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International audience; Branchial chambers constitute the main osmoregulatory site in almost all decapod crustaceans. However, few studies have been devoted to elucidate the cellular function of specific cells in every osmoregulatory structure of the branchial chambers. In decapod crustaceans, it is well-known that the osmoregulatory function is localized in specific structures that progressively specialize from early developmental stages while specific molecular mechanisms occur. In this study, we found that although the structures developed progressively during the larval and postlarval stages, before reaching juvenile or adult morphology, the osmoregulatory capabilities of Litopenaeus vannamei were gradually established only during the development of branchiostegites and epipodites, but not gills. The cellular structures of the branchial chambers observed during the larval phase do not present the typical ultrastructure of ionocytes, neither N a + /K +-ATPase expression, likely indicating that pleura, branchiostegites, or bud gills do not participate in osmoregulation. During early postlarval stages, the lack of N a + / K +-ATPase immunoreactivity of the ionocytes from the branchiostegites and epipodites suggests that they are immature ionocytes (ionocytes type I). It could be inferred from IIF and TEM results that epipodites and branchiostegites are involved in iono-osmoregulation from PL15, while gills and pleura do not participate in this function.

The white spot syndrome virus (WSSV), currently affecting cultured shrimp, causes substantial economic losses to the worldwide shrimp industry. An antiviral therapy using double-stranded RNA interference (dsRNAi) by intramuscular injection (IM) has proven the most effective shrimp protection against WSSV. However, IM treatment is still not viable for shrimp farms. The challenge is to develop an efficient oral delivery system that manages to avoid the degradation of antiviral RNA molecules. The present work demonstrates that VLPs (virus-like particles) allow efficient delivery of dsRNAi as antiviral therapy in shrimp. In particular, VLPs derived from a virus that infects plants, such as cowpea chlorotic mottle virus (CCMV), in which the capsid protein (CP) encapsidates the dsRNA of 563 bp, are shown to silence the WSSV glycoprotein VP28 (dsRNAvp28). In experimental challenges in vivo, the VLPs- dsRNAvp28 protect shrimp against WSSV up to 40% by oral administration and 100% by IM. The novel research demonstrates that plant VLPs, which avoid zoonosis, can be applied to pathogen control in shrimp and also other organisms, widening the application window in nanomedicine.

Branchial chambers constitute the main osmoregulatory site in almost all decapod crustaceans. However, few studies have been devoted to elucidate the cellular function of specific cells in every osmoregulatory structure of the branchial chambers. In decapod crustaceans, it is well-known that the osmoregulatory function is localized in specific structures that progressively specialize from early developmental stages while specific molecular mechanisms occur. In this study, we found that although the structures developed progressively during the larval and postlarval stages, before reaching juvenile or adult morphology, the osmoregulatory capabilities of Litopenaeus vannamei were gradually established only during the development of branchiostegites and epipodites, but not gills. The cellular structures of the branchial chambers observed during the larval phase do not present the typical ultrastructure of ionocytes, neither Na

WOS:000614765100005; European sea bass (Dicentrarchus labrax), a major aquaculture species, is distributed along the coasts of the North-Eastern Atlantic Ocean, Mediterranean and Black Sea. D. labrax enter lagoons and estuaries where salinity fluctuates and sometimes reaches levels over 60%o, notably in Mediterranean lagoons. Keeping in mind that European sea bass are genetically subdivided in an Atlantic and a Mediterranean lineage, we compared fish from Atlantic (A) and West Mediterranean (M) populations regarding their capacity to tolerate hypersalinity with a focus on the kidney, a key organ involved in water reabsorption at high salinity. Fish were analyzed following a two-week transfer from seawater (SW, 36%o) to either seawater (SW, 36%o) or hypersaline water (HW, 55%o). Plasma osmolality was significantly increased in the MHW group compared to the other groups. Plasma sodium levels were significantly increased in hypersaline water compared to seawater in both lineages whereas plasma chloride levels showed an opposite trend. In order to estimate water filtration at the kidney level, the size of renal glomeruli was investigated and showed a decreased glomerulus perimeter and area in hypersaline water compared to seawater. NKA was highly expressed in all kidney tubules notably collecting tubules and ducts. There was an effect of salinity on renal nka alpha 1a mRNA expression with slightly lower transcript levels at 55%o compared to 36%o. Relative protein amounts and activity of NKA however were significantly higher in fish exposed to hypersalinity regardless of their origin. AQP1a immunolabeling differed between proximal tubules subtypes and only faint AQP1a was detected in subapical parts of cells lining collecting ducts. The transcript levels of renal aqp 1a were lower in the HW group than the SW group whereas the expression of other aqp paralogs (aqp 1b, aqp 8b) did not change according to the analyzed conditions. This study showed an efficient acclimation of sea bass to high salinity by increasing active ion transport at the kidney and by decreasing the size of filtering glomeruli to minimize water loss through urine. Despite Mediterranean D. labrax are supposed to more often encounter high salinities in their habitat, their high blood osmolality in hypersaline water indicates that their overall response to hypersalinity seems not improved compared to the Atlantic lineage. However, at the kidney level, the traits analyzed differ slightly between genetic lineages, potentially as a response to high blood osmolalities in MHW.

The Crassostrea virginica oyster has biological and economic importance in the Gulf of Mexico, an area with a high extraction and production of hydrocarbons. Exposure to hydrocarbons affects the reproductive processes in bivalves. In C. virginica, the effect of hydrocarbons on the gonad of the undifferentiated organism has not been evaluated to determine the possible damage during the maturation process. To evaluate this effect, RNA-seq data was generated from C. virginica gonads exposed to a 200 μg/L of hydrocarbons at different exposure times (7, 14 and 21 days) and a control treatment (without hydrocarbons). The analysis of the gonad transcriptome showed the negative effect of hydrocarbons on maturation, with a sub-expression of 22 genes involved in different stages of this process. Additionally, genes in the immune system were down-regulated, which may indicate that exposure to hydrocarbons causes immunosuppression in bivalves. A group of oxidative stress genes was also reduced. These data contribute to a better understanding of the effect of hydrocarbons on the reproductive process in bivalves and, at the same time, allow us to identify possible biomarkers associated with hydrocarbon contamination in the gonad of C. virginica.

Some microalgae are recognized for producing pigments and other metabolites with biotechnological importance, particularly, Dunaliella salina is a remarkable one. These kind of compounds are used as food and have a great industrial potential. The pigment industry comprises a millionaire market value, being β-carotene one of the most profitable one. In this study we describe the morphology, molecular identification, growth dynamics, proximal composition, nutrients and pigment content of a recently isolated Dunaliella salina strain (SQ) under different salinity/light conditions, in order to highlight its remarkable properties for biotech/biomed industry. D. salina SQ reached the highest densities (1.07-1.25 cell mL -1 x10 6 ) at low salinities (100-500 mM NaCl) under continuous light regimen (24:0 h Light:Dark). Neoxanthin (Neo) and violaxanthin (Viol) were the most abundant pigments when exposed to 500 mM NaCl (18:6 h Light:Dark). Furthermore, this peculiar strain produces other compounds with high industrial value. Perfiles de crecimiento, composicion de nutrientes y analisis de pigmentos de Dunaliella salina cepa San Quintin Algunas microalgas son reconocidas por producir pigmentos y otros metabolitos con importancia biotecnologica, en particular, Dunaliella salina es una de las mas notables. Este tipo de compuestos se usan como alimento y tienen potencial industrial. La industria del pigmento tiene un valor de mercado millonario, siendo el β-caroteno uno de los mas rentables. En este estudio se describe la morfologia, la dinamica de crecimiento, composicion proximal, composicion de nutrientes y contenido de pigmentos de una cepa de Dunaliella salina (SQ) recientemente aislada. La identificacion de la especie se corroboro mediante tecnicas moleculares. Se cultivo a D. salina bajo diferentes condiciones de salinidad y luz, con el objetivo de resaltar sus propiedades para la industria biotecnologica y biomedica. D. salina SQ alcanzo las densidades mas altas (1.07-1.25 celulas mL -1 x10 6 ) a salinidades bajas (NaCl 100 y 500 mM) en un regimen de luz continua. La neoxantina (Neo) y la violaxantina (Viol) fueron los pigmentos mas abundantes en 500 mM NaCl y un ciclo de luz: oscuridad 18: 6 h. Ademas, esta peculiar cepa produce otros compuestos con alto valor industrial.

Totoaba macdonaldi, an endemic fish from the Gulf of California, is currently considered an endangered species by the Mexican Federal Government since its bladder is a high-priced item in China's black market. Totoaba is considered the cause of extinction of the marine porpoise vaquita marina (Phocoena sinus) due to Illegal fishing. It inhabits the Colorado Delta River Marine Reserve, an area with very high productivity, biomass, species endemism, and a marine nursery. To explore its osmoregulatory capabilities, totoaba specimens were exposed to different salinity conditions (from 5 to 40 psu) under laboratory trials. Several developmental stages were tested (eggs, larvae, and juveniles), from which blood and water osmotic pressure (OP), survival, water and total ash content were evaluated, confirming the euryhaline behavior of juveniles. However, larval stages were very dependent on external media salinity concentration. The responses to salinity acclimation and shifts in survival recorded were closely related to its migratory strategy, which can have important ecological consequences.

We analysed the effects of salinity on survival, growth and the osmoregulatory capacity (OC) of puffer fish larvae (Sphoeroides annulatus). In experiment 1, we compared the growth of larvae maintained at a constant temperature (28 ± 0.5 °C) under seven salinity levels (5, 12, 19, 26, 33, 35 and 40 psu) over a 28-day period. No significant differences were found for larval growth. However, salinity significantly affected survival. The larvae hyper-osmoregulated at low salinities and hypo-osmoregulated at high salinities. The isosmotic point ranged from 338.9 to 355.9 mOsm kg−1, depending on salinity. In experiment 2, survival increased with increasing salinity following direct exposure to the same seven salinity levels over a 72-h period. The isosmotic point ranged from 256.5 to 466.7 mOsm kg−1 depending on the developmental stage. This species hyper-regulated at 5–12 psu, hypo-regulated at 19–40 psu and demonstrated a high euryhalinity at 7 DAH with 95% survival.

Thirty adult organisms of Panopea globosa, an endemic geoduck species from Baja California, Mexico, were collected monthly during a maturation cycle (October through January). Histological and semiquantitative histochemical changes (total lipids and carbohydrates) were assessed in gonad tissue during the maturation process. Biochemical quantification of proteins, lipids, carbohydrates, vitellogenin, and vitellin was performed on hemolymph and gonad tissues of all specimens. The theoretical diameter of oocytes was also estimated from their surface area, measured in histological sections of gonads. Five distinct gonadal stages were identified in both male and female geoducks, with previtellogenic (PVt)/early spermatogenic (ES) gonads being observed in October. Spawning took place in December/January when the temperature reached a plateau of ;18.5C. Oocyte diameter varied between 25.5 mm (PVt stage) and 74.8 mm during the late vitellogenic stage (LVt). The percent of lipids and carbohydrates evaluated histochemically in females closely mirrored the gonadal stages, as well as the diameter. Quantitative changes in proteins, lipids, and carbohydrates in the hemolymph did not show a clear temporal pattern, yet the level of vitellogenin increased from 16.4 (PVt stage)-47.8 mg/mL (LVt stage) and correlated with the oocyte diameter. The weight- specific content of proteins, lipids, and carbohydrates in the gonads was significantly greater during PVt and ES than the other gonadal stages, and remained relatively constant thereafter. Vitellin content mirrored the evolution of each maturation stage and correlated significantly with oocyte diameter. Vitellogenin or vitellin can be used as a reliable quantitative index of gender and degree of gonadic maturity in females. Hemolymph can be obtained readily from the pericardial cavity without affecting the performance of the organism significantly, which further makes vitellogenin a valuable, nonlethal marker for this genus.

To evaluate the effect of salinity on the hatching rate, hatching time, survival percentage, osmoregulation pattern and the incidence of abnormalities in newly hatched larvae, embryos of Sphoeroides annulatus (Jenyns 1842) were exposed to 5, 12, 19, 26, 33, 35 and 40 psu. The hatching percentage (HP), survival percentage (PS), normal larvae (PN), deformed larvae (PD) and hatching time (HT) were significantly affected by salinity (P

White spot syndrome virus (WSSV) has a worldwide distribution and is considered one of the most pathogenic and devastating viruses to the shrimp industry. A few studies have explored the effect of WSSV on shrimp acclimated to low (5 practical salinity units [psu]) or high ([40 psu) salinity conditions. In this work, we analysed the physiological response of WSSV-infected Litopenaeus vannamei juveniles that were acclimated to different salinities (5, 15, 28, 34 and 54 psu). We evaluated the osmotic response and survival of the shrimp at different times after infection (0 to 48 hours), and we followed the expression levels of a viral gene (vp664) in shrimp haemolymph using real-time PCR. Our results indicate that the susceptibility of the shrimp to the virus increased at extreme salinities (5 and 54 psu), with higher survival rates at 15 and 28 psu, which were closer to the iso-osmotic point (24.7 psu, 727.5 mOsmol/kg). Acute exposure to the virus made the haemolymph less hyperosmotic at 5 and 15 psu and less hypo-osmotic at higher salinities ([28 psu). The capacity of white shrimp to osmoregulate, and thus survive, significantly decreased following WSSV infection. According to our results, extreme salinities (5 or 54 psu) are more harmful than seawater.

A physiological study was performed to explore the effects in Sphoeroides annulatus (Jenyns 1842) juveniles of exposure to different salinities 10, 17, 23, 29, 35 and 41‰ on oxygen consumption rate (OCR), ammonium excretion rate (AER), the oxygen-nitrogen atomic ratio (O:N), osmoregulation and Na+/K+-ATPase expression. The OCR values ranged from 27.9 to 30.9 mg O2 h−1 kg−1, displaying a Type 1 response pattern Kinne (1977). AER ranged from 0.60 to 0.69 mg h−1 kg−1, and O:N values were from 53.12 to 59.26, indicating that the puffers use proteins and lipids as an energy-substrate. Osmoregulation in S. annulatus was hyposmotic in salinities of 23, 29, 35 and 41‰ and hyperosmotic in a salinity of 10‰. The isosmotic point of the bullseye puffer was 356 mmol kg−1 (10.5‰). The enzyme expression analysis indicates that the fish acclimated to 41‰ had the highest Na+/K+-ATPase expression level, whereas, the lowest expression level was found close to the isosmotic point. Na+/K+-ATPase expression in the gills was found to have a U-shaped relationship with environmental salinity. We conclude that the bullseye puffer is strongly euryhaline and can be cultivated in a wide range of environments that has important economic implications.

Sea-bass (Dicentrarchus labrax) grow under different salinity regimes, from the open sea to lagoons and even rivers, but some mortality has been recorded in juvenile stages when exposed to low salinity water. Changes in water permeability of different osmoregulatory tissues could be the cause of reduction in blood osmotic pressure and death in some fish in fresh water (FW). In order to explore this condition, we have studied the changes of aquaporins (AQP1 and AQP3), alpha 1 and alpha 4 Na+/K(+-)ATPase transcript levels in the digestive tract, kidney and gills after a long-term exposure of juvenile sea-bass to sea water (SW) and FW fish able to survive in SW and FW are called SW-adapted fish (SWS), FW successfully-adapted fish (FWS) respectively, while fish that die in FW are called FW unsuccessfully-adapted fish (FWU). AQP1 was highly expressed in SWS digestive tract and kidney, suggesting its involvement in water absorption. In FWU, AQP1 transcript levels in the digestive tract were higher than in FWS, suggesting higher water absorption. AQP3 transcript levels in gills were higher in FWS compared to SWS, suggesting a role in FW adaptation. AQP3 transcript levels in gills were higher in FWU than in FWS, suggesting an increase in gill water permeability or other solutes. Transfer to FW was followed in gills by an increase in alpha 1 and alpha 4 Na+/K+-ATPase levels in FWS and FWU, supporting the current model of ion absorption through the gills. (C) 2008 Elsevier Inc. All rights reserved.

Euryhaline fish possess the ability to compensate for environmental salinity changes through hydro-mineral regulation. A number of proteins have been studied in order to understand water and ion exchanges, known as fish osmoregulation. Sea-bass (Dicentrarchus labrax) cDNA sequences encoding a homologue of mammalian aquaporin (termed AQP1) and a homologue of mammalian aquaglyceroporin (termed AQP3) have been isolated and sequenced. The aquaporin amino acid sequences share respectively more than 60% and 65% identity with other known aquaporins. We have shown that salinity influences aquaporin expression levels in the gill, kidney and digestive tract, the main osmoregulatory organs. AQP1 may have a major osmoregulatory role in water transport in kidney and gut in SW-acclimated fish, whereas AQP3 could be implicated in gill water transport in FW-acclimated fish.

The ontogeny of the digestive tract (DT) and of Na(+)/K(+)-ATPase localization was investigated during the early postembryonic development (from yolk sac larva to juvenile) of the euryhaline teleost Dicentrarchus labrax reared at two salinities: seawater and diluted seawater. Histology, electron microscopy and immunocytochemistry were used to determine the presence and differentiation of ion transporting cells. At hatching, the DT is an undifferentiated straight tube over the yolk sac. At the mouth opening (day 5), it comprises six segments: buccopharynx, esophagus, stomach, anterior intestine, posterior intestine and rectum, well differentiated at the juvenile stage (day 72). The enterocytes displayed ultrastructural features similar to those of mitochondria-rich cells known to be involved in active ion transport. At hatching, ion transporting cells lining the intestine and the rectum exhibited a Na(+)/K(+)-ATPase activity which increased mainly after the larva/juvenile (20 mm) metamorphic transition. The immunofluorescence intensity was dependent upon the stage of development of the gut as well as on the histological configuration of the analyzed segment. The appearance and distribution of enteric ionocytes and the implication of the DT in osmoregulation are discussed.

The successful establishment of a species in a given habitat depends on the ability of each of its developing stages to adapt to the environment. In order to understand this process we have studied the adaptation of a euryhaline fish, the sea-bass Dicentrarchus labrax, to various salinities during its ontogeny. The expression and localization of Aquaporin 1a (AQP1a) mRNA and protein were determined in different osmoregulatory tissues. In larvae, the sites of AQP1a expression are variable and they shift according to age, implying functional changes. In juveniles after metamorphosis (D32–D48 post-hatch, 15–25mm) and in pre-adults, an increase in AQP1a transcript abundance was noted in the digestive tract, and the AQP1a location was observed in the intestine. In juveniles (D87–D100 post-hatch, 38–48 mm), the transcript levels of AQP1a in the digestive tract and in the kidney were higher in sea water (SW) than at lower salinity. These observations, in agreement with existing models, suggest that in SW-acclimated fish, the imbibed water is absorbed via AQP1a through the digestive tract, particularly the intestine and the rectum. In addition, AQP1a may play a role in water reabsorption in the kidney. These mechanisms compensate dehydration in SW, and they contribute to the adaptation of juveniles to salinity changes during sea-lagoon migrations. These results contribute to the interpretation of the adaptation of populations to habitats where salinity varies. Publisher PDF

En diversos laboratorios de producción de larvas de camarón del país se han presentado eventos de luminiscencia asociados con mortalidades en los estadíos Zoea, Misis y Postlarva. En México el único trabajo formal enfocado a su estudio es sobre larvas de Penaeus vannamei, aún cuando en Asia, Ecuador y Venezuela está ampliamente documentada su importancia desde hace más de una década debido a las mortalidades masivas registradas (LaVilla-Pitogo et al., 1998; Alvarez et al., 1998; Robertson et al., 1998). Corroboramos la presencia de Vibrio harveyi en el sistema de cultivo larvario de Penaeus stylirostris en dos laboratorios mexicanos productores de postlarvas, uno ubicado en Sinaloa y el otro en el norte de Sonora. Durante los muestreos realizados, no hubo eventos de luminiscencia ni mortalidades masivas de larvas. La identificación de la especie y otras bacterias luminiscentes marinas, se basó en una clave taxonómica desarrollada a partir de datos de la literatura. Las cepas aisladas en los laboratorios de producción fueron resistentes hasta 30 ppm de Argentyne y 30 ppm de formol, casi el doble que la cepa de colección de la ATCC; a densidades celulares en el orden de 102 cel/ml Esta resistencia varía según el estadío del que fueron aisladas. Los reproductores, importados de Venezuela, parecen ser la fuente de V. harveyi al sistema de producción. Se evidenció su presencia en larvas de Nauplio, Zoea, Misis y Postlarva así como en agua y paredes del estanque de reproductores y en la fosa de oxidación. There have been luminescence events in different shrimp hatcheries of México related with larvae mortalities, mainly in Zoea, Mysis and Postlarvae stages. The only formal work focused to their study in Mexico was due on Penaeus vannamei larvae, even that their pathogenic importance has been reported a decade ago in Asia, Ecuador and Venezuela (LaVilla-Pitogo et al., 1998; Alvarez et al., 1998; Robertson et al., 1998). The presence of Vibrio harveyi was confirmed in two Mexican shrimp hatcheries, one located in Sinaloa and the other in the north of Sonora. There was no mortalities or luminescence event during our period of sampling. The identification of this specie and other other luminiscence bacteria, was based on a taxonomy key developed from literature data. The colonies isolated from hatcheries production systems were resistant until 30 ppm of Argentyne and 30 ppm of formaline, almost a double concentration than reference strains. This resistance change according to the larval stage. The source of V. harveyi into production system, was the broodstock imported from Venezuela. The bacteria was isolated from water and walls of stock tanks, and their incidence was also detected in Nauplii, Zoea, Mysis, Postlarvae and seawater sewage system.

El virus de la mancha blanca o White Spot Syndrome Virus (WSSV, por sus siglas en inglés) es un patógeno letal que afecta el cultivo de camarón a nivel mundial. Los síntomas visibles de los animales infectados son letargia, pérdida del apetito, expansión de cromatóforos y nado errático, pero se ha observado también una pérdida de la capacidad osmorreguladora y la presencia de inclusiones blancas de 0.2 a 0.5 mm (depósitos de calcio) al interior de la cutícula en las etapas tardías de la infección. Las medidas para contrarrestar la infección se han enfocado en mejorar los sistemas de bioseguridad, otra opción es el desarrollar camarones resistentes a patógenos específicos (SPR, por sus siglas en inglés) mediante programas de selección genética. En México se han desarrollado programas de selección genética desde hace algunos años enfocados a mejorar el crecimiento, y los organismos provenientes de familias seleccionadas son distribuidos por todo el país, sin embrago se desconoce si estas poblaciones presentan mayor ó menor susceptibilidad a patógenos, especialmente al WSSV. En el presente trabajo se evaluó mediante PCR en tiempo real la respuesta de tres familias de camarones provenientes de un programa de selección genética y un lote domesticado ante una infección experimental con el WSSV. Se cuantificó la expresión de genes implicados en el sistema inmune (crustinas y peneidinas), la osmorregulación (ATPasa Na+/K+) y el gen viral VP664, para detectar respuestas diferenciales entre familias y examinar la relación del mecanismo de osmorregulación con el proceso de infección viral. Los camarones de las tres familias seleccionadas presentaron mayor sobrevivencia que el lote domesticado al desafiarlos experimentalmente con el WSSV. Los camarones infectados con el WSSV alcanzaron un 100 % de mortalidad entre las 75 y 85 hpi. Aunque no fue posible determinar la sobrevivencia en condiciones naturales debido a que en esta tesis se infectó mediante inyección vía intramuscular este método permitió diferenciar la susceptibilidad entre familias. Los niveles de transcritos de ATPasa Na+/K+ no se vieron afectados por el WSSV, el cual incrementa el número de copias de su proteína estructural VP664 de manera exponencial entre las 6 y 24 hpi. La expresión de las crustinas y penaeidinas se presentaron de manera fluctuante entre familias y tratamientos siendo suprimida su expresión en organismos domesticados y seleccionados infectados. La crustina presentó una correlación positiva con mayor tiempo de sobrevivencia post inyección en solo una de las tres familias (rosa), lo cual hace un posible candidato como marcador inmunológico. The white spot syndrome virus (WSSV) is a lethal pathogen in the shrimp farming industry worldwide. Visible symptoms of infected animals are lethargy, food consumption loss, chromatophores expansion and erratic swimming behavior. It also has been observed that they lose osmoregulation capacity. Infected shrimp usually show white spot inclusions of 0.5 – 2.0 mm in diameter (calcium deposits) on the inside cuticle during the last stages of the infection. Countermeasures have focused on the improvement of biosecurity protocols in order to prevent the infection. Another option is the development of specific pathogen resistant shrimps (SPR) through genetic selection programs. Even when, some genetic selection programs had been developed in Mexico during the last years they mainly focused on growing improvement. Organisms originated from these programs are widely distributed along the country, but It is unknown if these populations are more or less susceptible to pathogens, particularly to WSSV. The present work has the purpose to evaluate, through Real Time PCR, the response of descendant shrimps from a genetic selection program and a domesticated lot both infected experimentally with WSSV. We quantified two genes involved in the immune system response (crustins and penaeidins), one involved in osmoregulation process (ATPase Na+/K+) and the viral gene VP664 to detect differential responses between families and examine the relation within osmoregulation mechanism and the viral infection process. Three selected families had higher survival than the domesticated lot challenged experimentally with WSSV. Infected shrimps reach 100% mortality between 75 and 85 hpi. Although is not possible to determine survival under natural conditions because virus was inoculated by injection, this method allowed us to differentiate the susceptibility between families. ATPase Na+/K+ transcripts levels was not affected by WSSV infection, copy number of viral structural protein VP664 increases exponentially between 6 and 24 hpi. Expression levels of crustins and penaeidins fluctuates between families and treatments with suppressed expression on selected and domesticated infected organisms. Crustin presented a positive co-relation with major post-injection survival time in only one of three families (pink), which makes it a possible immunological marker to measure the susceptibility to WSSV.