Intestinal morphology and microflora to Vibrio alginolyticus in pacific white shrimp (Litopenaeus vannamei).

In recent years, the shrimp farming industry encountered significant economic losses induced by Vibrio alginolyticus. In this study, the influence of Vibrio alginolyticus on intestinal histomorphology and microbiome composition in Litopenaeus vannamei were studied. The results showed that the intestinal mucosal epithelial cells of Vibrio group (VA group) injected only with Vibrio alginolyticus showed large area exfoliation at 12 h, and the tissue morphology of intestine recovered at 48 h. Compared with the control group (CK group), the abundance of Proteobacteria was significantly higher (P < 0.05), while the abundance of Actinobacteria was significantly lower after infection with Vibrio alginolyticus. The abundance of Shewanella in intestinal microbiome of Litopenaeus vannamei was significantly higher at 12 h (P < 0.05), but the abundance of Candidatus_Bacilloplasma was significantly lower at 48 h after infection (P < 0.05). In VA group, the diversity of intestinal microbiome was significantly lower at 12 h, which could be caused by the proliferation of Candidatus_Bacilloplasma and Shewanella. All above findings suggested that the stability of the dynamic balance of microbiome in the intestine helped Litopenaeus vannamei to resist pathogen colonization.

Population structure of the Atlantic seabob shrimp Xiphopenaeus kroyeri (Heller, 1862) based on geometric morphometrics / Estructura de la población del camarón langostino del atlántico Xiphopenaeus kroyeri (Heller, 1862) basada en morfometría geométrica

SUMMARY: In 2004, Xiphopenaeus kroyeri, one of major species in commercial fisheries in Brazil was included in the list of brazilian overfished species and, in 2006, two cryptic species were identified in the Atlantic Ocean by molecular approaches: Xiphopenaeus sp. I and II. In 2019, Carvalho-Batista et al. described both Xiphopenaeus sp. I and Xiphopenaeus sp. II and these species were named X. kroyeri and X. dincao, respectively. This study aimed at performing morphometric analysis in order to identify potential fishing stocks of X. kroyeri sensu strictum along Brazilian coast. The results obtained separate Caravelas, Atafona and Balneário Camboriú from all the other populations studied and showed three groups: Ubatuba, Nova Almeida; Ubatuba, Cananéia; Ubatuba, Santos. These results indicate that the maritime limits practiced in closed seasons along Brazil are embracing the detected morphometric stock boundaries observed for Xiphopenaeus kroyeris.s.

RESUMEN: En 2004, Xiphopenaeus kroyeri, una de las principales especies de la pesca comercial en Brasil, fue incluida en la lista de especies brasileñas sobre explotadas y, en 2006, se identificaron dos especies crípticas en el Océano Atlántico mediante enfoques moleculares: Xiphopenaeus sp. I y II. En 2019, Carvalho-Batista et al. describieron tanto Xiphopenaeus sp. I y Xiphopenaeus sp. II y a estas especies denominaron X. kroyeri y X. dincao, respectivamente. Este estudio tuvo como objetivo realizar un análisis morfométrico con el fin de identificar posibles poblaciones de pesca de X. kroyeri sensu strictum a lo largo de la costa brasileña. Los resultados obtenidos en Caravelas, Atafona y Balneário Camboriú se separaron de todas las demás poblaciones estudiadas y mostraron tres grupos: Ubatuba, Nova Almeida; Ubatuba, Cananéia; Ubatuba, Santos. Estos resultados indican que los límites marítimos practicados en temporadas de veda a lo largo de Brasil están abarcando los límites de stock morfométricos observados para Xiphopenaeus kroyeris.s.

A Simple One-Step Modification of Shrimp Shell for the Efficient Adsorption and Desorption of Copper Ions.

Removing toxic heavy metal species from aqueous solutions is a point of concern in our society. In this paper, a promising biomass adsorbent, the modified waste shrimp shell (MS), for Cu (II) removal was successfully prepared using a facile and simple one-step modification, making it possible to achieve high-efficiency recycling of the waste NaOH solution as the modification agent. The outcome shows that with the continuous increase in pH, temperature and ion concentration, the adsorption effect of MS on Cu (II) can also be continuously improved. Adsorption isotherm and adsorption kinetics were fitted with the Langmuir isotherm model and the pseudo-second-order model, respectively, and the maximum adsorption capacity of Cu (II) as obtained from the Langmuir isotherm model fitting reached 1.04 mmol/g. The systematic desorption results indicated that the desorption rate of Cu (II) in the MS could reach 100% within 6 min, where HNO3 is used as the desorption agent. Moreover, experiments have proven that after five successive recycles of NaOH as a modifier, the adsorption capacity of MS on Cu (II) was efficient and stable, maintaining tendency in 0.83-0.85 mmol/g, which shows that waste NaOH solution can be used as a modification agent in the preparation of waste shrimp shell adsorbent, such as waste NaOH solution produced in industrial production, thereby making it possible to turn waste into renewable resources and providing a new way to recycle resources.

Morphological description of the first protozoeal stage of the deep-sea shrimps Aristeus antennatus and Gennadas elegans, with a key.

Accurate information on commercial marine species larvae is key to fisheries science, as their correct identification is the first step towards studying the species' connectivity patterns. In this study, we provide a complete morphological description of the first protozoeal stage of the valued deep-sea blue and red shrimp Aristeus antennatus and of the small mesopelagic shrimp Gennadas elegans. These two larval morphologies previously posed a risk of misidentification, thus hindering the study of A. antennatus larval ecology and dynamics in the context of fisheries science. Using specimens caught in the plankton at various locations in the Northwestern Mediterranean Sea and identification confirmed by molecular methods, the larvae of A. antennatus and G. elegans are distinguished from each other by the ornamentation of the antennula. A possible confusion in previous descriptions of Aristeidae larvae is addressed and a new key for the identification of Dendrobranchiata larvae provided.

The circulatory system of Penaeus vannamei Boone, 1931-Lacunar function and a reconsideration of the "open vs. closed system" debate.

The morphology of hemolymph circulatory systems has been studied in many arthropod groups over the past decades. In most cases, however, the focus of these studies has been the vascular system, while its counterpart, the lacunar system, has often been neglected. To further understanding of the interrelationships between these two complementary subsystems, we investigated both, the hemolymph vascular system and the hemolymph lacunar system, of the decapod Penaeus vannamei using 3D-imaging techniques (micro-computed tomography and confocal laser scanning microscopy) in combination with 3D reconstruction. Major parts of the vascular and lacunar system are described. Our insights into their morphology are used to derive functional conclusions for a model illustrating the interrelationships between the two subsystems. The morphology of and the functional interaction between the vascular and lacunar systems are discussed in the context of the debate on "open vs. closed circulatory systems."

Effects of dietary mixed probiotics on growth, non-specific immunity, intestinal morphology and microbiota of juvenile pacific white shrimp, Litopenaeus vannamei.

This study was conducted to elucidate the effects of dietary mixed probiotics on growth, non-specific immunity, intestinal morphology and microbiota of juvenile pacific white shrimp, Litopenaeus vannamei. Juvenile shrimp (initial body weight 1.21 ±â€¯0.01 g) were fed diets containing graded probiotics (F1: 0 mg/kg probiotics; F2: 1000 mg/kg probiotics; F3: 2000 mg/kg probiotics; F4: 4000 mg/kg compound probiotics; F5: 6000 mg/kg probiotics; F6: 8000 mg/kg probiotics) for 8 weeks. The result of this trial showed that the growth performance (SGR, WG, FBW) of shrimp fed diets containing probiotics (F2∼F6) were significantly higher than that of shrimp fed diet without supplemental probiotics (F1) (P < 0.05), and the highest values of the growth performance (SGR, WG, FBW) and lowest FCR were found in shrimp fed the diet containing 2000 mg/kg probiotics. Total antioxidant capacity of shrimp fed diet F2 and F3 were significantly higher than that of shrimp fed the basal diets (P < 0.05). Superoxide dismutase in F4 treatment was significantly higher than that of basal treatment (P < 0.05). Catalase of shrimp in all probiotics supplemented (F2∼F6) treatments were significantly higher than that of the control one (F1) (P < 0.05). Malondialdehyde in F5 groups was significantly lower than that of F1 groups (P < 0.05). Alkline phosphatase and acid phosphatase in F3 treatments were significantly higher than those of the basal one (P < 0.05). Lysozyme of shrimp fed F2∼F6 were significantly higher than that of shrimp fed F1 diet (P < 0.05). The lipase and amylase activities in 2000 mg/kg probiotics groups showed the highest activities and were significantly higher than that of control one (P < 0.05). Intestinal villi height in F3∼F6 treatments were significantly higher than that of control one (P < 0.05). Alpha diversity indices including observed species, chao1, ACE and shannon indices showed that F2 and F3 groups had higher microbial diversity in their intestines, both richness and evenness. PCA plot showed that there was a clear shift of F2 and F3 groups from the control groups in microbial community structure. The dominant phyla in pacific white shrimp are proteobacteria, bacteroidetes and actinobacteria, the dominant genus were algoriphagus and vibrio. As the probiotics increased, the gemmatimonadetes, acidobacteria, deltaproteobacteria and xanthomonadales firstly increased and then decreased, with the highest content in F2 group, which was no significant difference to F3 group (P > 0.05) while significantly higher than other groups (P < 0.05). In conclusion, the supplement of mixed species probiotics can promote growth performance, enhance the non-specific immunity, influence the microbiota of the pacific white shrimps and the recommended optimum dosage in diet of Litopenaeus vannamei was 2000 mg/kg.

Morphometric variation in pink shrimp populations at Rio de Janeiro coast (SE Brazil): are they really similar in closer areas?

Farfantepenaeus brasiliensis and F. paulensis are the most exploited shrimps of SE-S Brazilian coast. Our aim was to verify if adjacent nursery areas with different environmental condition (Sepetiba and Guanabara bays, SE Brazil) influence on shrimp populations (eg, CPUE) and body shapes. Samplings were carried out during 12 months in those bays ca. 85 Km far from each other. Carapace length (CL), total body length (TL), wet weight, abdomen size and TL/CL ratio were used to analyze variations in shape through regressions. In general, F. brasiliensis was 4 to 6 times more abundant than F. paulensis. The sex ratio differed from 1:1 in F. brasiliensis in both bays, with dominance of females, largest catches occur in autumn. However, differences in size and morphology were found between bays, mainly regarding the TL/CL ratio. Shrimps in Sepetiba Bay have higher TL/CL showing a more "elongated shape" (larger abdomen) when compared to those from Guanabara Bay. Results suggest the existence of an estuary vs shrimp morphology relationship which results in differences in body shape even in spatially close areas. TL/CL ratio has proven useful for assessing shrimp populations differences and might be tested for tracking the origin of adult shrimps stocks at the coast.

Dietary supplementation of probiotic Bacillus coagulans ATCC 7050, improves the growth performance, intestinal morphology, microflora, immune response, and disease confrontation of Pacific white shrimp, Litopenaeus vannamei.

The present study assessed the effects of probiotic bacterium Bacillus coagulans ATCC 7050 (BC) fed at different inclusion levels (0 (BO), 1 × 106 (BC1), 1 × 107 (BC2) and 1 × 108 (BC3) CFU g-1 feed) on growth, feed utilization, body composition, intestinal morphology, microflora, immune response, and resistance to Vibrio parahaemolyticus infection in Litopenaeus vannamei. After 56 days of the feeding trial, the survival rate ranged from 83.33 to 94.17% with no significant difference between dietary treatments (P > 0.05). Dietary probiotic supplementation also affected the intestinal microflora composition. At the phylum level, Proteobacteria accounted for the majority of bacteria followed by Bacteroidetes irrespective of the group. At the genus level, the abundance of opportunistic pathogenic bacteria, such as Vibrio, Tenacibaculum, and Photobacterium significantly decreased (P < 0.05) with an increasing probiotic concentration, and BC3 group experiencing the least. Additionally, increasing probiotic inclusion in diet downregulated the abundance of Muricauda, Kangiella, and Shewanella in shrimps, with the least, observed in the BC3 group. However, beneficial bacteria Pseudoalteromonas significantly increased (P < 0.05) in the intestines of shrimp fed BC3 diet (P < 0.05) compared to other groups including the control. Compared to the control, a significant increase (P < 0.05) of the probiotic treated groups in the final weight, weight gain rate (WGR), specific growth rate (SGR), condition factor (K), activity of lysozyme (LYZ), acid phosphatase (ACP), superoxide dismutase (SOD), total protein (TP), albumin (ALB) in serum, glutathione peroxidase (GSH-Px) in serum and liver, and a significant decrease (P < 0.05) in feed conversion ratio (FCR), triglyceride (TG) in serum, and Malondialdehyde (MDA) in serum and liver were achieved. Increasing probiotic treatment again improved the digestive ability, thus; a significant increase in the activities of lipase, amylase, trypsin, and an enhancement in the villus height, villus width, and muscle thickness of the intestines of the shrimps which correspondingly alleviated intestinal injury. Furthermore, the supplementation of probiotics in challenge test significantly (P < 0.05) enhanced the resistance of shrimp against V. parahaemolyticus infection recording BC3 to receive the highest relative percentage survival (RPS) value of 76%. In conclusion, higher inclusion levels of probiotic BC at 1 × 108 CFU g-1 feed (BC3) in diets can be considered to enhance the growth, intestinal morphology and microflora, immune response and resistance to Vibrio parahaemolyticus of L. vannamei.

Insights into the intestine immune of Marsupenaeus japonicus under the white spot syndrome virus challenge using RNA sequencing.

Intestine is not only the nutrients digestion and absorption centers, but also an important place of microbial infection. Therefore, intestine immunity plays a key defense means for the host against the invasion of pathogenic microorganisms. In this study, we use kuruma shrimp (Marsupenaeus japonicus) as a model to study the intestine immune characteristics of shrimp against WSSV through next-generation sequencing technique. A total of 63,458 and 44,350 unigenes were generated from the control sample and the WSSV infection sample, respectively. Based on homology searches, KEGG, GO, and COG analysis, 39,520 unigenes were annotated. Among them, 12,920 differentially expressed genes were identified. Some of them, including mucin, peritrophin, chitinase, et al., are involved in immune response. These results contribute to a better understanding of the intestine immune response of the shrimp to WSSV.

Effect of dietary supplementation with apple cider vinegar and propionic acid on hemolymph chemistry, intestinal microbiota and histological structure of hepatopancreas in white shrimp, Litopenaeus vannamei.

This experiment was conducted to evaluate the effects of dietary supplementation of Apple cider vinegar (ACV) and propionic acid (PA) on biochemical parameters of hemolymph, intestinal microbiota and histology of hepatopancreas in white shrimp (Litopenaeus vannamei). Five experimental diets were evaluated in this study including diets supplemented with 1.0, 2.0 and 4.0% of ACV, 0.5% propionic acid, and a control diet with no supplements. Shrimps (initial weight of 10.2 ±â€¯0.04 g) in triplicate groups with the density of 25 shrimps per tank were fed the diets for 60 days. At the end of the feeding trial, shrimps fed with ACV and PA supplemented diets had significantly higher total protein level than those fed the control diet (P < 0.05). The number of Vibrio spp., R-cells (lipid storage cells) of hepatopancreas and cholesterol level in shrimps fed the diets containing ACV and PA were lower compared to the control group (P < 0.05). However, there was no remarkable variations in glucose concentration, B-cell number and tubule diameter among the experimental diets (P > 0.05). In addition, shrimps fed the ACV diets had significantly lower total heterotrophic marine bacteria compared to the control or PA groups, and the lowest bacterial number was observed in shrimp fed 4% ACV supplemented diet (P < 0.05). Supplementation of 2 and 4% ACV as well as 0.5% PA in the diet led to a significantly higher calcium concentration than the control treatment (P < 0.05). The lowest triglyceride concentration was observed in the shrimps fed diets containing 2.0 and 4.0% ACV, which resulted in 15 and 20% reduction, respectively (P < 0.05). Overall, the findings indicates that ACV and PA possess antimicrobial activity and demonstrate beneficial effects on health status, so they can be potentially used as feed additive in the feeding of L. vannamei.

Effect of deoxynivalenol on growth performance, histological morphology, anti-oxidative ability and immune response of juvenile Pacific white shrimp, Litopenaeus vannamei.

A 5-weeks experiment was conducted to evaluate the effect of deoxynivalenol on growth performance, histological morphology, anti-oxidative ability and immune capacity of Litopenaeus vannamei. White shrimp (mean initial weight 1.02 g) were fed seven isonitrogenous diets, Diet 1 as the control, Diet 2-4 was supplemented with grade levels (250, 500 and 1000 µg kg-1) of deoxynivalenol (DON), Diet 5-7 were formulated to contain graded levels of contaminated wheat flour. Each diet was assigned to four tanks (30 shrimp). The weight gain was decreased with the increasing dietary DON levels, survival was lower in shrimp fed high levels of DON-contaminated wheat flour (P < 0.05). Feed intake and feed conversion ratio did not show any difference among all the groups. After 4 h hypoxia stress, survival of shrimp was decreased in shrimp fed high levels of DON-contaminated wheat flour (P < 0.05). Total antioxidant capacity in hepatopancreas was higher in shrimp fed the control diet, glutathione S-transferase (GST) activity were higher in shrimp fed the Diet 3 and Diet 6, superoxide dismutase (SOD) activity was higher in shrimp fed the highest dietary DON (Diet 4), while the gene expression of SOD and GPx were lower in shrimp fed the Diet 3-7. The expression of HSP70, Toll 1 and Dorsal were higher in shrimp fed the Diet 2, the expression of AKT were higher in shrimp fed the Diet 1 and Diet 2. The expression of proPO, LGBP and PPAF were higher in shrimp fed the Diet 4 and Diet 7. The H&E stain indicated intestinal mucosal folds were impaired in shrimp fed the Diet 3-7, and B cells number and diameters of the hepatopancreas tubules were affected by DON levels, and transmission electron microscope (TEM) analysis indicated the apopotosis occurs in intestinal epithelial cell of shrimp fed the Diet 2-7. Based on the present results, the safety level of DON for white shrimp should below 0.5 ppm, which was much less than the European Communities recommendation values for aquatic animals (5 ppm). High level of DON would damage the cell structural and affect the NF-κB pathway and proPO system of shrimp.

A morphological study of the male reproductive tract, post-testicular acrosome maturation and spermatophore formation in the black tiger prawn (Penaeus monodon).

Inferior larval production rates of domesticated Penaeus monodon broodstock has been a major hurdle to the expansion of its aquaculture, so that a better understanding of basic male reproductive biology is critical to improve the reproductive performance of this commercially important penaeid species. Following our previous study of spermatogenesis in the species, this study explored the mechanism of spermatophore formation with regards to the contribution of the reproductive tract epithelium by light and transmission electron microscopy. Four types of epithelial secretions (S1-4) were observed contributing to the three layers of the spermatophore. The primary layer of spermatophore was composed of S1 and S2, which were released from the secretory epithelial cells of the proximal vas deferens (PVD) and the secretory epithelial cells of the sperm-bearing lumen of the mid vas deferens, respectively. The secondary layer of the spermatophore was composed of S3, the secretory product of epithelial cells in the accessory tubule lumen of the mid vas deferens. The outer layer of the spermatophore was formed from S4 which was secreted by the epithelial cells in the posterior mid vas deferens and the terminal ampulla. Unique folds of the vas deferens epithelium appeared to play an important role in the formation of the spermatophore, particularly in the formation of the laminated structure of the spermatophore appendage. With respect to acrosome maturation along the reproductive tract, most spermatozoa did not have a fully developed anterior spike and a subacrosomal region when in the PVD, whereas both structures were fully formed by the time the spermatozoa reached the mid vas deferens and increased electron density when in the terminal ampulla; this observation represents the first morphological evidence of post-testicular acrosome maturation in this taxon.

The functional anatomy of external genitalia in the black tiger prawn (Penaeus monodon) studied by micro-computed tomography and scanning electron microscopy.

Although artificial insemination has been used for decades in Penaeus monodon aquaculture, the interaction of male and female external genitalia during spermatophore transfer has not been fully documented. As a result, studying the functional anatomy of this process may help to better refine the insemination technique. The sexual act in penaeoid prawns is virtually impossible to observe directly; as a result, this study aimed to describe the functional anatomy and interaction of external genitalia, such as the petasma, appendices masculinae and genital papillae of the male, with that of the thelycum and genital lobes of the female, using a combination of micro-computed tomography and scanning electron microscopy. We hypothesise that the spermatophores are ejaculated into the ventromedial groove of the petasma and squeezed by abdominal flexure into the spermathecae of female's thelycum. During this process, the 'spike-like' setae observed on the petasma and appendices masculinae are speculated to control the transferring direction of the spermatophores. The approach of three dimensional remodelling and animation reported in this study may prove useful in the examination of further hypotheses related to the functional anatomy of external genitalia and/or appendages for other crustacean species.

Cell cycle regulation and apoptosis mediated by p53 in response to hypoxia in hepatopancreas of the white shrimp Litopenaeus vannamei.

Although hypoxic aquatic environments cause negative effects on shrimp, these animals can withstand somewhat hypoxia, but the cellular mechanisms underlying this capacity are still poorly understood. In humans, mild hypoxia causes the induction of many proteins to allow cell survival. In contrast, apoptosis is induced during severe hypoxia leading to cell death. p53 is a key transcription factor that determines cells fate towards cell cycle arrest or induction of apoptosis in humans. The aim of this work was to study the role of p53 in cell cycle regulation and apoptosis in response to hypoxia in hepatopancreas of the white shrimp Litopenaeus vannamei. p53 was silenced by RNAi and afterwards the shrimp were exposed to hypoxia. Cdk-2 was used as indicator of cell cycle progression while caspase-3 expression and caspase activity were analyzed as indicators of apoptosis. p53 levels in hepatopancreas were significantly higher at 48 h after hypoxic treatment. Increased expression levels of Cdk-2 were found in p53-silenced shrimp after 24 and 48 h in the normoxic treatments as well as 48 h after hypoxia, indicating a possible role of p53 in cell cycle regulation. In response to hypoxia, unsilenced shrimp showed an increase in caspase-3 expression levels, however an increase was also observed in caspase activity at 24 h of normoxic conditions in p53-silenced shrimps. Taken together these results indicate the involvement of p53 in regulation of cell cycle and apoptosis in the white shrimp in response to hypoxia.

Effect of Low Temperature on Globin Expression, Respiratory Metabolic Enzyme Activities, and Gill Structure of Litopenaeus vannamei.

Low temperature frequently influences growth, development, and even survival of aquatic animals. In the present study, physiological and molecular responses to low temperature in Litopenaeus vannamei were investigated. The cDNA sequences of two oxygen-carrying proteins, cytoglobin (Cygb) and neuroglobin (Ngb), were isolated. Protein structure analysis revealed that both proteins share a globin superfamily domain. Real-time PCR analysis indicated that Cygb and Ngb mRNA levels gradually increased during decrease in temperatures from 25 to 15°C and then decreased at 10°C in muscle, brain, stomach, and heart, except for a continuing increase in gills, whereas they showed a different expression trend in the hepatopancreas. Hemocyanin concentration gradually reduced as the temperature decreased. Moreover, the activities of respiratory metabolic enzymes including lactate dehydrogenase (LDH) and succinate dehydrogenase (SDH) were measured, and it was found that LDH activity gradually increased while SDH activity decreased after low-temperature treatment. Finally, damage to gill structure at low temperature was also observed, and this intensified with further decrease in temperature. Taken together, these results show that low temperature has an adverse influence in L. vannamei, which contributes to systematic understanding of the adaptation mechanisms of shrimp at low temperature.

Population dynamics of Rimapenaeus constrictus (Stimpson, 1874) (Penaeoidea) on the southeastern Brazilian coast: implications for shrimp fishing management from a 5-year study on a bycatch species

ABSTRACT This is the first study to evaluate in broad spatiotemporal scales the growth parameters and population structure of Rimapenaeus constrictus, a barely damaged species composing the bycatch from shrimp fishing in the Western Atlantic. The abundance and size-class frequency distribution, growth, longevity and sex ratio were evaluated from monthly samples obtained in the northern littoral of São Paulo state from Jan/1998 to Jun/2003. We measured 5,812 individuals in which the sex ratio was skewed toward females; this was more evident in size classes greater than 10 mm in CL (carapace length) (binomial test, p<0.05). We selected 16 growth cohorts of females, and 8 of males, the majority consisting of younger individual cohorts excluded from the fisheries closure period. Growth estimates resulted in a CL∞ of 17.42 mm, a growth coefficient of 0.008 and a longevity of 579 days (1.60 year) for females, as well as a CL∞ of 16.3 mm, a growth coefficient of 0.01 and a longevity of 425 days (1.17 year) for males. Our results provide information of incontestable relevance to our knowledge of fishing management. We therefore strongly recommend that the fisheries closure period be changed to protect this species' recruitment period and consequently its adult individuals.

Effect of starvation and refeeding on the hepatopancreas of whiteleg shrimp Penaeus vannamei (Boone) using computer-assisted image analysis.

Under normal farming conditions, shrimp can experience starvation periods attributable to disease outbreaks or adverse environmental conditions. Starvation leads to significant morphological changes in the hepatopancreas (HP), being the main organ for absorption and storage of nutrients. In the literature, limited research has described the effect on the HP of periods of starvation followed by refeeding and none in whiteleg shrimp (Penaeus vannamei) using computer-assisted image analysis (CAIA). This study describes the effect of starvation and starvation followed by refeeding on the HP of whiteleg shrimp using CAIA. Visiopharm® software was used to quantify the following morphological parameters, measured as ratio to the total tissue area (TLA): total lumen area (TLA:TTA), haemocytic infiltration area in the intertubular spaces (HIA:TTA), B-cell vacuole area (VBA:TTA), lipid droplet area within R cells (LDA:TTA) and F-cell area (FCA:TTA). Significant changes were measured for HIA:TTA and LDA:TTA during starvation (increase in HIA:TTA associated with decrease in LDA:TTA) and starvation followed by refeeding (decrease in HIA:TTA associated with increase in LDA:TTA). In the future, HIA:TTA and LDA:TTA have the potential to be used in a pre-emptive manner to monitor the health of the HP, facilitate early diagnosis of diseases and study the pathophysiology of the organ.

Population dynamics of Rimapenaeus constrictus (Stimpson, 1874) (Penaeoidea) on the southeastern Brazilian coast: implications for shrimp fishing management from a 5-year study on a bycatch species.

This is the first study to evaluate in broad spatiotemporal scales the growth parameters and population structure of Rimapenaeus constrictus, a barely damaged species composing the bycatch from shrimp fishing in the Western Atlantic. The abundance and size-class frequency distribution, growth, longevity and sex ratio were evaluated from monthly samples obtained in the northern littoral of São Paulo state from Jan/1998 to Jun/2003. We measured 5,812 individuals in which the sex ratio was skewed toward females; this was more evident in size classes greater than 10 mm in CL (carapace length) (binomial test, p<0.05). We selected 16 growth cohorts of females, and 8 of males, the majority consisting of younger individual cohorts excluded from the fisheries closure period. Growth estimates resulted in a CL∞ of 17.42 mm, a growth coefficient of 0.008 and a longevity of 579 days (1.60 year) for females, as well as a CL∞ of 16.3 mm, a growth coefficient of 0.01 and a longevity of 425 days (1.17 year) for males. Our results provide information of incontestable relevance to our knowledge of fishing management. We therefore strongly recommend that the fisheries closure period be changed to protect this species' recruitment period and consequently its adult individuals.

Brain architecture of the Pacific White Shrimp Penaeus vannamei Boone, 1931 (Malacostraca, Dendrobranchiata): correspondence of brain structure and sensory input?

Penaeus vannamei (Dendrobranchiata, Decapoda) is best known as the "Pacific White Shrimp" and is currently the most important crustacean in commercial aquaculture worldwide. Although the neuroanatomy of crustaceans has been well examined in representatives of reptant decapods ("ground-dwelling decapods"), there are only a few studies focusing on shrimps and prawns. In order to obtain insights into the architecture of the brain of P. vannamei, we use neuroanatomical methods including X-ray micro-computed tomography, 3D reconstruction and immunohistochemical staining combined with confocal laser-scanning microscopy and serial sectioning. The brain of P. vannamei exhibits all the prominent neuropils and tracts that characterize the ground pattern of decapod crustaceans. However, the size proportion of some neuropils is salient. The large lateral protocerebrum that comprises the visual neuropils as well as the hemiellipsoid body and medulla terminalis is remarkable. This observation corresponds with the large size of the compound eyes of these animals. In contrast, the remaining median part of the brain is relatively small. It is dominated by the paired antenna 2 neuropils, while the deutocerebral chemosensory lobes play a minor role. Our findings suggest that visual input from the compound eyes and mechanosensory input from the second pair of antennae are major sensory modalities, which this brain processes.

Diel variation in the catch of the shrimp Farfantepenaeus duorarum (Decapoda, Penaeidae) and length-weight relationship, in a nursery area of the Terminos Lagoon, Mexico / Variación diaria en la captura del camarón Farfantepenaeus duorarum (Decapoda: Penaeidae) y relaciones largo peso en un área de cría de la Laguna de Términos, México

Abstract:The pink shrimp, Farfantepenaeus duorarum is an important commercial species in the Gulf of Mexico, which supports significant commercial fisheries near Dry Tortugas, in Southern Florida and in Campeche Sound, Southern Gulf of Mexico. There is information about the nictemeral behavior of the pink shrimp related to sunset, what is crucial to more accurate estimation of shrimp population biomass, and to assess the potential of this resource and its proper management. To contribute to the knowledge and the population dynamics of the species, shrimp surveys were conducted in a nursery area near "El Cayo" in the Northeastern part of Terminos Lagoon, Mexico during October 2010. Three sampling sites with substrate covered by submerged vegetation were chosen; two set of samples were collected at each site, one in the morning and the other just after sunset. Three trawls were performed per sampling site using a small otter trawl. A total of 1 418 shrimp (between 5.5 to 28.8 mm Carapace Length (CL)) were collected during the study; 1 416 F. duorarum and only two individuals of Litopenaeus setiferus. Shrimps CL and Total Length (TL) were measured in mm and individuals were weighted to the nearest 0.01 g. In general, shrimp biomass and density were significantly higher in all sites during dusk (biomass= 46.36 g.100 m-2, n= 1 344), than daylight samples (biomass= 2.78 g.100 m-2, n= 72). The One-way ANOVA and the Tukey test performed to evaluate variability in CL found significant differences between sites (CL= 14.12 mm, 12.46 mm and 15.13 mm, for site 1, 2 and 3 respectively, F= 64.92, P < 0.001) which might be related to the substrate type. The length-weight relationships reflected positive allometric growth for juveniles but isometric for subadults and two nonlinear power functions were estimated (W= 0.0004CL3.157 for juveniles, and W= 0.0009CL2.902 for subadults). The results of the analysis of covariance (ANCOVA) test indicated that the Total Length - Carapace Length (TL-CL) relationships were significantly different between juveniles and subadults, and two linear equations (TL= 2.615 + 4.476CL and TL= 8.931 + 4.062CL for juveniles and subadults respectively) were fitted. It is important that population assessment takes into account the day or night period as a bias factor when sampling the abundance of the juveniles of F. duorarum in this important nursery ground of the Campeche Sound. Rev. Biol. Trop. 65 (1): 65-75. Epub 2017 March 01.

ResumenEl camarón rosado Farfantepenaeus duorarum es una especie de importancia comercial en el Golfo de México, mantiene pesquerías comerciales relevantes cerca de Dry Tortugas en el Sureste de la Florida y en la Sonda de Campeche, Sureste del Golfo de México. Existe información acerca de la conducta nictemeral del camarón rosado relacionada con la puesta del sol, lo cual resulta crucial para una estimación más precisa de las poblaciones y de la biomasa así como para evaluar el potencial del recurso y de su adecuado manejo. Para contribuir con el conocimiento de la dinámica de poblaciones de esta especie de camarón, se realizó un estudio en una zona de cría cerca de "El Cayo", área del Noreste de la Laguna de Términos, México, durante octubre 2010. Se seleccionaron tres sitios de muestreo cubiertos con vegetación sumergida. En cada sitio se tomó una muestra en la mañana y otra justamente después de la puesta del sol. Se realizaron tres arrastres por sitio de muestreo usando una pequeña red de arrastre. Durante el estudio fueron recolectados un total de 1 418 camarones (entre 5.5 y 28.8 mm longitud del carapacho (LC)); 1 416 Farfantepenaeus duorarum y dos individuos de Litopenaeus setiferus. Se midió la LC y la longitud total (LT) de los camarones (mm) y se pesaron con una precisión de 0.01g. En general, la biomasa y la densidad fueron significativamente mayores en todos los sitios durante el anochecer (biomasa= 446.36 g.100 m-2, n= 1 344) que durante el día (biomasa= 2.78 g.100 m-2, n= 72). El ANOVA y la prueba Tukey realizada para evaluar la variación en LC en los diferentes sitios, mostraron diferencias significativas (LC= 14.12 mm, 12.46 mm, 15.13 mm, para los sitios 1, 2 and 3 respectivamente, F= 64.92, P < 0.001), lo cual puede estar relacionado con el tipo de sustrato. La relación de la longitud con el peso refleja un crecimiento alométrico positivo para los juveniles pero no para los subadultos por lo que se estimaron dos funciones no lineales (Peso= 0.0004LC3.157 para juveniles and Peso= 0.0009LC2.902 para subadultos). Los resultados del ANCOVA realizados indicaron que la relación Largo Total-Longitud del Carapacho (LT-LC) fue significativamente diferente entre juveniles y subadultos y se ajustaron a dos ecuaciones lineales (LT= 2.615 + 4.476LC y LT= 8.931 + 4.062 LC, para juveniles y subadultos respectivamente). Para la evaluación de la población es importante que se considere el momento del muestreo como un factor que afecta la estimación de la abundancia de juveniles de F. duorarum en esta importante zona de cría de la Sonda de Campeche.