Pedro Moisés Nina Saucedo - Academia.edu (original) (raw)

Papers by Pedro Moisés Nina Saucedo

Journal of Shellfish Research, 2005

We evaluated experimental collection of Pinctada mazatlanica spat on substrates of different text... more We evaluated experimental collection of Pinctada mazatlanica spat on substrates of different textures and colors placed at different depths within settlement tanks. When larvae reached the pediveliger stage (day 25), black-colored spat collectors ("envelope" type) composed of the following materials were offered as settlement substrates: onion bag, mosquito net, fishing net, and 63% shade-cloth. Spat collectors measured 30 × 30 cm and were composed of an outer bag and inner substrate made of the same material. The influence of the color of spat collector material on recruitment was investigated using a second type of spat collector composed of onion bags as the outer bag and inner substrate ("bag" type). Bags were prepared in 3 different outer/inner (O/I) color combinations of green/green, green/black, and red/black (O/I). Both types of collectors were deployed at different depths within settlement tanks. Approximately 2.7% of the initial larval population survived, resulting in 35,583 spat. Of these, 71.3% recruited to bag type collectors, 21.9% to envelope type collectors, and 6.8% to the surfaces of the culture tanks. Spat recruitment was significantly affected by collector material (P < 0.01), with fishing net and shade-cloth yielding highest and lowest density of spat, respectively. Similarly, spat collector color combination significantly influenced spat collection (P < 0.01), with higher recruitment to red and green substrates. For both spat collector types, there was significantly greater (P < 0.01) recruitment of spat to collectors in the middle of the water column (60-90-cm depth). This study showed that both the type and color of material used for spat collectors, as well as depth of deployment, influenced recruitment of P. mazatlanica spat. These results will help fine-tune current hatchery techniques for this species.

Journal of Shellfish Research, 2005

We applied quantitative histochemical techniques and digital image analysis to study seasonal cyc... more We applied quantitative histochemical techniques and digital image analysis to study seasonal cycles of use of lipid and protein reserves during vitellogenesis in the pearl oyster Pinctada mazatlanica. Female gonad samples were collected seasonally during an annual cycle and processed histologically to characterize the gametogenic cycle, analyze variations in the frequency and size of vitellogenic and postvitellogenic oocytes and calculate the ooplasm:nucleoplasm ratio for both types of oocytes. Lipid and protein inclusions in each type of oocyte were identified using Sudan Black B and Schiff's ninhydrin stains. In both cases, quantification of lipid and protein components was performed through measuring variations in the color coverage area of the oocyte with a digital image analysis system. With this procedure, we calculated a lipid index and a protein index to refer oocyte quality. The lipid index was higher in winter, suggesting a strategy towards storage in the gonad. The protein index was highest during spring in vitellogenic oocytes and during winter in postvitellogenic oocytes, indicating that proteins are actively used during oocyte growth. These results, together with data of the ooplasm:nucleoplasm ratio, suggest differential accumulation of lipid and protein components within the ooplasm during oocyte development. Quantitative histochemistry and digital image analysis represent a combination of reliable techniques for evaluating reproductive processes and oocyte growth and quality.

Latin American Journal of Aquatic Research, 2016

We evaluated the effect of nine isocaloric diets prepared with a mixture of microalgae alone (Tis... more We evaluated the effect of nine isocaloric diets prepared with a mixture of microalgae alone (Tisochrysis lutea + Chaetoceros calcitrans + Ch. gracilis; 1:1:1) and different combinations of the algal mixture and cornstarch or wheat flour, on the Scope for Growth (SFG) of Cortez oyster Crassostrea corteziensis juveniles (7.2 ± 1.1 mm shell length). A total 15,000 spat was acclimated to the experimental diets for 30 days at 21ºC, prior SFG determinations. Consumed energy, absorbed energy, and SFG decreased with a corresponding decrease in the proportion of live microalgae in the diet. Oysters fed the microalgal diet showed significantly increased physiological activity in all parameters except absorption efficiency. Oysters fed diets containing up to 50% dry feedstuff showed positive SFG values but these were significantly lower than SFG shown in oysters fed microalgae alone. Oysters fed diets containing ≥75% dry feedstuff showed negative SFG. These results suggest that cereals can be used as complementary food or C. corteziensis spat in hatchery operations, provided replacement of microalgae is kept below 50%.

Tropical and Subtropical Agroecosystems, Apr 12, 2013

How to cite Complete issue More information about this article Journal's homepage in redalyc.org ... more How to cite Complete issue More information about this article Journal's homepage in redalyc.org Scientific Information System Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Non-profit academic project, developed under the open access initiative

Pteria penguin were collected at Orpheus Island, north-eastern Queensland to observe sexual devel... more Pteria penguin were collected at Orpheus Island, north-eastern Queensland to observe sexual development, sex ratio and changes in morphometric relationships during growth. P. penguin are protandrous hermaphrodites, with all sexually mature oysters below 88.8 mm dorso-ventral height (DVH) being males. Evidence of male primary gonad development was seen in oysters with a DVH of ≥33.9 mm. Sexual maturity of males was first seen in oysters at ≥56.0 mm DVH, but was common in oysters at ≥70.0 mm DVH. Mean female size was 150.1 (±3.6) mm DVH, and mean male size was 111.3 (±2.2) mm DVH. In oysters 180 mm DVH. Significant linear correlations were found between anterior-posterior length of the shell (APL) and DVH (r2 = 0.97, p <0.001) and between shell thickness (ST) and DVH (r2 = 0.95, p <0.001), and a curvilinear relationship was recorded between adductor muscle weight (AW) and DVH (r2 = 0.93, p <0.001). These findings have industry applications for collection of juvenile stock, spawning induction procedures and determining optimal shell size for pearl nucleus implanting.

Journal of Shellfish Research

Anesthetic drugs are common in management sequences of commercial aquaculture that imply relaxati... more Anesthetic drugs are common in management sequences of commercial aquaculture that imply relaxation of specimens. Studies on physiologic response and relationships with functions of body parts are particularly centered in fishes to improve transport, handling, or surgery (i.e., spawning stimulation, sampling of blood and fluids). In pearl oysters, relaxation therapies are important to induce round pearl formation with nucleus-mantle insertions, but the physiologic effect of drugs are poorly known. In the current work, respiration rate (Rr, in μL L-1 g-1 min-1) was used as index to establish recovery profiles in Pinctada mazatlanica and evaluate relaxation therapies of three doses and two exposure times using propylene phenoxetol (PP), MS-222 (MS), and quinaldine (QN), in comparison with an untreated (CTRL) model. Recovery profiles were explored with median Box-Whiskers plots. Intercept position, dispersion pattern, and range values of Rr, and slope attributes, were inferred through ...

Aquaculture Research, 2015

We isolated microbiota from the digestive tract of Nodipecten subnodosus and Pteria sterna and de... more We isolated microbiota from the digestive tract of Nodipecten subnodosus and Pteria sterna and determined in vitro their haemolytic activity, antagonism against Vibrio spp., bacterial hydrophobicity, production of extracellular enzymes and molecular identification. Five bacterial strains were selected: RL5 and C3 (Lactobacillus spp.) and PB1-1, PB1-5 and PB1-6 (Bacillus spp.). The RL5 and C3 isolates showed antimicrobial activity against Vibrio spp. and the PB1-1, PB1-5 and PB1-6 isolates showed enzymatic activity for amylase, protease, lipase and cellulose; the C3 and PB1-5 isolates were highly hydrophobic. The selected strains of bacteria were tested in vivo as probiotics, together with a treatment of ampicillin and a control without bacteria on juvenile Kumamoto oysters Crassostrea sikamea. The strains were provided individually and as mixes of isolates. Survival, growth and biochemical composition of the juveniles were determined as in vivo indicators. Juveniles grew significantly larger and faster when treated with a specific mix of isolates (MIX-B), compared with the control. The protein, lipid and carbohydrate concentrations were also significantly higher in oysters exposed to probiotic treatments, compared with the control and the antibiotic treatment. The selected microbiota showed probiotic proprieties for cultivating C. sikamea juveniles.

Ciencias Marinas, 2014

The winged pearl oyster, Pteria sterna, sustains a growing pearl industry in northwestern Mexico,... more The winged pearl oyster, Pteria sterna, sustains a growing pearl industry in northwestern Mexico, where a subtropical climate prevails. In tropical areas of Mexico, pearl cultivation may be profitable, but insufficient information on the biology and ecology of the species limits the definition of protocols for creating pearl farms. We measured absolute growth, growth rate, reproductive stages, changes in oocyte size, and size at first maturity of juvenile P. sterna cultivated in Bahía de Acapulco over one annual cycle (2009–2010), and compared their response in this tropical area with reports from subtropical areas of Mexico. We also compared the von Bertalanffy growth model with one proposed in this study for aquaculture purposes. The growth rate was higher during the first six months (5.3 mm month–1) and then decreased to 3 mm month–1 until juveniles reached a size of 60 mm in one year. Growth rates were higher in February and lower in July through September. Both models described...

Veterinary World, 2015

Aim: This study was designed to describe a series of in vitro tests that may aid the discovery of... more Aim: This study was designed to describe a series of in vitro tests that may aid the discovery of probiotic strains from actinomycetes. Materials and Methods: Actinomycetes were isolated from marine sediments using four different isolation media, followed by antimicrobial activity and toxicity assessment by the agar diffusion method and the hemolysis of human blood cells, respectively. Extracellular enzymatic production was monitored by the hydrolysis of proteins, lipids and carbohydrates. Tolerance to different pH values and salt concentrations was also determined, followed by hydrophobicity analysis and genetic identification of the most promising strains. Results: Five out of 31 isolated strains showed antimicrobial activity against three Vibrio species. Three non-hemolytic strains (N7, RL8 and V4) among these active isolates yielded positive results in hydrophobicity tests and exhibited good growth at salt concentrations ranging from 0% to 10%, except strain RL8, which required a salt concentration >0.6%. Although these strains did not grow at pH<3, they showed different enzymatic activities. Phylogenetic analysis revealed that strains N7 and V4 have more than 99% identity with several Streptomyces species, whereas the closest matches to strain RL8 are Streptomyces panacagri and Streptomyces flocculus, with 98% and 98.2% similarity, respectively. Conclusion: Three actinomycetes strains showing probiotic-like properties were discovered using several in vitro tests that can be easily implemented in different institutions around the world.

Aquaculture, 2014

ABSTRACT Ensuring supplies of pearl oyster spat for commercial grafting operations in Mexico is a... more ABSTRACT Ensuring supplies of pearl oyster spat for commercial grafting operations in Mexico is an ongoing problem. This has refocused research toward improving hatchery propagation protocols. Since gender plays an important role in the physiology of bivalves,we studied the use of fatty acids in the gonad and digestive gland ofmale and female winged pearl oyster (Pteria sterna) over its natural breeding season. Sampling included two peaks of ripening (February and April 2009), a pre-reproductive period (November 2008), and a post-reproductive period (June 2009). We found a significant increase in storage of docosapolyenoic fatty acids during development and ripe stages only in the female gonad,which indicates that these fatty acids could be a limiting factor for successful development of high quality eggs. The content of total monounsaturated fatty acids in male gonads, especially the fatty acid 16:1 n7, was significantly higher than in female gonads at the development and ripe stages. We also found differences between males and females in the use of some fatty acids in the digestive gland, especially at the spawned stage. Our results have future application in developing protocols for rearing of this pearl oyster in hatcheries. Incorporating dietary supplements containing docosapolyenoic fatty acids into diets of pearl oyster broodstock could be a practicalway to improve their performance, which is crucial for enhancing the viability of larvae and spat.

Communications in Computer and Information Science, 2008

An important goal for rehabilitation engineering is to develop technology that allows individuals... more An important goal for rehabilitation engineering is to develop technology that allows individuals with stroke to practice intensive movement training without the expense of an always-present therapist. We have developed a low-cost, computer vision system that allows individuals with stroke to practice arm movement exercises at home or at the clinic, with periodic interactions with a therapist. The system intgrates a webbased system for facilitating repetitive movement training, with state-of-the art computer vision algorithms that track the hand of a patient and obtain its 3-D coordinates, using two inexpensive cameras and a conventional personal computer. An initial prototype of the system has been evaluated in a pilot clinical study with positive results.

Journal of Shellfish Research, 2012

ABSTRACT Fifteen-day pediveliger larvae of Anadara grandis (shell length, 230 ± 20 µm (mean ± SD,... more ABSTRACT Fifteen-day pediveliger larvae of Anadara grandis (shell length, 230 ± 20 µm (mean ± SD, n = 20) were cultivated up to the juvenile stage by testing 2 densities: 71 larvae/cm2 and 283 larvae/cm2 for 37 days. During this time, we registered morphological changes of the larvae from pediveliger up to the juvenile stage, as well as absolute growth, and growth and survival rates. The growth rate was 53.5 µm/day at a density of 71 larvae/cm2, with a survival of 60%; at a density of 283 larvae/cm2, the growth rate was 33.6 µm/day, with a survival of 40%. Subsequently, the juveniles obtained were nursed for 57 days in 2 types of experimental units: Nestier trays suspended in a pond and cylindrical upwelling containers with increasing water flow in the laboratory. In each experimental unit we cultured 66,666 juveniles with a shell length of 1.57 ± 0.05 mm (n = 20). In the Nestier trays, growth was 4–6 µm/day, with a survival of 15%. In the upwelling-type units, growth was 5–6 µm/day, with a survival of 93%. ANOVA revealed significant differences (P < 0.05) in juvenile growth between the Nestier trays and the upwelling-type containers. Low juvenile survival in Nestier trays is attributed to clogging with wind-blown slime. However, a nursery of A. grandis juveniles in ponds requires further research to show its economic feasibility.

Journal of Shellfish Research, 2010

The reproductive cycle of the eared ark Anadara notabilis and its relationship with environmental... more The reproductive cycle of the eared ark Anadara notabilis and its relationship with environmental factors was evaluated every 15 days between March 2004 and February 2005 at the northern part of the Peninsula de Araya, Venezuela. Environmental factors measured included temperature, salinity, chlorophyll a, and total seston, including the particulate organic matter and particulate inorganic matter fractions. Adult specimens were collected using a net drag and then randomly selected to estimate wet live biomass and dry biomass of soft body tissues. Gonad samples were processed with histological analysis to determine sex ratio, developmental stages, and variations of follicle size. Reproduction in A. notabilis was continuous throughout the year, with spawning peaks occurring in June and October, coinciding with the lowest water temperatures. In March, September, and November 2004, specimens attained the highest dry biomass values, whereas lowest dry biomass occurred in June and October 2004. Stepwise regression analyses demonstrated that temperature and particulate organic matter values are the main modulators of reproductive events. When temperature decreased, dribble spawning was detected in this species, possibly inducing a survival strategy whereby the spawning period is extended to increase reproductive success.

Journal of Shellfish Research, 2010

... Marco A. Angel-Dapa, 1 Carmen Rodríguez-Jaramillo, 1 Carlos J. Cáceres-Martínez 2 and ... Maz... more ... Marco A. Angel-Dapa, 1 Carmen Rodríguez-Jaramillo, 1 Carlos J. Cáceres-Martínez 2 and ... Mazón-Suástegui, JM, A. Parres-Haro, K. Ruíz-Ruíz, C. Rodríguez-Jaramillo &amp;amp;amp; PE Saucedo ... Rodríguez-Jaramillo, C., MA Hurtado, E. Romero-Vivas, JL Ramírez, E. Manzano &amp;amp;amp; E. Palacios ...

Journal of Shellfish Research, 2008

Seasonal variations in storage, partitioning, and allocation of energy reserves (proteins, carboh... more Seasonal variations in storage, partitioning, and allocation of energy reserves (proteins, carbohydrates, lipids, and triglycerides) between germinal and somatic tissues (gonad, digestive gland, mantle tissue, and adductor muscle), were investigated related to reproduction of Pacific winged pearl oyster Pteria sterna. Tissue samples were collected every three months and analyzed with histological and biochemical techniques. Energy coefficients were also calculated with data from chemical composition of tissues. Gonad samples in almost all developmental stages occurred throughout the year, suggesting that P. sterna is a multispawning species. The evidence indicates that the main reproductive season runs from January through April (21°C to 22°C) and was identified by higher frequency of ripe gonads, more and larger postvitellogenic oocytes and higher protein, lipid, and triglyceride levels in gonad tissue. Within this study period, there were two spawning peaks, July 2003 and January 2004. Gametogenesis was sustained from energy mainly obtained from the digestive gland and secondly from the adductor muscle. Only proteins from these two tissues were mobilized to the gonad for maturation of sex organs, because carbohydrates were stored despite the progress of gametogenesis. The role of mantle tissue was negligible. P. sterna appears to use a combination of stored reserves (conservative strategy) and food supply (opportunistic strategy) as an overall strategy to regulate reproduction.

Journal of Shellfish Research, 2009

Using a combination of stereological and calorimetric methods, we studied reproductive effort of ... more Using a combination of stereological and calorimetric methods, we studied reproductive effort of Pacific winged pearl oyster Pteria sterna during an annual cycle in Bahı´a de La Paz, B.C.S., Mexico. The relationship between changes in the volumetric fraction of germinal and somatic tissues (gonad, digestive gland, adductor muscle, and mantle tissue) and changes in their energy content was analyzed. These data were also correlated with changes in water temperature and availability of food (seston). Because P. sterna spawns several times a year, reproductive effort was estimated ;400% in terms of energy increase from early development in October 2006 to the spawning occurring in January to February 2007. During this period, when water temperature was decreasing and seston concentration was increasing, P. sterna followed a conservative strategy for allocating energy from reserves previously stored in somatic tissues. In contrast, when productivity dropped in spring, the species followed an opportunistic strategy for sustaining gametogenesis from food energy. In decreasing order, total energy channeled for reproduction came from the digestive gland (23 kJ g-1), adductor muscle (19 kJ g-1), and mantle tissue (16 kJ g-1). Based on these results, we recommend that commercial pearl culture practices be conducted from mid-autumn (October) through early spring (April), when P. sterna is energetically more resistant to manipulation. An additional recommendation is to avoid grafting during the summer (June through September), when the species is energetically exhausted and highly vulnerable to manipulation.

Journal of Shellfish Research, 2009

We evaluated indicators of quality for female gonads (ovary and oocytes), male gonads (testis and... more We evaluated indicators of quality for female gonads (ovary and oocytes), male gonads (testis and seminal tubules), and selected somatic tissues (fiber packages in the adductor muscle and adenomeres in the digestive gland) that participate in reproduction of the pearl oyster Pinctada mazatlanica. The goal was to identify timing of optimal broodstock condition for larval rearing practices. Tissue samples were collected seasonally and processed with a combination of histochemistry and digital image analysis to develop a gonad tissue index, a lipid index, and a glycogen index. Seasonal changes in these indicators were correlated with changes in water temperature and chlorophyll a in the water. P. mazatlanica uses a combination of stored reserves and food supply (conservative vs. opportunistic strategy) to regulate reproduction, but the way energy is acquired and allocated varies between sexes. Female gonads contained higher lipid contents during spring. We suggest energy allocation from digestive gland, because this tissue showed lower lipid contents in the same season (conservative strategy). Within oocytes, the accumulation of lipids occurred from nutrients obtained from food supply during winter (19.6°C and ;650 ng/L) (opportunistic strategy). Male gonads contained higher glycogen contents in spring. A decreasing trend in the glycogen content of the adductor muscle was also detected in spring. This suggests that sperm build-up occurs partly at the expense of the glycogen stored in this tissue (conservative strategy). In seminal tubules, no correlation with the glycogen content of adductor muscle was detected, suggesting that these reserves were obtained from food supply in spring (22°C and ;400 ng/L) (opportunistic strategy). Optimal broodstock condition occurs mainly in spring and secondly in early winter.

Journal of the World Aquaculture Society, 2010

Survival and growth of pearl oyster, Pinctada mazatlanica, juveniles fed microalgae supplemented ... more Survival and growth of pearl oyster, Pinctada mazatlanica, juveniles fed microalgae supplemented with natural and commercial probiotics were measured for 21 d at the hatchery. Probiotics tested were (1) a Lactobacillus sp., (2) a mix of two bacilli, Burkholderia cepacia and Pseudomonas aeruginosa, (3) a marine yeast, Yarrowia lipolytica, (4) Epicin-hatchery ® as commercial probiotic, (5) an antibiotic oxytetracycline, and (6) the control group fed Isochrysis galbana, Pavlova salina, and Chaetoceros muelleri only. When the hatchery phase ended, the effects of probiotics were followed during the early stages of field cultivation (90 d). Different from the control group, natural probiotics significantly improved performance of juveniles during both phases, particularly in the field. The treatment with Lactobacillus sp. significantly increased survival by 72%, growth in shell height by 63%, and growth in wet weight by 83% over the control. The marine yeast and mix of bacilli provided intermediate results, enhancing survival by 55-65%, shell height by 55-58%, and wet weight by 70-76% compared with the control. Conversely, growth and survival in the treatments with Epicin and oxytetracycline were significantly lower than in the control. These results show the potential of natural probiotics for improving hatchery rearing of this pearl oyster.

Journal of Shellfish Research, 2005

We evaluated experimental collection of Pinctada mazatlanica spat on substrates of different text... more We evaluated experimental collection of Pinctada mazatlanica spat on substrates of different textures and colors placed at different depths within settlement tanks. When larvae reached the pediveliger stage (day 25), black-colored spat collectors ("envelope" type) composed of the following materials were offered as settlement substrates: onion bag, mosquito net, fishing net, and 63% shade-cloth. Spat collectors measured 30 × 30 cm and were composed of an outer bag and inner substrate made of the same material. The influence of the color of spat collector material on recruitment was investigated using a second type of spat collector composed of onion bags as the outer bag and inner substrate ("bag" type). Bags were prepared in 3 different outer/inner (O/I) color combinations of green/green, green/black, and red/black (O/I). Both types of collectors were deployed at different depths within settlement tanks. Approximately 2.7% of the initial larval population survived, resulting in 35,583 spat. Of these, 71.3% recruited to bag type collectors, 21.9% to envelope type collectors, and 6.8% to the surfaces of the culture tanks. Spat recruitment was significantly affected by collector material (P < 0.01), with fishing net and shade-cloth yielding highest and lowest density of spat, respectively. Similarly, spat collector color combination significantly influenced spat collection (P < 0.01), with higher recruitment to red and green substrates. For both spat collector types, there was significantly greater (P < 0.01) recruitment of spat to collectors in the middle of the water column (60-90-cm depth). This study showed that both the type and color of material used for spat collectors, as well as depth of deployment, influenced recruitment of P. mazatlanica spat. These results will help fine-tune current hatchery techniques for this species.

Journal of Shellfish Research, 2005

We applied quantitative histochemical techniques and digital image analysis to study seasonal cyc... more We applied quantitative histochemical techniques and digital image analysis to study seasonal cycles of use of lipid and protein reserves during vitellogenesis in the pearl oyster Pinctada mazatlanica. Female gonad samples were collected seasonally during an annual cycle and processed histologically to characterize the gametogenic cycle, analyze variations in the frequency and size of vitellogenic and postvitellogenic oocytes and calculate the ooplasm:nucleoplasm ratio for both types of oocytes. Lipid and protein inclusions in each type of oocyte were identified using Sudan Black B and Schiff's ninhydrin stains. In both cases, quantification of lipid and protein components was performed through measuring variations in the color coverage area of the oocyte with a digital image analysis system. With this procedure, we calculated a lipid index and a protein index to refer oocyte quality. The lipid index was higher in winter, suggesting a strategy towards storage in the gonad. The protein index was highest during spring in vitellogenic oocytes and during winter in postvitellogenic oocytes, indicating that proteins are actively used during oocyte growth. These results, together with data of the ooplasm:nucleoplasm ratio, suggest differential accumulation of lipid and protein components within the ooplasm during oocyte development. Quantitative histochemistry and digital image analysis represent a combination of reliable techniques for evaluating reproductive processes and oocyte growth and quality.

Latin American Journal of Aquatic Research, 2016

We evaluated the effect of nine isocaloric diets prepared with a mixture of microalgae alone (Tis... more We evaluated the effect of nine isocaloric diets prepared with a mixture of microalgae alone (Tisochrysis lutea + Chaetoceros calcitrans + Ch. gracilis; 1:1:1) and different combinations of the algal mixture and cornstarch or wheat flour, on the Scope for Growth (SFG) of Cortez oyster Crassostrea corteziensis juveniles (7.2 ± 1.1 mm shell length). A total 15,000 spat was acclimated to the experimental diets for 30 days at 21ºC, prior SFG determinations. Consumed energy, absorbed energy, and SFG decreased with a corresponding decrease in the proportion of live microalgae in the diet. Oysters fed the microalgal diet showed significantly increased physiological activity in all parameters except absorption efficiency. Oysters fed diets containing up to 50% dry feedstuff showed positive SFG values but these were significantly lower than SFG shown in oysters fed microalgae alone. Oysters fed diets containing ≥75% dry feedstuff showed negative SFG. These results suggest that cereals can be used as complementary food or C. corteziensis spat in hatchery operations, provided replacement of microalgae is kept below 50%.

Tropical and Subtropical Agroecosystems, Apr 12, 2013

How to cite Complete issue More information about this article Journal's homepage in redalyc.org ... more How to cite Complete issue More information about this article Journal's homepage in redalyc.org Scientific Information System Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Non-profit academic project, developed under the open access initiative

Pteria penguin were collected at Orpheus Island, north-eastern Queensland to observe sexual devel... more Pteria penguin were collected at Orpheus Island, north-eastern Queensland to observe sexual development, sex ratio and changes in morphometric relationships during growth. P. penguin are protandrous hermaphrodites, with all sexually mature oysters below 88.8 mm dorso-ventral height (DVH) being males. Evidence of male primary gonad development was seen in oysters with a DVH of ≥33.9 mm. Sexual maturity of males was first seen in oysters at ≥56.0 mm DVH, but was common in oysters at ≥70.0 mm DVH. Mean female size was 150.1 (±3.6) mm DVH, and mean male size was 111.3 (±2.2) mm DVH. In oysters 180 mm DVH. Significant linear correlations were found between anterior-posterior length of the shell (APL) and DVH (r2 = 0.97, p <0.001) and between shell thickness (ST) and DVH (r2 = 0.95, p <0.001), and a curvilinear relationship was recorded between adductor muscle weight (AW) and DVH (r2 = 0.93, p <0.001). These findings have industry applications for collection of juvenile stock, spawning induction procedures and determining optimal shell size for pearl nucleus implanting.

Journal of Shellfish Research

Anesthetic drugs are common in management sequences of commercial aquaculture that imply relaxati... more Anesthetic drugs are common in management sequences of commercial aquaculture that imply relaxation of specimens. Studies on physiologic response and relationships with functions of body parts are particularly centered in fishes to improve transport, handling, or surgery (i.e., spawning stimulation, sampling of blood and fluids). In pearl oysters, relaxation therapies are important to induce round pearl formation with nucleus-mantle insertions, but the physiologic effect of drugs are poorly known. In the current work, respiration rate (Rr, in μL L-1 g-1 min-1) was used as index to establish recovery profiles in Pinctada mazatlanica and evaluate relaxation therapies of three doses and two exposure times using propylene phenoxetol (PP), MS-222 (MS), and quinaldine (QN), in comparison with an untreated (CTRL) model. Recovery profiles were explored with median Box-Whiskers plots. Intercept position, dispersion pattern, and range values of Rr, and slope attributes, were inferred through ...

Aquaculture Research, 2015

We isolated microbiota from the digestive tract of Nodipecten subnodosus and Pteria sterna and de... more We isolated microbiota from the digestive tract of Nodipecten subnodosus and Pteria sterna and determined in vitro their haemolytic activity, antagonism against Vibrio spp., bacterial hydrophobicity, production of extracellular enzymes and molecular identification. Five bacterial strains were selected: RL5 and C3 (Lactobacillus spp.) and PB1-1, PB1-5 and PB1-6 (Bacillus spp.). The RL5 and C3 isolates showed antimicrobial activity against Vibrio spp. and the PB1-1, PB1-5 and PB1-6 isolates showed enzymatic activity for amylase, protease, lipase and cellulose; the C3 and PB1-5 isolates were highly hydrophobic. The selected strains of bacteria were tested in vivo as probiotics, together with a treatment of ampicillin and a control without bacteria on juvenile Kumamoto oysters Crassostrea sikamea. The strains were provided individually and as mixes of isolates. Survival, growth and biochemical composition of the juveniles were determined as in vivo indicators. Juveniles grew significantly larger and faster when treated with a specific mix of isolates (MIX-B), compared with the control. The protein, lipid and carbohydrate concentrations were also significantly higher in oysters exposed to probiotic treatments, compared with the control and the antibiotic treatment. The selected microbiota showed probiotic proprieties for cultivating C. sikamea juveniles.

Ciencias Marinas, 2014

The winged pearl oyster, Pteria sterna, sustains a growing pearl industry in northwestern Mexico,... more The winged pearl oyster, Pteria sterna, sustains a growing pearl industry in northwestern Mexico, where a subtropical climate prevails. In tropical areas of Mexico, pearl cultivation may be profitable, but insufficient information on the biology and ecology of the species limits the definition of protocols for creating pearl farms. We measured absolute growth, growth rate, reproductive stages, changes in oocyte size, and size at first maturity of juvenile P. sterna cultivated in Bahía de Acapulco over one annual cycle (2009–2010), and compared their response in this tropical area with reports from subtropical areas of Mexico. We also compared the von Bertalanffy growth model with one proposed in this study for aquaculture purposes. The growth rate was higher during the first six months (5.3 mm month–1) and then decreased to 3 mm month–1 until juveniles reached a size of 60 mm in one year. Growth rates were higher in February and lower in July through September. Both models described...

Veterinary World, 2015

Aim: This study was designed to describe a series of in vitro tests that may aid the discovery of... more Aim: This study was designed to describe a series of in vitro tests that may aid the discovery of probiotic strains from actinomycetes. Materials and Methods: Actinomycetes were isolated from marine sediments using four different isolation media, followed by antimicrobial activity and toxicity assessment by the agar diffusion method and the hemolysis of human blood cells, respectively. Extracellular enzymatic production was monitored by the hydrolysis of proteins, lipids and carbohydrates. Tolerance to different pH values and salt concentrations was also determined, followed by hydrophobicity analysis and genetic identification of the most promising strains. Results: Five out of 31 isolated strains showed antimicrobial activity against three Vibrio species. Three non-hemolytic strains (N7, RL8 and V4) among these active isolates yielded positive results in hydrophobicity tests and exhibited good growth at salt concentrations ranging from 0% to 10%, except strain RL8, which required a salt concentration >0.6%. Although these strains did not grow at pH<3, they showed different enzymatic activities. Phylogenetic analysis revealed that strains N7 and V4 have more than 99% identity with several Streptomyces species, whereas the closest matches to strain RL8 are Streptomyces panacagri and Streptomyces flocculus, with 98% and 98.2% similarity, respectively. Conclusion: Three actinomycetes strains showing probiotic-like properties were discovered using several in vitro tests that can be easily implemented in different institutions around the world.

Aquaculture, 2014

ABSTRACT Ensuring supplies of pearl oyster spat for commercial grafting operations in Mexico is a... more ABSTRACT Ensuring supplies of pearl oyster spat for commercial grafting operations in Mexico is an ongoing problem. This has refocused research toward improving hatchery propagation protocols. Since gender plays an important role in the physiology of bivalves,we studied the use of fatty acids in the gonad and digestive gland ofmale and female winged pearl oyster (Pteria sterna) over its natural breeding season. Sampling included two peaks of ripening (February and April 2009), a pre-reproductive period (November 2008), and a post-reproductive period (June 2009). We found a significant increase in storage of docosapolyenoic fatty acids during development and ripe stages only in the female gonad,which indicates that these fatty acids could be a limiting factor for successful development of high quality eggs. The content of total monounsaturated fatty acids in male gonads, especially the fatty acid 16:1 n7, was significantly higher than in female gonads at the development and ripe stages. We also found differences between males and females in the use of some fatty acids in the digestive gland, especially at the spawned stage. Our results have future application in developing protocols for rearing of this pearl oyster in hatcheries. Incorporating dietary supplements containing docosapolyenoic fatty acids into diets of pearl oyster broodstock could be a practicalway to improve their performance, which is crucial for enhancing the viability of larvae and spat.

Communications in Computer and Information Science, 2008

An important goal for rehabilitation engineering is to develop technology that allows individuals... more An important goal for rehabilitation engineering is to develop technology that allows individuals with stroke to practice intensive movement training without the expense of an always-present therapist. We have developed a low-cost, computer vision system that allows individuals with stroke to practice arm movement exercises at home or at the clinic, with periodic interactions with a therapist. The system intgrates a webbased system for facilitating repetitive movement training, with state-of-the art computer vision algorithms that track the hand of a patient and obtain its 3-D coordinates, using two inexpensive cameras and a conventional personal computer. An initial prototype of the system has been evaluated in a pilot clinical study with positive results.

Journal of Shellfish Research, 2012

ABSTRACT Fifteen-day pediveliger larvae of Anadara grandis (shell length, 230 ± 20 µm (mean ± SD,... more ABSTRACT Fifteen-day pediveliger larvae of Anadara grandis (shell length, 230 ± 20 µm (mean ± SD, n = 20) were cultivated up to the juvenile stage by testing 2 densities: 71 larvae/cm2 and 283 larvae/cm2 for 37 days. During this time, we registered morphological changes of the larvae from pediveliger up to the juvenile stage, as well as absolute growth, and growth and survival rates. The growth rate was 53.5 µm/day at a density of 71 larvae/cm2, with a survival of 60%; at a density of 283 larvae/cm2, the growth rate was 33.6 µm/day, with a survival of 40%. Subsequently, the juveniles obtained were nursed for 57 days in 2 types of experimental units: Nestier trays suspended in a pond and cylindrical upwelling containers with increasing water flow in the laboratory. In each experimental unit we cultured 66,666 juveniles with a shell length of 1.57 ± 0.05 mm (n = 20). In the Nestier trays, growth was 4–6 µm/day, with a survival of 15%. In the upwelling-type units, growth was 5–6 µm/day, with a survival of 93%. ANOVA revealed significant differences (P < 0.05) in juvenile growth between the Nestier trays and the upwelling-type containers. Low juvenile survival in Nestier trays is attributed to clogging with wind-blown slime. However, a nursery of A. grandis juveniles in ponds requires further research to show its economic feasibility.

Journal of Shellfish Research, 2010

The reproductive cycle of the eared ark Anadara notabilis and its relationship with environmental... more The reproductive cycle of the eared ark Anadara notabilis and its relationship with environmental factors was evaluated every 15 days between March 2004 and February 2005 at the northern part of the Peninsula de Araya, Venezuela. Environmental factors measured included temperature, salinity, chlorophyll a, and total seston, including the particulate organic matter and particulate inorganic matter fractions. Adult specimens were collected using a net drag and then randomly selected to estimate wet live biomass and dry biomass of soft body tissues. Gonad samples were processed with histological analysis to determine sex ratio, developmental stages, and variations of follicle size. Reproduction in A. notabilis was continuous throughout the year, with spawning peaks occurring in June and October, coinciding with the lowest water temperatures. In March, September, and November 2004, specimens attained the highest dry biomass values, whereas lowest dry biomass occurred in June and October 2004. Stepwise regression analyses demonstrated that temperature and particulate organic matter values are the main modulators of reproductive events. When temperature decreased, dribble spawning was detected in this species, possibly inducing a survival strategy whereby the spawning period is extended to increase reproductive success.

Journal of Shellfish Research, 2010

... Marco A. Angel-Dapa, 1 Carmen Rodríguez-Jaramillo, 1 Carlos J. Cáceres-Martínez 2 and ... Maz... more ... Marco A. Angel-Dapa, 1 Carmen Rodríguez-Jaramillo, 1 Carlos J. Cáceres-Martínez 2 and ... Mazón-Suástegui, JM, A. Parres-Haro, K. Ruíz-Ruíz, C. Rodríguez-Jaramillo &amp;amp;amp; PE Saucedo ... Rodríguez-Jaramillo, C., MA Hurtado, E. Romero-Vivas, JL Ramírez, E. Manzano &amp;amp;amp; E. Palacios ...

Journal of Shellfish Research, 2008

Seasonal variations in storage, partitioning, and allocation of energy reserves (proteins, carboh... more Seasonal variations in storage, partitioning, and allocation of energy reserves (proteins, carbohydrates, lipids, and triglycerides) between germinal and somatic tissues (gonad, digestive gland, mantle tissue, and adductor muscle), were investigated related to reproduction of Pacific winged pearl oyster Pteria sterna. Tissue samples were collected every three months and analyzed with histological and biochemical techniques. Energy coefficients were also calculated with data from chemical composition of tissues. Gonad samples in almost all developmental stages occurred throughout the year, suggesting that P. sterna is a multispawning species. The evidence indicates that the main reproductive season runs from January through April (21°C to 22°C) and was identified by higher frequency of ripe gonads, more and larger postvitellogenic oocytes and higher protein, lipid, and triglyceride levels in gonad tissue. Within this study period, there were two spawning peaks, July 2003 and January 2004. Gametogenesis was sustained from energy mainly obtained from the digestive gland and secondly from the adductor muscle. Only proteins from these two tissues were mobilized to the gonad for maturation of sex organs, because carbohydrates were stored despite the progress of gametogenesis. The role of mantle tissue was negligible. P. sterna appears to use a combination of stored reserves (conservative strategy) and food supply (opportunistic strategy) as an overall strategy to regulate reproduction.

Journal of Shellfish Research, 2009

Using a combination of stereological and calorimetric methods, we studied reproductive effort of ... more Using a combination of stereological and calorimetric methods, we studied reproductive effort of Pacific winged pearl oyster Pteria sterna during an annual cycle in Bahı´a de La Paz, B.C.S., Mexico. The relationship between changes in the volumetric fraction of germinal and somatic tissues (gonad, digestive gland, adductor muscle, and mantle tissue) and changes in their energy content was analyzed. These data were also correlated with changes in water temperature and availability of food (seston). Because P. sterna spawns several times a year, reproductive effort was estimated ;400% in terms of energy increase from early development in October 2006 to the spawning occurring in January to February 2007. During this period, when water temperature was decreasing and seston concentration was increasing, P. sterna followed a conservative strategy for allocating energy from reserves previously stored in somatic tissues. In contrast, when productivity dropped in spring, the species followed an opportunistic strategy for sustaining gametogenesis from food energy. In decreasing order, total energy channeled for reproduction came from the digestive gland (23 kJ g-1), adductor muscle (19 kJ g-1), and mantle tissue (16 kJ g-1). Based on these results, we recommend that commercial pearl culture practices be conducted from mid-autumn (October) through early spring (April), when P. sterna is energetically more resistant to manipulation. An additional recommendation is to avoid grafting during the summer (June through September), when the species is energetically exhausted and highly vulnerable to manipulation.

Journal of Shellfish Research, 2009

We evaluated indicators of quality for female gonads (ovary and oocytes), male gonads (testis and... more We evaluated indicators of quality for female gonads (ovary and oocytes), male gonads (testis and seminal tubules), and selected somatic tissues (fiber packages in the adductor muscle and adenomeres in the digestive gland) that participate in reproduction of the pearl oyster Pinctada mazatlanica. The goal was to identify timing of optimal broodstock condition for larval rearing practices. Tissue samples were collected seasonally and processed with a combination of histochemistry and digital image analysis to develop a gonad tissue index, a lipid index, and a glycogen index. Seasonal changes in these indicators were correlated with changes in water temperature and chlorophyll a in the water. P. mazatlanica uses a combination of stored reserves and food supply (conservative vs. opportunistic strategy) to regulate reproduction, but the way energy is acquired and allocated varies between sexes. Female gonads contained higher lipid contents during spring. We suggest energy allocation from digestive gland, because this tissue showed lower lipid contents in the same season (conservative strategy). Within oocytes, the accumulation of lipids occurred from nutrients obtained from food supply during winter (19.6°C and ;650 ng/L) (opportunistic strategy). Male gonads contained higher glycogen contents in spring. A decreasing trend in the glycogen content of the adductor muscle was also detected in spring. This suggests that sperm build-up occurs partly at the expense of the glycogen stored in this tissue (conservative strategy). In seminal tubules, no correlation with the glycogen content of adductor muscle was detected, suggesting that these reserves were obtained from food supply in spring (22°C and ;400 ng/L) (opportunistic strategy). Optimal broodstock condition occurs mainly in spring and secondly in early winter.

Journal of the World Aquaculture Society, 2010

Survival and growth of pearl oyster, Pinctada mazatlanica, juveniles fed microalgae supplemented ... more Survival and growth of pearl oyster, Pinctada mazatlanica, juveniles fed microalgae supplemented with natural and commercial probiotics were measured for 21 d at the hatchery. Probiotics tested were (1) a Lactobacillus sp., (2) a mix of two bacilli, Burkholderia cepacia and Pseudomonas aeruginosa, (3) a marine yeast, Yarrowia lipolytica, (4) Epicin-hatchery ® as commercial probiotic, (5) an antibiotic oxytetracycline, and (6) the control group fed Isochrysis galbana, Pavlova salina, and Chaetoceros muelleri only. When the hatchery phase ended, the effects of probiotics were followed during the early stages of field cultivation (90 d). Different from the control group, natural probiotics significantly improved performance of juveniles during both phases, particularly in the field. The treatment with Lactobacillus sp. significantly increased survival by 72%, growth in shell height by 63%, and growth in wet weight by 83% over the control. The marine yeast and mix of bacilli provided intermediate results, enhancing survival by 55-65%, shell height by 55-58%, and wet weight by 70-76% compared with the control. Conversely, growth and survival in the treatments with Epicin and oxytetracycline were significantly lower than in the control. These results show the potential of natural probiotics for improving hatchery rearing of this pearl oyster.