Microbial signature profiles of Penaeus vannamei larvae in low-survival hatchery tanks affected by vibriosis.

Vibriosis is caused by some pathogenic Vibrio and produces significant mortality in Pacific white shrimp Penaeus (Litopenaeus) vannamei larvae in commercial hatcheries. Acute hepatopancreatic necrosis disease (AHPND) is an emerging vibriosis affecting shrimp-producing countries worldwide. Zoea 2 syndrome is another type of vibriosis that affects the early stages of P. vannamei larvae. Although the pathogenesis of AHPND and zoea 2 syndrome is well known, there is scarce information about microbial composition and biomarkers of P.vannamei larvae affected by AHPND, and there is no study of the microbiome of larvae affected by zoea 2 syndrome. In this work, we characterized the microbiome of P. vannamei larvae collected from 12 commercial hatchery tanks by high-throughput sequencing. Seven tanks were affected by AHPND, and five tanks were affected by zoea 2 syndrome. Subsequently, all samples were selected for sequencing of the V3-V4 region of the16S rRNA gene. Similarity analysis using the beta diversity index revealed significant differences in the larval bacterial communities between disease conditions, particularly when Vibrio was analyzed. Linear discriminant analysis with effect size determined specific microbial signatures for AHPND and zoea 2 syndrome. Sneathiella, Cyclobacterium, Haliea, Lewinella, among other genera, were abundant in AHPND-affected larvae. Meanwhile, Vibrio, Spongiimonas, Meridianimaribacter, Tenacibaculum, among other genera, were significantly abundant in larvae affected by zoea 2 syndrome. The bacterial network at the phylum level for larvae collected from tanks affected by AHPND showed greater complexity and connectivity than in samples collected from tanks affected by zoea 2 syndrome. The bacterial connections inter Vibrio genera were higher in larvae from tanks affected by zoea 2 syndrome, also presenting other connections between the genera Vibrio and Catenococcus. The identification of specific biomarkers found in this study could be useful for understanding the microbial dynamics during different types of vibriosis.

White spot syndrome virus (WSSV) disturbs the intestinal microbiota of shrimp (Penaeus vannamei) reared in biofloc and clear seawater.

White spot syndrome virus (WSSV) is one of the most virulent pathogens afflicting shrimp farming. Understanding its influence on shrimp intestinal microbiota is paramount for the advancement of aquaculture, since gut dysbiosis can negatively impact shrimp development, physiology, and immunological response. Thereupon, the data presented herein assesses the influence of WSSV infection and different rearing systems on the intestinal microbiota of Penaeus vannamei. Our study aimed to describe and correlate the composition of shrimp (Penaeus vannamei) gut microbiota, when reared in biofloc and clear seawater, before and (48 h) after WSSV experimental infection. Shrimp were kept in two different systems (biofloc and clear seawater) and experimentally infected with WSSV. Intestine and water samples were characterized by 16S rRNA gene sequencing, before and after viral infection. We observed (i) WSSV induced higher mortality among shrimp reared in biofloc; (ii) WSSV led to a loss of intestinal microbiota heterogeneity, at the genus level, in shrimp kept in clear seawater; (iii) there was a prevalence of Cetobacterium and Bacillus in the intestine of shrimp from both systems; (iv) WSSV did not cause significant changes in intestinal microbiota diversity or richness; (v) regardless of the type of system and time of infection, intestinal microbiota was dissimilar to that of the surrounding water, despite being influenced by the type of system. Therefore, WSSV infection leads to punctual dysbiotic changes in shrimp microbiota, although the virus is sufficiently virulent to cause high mortalities even in well-managed systems, such as a balanced experimental biofloc system. KEY POINTS: • WSSV infection leads to a perturbed gut microbiota in shrimp. • WSSV infection greater impacts microbiota of shrimp reared in CSW than those in BFT. • WSSV infection caused higher mortality levels in shrimp reared in BFT than in CSW. • Rearing system influences shrimp gut microbiota composition. Graphical abstract.

Acute toxicity of nitrate in Litopenaeus vannamei juveniles at low salinity levels / Toxicidade aguda do nitrato em juvenis de Litopenaeus vannamei em baixa salinidade

Different technologies have been developed to improve the performance of Litopenaeus vannamei in low salinity, mainly in super-intensive systems like recirculation and BFT (Biofloc Technology System) systems. However, there is an accumulation of toxic nitrogenous compounds to the shrimps such as nitrate, that at high concentrations and depending on the salinity of the culture water can be lethal. Acute toxicity tests allow to analyze the relationship between the compound and other abiotic or biotic variables. The aim of this research was to determine the acute toxicity and safety level of nitrate (N-NO3 -) for juveniles of L. vannamei at salinities of 5 and 10g.L-1. For salinity of 5g.L-1, a control and 5 treatments were tested, with nitrate concentrations of 100, 500, 1500, 2500 and 3500mg.L-1.For salinity of 10mg.L-1, a 4500mg.L-1nitrate concentration was added. Juveniles were exposed to concentrations during 24, 48, 72, 96 hours in static system. The Mean Lethal Concentration (LCC50) was calculated and the recommended safety level for L. vannamei cultivation is 60.05 and 127.61mg.L-1 of nitrate for salinities 5 and 10g.L-1, respectively.(AU)

Diferentes tecnologias foram desenvolvidas para melhorar o desempenho do Litopenaeus vannamei em baixa salinidade, principalmente em sistemas super intensivos como sistema de recirculação e BFT (Biofloc Technology System). No entanto, há um acúmulo de compostos nitrogenados tóxicos aos camarões, como o nitrato, que em altas concentrações e dependendo da salinidade da água pode ser letal. Os testes de toxicidade aguda permitem analisar a relação entre o composto e outras variáveis ​​abióticas ou bióticas. O objetivo deste trabalho foi determinar a toxicidade aguda e o nível de segurança do nitrato (N-NO3 -) em juvenis de L. vannamei nas salinidades de 5 e 10g.L-1. Para a salinidade de 5g.L-1, um controle e cinco tratamentos foram testados, com concentrações de nitrato 100, 500, 1500, 2500 e 3500mg.L-1. Para salinidade de 10mg.L-1, foi adicionada uma concentração de nitrato de 4500mg.L-1. Os juvenis foram expostos às concentrações durante 24, 48, 72, 96 horas em sistema estático. A Concentração Letal Média (CL50) foi calculada e o nível de segurança recomendado para o cultivo de L. vannamei é de 60,05 e 127,61mg.L-1 de nitrato para salinidadesde 5 e 10g.L-1, respectivamente.(AU)

Lysobacter penaei sp. nov., isolated from intestinal content of a Pacific white shrimp (Penaeus vannamei).

The polyphasic taxonomic approach was used to characterize a novel bacteria strain, designated SG-8T, which was isolated from intestinal content of a Pacific white shrimp (Penaeus vannamei). Cells were Gram-stain-negative, aerobic, non-gliding rods. Growth occurred at 10-45 °C (optimum, 20-30 °C), pH 5.0-10.0 (optimum, 6.0-7.0) and in 0-6.0 % (w/v) NaCl (optimum, 0-4.0 %). The 16S rRNA gene sequence of strain SG-8T showed the highest sequence similarity to Lysobacter maris KMU-14T (98.6 %). On phylogenetic trees, strain SG-8T formed a stable cluster with Lysobacter maris KMU-14T, Lysobacter alkalisoli SJ-36T, Lysobacter spongiae 119BY6-57T and Lysobacter aestuarii S2-CT. The average nucleotide identity and digital DNA-DNA hybridization values between strain SG-8T and the four reference type strains listed above were 83.3, 82.3, 83.5, 83.3% and 22.8, 22.7, 22.7, 22.9 %, respectively. The major fatty acids (>5 %) were iso-C15 : 0, summed feature 9 (iso-C17 : 1 ω9c and/or 10-methyl C16 : 0), iso-C16 : 0, summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c), iso-C17 : 0, iso-C11 : 0 3OH and iso-C11 : 0. Ubiquinone-8 (Q-8) was the only respiratory quinone. The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. The DNA G+C content was 68.8 mol%. Based on the results of genomic, phylogenetic, phenotypic and chemotaxonomic analyses, strain SG-8T represents a novel species of the genus Lysobacter, for which the name Lysobacter penaei sp. nov. is proposed. The type strain is SG-8T (=GDMCC 1.1817T=KACC 21942T).

Acute toxicity of nitrate in Litopenaeus vannamei juveniles at low salinity levels / Toxicidade aguda do nitrato em juvenis de Litopenaeus vannamei em baixa salinidade

ABSTRACT: Different technologies have been developed to improve the performance of Litopenaeus vannamei in low salinity, mainly in super-intensive systems like recirculation and BFT (Biofloc Technology System) systems. However, there is an accumulation of toxic nitrogenous compounds to the shrimps such as nitrate, that at high concentrations and depending on the salinity of the culture water can be lethal. Acute toxicity tests allow to analyze the relationship between the compound and other abiotic or biotic variables. The aim of this research was to determine the acute toxicity and safety level of nitrate (N-NO3 -) for juveniles of L. vannamei at salinities of 5 and 10g.L-1. For salinity of 5g.L-1, a control and 5 treatments were tested, with nitrate concentrations of 100, 500, 1500, 2500 and 3500mg.L-1.For salinity of 10mg.L-1, a 4500mg.L-1nitrate concentration was added. Juveniles were exposed to concentrations during 24, 48, 72, 96 hours in static system. The Mean Lethal Concentration (LCC50) was calculated and the recommended safety level for L. vannamei cultivation is 60.05 and 127.61mg.L-1 of nitrate for salinities 5 and 10g.L-1, respectively.

RESUMO: Diferentes tecnologias foram desenvolvidas para melhorar o desempenho do Litopenaeus vannamei em baixa salinidade, principalmente em sistemas super intensivos como sistema de recirculação e BFT (Biofloc Technology System). No entanto, há um acúmulo de compostos nitrogenados tóxicos aos camarões, como o nitrato, que em altas concentrações e dependendo da salinidade da água pode ser letal. Os testes de toxicidade aguda permitem analisar a relação entre o composto e outras variáveis ​​abióticas ou bióticas. O objetivo deste trabalho foi determinar a toxicidade aguda e o nível de segurança do nitrato (N-NO3 -) em juvenis de L. vannamei nas salinidades de 5 e 10g.L-1. Para a salinidade de 5g.L-1, um controle e cinco tratamentos foram testados, com concentrações de nitrato 100, 500, 1500, 2500 e 3500mg.L-1. Para salinidade de 10mg.L-1, foi adicionada uma concentração de nitrato de 4500mg.L-1. Os juvenis foram expostos às concentrações durante 24, 48, 72, 96 horas em sistema estático. A Concentração Letal Média (CL50) foi calculada e o nível de segurança recomendado para o cultivo de L. vannamei é de 60,05 e 127,61mg.L-1 de nitrato para salinidadesde 5 e 10g.L-1, respectivamente.

Effects of dietary replacement of fishmeal by mealworm meal on muscle quality of farmed shrimp Litopenaeus vannamei.

This study investigated the muscle quality of the shrimp Litopenaeus vannamei fed on a diet containing different proportions of mealworm meal (MW) (0, 25, 50, 75 and 100%) as a substitute for fishmeal, which is the normal diet used in shrimp commercial production. The proximate composition, fatty acid profile, colour and texture of the shrimps were evaluated. Moisture, protein, and ash content of shrimp muscle were not significantly altered when fishmeal was replaced by MW (p>0.05). However, the replacement resulted in a linear increase in lipid content (p<0.05). The fatty acid composition of the experimental diets directly mirrored the fatty acid composition of shrimp muscle. The absence of long-chain polyunsaturated fatty acids in MW composition resulted in a linear decrease in eicosapentaenoic and docosahexaenoic fatty acids in shrimp muscle with increasing levels of MW in the diet. The n-3/n-6 ratio ranged from 0.50 to 0.67. Colour and firmness were unchanged between the treatments. Although the use of MW as a fishmeal substitute in L. vannamei diets has affected the lipid and fatty acid composition of shrimp muscle, from a human nutritional perspective, the lipid content of the shrimps is considered low and the n-3/n-6 ratio remained within the human dietary requirements. Therefore the use of a mealworm diet for shrimp production is a viable alternative to increasingly expensive fishmeal based diets.

Efecto combinado de temperatura y salinidad en el consumo de oxígeno en postlarvas de camarón blanco Litopenaeu vannamei / Combined effect of temperature and salinity on oxygen consumption on white shrimp Litopenaeus vannamei postlarvae / Efeito combinado de temperatura e salinidade no consumo de oxigênio de póslarvas de camarao branco Litopenaeus vannamei

El objetivo fue analizar el efecto combinado de temperatura y salinidad sobre el consumo de oxígeno en postlarvas (PL12) de camarón blanco Litopenaeus vannamei. Se realizaron cinco experimentos en combinación de temperatura (15, 20, 25, 30 y 35 °C) y salinidad (5, 15, 25, 35 y45 ups). Por cada temperatura se utilizaron en total 125 botellas DBO de 300 mL, de las cuales, 100 correspondieron a los tratamientos (temperatura x salinidad) con 20 postlarvas cada una, 20 botellas a los blancos (sin postlarvas) y las 5 restantes como iniciales. Las botellas se mantuvieron en agua recirculando con temperatura controlada dentro de cinco tinas de fibra de vidrio (124X60X19 cm). Se realizaron cuatro lecturas del consumo de oxígeno para un tiempo transcurrido de 1, 2, 4 y 8 h. Ala primera hora, se obtuvieron 35 lecturas del consumo (25 tratamientos [con postlarvas], 5 blancos y 5 iniciales). A las 2 h, correspondieron a 30 botellas (25 con postlarvas y 5 blancos), e igualmente a las 4 y 8 h. Se obtuvo los mayores consumos de oxígeno a una mayor temperatura y salinidad, aunque, los máximos fueron 14.36 (35 °C, 25 ups) y 13.52 (30 °C, 45 ups) µg L-1 h-1 PL y el mínimo en 0.07 (20 °C, 5 ups) µg L-1 h-1 PL. La temperatura, salinidad y su interacción fueron significativas (P<0.05) sobre el consumo de oxígeno. Los mejores consumos de oxígeno en las postlarvas de L. vannamei fueron en temperatura de 25 a 30 °C y salinidad entre 15 y 25 ups.

The aim was evaluated the combined effect of temperature and salinity on consumption oxygen in postlarvae (PL12) white shrimp Litopenaeus vannamei. There were realized five experiments in combination of temperature (15, 20, 25, 30 and 35 ºC) and salinity (5, 15, 25, 35 y 45 psu). There were used for each experiment 125 bottles DBO of 300 mL, of which, 100 corresponded to the treatments (temperature x salinity) with 20 postlarvae, 20 to the whites (without postlarvae) and 5 were considered to be initial. The bottles were kept in water re-circulating with temperature controlled inside of five reservoir of glass fiber. There were realized four readings of the consumption of oxygen for a time of 1, 2, 4 and 8 h. In the first hour, there were obtained 35 readings of the consumption (25 treatments [with postlarvae], 5 whites and 5 initials). At 2 h, corresponded to 30 bottles (25 with postlarvae and 5 whites), and equally at after 4 y 8 h. The high consumption oxygen were obtained to a highest salinity and temperature, though the maximum was 14.36 (35 °C, 25 psu) and 13.52 (30 °C, 45 psu) µg L-1 h-1 PL and the minim in 0.07 (20 °C, 5 psu) µg L-1 h-1 PL. The oxygen consumption were significantly (P<0.05) affected by temperature, salinity and interaction of both factors. Whereas at 25 and 30 °C and 15 and 25 psu, showed the best oxygen consumption.

O objetivo foi analisar o efeito combinado de temperatura e salinidade sobre o consumo de oxigênio em póslarvas (PL12) de camarão branco Litopenaeus vannamei. Realizaram-se cinco experimentos em combinação de temperatura (15, 20, 25, 30 e 35 ºC) e salinidade (5, 15, 25, 35 e 45 ups). Para cada experimento foram utilizadas, no total, 125 garrafas de DBO de 300 mL, das quais 100 corresponderam aos tratamentos (temperatura x salinidade), com 20 pós-larvas cada uma, 20 garrafas como controle (sem pós-larvas) e as 5 restantes, como iniciais. As garrafas mantiveram-se em água recirculando com temperatura controlada dentro de cinco tinas de fibra de vidro (124X60X19 cm). Realizaram-se quatro leituras do consumo de oxigênio para um tempo decorrido de 1, 2, 4 e 8 h. À primeira hora, obtiveram-se 35 leituras do consumo (25 para os tratamentos [com póslarvas], 5 brancos e 5 iniciais). Às 2 h, as leituras corresponderam a 30 garrafas (25 com pós-larvas e 5 brancos), e igualmente às 4 e 8 h. Os maiores consumos de oxigênio foram obtidos na maior temperatura e salinidade, sendo que os máximos foram 14,36 (35 °C, 25 ups) e 13,52 (30 °C, 45 ups) µg L-1 h-1 PL e o mínimo 0,07 (20 °C, 5 ups) µg L-1 h-1 PL. A temperatura,salinidade e sua interação foram significativas (P<0.05) sobre o consumo de oxigênio. Os melhores consumos de oxigênio nas pós-larvas de L. vannamei foram a temperaturas de 25 e 30 °C e salinidadde 15 e 25 ups.

Efecto combinado de temperatura y salinidad en el consumo de oxígeno en postlarvas de camarón blanco Litopenaeu vannamei / Combined effect of temperature and salinity on oxygen consumption on white shrimp Litopenaeus vannamei postlarvae / Efeito combinado de temperatura e salinidade no consumo de oxigênio de póslarvas de camarao branco Litopenaeus vannamei

El objetivo fue analizar el efecto combinado de temperatura y salinidad sobre el consumo de oxígeno en postlarvas (PL12) de camarón blanco Litopenaeus vannamei. Se realizaron cinco experimentos en combinación de temperatura (15, 20, 25, 30 y 35 °C) y salinidad (5, 15, 25, 35 y45 ups). Por cada temperatura se utilizaron en total 125 botellas DBO de 300 mL, de las cuales, 100 correspondieron a los tratamientos (temperatura x salinidad) con 20 postlarvas cada una, 20 botellas a los blancos (sin postlarvas) y las 5 restantes como iniciales. Las botellas se mantuvieron en agua recirculando con temperatura controlada dentro de cinco tinas de fibra de vidrio (124X60X19 cm). Se realizaron cuatro lecturas del consumo de oxígeno para un tiempo transcurrido de 1, 2, 4 y 8 h. Ala primera hora, se obtuvieron 35 lecturas del consumo (25 tratamientos [con postlarvas], 5 blancos y 5 iniciales). A las 2 h, correspondieron a 30 botellas (25 con postlarvas y 5 blancos), e igualmente a las 4 y 8 h. Se obtuvo los mayores consumos de oxígeno a una mayor temperatura y salinidad, aunque, los máximos fueron 14.36 (35 °C, 25 ups) y 13.52 (30 °C, 45 ups) µg L-1 h-1 PL y el mínimo en 0.07 (20 °C, 5 ups) µg L-1 h-1 PL. La temperatura, salinidad y su interacción fueron significativas (P<0.05) sobre el consumo de oxígeno. Los mejores consumos de oxígeno en las postlarvas de L. vannamei fueron en temperatura de 25 a 30 °C y salinidad entre 15 y 25 ups.(AU)

The aim was evaluated the combined effect of temperature and salinity on consumption oxygen in postlarvae (PL12) white shrimp Litopenaeus vannamei. There were realized five experiments in combination of temperature (15, 20, 25, 30 and 35 ºC) and salinity (5, 15, 25, 35 y 45 psu). There were used for each experiment 125 bottles DBO of 300 mL, of which, 100 corresponded to the treatments (temperature x salinity) with 20 postlarvae, 20 to the whites (without postlarvae) and 5 were considered to be initial. The bottles were kept in water re-circulating with temperature controlled inside of five reservoir of glass fiber. There were realized four readings of the consumption of oxygen for a time of 1, 2, 4 and 8 h. In the first hour, there were obtained 35 readings of the consumption (25 treatments [with postlarvae], 5 whites and 5 initials). At 2 h, corresponded to 30 bottles (25 with postlarvae and 5 whites), and equally at after 4 y 8 h. The high consumption oxygen were obtained to a highest salinity and temperature, though the maximum was 14.36 (35 °C, 25 psu) and 13.52 (30 °C, 45 psu) µg L-1 h-1 PL and the minim in 0.07 (20 °C, 5 psu) µg L-1 h-1 PL. The oxygen consumption were significantly (P<0.05) affected by temperature, salinity and interaction of both factors. Whereas at 25 and 30 °C and 15 and 25 psu, showed the best oxygen consumption.(AU)

O objetivo foi analisar o efeito combinado de temperatura e salinidade sobre o consumo de oxigênio em póslarvas (PL12) de camarão branco Litopenaeus vannamei. Realizaram-se cinco experimentos em combinação de temperatura (15, 20, 25, 30 e 35 ºC) e salinidade (5, 15, 25, 35 e 45 ups). Para cada experimento foram utilizadas, no total, 125 garrafas de DBO de 300 mL, das quais 100 corresponderam aos tratamentos (temperatura x salinidade), com 20 pós-larvas cada uma, 20 garrafas como controle (sem pós-larvas) e as 5 restantes, como iniciais. As garrafas mantiveram-se em água recirculando com temperatura controlada dentro de cinco tinas de fibra de vidro (124X60X19 cm). Realizaram-se quatro leituras do consumo de oxigênio para um tempo decorrido de 1, 2, 4 e 8 h. À primeira hora, obtiveram-se 35 leituras do consumo (25 para os tratamentos [com póslarvas], 5 brancos e 5 iniciais). Às 2 h, as leituras corresponderam a 30 garrafas (25 com pós-larvas e 5 brancos), e igualmente às 4 e 8 h. Os maiores consumos de oxigênio foram obtidos na maior temperatura e salinidade, sendo que os máximos foram 14,36 (35 °C, 25 ups) e 13,52 (30 °C, 45 ups) µg L-1 h-1 PL e o mínimo 0,07 (20 °C, 5 ups) µg L-1 h-1 PL. A temperatura,salinidade e sua interação foram significativas (P<0.05) sobre o consumo de oxigênio. Os melhores consumos de oxigênio nas pós-larvas de L. vannamei foram a temperaturas de 25 e 30 °C e salinidadde 15 e 25 ups.(AU)

Distribución esaacial de las especies del géner buenoa kirkaldy 1904 (hemipterra: notonectidae) en tumaco (nariño, Colombia) / Spatial Distribution of the Species of the Genus Buenoa (Hemiptera: Notonectidae) in Tumaco (Nariño, Colombia)

El trabajo se realizó en la finca Mar Agrícola del municipio de Tumaco, con el objetivo de estudiar la distribución de las especies del género Buenoa en condiciones ambientales homogéneas respecto a la temperatura, humedad y altitud, en hábitats acuáticos de agua dulce y otros, con diferentes grados de conductividad y dedicados al criadero del camarón marino Litopenaeus vannamei (Boone, 1931). Los lagos estudiados fueron cuatro de agua dulce y cuatro con diferente conductividad, en los meses de junio a noviembre del 2010. Los resultados indican la distribución heterogénea de las especies del género Buenoa con mayor diversidad en ambientes dulceacuícolas (5 especies) y menor abundancia; mientras en ambientes salobres hay menor diversidad (4 especies) y mayor abundancia. Solo la especie Buenoa dactylis Padilla-Gil 2010 se encuentra en ambos ambientes acuícolas. Se discute posibles implicaciones ecológicas que puedan influir en este patrón de distribución.

The work was carried in the Mar Agrícola farm of the municipality Tumaco, with the objective of studying the distribution of the species of the genus Buenoa in homogeneous environmental conditions regarding temperature, humidity, altitude and aquatic habitats of the freshwater and the others with different grade of conductivity and dedicated to the marine shrimp farming Litopenaeus vannamei (Boone, 1931). The studied lakes were four of freshwater and four with different conductivity, in the months of June to November 2010. The results showed heterogeneous distribution of the species of the genus Buenoa with major diversity in freshwater (5 species) and lower abundance; while in saltwater had lower diversity (4 species) and major abundance. Only Buenoa dactylis Padilla-Gil 2010 was found in both aquatic environments. It is discussed possible ecological implications than can influence this distribution pattern are discussed.

New method for the extraction of volatile lipid oxidation products from shrimp by headspace-solid-phase microextraction-gas chromatography-mass spectrometry and evaluation of the effect of salting and drying.

A new method based on headspace-solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) was developed, aimed at evaluating the formation of volatile lipid oxidation products (VLOPs) in shrimp during the salting and drying process. Of the four fibers evaluated, the fiber coated with divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) was the most adequate for the quantification of the VLOPs. The best analytical conditions were obtained by homogenization in an ultraturrax followed by extraction at 40 °C for 30 min. The optimized method allowed for the rapid and simple extraction of the VLOPs, with low detection (≤0.15 ng g(-1)) and quantification (≤0.50 ng g(-1)) limits and satisfactory precision (≤12.67%) and extraction efficiency (≥94.28%). The salting and drying negatively affected shrimp quality, reducing the fatty acid content and increasing the VLOPs, especially hexanal.

Efectos de interacción genotipo por ambiente para peso corporal a los 130 días en camarón blanco del Pacífico [Penaeus (Litopenaeus) vannamei] / Genotype by environment interaction effects for body weight at 130 days of age in the Pacific white shrimp [Penaeus (Litopenaeus) vannamei]

Body weight of Pacific white shrimp [Penaeus (Litopenaeus) vannamei] at 130 days of age was analyzed in three environments corresponding to different management systems: semi-intensive (10 shrimp/m²) in Pozos, Sinaloa (POZOS10), intensive (30 shrimp/ m²) in Pozos, Sinaloa (POZOS30), and super-intensive (85 shrimp/m²) in Bahia de Kino, Sonora (KINO85). Data were obtained from 18 087 sibs from 113 sires and 143 dams. The aim of the study was to evaluate the presence of genotype by environment interaction effects (IGA) and the effect of the (co) variance between full-sibs family common effects on the genetic parameter estimates. Estimates of h² with a model including independent full-sibs family common effects were between 0.26 and 0.39 across environments, while the estimates for a model with correlated full-sibs family common effects were estimated between 0.14 and 0.23. No differences were found for h² values between environments. The genetic correlations between environments were not lower from unity with any model; therefore, it is concluded that no evidence of genotype-environment interaction exists for body weight at 130 days in Pacific white shrimp, under the environments used in this study. The inclusion of the (co)variance between full-sibs family common effects of different environments affected the parameter estimates. These results also indicate that ranking of the breeding animals will be similar in all the studied production environments.

Se analizó información de peso corporal de camarón blanco del Pacífico [Penaeus (Litopenaeus) vannamei] a los 130 días, en tres sistemas de manejo: semiintensivo (10 camarones/m²); intensivo (30 camarones/m²), ambos en Pozos, Sinaloa, y super-intensivo (85 camarones/m²), en Bahía de Kino, Sonora. Los registros corresponden a 18 087 individuos, hijos de 113 sementales y 143 hembras, con la finalidad de evaluar la existencia de interacciones genotipo por ambiente (IGA) y el efecto de la covarianza de los efectos comunes de familia de hermanos en la estimación de parámetros genéticos. Las estimaciones de h² con un modelo que consideró los efectos comunes de familia de hermanos como independientes, fueron de 0.26 a 0.39 y de 0.14 a 0.23, para un modelo que consideró dichos efectos como correlacionados. No existió diferencia significativa entre los valores de h² de los ambientes, y las correlaciones genéticas entre ambientes no fueron menores a uno con ninguno de ambos modelos, se concluye que no hay evidencia de IGA en el peso corporal a los 130 días de P. vannamei en los ambientes estudiados en este trabajo. La inclusión de la covarianza entre efectos de familias de hermanos en el análisis afectó los valores de los parámetros. Se concluye que el ordenamiento de los reproductores será similar en los ambientes estudiados.