Atypical clinical and sonographic manifestations of lymphadenopathy in a child with cat-scratch disease: A case report.

Cat-scratch disease is a well-known infection in childhood. It usually presents as tender lymphadenopathy and should be included in the differential diagnosis of any lymphadenopathy syndrome. An history of exposure to cats supports the suspect and a positive serologic test to Bartonella henselae confirms the diagnosis. Ultrasound is the first line radiologic imaging performed in case of lymphadenopathy. The presence of hypoechoic lobular or oval mass with central hyperaemia and a possible adjacent fluid collection and surrounding oedema may differentiate the disease from other aetiologies. We describe the case of a 7-year-old girl presenting with an axillary lymphadenopathy, without a reported recent history of exposure to cats, with sonographic findings suggestive for cat-scratch disease. In this case, ultrasound was very useful in orienteering the diagnosis and insist on the medical history. Serology resulted positive for B. henselae and at the end the family remembered that 6 months before the child was scratched by a kitten.

Testicular juvenile granulosa cell tumor: a case report.

The Testicular Juvenile Granulosa Cell Tumor (JGCT) is a rare testicular neoplasm that appears in the first months of life as a painless testicular mass. Following an accurate radiological ultrasound diagnosis, through which the cystic appearance of the lesion is observed, and histological confirmation, showing follicular growth pattern and an immunoreactivity for inhibin, the treatment process involves, when feasible, conservative surgery. We present the case of a 2-months old infant with a bilateral JGCT of the testis and we review the classical findings of the patology.

A multicentric study of radiomics and artificial intelligence analysis on contrast-enhanced mammography to identify different histotypes of breast cancer.

OBJECTIVE: To evaluate the performance of radiomic analysis on contrast-enhanced mammography images to identify different histotypes of breast cancer mainly in order to predict grading, to identify hormone receptors, to discriminate human epidermal growth factor receptor 2 (HER2) and to identify luminal histotype of the breast cancer. METHODS: From four Italian centers were recruited 180 malignant lesions and 68 benign lesions. However, only the malignant lesions were considered for the analysis. All patients underwent contrast-enhanced mammography in cranium caudal (CC) and medium lateral oblique (MLO) view. Considering histological findings as the ground truth, four outcomes were considered: (1) G1 + G2 vs. G3; (2) HER2 + vs. HER2 - ; (3) HR + vs. HR - ; and (4) non-luminal vs. luminal A or HR + /HER2- and luminal B or HR + /HER2 + . For multivariate analysis feature selection, balancing techniques and patter recognition approaches were considered. RESULTS: The univariate findings showed that the diagnostic performance is low for each outcome, while the results of the multivariate analysis showed that better performances can be obtained. In the HER2 + detection, the best performance (73% of accuracy and AUC = 0.77) was obtained using a linear regression model (LRM) with 12 features extracted by MLO view. In the HR + detection, the best performance (77% of accuracy and AUC = 0.80) was obtained using a LRM with 14 features extracted by MLO view. In grading classification, the best performance was obtained by a decision tree trained with three predictors extracted by MLO view reaching an accuracy of 82% on validation set. In the luminal versus non-luminal histotype classification, the best performance was obtained by a bagged tree trained with 15 predictors extracted by CC view reaching an accuracy of 94% on validation set. CONCLUSIONS: The results suggest that radiomics analysis can be effectively applied to design a tool to support physician decision making in breast cancer classification. In particular, the classification of luminal versus non-luminal histotypes can be performed with high accuracy.

Profile of the gut microbiota of Pacific white shrimp under industrial indoor farming system.

The gut microbial communities interact with the host immunity and physiological functions. In this study, we investigated the bacterial composition in Litopenaeus vannamei shrimp's gut and rearing water under different host (developmental stage: juvenile and adult; health status: healthy and diseased) and environmental factors (temperature 25 °C and 28 °C; and light intensity: low and high). The PCoA analysis showed that all water samples were clustered together in a quarter, whereas the gut samples spread among three quarters. In terms of functional bacteria, gut samples of adult shrimp, healthy adult shrimp, adult shrimp raised at 28 °C, and juvenile shrimp under high light intensity exhibited a higher abundance of Vibrionaceae compared to each other opposite group. Gut samples of juvenile shrimp, infected adult shrimp, juvenile shrimp with low light intensity, and adult shrimp with a water temperature of 25 °C showed a higher abundance of Pseudoaltromonadaceae bacteria compared to each other opposite group. Gut samples of juvenile shrimp, healthy adult shrimp, adult shrimp raised at a water temperature of 28 °C, and juvenile shrimp with high light intensity showed the higher abundance of Firmicutes/Bacteroidota ratio compared to each other opposite group. Our results showed that L. vannamei juveniles are more sensitive to bacterial infections; besides, water temperature of 28 °C and high light intensity groups were both important conditions improving the shrimp gut bacterial composition under industrial indoor farming systems. KEY POINTS: • Bacteria diversity was higher among shrimp intestinal microbiota compared to the rearing water. • Shrimp juveniles are more sensitive to bacterial infection compared to adults. • Water temperature of 28 °C and high light intensity are recommended conditions for white shrimp aquaculture.

Genetic influences on circulating retinol and its relationship to human health.

Retinol is a fat-soluble vitamin that plays an essential role in many biological processes throughout the human lifespan. Here, we perform the largest genome-wide association study (GWAS) of retinol to date in up to 22,274 participants. We identify eight common variant loci associated with retinol, as well as a rare-variant signal. An integrative gene prioritisation pipeline supports novel retinol-associated genes outside of the main retinol transport complex (RBP4:TTR) related to lipid biology, energy homoeostasis, and endocrine signalling. Genetic proxies of circulating retinol were then used to estimate causal relationships with almost 20,000 clinical phenotypes via a phenome-wide Mendelian randomisation study (MR-pheWAS). The MR-pheWAS suggests that retinol may exert causal effects on inflammation, adiposity, ocular measures, the microbiome, and MRI-derived brain phenotypes, amongst several others. Conversely, circulating retinol may be causally influenced by factors including lipids and serum creatinine. Finally, we demonstrate how a retinol polygenic score could identify individuals more likely to fall outside of the normative range of circulating retinol for a given age. In summary, this study provides a comprehensive evaluation of the genetics of circulating retinol, as well as revealing traits which should be prioritised for further investigation with respect to retinol related therapies or nutritional intervention.

Radiomics and artificial intelligence analysis by T2-weighted imaging and dynamic contrast-enhanced magnetic resonance imaging to predict Breast Cancer Histological Outcome.

OBJECTIVE: The objective of the study was to evaluate the accuracy of radiomics features obtained by MR images to predict Breast Cancer Histological Outcome. METHODS: A total of 217 patients with malignant lesions were analysed underwent MRI examinations. Considering histological findings as the ground truth, four different types of findings were used in both univariate and multivariate analyses: (1) G1 + G2 vs G3 classification; (2) presence of human epidermal growth factor receptor 2 (HER2 + vs HER2 -); (3) presence of the hormone receptor (HR + vs HR -); and (4) presence of luminal subtypes of breast cancer. RESULTS: The best accuracy for discriminating HER2 + versus HER2 - breast cancers was obtained considering nine predictors by early phase T1-weighted subtraction images and a decision tree (accuracy of 88% on validation set). The best accuracy for discriminating HR + versus HR - breast cancers was obtained considering nine predictors by T2-weighted subtraction images and a decision tree (accuracy of 90% on validation set). The best accuracy for discriminating G1 + G2 versus G3 breast cancers was obtained considering 16 predictors by early phase T1-weighted subtraction images in a linear regression model with an accuracy of 75%. The best accuracy for discriminating luminal versus non-luminal breast cancers was obtained considering 27 predictors by early phase T1-weighted subtraction images and a decision tree (accuracy of 94% on validation set). CONCLUSIONS: The combination of radiomics analysis and artificial intelligence techniques could be used to support physician decision-making in prediction of Breast Cancer Histological Outcome.

Long-Term Exposure of the Red Cherry Shrimp Neocaridina davidi to Diclofenac: Impact on Survival, Growth, and Reproductive Potential.

The current study was aimed at studying the long-term effects of diclofenac on the freshwater shrimp Neocaridina davidi, concerning survival, somatic growth, and reproduction. In this study, both ovigerous females and males of this species were exposed for 63 d to 0 (control), 0.1, or 1 mg/L of diclofenac. At the highest concentration, significant mortality was detected, and the somatic growth of females was significantly decreased. The percentage of females with a second spawn, observable from day 45, significantly increased at 1 mg/L, while the time between spawns was significantly reduced at both concentrations assayed. However, the gonadal analysis made at the end of the assay in the surviving females showed a significantly lower proportion of advanced oocytes in females exposed to 1 mg/L, as compared to control. Concerning hatching, the percentage of ovigerous females that could have successful hatching was reduced at 1 mg/L of diclofenac, especially for the first spawn. For the second spawn, the low number of juveniles hatched from females exposed to 1 mg/L also showed a significantly higher incidence of morphological abnormalities, such as hydropsy and underdeveloped appendages. Taken together, these results showed that even when diclofenac was able to produce earlier spawns, the reproductive output of each spawn was reduced.

Patients With Brain Metastases Deserve Better-A Hard-Won Perspective.

This Viewpoint advocates for better research in treatments and clinical practice for brain metastasis stemming from lung cancer.

Exploring opportunities for drug repurposing and precision medicine in cannabis use disorder using genetics.

Cannabis use disorder (CUD) remains a significant public health issue globally, affecting up to one in five adults who use cannabis. Despite extensive research into the molecular underpinnings of the condition, there are no effective pharmacological treatment options available. Therefore, we sought to further explore genetic analyses to prioritise opportunities to repurpose existing drugs for CUD. Specifically, we aimed to identify druggable genes associated with the disorder, integrate transcriptomic/proteomic data and estimate genetic relationships with clinically actionable biochemical traits. Aggregating variants to genes based on genomic position, prioritised the phosphodiesterase gene PDE4B as an interesting target for drug repurposing in CUD. Credible causal PDE4B variants revealed by probabilistic finemapping in and around this locus demonstrated an association with inflammatory and other substance use phenotypes. Gene and protein expression data integrated with the GWAS data revealed a novel CUD associated gene, NPTX1, in whole blood and supported a role for hyaluronidase, a key enzyme in the extracellular matrix in the brain and other tissues. Finally, genetic correlation with biochemical traits revealed a genetic overlap between CUD and immune-related markers such as lymphocyte count, as well as serum triglycerides.

Clinical-radiomic models based on digital breast tomosynthesis images: a preliminary investigation of a predictive tool for cancer diagnosis.

Objective: This study aimed to develop a clinical-radiomic model based on radiomic features extracted from digital breast tomosynthesis (DBT) images and clinical factors that may help to discriminate between benign and malignant breast lesions. Materials and methods: A total of 150 patients were included in this study. DBT images acquired in the setting of a screening protocol were used. Lesions were delineated by two expert radiologists. Malignity was always confirmed by histopathological data. The data were randomly divided into training and validation set with an 80:20 ratio. A total of 58 radiomic features were extracted from each lesion using the LIFEx Software. Three different key methods of feature selection were implemented in Python: (1) K best (KB), (2) sequential (S), and (3) Random Forrest (RF). A model was therefore produced for each subset of seven variables using a machine-learning algorithm, which exploits the RF classification based on the Gini index. Results: All three clinical-radiomic models show significant differences (p < 0.05) between malignant and benign tumors. The area under the curve (AUC) values of the models obtained with three different feature selection methods were 0.72 [0.64,0.80], 0.72 [0.64,0.80] and 0.74 [0.66,0.82] for KB, SFS, and RF, respectively. Conclusion: The clinical-radiomic models developed by using radiomic features from DBT images showed a good discriminating power and hence may help radiologists in breast cancer tumor diagnoses already at the first screening.

Abnormal Locations of Thymic Tissue as an Uncommon Cause of Neck Masses in Children: A Practical Approach.

BACKGROUND: The thymus gland is a lymphoid organ normally located in the anterior mediastinum. Location abnormalities of the thymus, such as ectopic thymus or the superior herniation of a mediastinal thymus, could be responsible for the occurrence of cervical masses in pediatric patients, raising concerns among clinicians. The knowledge of these conditions is essential for a thorough differential diagnosis and for preventing unnecessary invasive procedures. METHODS: Descriptive retrospective series of three patients with a cervical mass, that was later diagnosed as ectopic thymic tissue. RESULTS: The thymus has a unique and distinctive ultrasound appearance that is the keystone to detecting thymic parenchyma in locations other than anterior mediastinum. In selected patients, an accurate ultrasound could be conclusive for the diagnosis, with no need for further and potentially risky procedures. CONCLUSIONS: This case series supports the use of ultrasound in both diagnosis and follow-up of thymus location abnormalities, advocating a minimal invasive and conservative approach.

Congenital lung malformations: can we avoid computed tomography? A five-year study.

Purpose: Congenital lung malformations (CLMs) consist of a variety of pulmonary development disorders. In the CLM approach, computed tomography (CT) is considered the gold standard imaging technique due to the high-resolution for the lung parenchyma evaluation, the study of the vascular system after contrast injection, and the multiplanar reconstructions. In the paediatric population CT is considered too invasive due to ionizing radiation and the use of contrast agent. Therefore, the indications for the use of magnetic resonance imaging (MRI) are increasing. The aim of our study is to compare retrospectively MRI and CT in the evaluation of CLMs, to reduce or avoid the use of contrast-enhanced CT in the paediatric population. Material and methods: We retrospectively evaluated 22 paediatric patients with prenatal diagnosis of CLMs. All the patients underwent postnatal MRI in the first 2 weeks of life (except for a patient) and pre-surgery contrast-enhanced CT. A total of 7 blinded radiologists divided into 3 different groups independently reviewed each MRI and CT examination. Sensitivity and specificity of radiologists with different years of experience on the field, as well as of MRI findings regarding every pathology, were evaluated using a ROC curve. The interobserver agreement regarding the MRI findings was also measured. Results: Analysing the ROC curves, we observed that MRI provided a satisfactory accuracy for diagnosing most congenital pulmonary diseases. Conclusions: Our study showed that MRI without contrast agent allows us to reach a CLM diagnosis in good agreement with contrast-enhanced CT, which is considered the gold standard imaging technique.

Temporal lobe atrophy as a potential predictor of functional outcome in older adults with acute ischemic stroke.

BACKGROUND: To explore whether temporal lobe atrophy predicts 3-month functional outcome in a population of patients with anterior circulation acute ischemic stroke (AIS) treated with mechanical thrombectomy (MT). METHODS: We retrospectively selected patients > 65 years from our prospective endovascular stroke registry between June 2013 and August 2018. According to 3-month modified Rankin Scale (mRS), patients were divided in two groups, named good (mRS ≤ 2) and poor (mRS > 2) outcome. Measures of temporal lobe atrophy (i.e., interuncal distance [IUD], medial temporal lobe thickness [mTLT] and radial width of temporal horn [rWTH]) were assessed on pre-treatment CT scan. Cutoff values for good outcome were obtained for IUD, mTLT and rWTH by means of non-parametric ROC curve analysis. Multivariate analysis was performed to identify predictors of outcome. Ordinal shift analysis based on cutoff values was built to evaluate differences in 3-month mRS. RESULTS: Among 340 patients, 130 (38.2%) had good and 210 (61.8%) had poor outcome. We found the following cutoff values for good outcome: < 25 mm for IUD, > 15 mm for mTLT and < 4 mm for rWTH. Lower IUD (OR 0.71; 95% CI 0.63-0.80; p < 0.0001) and rWTH (OR 0.73; 95% CI 0.61-0.87; p < 0.0001) and higher mTLT (OR 1.30; 95% CI 1.14-1.49; p < 0.0001) were independently associated with good outcome. Ordinal shift analysis based on cutoff values revealed significant differences in the rate of good outcome for rWTH (49 vs 27%; p < 0.0001), mTLT (52 vs 21%; p < 0.0001) and IUD (57 vs 17%; p < 0.0001). CONCLUSIONS: Assessment of temporal lobe atrophy may predict functional outcome in patients with AIS treated with MT.

Histological and Histochemical Dynamism of Oogenesis in the Cinnamon River Prawn Macrobrachium acanthurus (Caridea: Palaemonidae) Induced by Eyestalk Ablation.

Macrobrachium acanthurus is a caridean prawn native to Brazil, and studying techniques to assist in its cultivation is important due to economic interest in it. Eyestalk ablation is commonly used to promote ovarian development and maturation of captive crustaceans, but it can have possible consequences on fertility and brood quality. Histological and histochemical dynamism of oogenesis was analyzed under control (non-ablated females) and unilateral eyestalk ablated females. Females with ovaries in the spent stage of gonadal development were divided into two treatments: unilaterally ablated and non-ablated. A second experiment with the same treatments was conducted using females with mature gonads. Histological and histochemical analyses of the ovaries indicated that the ablation did not affect oogenesis based on ovarian structure, oocyte size, histochemical properties, and atretic oocytes. Ovarian maturation was not accelerated by ablation, either. Survival, nuptial molting, and spawning were also unaffected. From an applied point of view, unilateral eyestalk ablation is not needed in M. acanthurus farming because it does not improve reproductive performance.

Pairwise genetic meta-analyses between schizophrenia and substance dependence phenotypes reveals novel association signals with pharmacological significance.

Almost half of individuals diagnosed with schizophrenia also present with a substance use disorder, however, little is known about potential molecular mechanisms underlying this comorbidity. We used genetic analyses to enhance our understanding of the molecular overlap between these conditions. Our analyses revealed a positive genetic correlation between schizophrenia and the following dependence phenotypes: alcohol (rg = 0.368, SE = 0.076, P = 1.61 × 10-6), cannabis use disorder (rg = 0.309, SE = 0.033, P = 1.97 × 10-20) and nicotine (rg = 0.117, SE = 0.043, P = 7.0 × 10-3), as well as drinks per week (rg = 0.087, SE = 0.021, P = 6.36 × 10-5), cigarettes per day (rg = 0.11, SE = 0.024, P = 4.93 × 10-6) and life-time cannabis use (rg = 0.234, SE = 0.029, P = 3.74 × 10-15). We further constructed latent causal variable (LCV) models to test for partial genetic causality and found evidence for a potential causal relationship between alcohol dependence and schizophrenia (GCP = 0.6, SE = 0.22, P = 1.6 × 10-3). This putative causal effect with schizophrenia was not seen using a continuous phenotype of drinks consumed per week, suggesting that distinct molecular mechanisms underlying dependence are involved in the relationship between alcohol and schizophrenia. To localise the specific genetic overlap between schizophrenia and substance use disorders (SUDs), we conducted a gene-based and gene-set pairwise meta-analysis between schizophrenia and each of the four individual substance dependence phenotypes in up to 790,806 individuals. These bivariate meta-analyses identified 44 associations not observed in the individual GWAS, including five shared genes that play a key role in early central nervous system development. The results from this study further supports the existence of underlying shared biology that drives the overlap in substance dependence in schizophrenia, including specific biological systems related to metabolism and neuronal function.

Female energy dynamics in the southernmost fiddler crab: Mixed breeding strategy in Leptuca uruguayensis.

At the south of its geographical distribution, the fiddler crab Leptuca uruguayensis shows two population spawning events, with more than 65 % of the females being ovigerous. The aim of this study was to assess the energy dynamics in L. uruguayensis females to estimate how they mix the capital and the income breeding strategies in the first and second spawns of the short reproductive season. The relationship between the hepatosomatic (HIS) and gonadosomatic (GSI) indices was used to assess the contribution of the hepatopancreas to ovary maturation, as indicative of the capital breeding strategy, whereas the feeding rate and the energy available in the food resource (sediment) were estimated to assess the importance of energy intake in ovary maturation, as indicative of the income breeding strategy. Before the first spawn, a significant negative relationship between the HSI and GSI (p < 0.001) and an increase of 28.2 % in the feeding rate were recorded. This suggests that the first spawn was mainly supported by energy reserves in the hepatopancreas, indicating that females used mostly the capital breeding strategy. After the first spawn, total lipid content in the hepatopancreas decreased by 33 %. On the days before the second spawn, the relationship between the HSI and GSI showed a negative but not significant (p = 0.125) trend, whereas the feeding rate increased even more. This suggests that the intense feeding activity provided the most important energetic source for ovary re-maturation, indicating that females used mostly the income breeding strategy. Also, in the second spawn, the GSI was 24.1% smaller, a fact that affected female fecundity and weight of the egg clutches, which were respectively 12 % and 11 % lower than in the first spawn. However, the energy supply allocated to each embryo was equivalent in both spawns. This study shows how L. uruguayensis females mixed the capital and income breeding strategies to take advantage of all available resources to produce two spawns in a short reproductive season.

Plastics in scene: A review of the effect of plastics in aquatic crustaceans.

Plastic pollution in aquatic environments is present in all compartments from surface water to benthic sediment, becoming a topic of emerging concern due to the internalization, retention time, and its effects on aquatic biota. Crustacea with nearly 70,000 species, broad distribution and different roles in the trophic webs is a significant target of the increasing plastic pollution. At least 98 publications in the last 10 years report the impact of plastics in crustaceans, all suggesting that this taxon is at high risk for ecosystem disadvantage by plastic contamination loads. This review compiles the current knowledge on physiological effects (endpoints) by plastic contamination analyzed in crustaceans in the last 10 years, highlighting their use as model species for ecotoxicological tests, sentinels species and bioindicators. Plastic contamination analyzed in this review includes macroplastic, microplastic, and nanoplastic, in a wide variety of types. The studies were focused on 38 marine species with an economic interest in fisheries and aquaculture; 14 freshwater with a higher frequency in standard test species and 4 estuarial and 3 mangrove species with ecological interest. The publications reviewed were divided into studies describing plastic presence in crustaceans without reporting toxic effects and those with analysis of plastic toxicity. Publications describing the plastic presence in the organisms show that the ingestion in individual effects and food-web transfer in ecological effects were the most frequent endpoints. The publications that analyzed plastic toxicity through survival, nutrition-metabolism-assimilation, and reproduction in individual effects, and bioaccumulation in ecological effects were the most frequent endpoints. This review gathers the available information on the use of crustaceans as model species in environmental impact for toxicity screening and hazard assessment. Besides, identifying knowledge gaps will let us propose some future directions in research and the effects on target fisheries species which involves a possible effect on human health.

Factors Modulating the Female Reproductive Performance of the Fiddler Crab Leptuca uruguayensis with Short Reproductive Season.

AbstractThis study aimed to evaluate the factors modulating the female reproductive performance of the fiddler crab Leptuca uruguayensis (Nobili, 1901) during the short reproductive season of a temperate population. We proposed two modulating factors: the age of females (young and old) and the periods of the reproductive season (beginning, middle, and end); we then evaluated the fecundity, reproductive output, egg volume, and biochemical composition of eggs. The fecundity of L. uruguayensis was affected by the size of females, a variable related to their age. Although young females showed lower fecundity, the reproductive output was not affected by the age or by the periods of the reproductive season, suggesting a constant reproductive effort, proportional to female size. The egg volume decreased, and carotenoid content increased at the end of the season for both female ages, probably as a consequence of variations in food availability and changes in the breeding strategies during the season. However, the content of protein and lipids in the egg clutches decreased at the end of the season only in old females spawning for the second time in the season. The main differences in the reproductive parameters were recorded between the beginning and the end of the reproductive season, probably because in these periods females exclusively use one of the breeding strategies. Finally, we determined that both factors, that is, female age and the periods of the short reproductive season, can modulate the reproductive performance of L. uruguayensis in temperate estuaries.

From copula to fertilization: The reproduction of primitive crab Hypoconcha parasitica (Linnaeus, 1763) (Podotremata: Dromiidae).

This study describes the mating behavior of Hypoconcha parasitica under laboratory conditions highlighting the spermathecal morphology and focusing on the seminal fluid storage and release of spermatozoa. The pairs were kept in aquaria where the mating behavior was recorded and described. The spermathecae of the female were analyzed using scanning electron microscopy, X-ray micro-CT, histology, and histochemistry. No pre- or post-copulatory mate guarding was observed in H. parasitica. The sperm transfer occurred with each pair maintaining the protection shield (bivalve shell) on their dorsum. The pair of spermathecae is covered exclusively by the cuticle, following the Podotremata pattern. Many muscle fiber bundles are attached to the cuticular wall facing toward the cephalothorax cavity, especially covering the lateral and slightly dorso-anterior region toward the apodeme of Sternite 7. The spermathecal organization indicates that the process of sperm release during fertilization occurs through muscular action exerted by the female on the wall of the chamber. Thus, the musculature distribution in Hypoconchinae distinguishes them from described for other Podotremata such as Homolidae, which shows the musculature associated with the spermathecae aperture. Like the Homolidae, the first pleopod in H. parasitica seems to take part in the transfer/ movement of spermatozoa and oocytes between the sternum and abdomen, which forms a temporary chamber where fertilization occurs. In conclusion, the spermathecal morphology and associated structures bring new insights to the mechanisms involved in the sperm storage and fertilization of primitive crabs and how the Dromiidae spermatheca perform a new pattern among the poorly studied Podotremata.

Brothers are better than nothing: first report of incestuous mating and inbreeding depression in a freshwater decapod crustacean.

This study aimed at evaluating the effect of one generation of full-sibling mating on traits related to the fitness of the gregarious freshwater shrimp Neocaridina davidi, both under optimal and stressful (i.e. starvation) laboratory conditions. Females were maintained either with their brothers (Inbreeding treatment) or non-brothers (Outbreeding treatment), and the first and second broods were used to evaluate egg production and juvenile quality, respectively. The latter was analyzed in a 60-day period following hatching under optimal rearing conditions, and in a 20-day period following hatching under food deprivation conditions. All surviving females from both treatments mated and spawned, indicating that mating with brothers was as likely as mating with non-brothers. With respect to offspring production, inbreeding had no effect on fecundity and fertilization success, but negatively affected the number of hatched juveniles. These results suggest that egg loss was higher in inbred clutches, possibly due to lower embryonic survival. On the other hand, the effect of inbreeding on growth was absent for embryos and for juveniles under optimal rearing conditions, while it was significant for juveniles starved for 10 consecutive days following hatching. Inbreeding depression for survival was only detected in juveniles from stages S8-S9 under optimal rearing conditions. Overall, the present results show that N. davidi fitness decreases after one generation of full-sibling mating. The use of a potentially weak food deprivation protocol and/or the evaluation of only one inbred generation could explain the absence or subtle inbreeding depression for some of the evaluated traits. No evident relationship between life-history traits and the existence and magnitude of inbreeding was found when comparing our results with those previously reported in high-fecundity marine crustaceans and low-fecundity terrestrial crustaceans.