival, grazing, and growth rates of 6-day-old Haliotis rufescens postlarvae (pl) was evaluated. A factorial experiment with three replicates per treatment in blocks was conducted for 44 days in 2-L plastic containers with ca. 100 postlarvae each, inoculated every week with the cultured diatom Navicula incerta. Survival was highest (80%) in the treatment without water flow and with light, whereas the lowest (52%) corresponded to the 600-mL/min flow rate under darkness, but these differences were not significant. Initial grazing rate was significantly higher in darkness than in light (37 cell/pl/hr, SE ¼ 1.6, and 27 cell/pl/hr, SE ¼ 2.8, respectively). Growth rate was not significantly affected by the light treatments. However, in static conditions growth was higher in darkness (38-mm/day, SE ¼ 2.0) than in light (34-mm/day, SE ¼ 1.0). Growth rates of postlarvae were significantly affected by flow conditions, with means of 36 (SE ¼ 1.3), 33 (SE ¼ 0.7) and 31 (SE ¼ 0.7) mm/day in flows of 0, 200, and 600 mL/min, respectively). These results suggest that the benefits of dark conditions on the growth rate of abalone postlarvae shown in previous experiments might not occur under flow conditions. However, the flow rates tested here were apparently too high to allow an optimal postlarval growth and slower flows should be tested in future experiments. On the other hand, flow allowed the development of high diatom densities under the light condition, which were difficult to maintain in darkness.
Journal of Shellfish Research, 2007
The effects of chloramphenicol and streptomycin/penicillin on the concentration of heterotrophic ... more The effects of chloramphenicol and streptomycin/penicillin on the concentration of heterotrophic bacteria in biofilms associated with abalone postlarval culture and on the growth and survival of Haliotis rufescens postlarvae (3-5 days old) were studied under laboratory conditions. Two experiments were carried out in 12-well polystyrene tissue culture plates with 5 mL of 1-mm-filtered autoclaved seawater. Water was changed every other day and antibiotics were added during the water change. Experimental units were previously inoculated with the benthic diatom Navicula incerta. In the first experiment chloramphenicol at 0, 5, 10, and 20 mg L -1 was used and a mixture of streptomycin and penicillin at 0/0, 50/50, 100/100, and 150/150 mg L -1 was tested in the second experiment (in both cases with three replicates). Bacterial counts (Zobell plates) were performed for a period of 4 and 5 wk (experiments 1 and 2, respectively). Bacterial densities decreased 90% in 20 mg L -1 of chloramphenicol during the first 48 h; however, bacterial counts increased in all treatments thereafter and differences were not significant at the end of the experiment. The growth of abalone postlarvae was not significantly different among treatments. In the experiment with antibiotic mixtures, bacterial abundance was reduced 99% at the highest concentration (150/150) in the first 48 h, and remained significantly lower than the control for 2-3 wk. During this period, postlarval growth in this antibiotic treatment was also slower, as well as final survival, suggesting an important role of bacteria in the nutrition and/or digestion of abalone postlarvae. Results of this study also suggest that bacterial resistance to these antibiotics develops fast, discouraging their long-term use in abalone culture.
Journal of Shellfish Research, 2010
During the 2008 season, 318 mt (meat weight) of abalone (Haliotis spp.) were commercially fished ... more During the 2008 season, 318 mt (meat weight) of abalone (Haliotis spp.) were commercially fished in Me´xico. The species composition of the catch was H. fulgens (70.8%), H. corrugata (28.9%), and H. cracherodii (0.3%). During the past 5 y, total catches increased 29% as a result of the recovery of natural populations of the 2 main species. In particular, H. corrugata catches increased from 50.4 t in 2004 to 91.7 t in 2008 (up by 82%). Currently, 3 private farms culture abalone (mostly H. rufescens) to market size (approximately >7 cm), and 29.6 t of this product were sold in 2008, mostly to markets in Asia and the United States. One of these companies is also producing abalone pearls and jewelry. A new private farm with restocking and growout objectives has just started operations. In addition, 6 hatcheries of fishermen cooperatives produce larvae and seed for restocking purposes and at least 2 of these have started grow-out trials. During the past 2 y, more than 130 million larvae and 350 thousand seeds (approximately >1.5 cm) of H. fulgens and H. corrugata have been released in the wild stocks by these cooperative hatcheries.
Journal of Shellfish Research, 2007
Abalone aquaculture is rapidly developing in Chile although this mollusc does not occur naturally... more Abalone aquaculture is rapidly developing in Chile although this mollusc does not occur naturally in this country. The red abalone Haliotis rufescens was introduced in 1977 and the ezo abalone Haliotis discus hannai in 1982. After several years of research and development, the industry began in 1992 and Chile is currently the fifth producer of cultured abalone in the world with 304 tons in 2006. Twenty five companies are involved in this Chilean industry, culturing mainly red abalone. Most of the farms in the North include hatcheries and land-based grow-out operations, whereas most of the in-water grow-out facilities are located in the South. All farms in Chile use algae as the main food for growing abalone, but artificial feeds are also used in some land-based operations in the North. The average size of abalone harvested in Chile is 8 cm (100-120 g) after 3-5 y in culture systems. Whole frozen abalone (shell on) is the most important form of this Chilean product (82% in 2006) and the main market is Japan (90.2%). Abalone production has increased at a rate of around 50% per annum over the last 3 y. This development is expected to continue in the next years, fostered by favorable geographic, economic, and environmental conditions as well as an important government support to invest in abalone. A survey among producers revealed that feed availability and quality is currently considered a key issue to further develop this industry in Chile.
Journal of Shellfish Research, 2013
The effect of different strategies of opening water flow on the survival and growth of Haliotis r... more The effect of different strategies of opening water flow on the survival and growth of Haliotis rufescens 9-d postlarvae was evaluated using a randomized block design with 3 replicates for 63 days. Larvae were settled (1.5 mM gammaaminobutyric acid) in 2-L plastic vessels (total area, 701 cm 2 ) and were subjected to the following treatments: static conditions, static conditions with aeration (NF + A), flow opened after 10 d, flow opened after 17 d, and flow opened after 24 d. The experiment was conducted at constant temperature (17.5 ± 0.5°C) and light intensity (;750 lux). Water was changed daily in static treatments, and flow treatments received filtered seawater at ;60 mL/min. Postlarvae were fed the benthic diatom Navicula incerta per standardized protocols. Every week, all organisms in each experimental unit were counted to estimate survival, and samples of 15 postlarvae were recorded under an inverted microscope and measured using digital image analysis. At the end of the experiment, greater survival occurred in treatment NF + A (68.2%) and was the lowest in the treatment in which flow was opened after 10 days (26.9%); however, no significant differences were found (P > 0.37). The greatest growth rate was observed in the treatment in which flow was opened after 24 days (61.6 mm/d), and the lowest was seen in static conditions (47.6 mm/d and 44.6 mm/d for static conditions and NF + A treatments, respectively). An inverse relationship between final growth rates and postlarval densities was found. Our results suggest that abalone postlarvae can be cultured successfully in static conditions with aeration, but feeding routines should be improved to allow high growth rates at high stocking densities.
Journal of Shellfish Research, 2013
Abalone restocking in the peninsula of Baja California, Mexico, has been practiced for more than ... more Abalone restocking in the peninsula of Baja California, Mexico, has been practiced for more than 2 decades by fishermen cooperatives. We describe the methods used to produce and release abalone larvae and seeds by these organizations, and provide their recent production statistics. From 2005 to 2011, 2.2 million seeds (>15 mm) and 692 million competent larvae were produced by 6 cooperative hatcheries and released in their fishing grounds. Of these, 90.1% of the seeds and 80.7% of the larvae corresponded to Haliotis fulgens, whereas the figures for Haliotis corrugata were 9.9% and 19.3%, respectively. The research conducted in Mexico on the evaluation of the impact of restocking is also addressed. Preliminary results suggest that less than 5% of the seeds stocked are incorporated into commercial catches.
Journal of the World Aquaculture Society, 1998
The induction of larval metamorphosis is a critical step in abalone Haliotis spp. culture. Recent... more The induction of larval metamorphosis is a critical step in abalone Haliotis spp. culture. Recently, gamma-aminobutyric acid (GABA) has been used as an inducer by an increasing number of commercial hatcheries, because of its higher efficiency over other settlement methods. The conventional GABA concentration used is 1.0 micromolar as suggested by controlled laboratory experiments. However, poor results are occasionally reported in hatcheries, probably because the bacterial load in commercial systems degrade the inducer to levels below the required threshold. To cope with this problem, GABA concentration might be increased within safe limits to compensate for potential bacterial degradation, but information to adequately support this alternative is missing. This contribution describes two experiments on this issue with red abalone. H. rufescens larvae which suggest that GABA concentration could be increased at least 100% without causing the detrimental effects on metamorphosis induction or postlarval fitness reported for higher toxic levels. The impact of this result on abalone seed production is discussed.
Journal of Applied Phycology, 2010
Recently recruited urchins from the same brood, but with different initial sizes, may respond dif... more Recently recruited urchins from the same brood, but with different initial sizes, may respond differently to similar environmental factors. The aim of this study was to assess and compare the effects of starvation and diet on the survival, growth rates in size and weight, and gonad index among small and large sub-adult purple sea urchins, Strongylocentrotus purpuratus. Small urchins ranged from 7.3 to 7.8 mm and large urchins from 11.8 to 14.1 mm (test diameters). Two independent experiments were performed. In the first experiment, sea urchins were fed during 22 weeks on Egregia menziesii (ad libitum) and for only 1 day month -1 (starved condition). Feeding regime significantly affected survival, somatic growth rate in size and weight, and gonad index, with higher means in the ad libitum treatments than in starving conditions. A recurrent cannibalism event by conspecifics occurred in small sea urchins under starving conditions. In the second experiment, sea urchins were fed during 13 weeks ad libitum with four diets: kelp (E. menziesii), coralline algae (Bossiella orbigniana), eelgrass (Phyllospadix scouleri) and a mixed diet of the three species. Survival was not affected by diet or urchin size, but diet significantly affected somatic growth rate in size and weight and gonad index. Kelp promoted the highest growth rate (2.23±0.21 mm month -1 ), the mixed diet produced an intermediate growth (1.26±0.21 mm month -1 ), while the lowest values corresponded to coralline algae and the eelgrass (0.30±0.12 and 0.10±0.03 mm month -1 , respectively, means ± SE). The mean growth rate of small urchins (averaging all diets) was higher than in large specimens (1.17±0.37 and 0.77±0.28 mm month -1 , respectively).
Diseases of Aquatic Organisms, 2004
The effect of increasing concentrations of Vibrio alginolyticus on survival of Mytilus galloprovi... more The effect of increasing concentrations of Vibrio alginolyticus on survival of Mytilus galloprovincialis larvae was studied in a 48 h static bioassay in 1 l glass bottles. Five bacterial densities were tested ranging from 10 2 to 10 6 bacteria ml -1 . Larval survival and normality (veliger larvae with the typical D-shape) were evaluated after 48 h. An inverse relationship between bacterial concentration and larval survival and normality was observed. In spite of high larval survival (79%) under conditions of high bacterial density (10 5 bacteria ml -1 ), the percent of normal larvae was 11%. Besides an irregular shape, abnormal larvae also presented velum reduction. Results from this study suggest that concentrations of V. alginolyticus lower than 10 3 bacteria ml -1 should be maintained during M. galloprovincialis larval culture.
Effect of three bacterial isolates from a commercial hatchery on early red abalone (Haliotis rufescens) postlarvae
Aquaculture International, 2012
ABSTRACT Three bacterial strains, GHrC11, GHrC13 and GHrC15, were isolated from an abalone postla... more ABSTRACT Three bacterial strains, GHrC11, GHrC13 and GHrC15, were isolated from an abalone postlarval culture system in a commercial farm at Baja California, México. The strains were phenotypically characterized and sequenced (16S rDNA). Strain GHrC11 was a Gram-positive coccobacillum, while strains GHrC13 and GHrC15 were Gram-negative bacilli. Strain GHrC11 was identified as Exiguobacterium sp. The strains GHrC13 and GHrC15 were identified as Vibrio splendidus. The effects of these strains for the development of early abalone postlarvae (2 days old) were evaluated following a completely randomized design with three replicates using 5-mL-volume Petri dishes as experimental units. The experiment considered two different bacterial concentrations of each strain (103 and 105 cells ml−1) and two controls (with and without the benthic diatom Navicula incerta). After 10 days of experimentation, the highest mortality (90 ± 5.8 %) and the lowest growth rate (4.1 ± 0.1 μm day−1) were recorded for the strain GHrC11. In contrast, the lower mortality (16.7 ± 3.3 %) and the highest growth rate (11.2 ± 0.9 μm day−1) corresponded to the control fed N. incerta. Our results suggest that pathogenic effects of these bacterial strains were stronger than any potential benefits derived from the ingestion of bacteria by early abalone postlarvae. In conclusion, the most pathogenic strain was GHrC11, and the intensity of pathogenicity could be ordered as Exiguobacterium sp. &gt; V. splendidus (C13) &gt; V. splendidus (C15).
Effect of lipid emulsion and kelp meal supplementation on the maturation and productive performance of the geoduck clam, Panopea globosa
Aquaculture, 2013
Abstract Adult Panopea globosa clams were conditioned in the laboratory during 8 weeks (mid Oct–D... more Abstract Adult Panopea globosa clams were conditioned in the laboratory during 8 weeks (mid Oct–Dec) under a decreasing temperature regime (22–18 °C) and using a semi-open recirculating system to investigate the effect of kelp meal (powdered Macrocystis pyrifera ) or fish oil supplementation to live microalgal diets (w/w basis) on the live body weight (BW), flesh weight (FW), body water content (BWC), gonad weight, gonadosomatic (GI) and condition indices (CI) of experimental organisms. Three dietary treatments were used, and consisted of 100% of the flagellate Isochrysis sp. clone T-ISO (treatment I), 70% T-ISO + 30% kelp meal (IK), and 70% T-ISO + 30% cod liver oil (IO). Ingestion rates (IR) were also assessed during the first month of the experiment in clams from treatment I. The IR exhibited by adult P . globosa remained relatively constant during the evaluation period (0.027–0.035% BW d − 1 ). In contrast, significant time- and diet-dependent effects were observed in the live weight of conditioned organisms, those from treatment I showing the maximum values (1369 to 1533 g) after 7 weeks, followed by IO and IK. Lowest BWC (39.0 to 42.1%) coincided with the timing of maximum live weight and female gonad weight. Female and male gonad weights increased 2-fold and 1.4-fold respectively within the first month. Gonads from the IK treatment tended to be lighter than those from diets I or IO. Significant time, diet, and time × diet effects were observed on the flesh weight of the organisms, with higher values on the 8th week for organisms from treatment I. Neither CI nor GI was significantly affected by the test factors. Viable oocytes were detected only after 6 weeks of conditioning. Overall, the ration demanded by adults of P . globosa is relatively low, and adults can be successfully matured in the laboratory within a period of 6 to 8 weeks with Isochrysis sp . clone T-ISO as the sole diet, and an effective accumulated temperature of ca. 230 degree-days.
Boundary layers and abalone postlarval culture: Preliminary studies
Aquaculture, 1996
Aquaculture ELSEVIER Aquaculture 140 ( 1996) 129137 Boundary layers and abalone postlarval cultur... more Aquaculture ELSEVIER Aquaculture 140 ( 1996) 129137 Boundary layers and abalone postlarval culture: Preliminary studies Ricardo SearcyBemal Instituto de Investigaciones Oceanologicas, UniversidadAutonoma de Baja California, Apartado Postal 453 ...
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Papers by Ricardo Searcy Bernal