Palaemon Longirostris Research Articles

Non-native shrimps in Polish coastal waters: first record of Palaemon longirostris H. Milne Edwards, 1837 and new sites for P. macrodactylus Rathbun, 1902

Non-native shrimps in Polish coastal waters: first record of Palaemon longirostris H. Milne Edwards, 1837 and new sites for P. macrodactylus Rathbun, 1902

First record of the white prawn Palaemon longirostris H. Milne Edwards, 1837 in the Mediterranean waters of Morocco

In this paper, we provide the first record of the white prawn Palaemon longirostris, a palaemonid shrimp with socio–economic interests, in the northeastern coasts of Morocco, and the third confirmed record for the Mediterranean. Future surveys may increase its known range in the Mediterranean Sea.

The cross-shore distribution of epibenthic predators and its effect on zonation of intertidal macrobenthos: a case study in the river Scheldt

Available research is inconclusive on how circatidal habitat use and cross-shore distribution of aquatic epibenthic predators may affect the vertical zonation of infauna in muddy, soft-bottom substrates in estuaries. We placed fyke traps at different heights on the intertidal mudflat to assess the circatidal density of epibenthic predators. Infauna was sampled across the same tidal gradient. The abundance of epibenthic predators in the fykes decreased with elevation (decreasing inundation time), yet for the shrimp Palaemon longirostris abundance did not change with elevation in autumn. When corrected for inundation time, predator density was equal over the tidal range or higher on the high mudflat in some instances, indicating that predators evenly distributed over the mudflat or moved to the highest part during a high tide. The density of epibenthic predators did not correlate with the density of infauna, whereas the latter did show a close relationship with sediment characteristics. Our data suggest epibenthic predator density does not shape the present distribution of infauna across the tidal gradient on the oligohaline mudflats in the Scheldt.

Palaemon longirostris (Decapoda, Caridea) Is an Alien Species in the Russian Sector of the Black Sea

The paper reports the find of shrimp species from the Palaemonidae family Palaemon longirostris H. Milne Edwards, 1837, new for the Russian sector of the Black Sea in the coastal zone of Crimea. The species was recorded in the Sevastopol Bay (the city of Sevastopol) in July 2018.

Assessment of sperm DNA integrity within the Palaemon longirostris (H. ) population of the Seine estuary

The interpretation of biomarkers in natura should be based on a referential of expected values in uncontaminated conditions. Nevertheless, to build a reference data set of biomarker responses in estuarine areas, which receive chronic pollution loads due to their transition position between continent and sea, is impossible. In this context, the aim of the present work was to propose the use of laboratory recovery period to define a baseline for the measurement of sperm DNA damage by Comet assay in the estuarine prawn Palaemon longirostris. For that, sperm DNA integrity was observed after both a passive (i.e. 20 days in a clean environment) and an active (i.e. forced renewal of spermatophores) recovery of wild P. longirostris specimens from the Seine estuary, in laboratory conditions. Then, the levels of sperm DNA damage recorded within the P. longirostris population of the Seine estuary, during six campaigns of sampling from April 2015 to October 2017, have been interpreted according to the defined threshold values. The results showed a persistence in the level of DNA damage after 20-day in clean environment with the passive recovery. This strategy was inconclusive to reach a baseline level but it revealed the lack of DNA repair mechanisms. For the active recovery, a decrease of 54% of the level of DNA damage has been observed after the first renewal of spermatophores and this level stabilized after the second renewal. On the basis of this second strategy, we defined a mean basal value of sperm DNA damage of 54.9 A.U. and a maximum threshold of 69.7 A.U. (i.e. 95 %CI). The analysis of the results using the reference value highlighted significant abnormal sperm DNA damage within the native population of P. longirostris from the Seine estuary on all stations during the six-sampling campaigns.

Re-description of the growth pattern of four decapod species by information theory

ABSTRACTThe growth pattern of four commercial decapod crustacean species (Arenaeus cribrarius, Ucides cordatus, Palaemon longirostris and Plesionika izumiae) was reanalyzed using published data. Six candidate growth models with asymptotic and non-asymptotic characteristics were tested. The best model was determined by information theory, according to Bayesian (BIC) and Akaike (AICc) information criteria and the weight of evidence in favour of model i (Wi). For U. cordatus, P. izumiae and the females of A. cribrarius, the best growth model corresponded to case 1 of Schnute model. In male A. cribrarius, the highest Wi was observed for the case 1 of Schnute model according to both criteria, but seasonal models were also plausible to describe growth. In P. longirostris, discrepancies were observed between criteria. The BIC supported the case 1 of Schnute in females, but the AICc did not identify a winner model (Wi > 90%); the case 1 and case 4 of Schnute displayed the highest Wi. The males that exhibited the highest Wi values were Schnute case 4 > Schnute case 3 > von Bertalanffy > Gompertz > Logistic. This study highlights the importance of considering different assumptions in growth patterns of the species and does not impose any a priori mathematical framework to available data.Abbreviations: AIC: Akaike Information Criterion. BIC: Bayesian Information CriterionImpact StatementThe multi-model approach improves the model selection based on information criteria to re-describe patterns of growth in some decapod crustaceans.The von Bertalanffy growth model is not appropriate to describe the growth pattern based on the available data.The growth patterns found were asymptotic and not asymptotic, described mainly through the Schnute model.

Seasonal variations of contamination and exoskeletal malformations in the white shrimps Palaemon longirostris in the Gironde estuary, France.

Since the end of the 1980s, white shrimps (Palaemon longirostris) from the Gironde estuary have exhibited exoskeletal malformations, mainly involving cephalothorax, rostrum, scaphocerites and uropods. An 8-month study was carried out in 2015. Each month, 200 individuals were sampled and examined for exoskeletal malformations. Temporal variations in malformation frequency were noted, particularly during the breeding period, along with decreases in the size of non-deformed shrimps related to the appearance of juveniles in breeding sites, and high mortality among deformed shrimps. A significant increase in proportions of deformed shrimp was observed, relating particularly to the size (and therefore the age) of individuals. No significant difference was found between shrimp proportions with different numbers of malformations (one to four) for a fixed size class, nor was there any variation in proportions within different size classes for a fixed number of malformations. This would appear to indicate that the number of malformations is acquired and new malformations do not seem to appear during the life cycle, except for the smallest (youngest) shrimps. The malformation spectrum showed no significant differences between the biggest and smallest individuals for the different malformation associations, except for those involving cephalothorax, rostrum and uropods. This would suggest that some malformation associations lead to a higher mortality rate in shrimps subjected to them, due to greater impairment of feeding and/or swimming behaviour. Multiple component analysis of the different types of malformation showed correlations between exoskeletal pieces (rostrum and cephalothorax) and appendixes (scaphocerites and uropods). Regarding metal contamination in shrimp, no significant difference was highlighted between deformed and non-deformed shrimps. Organic pollutants were not measured in tissues. Certain herbicides such as metolachlore and chlortoluron were detected at high concentrations in the Gironde estuary during the breeding period corresponding to the higher occurrence of exoskeletal malformations.

Transcriptomic response to thermal and salinity stress in introduced and native sympatric Palaemon caridean shrimps

Organisms develop local adaptations to cope with spatially and temporally variable environments such as estuarine habitats, where abiotic parameters such as salinity and temperature fluctuate continuously. Studying the regulation of gene expression in a variable environment allows us to understand the underlying molecular mechanisms of these adaptations and the relative roles of the genetic and plastic response. The transcriptomes of the European native Palaemon longirostris (PL) and the introduced P. macrodactylus (PM) shrimps are described and compared after an experiment simulating summer conditions in the Guadalquivir Estuary, Spain. Specimens, collected in the Guadalquivir Estuary, were maintained at a temperature and salinity of 20 °C and 5 ppt for the control, and 30 °C and 15 ppt for the stress treatment. A large amount of differential gene expression was observed: 16,013 and 2,594 for PL and PM respectively. Functionally annotated unigenes revealed some differences, with PL seemingly having to face stronger physiological stress than PM. Thus, PM seems to have greater resistance than PL under conditions of high temperature and salinity. These results constitute a step forward in the understanding of the underlying molecular mechanisms of genetic adaptation of native invertebrates, and alien taxa that have successfully invaded estuaries in temperate regions around the world.

Life Under Exceptional Conditions—Isotopic Niches of Benthic Invertebrates in the Estuarine Maximum Turbidity Zone

The estuarine maximum turbidity zone (MTZ) can be assumed to be a stressful environment featuring special conditions of great biological importance with an excess of organic matter, high-deposition rates, large variations in salinity, and dredging activities. Under such harsh conditions, populations may remain below the carrying capacity and competition is assumed to be of little importance, as predicted by the stress-gradient hypothesis. Therefore, we hypothesized that invertebrates of similar feeding types may utilize the same resources. To test our hypothesis, we chose the three most abundant taxa classified in literature as deposit feeders (Bathyporeia pilosa, Boccardiella ligerica, Marenzelleria sp.) and two taxa classified as predominately predacious (Palaemon longirostris, Crangon crangon) and determined their isotopic niches based on a stable isotope analysis for the MTZ of the Elbe Estuary (Germany). We expected the isotopic niches of similar feeding types to show a clear overlap if our hypothesis was true. Our results showed that the isotopic niches of no two taxa overlapped within each feeding group, indicating different resource use and the absence of competition. The sediment analysis revealed that two of the deposit feeders inhabited significantly different mean grain sizes. The lack of overlap of isotopic niches within each feeding group may be due to differences in habitat and feeding behavior in the case of the deposit feeders and due to different migration behavior in the case of the predominately predacious species. However, competition may have occurred in the past, resulting in a divergence of feeding niches during evolution.

Diet analysis indicates seasonal fluctuation in trophic overlap and separation between a native and an introduced shrimp species (Decapoda, Palaemonidae) in the tidal river Thames (U.K.)

The diets of Palaemon longirostris and the non-native P. macrodactylus were investigated to explore their competitive interactions. Both species are largely carnivorous with amphipods being the dominant prey. Chironomid larvae were consumed in large numbers by both species in summer. Vacuity coefficients were higher for both species in winter than summer. A high degree of dietary overlap occurs in winter, with less overlap in summer suggesting that the two species compete for food on a seasonal basis, which may be partly attributed to the absence of chironomid larvae, and generally reduced prey availability, in the winter. If summer prey also become limited then competition for food may increase and P. macrodactylus may then have an adverse effect on P. longirostris. An introduction of P. macrodactylus in the summer, when there is less competition for food, may be more likely to lead to a successful colonisation than one in the winter.

Individual and mixture effects of selected pharmaceuticals on larval development of the estuarine shrimp Palaemon longirostris

Few ecotoxicological studies incorporate within the experimental design environmental variability and mixture effects when assessing the impact of pollutants on organisms. We have studied the combined effects of selected pharmaceutical compounds and environmental variability in terms of salinity and temperature on survival, development and body mass of larvae of the estuarine shrimp Palaemon longirostris. Drug residues found in coastal waters occur as mixture, and the evaluation of combined effects of simultaneously occurring compounds is indispensable for their environmental risk assessment. All larval stages of P. longirostris were exposed to the nonsteroidal anti-inflammatory drug (NSAID) diclofenac sodium (DS: 40 and 750μgL−1), the lipid regulator clofibric acid (CA: 17 and 361μgL−1) and the fungicide clotrimazole (CLZ: 0.14 and 4μgL−1). We observed no effect on larval survival of P. longirostris with the tested pharmaceuticals. However, and in contrast to previous studies on larvae of the related marine species Palaemon serratus, CA affected development through an increase in intermoult duration and reduced growth without affecting larval body mass. These developmental effects in P. longirostris larvae were similar to those observed in the mixture of DS and CA confirming the toxic effects of CA. In the case of CLZ, its effects were similar to those observed previously in P. serratus: high doses affected development altering intermoult duration, tended to reduce the number of larval instars and decreased significantly the growth rate. This study suggests that an inter-specific life histories approach should be taken into account to assess the effect of emergent compounds in coastal waters.

Morphometric and molecular analyses for populations of Palaemon longirostris and Palaemon garciacidi (Crustacea, Palaemonidae): Evidence for a single species

Authors have disagreed on the taxonomic status of the white prawns along the coasts of the Northeast Atlantic Ocean and the Mediterranean Sea. The present study compares variation in morphology and mtDNA in populations of white prawns, identified as Palaemon longirostris and P. garciacidi, from the United Kingdom, The Netherlands, France, Spain, Portugal, Morocco and Tunisia. Differences in morphology among populations were tested using a multiple discriminant analyses (DA) on morphometric data. In order to resolve variation in mtDNA, 16S and COI mitochondrial (mt) genes were used. The morphometric analyses do not support their separation into distinct species, since individual prawns could not be assigned unequivocally to one of the various studied populations and a geographic pattern could be detected only in females. Molecular data corroborate the morphological analyses, since no geographic structure was found and the levels of sequence divergence observed among haplotypes from distinct populations (0.1–0.8%) are consistent with other 16S and COI intraspecific divergences of decapod crustaceans. Therefore, findings from this study do not support the distinction of P. longirostris and P. garciacidi as different species.

Do invaders always perform better? Comparing the response of native and invasive shrimps to temperature and salinity gradients in south-west Spain

Invasive species are often thought to benefit from climate change, outcompeting native species as temperatures increase. However, the physiological tolerance has been little explored as a potential mechanism explaining biological invasion success. In this study, we used empirical data from both invasive and native estuarine species as a case study to address the hypotheses that (1) invasive species show a better resistance to acute thermal stress, (2) invasive species present lower oxygen consumption rates owing to greater resistance to environmental stressors, and (3) native species have lower survival rates under chronic temperature and salinity stress. We conducted various comparative experiments on three sympatric and syntopic closely related shrimp species (one invasive Palaemon macrodactylus, and two natives Palaemon longirostris and Palaemonetes varians). We evaluated their critical temperature maxima, their oxygen consumption rates under different salinities and temperatures, and their survival rates under chronic salinity and temperature. We found that the invasive species was the most tolerant to rapid increase in temperature, and consistently consumed less oxygen over a broad range of temperatures and salinities. Palaemon macrodactylus also had lower mortality rates at high temperatures than P. longirostris. These results support previously reported differences in physiological tolerance between native and invasive species, with the invasive species always performing better. The consistently higher tolerance of the non-indigenous species to temperature variation suggests that climate change will increase the success of invaders.

Long-term changes of the Seine estuary suprabenthos (1996–2012)

The freshwater discharge into the Seine estuary decreased between 1996 and 2012 and no discharge>1200m3s−1 has occurred after 2001. The suprabenthic community in the navigational channel of the Seine estuary was characterised in 1996 by high abundances and biomass of mysids and the decapod Palaemon longirostris, which were among the highest in the world for transitional waters during a period of high discharge of the Seine River. A recent sampling (2011–2012) of the suprabenthos in new hydrological conditions (i.e., low river discharge) showed subsequent changes of the quantitative composition of the community with both decreases of abundance and biomass. Such long-term changes were probably due to the combination of hydrological changes, and anthropogenic modifications of the entrance of the Estuary, the Port 2000 construction, and supplementary dredging in the navigational channel of the Rouen harbour. The changes of the suprabenthic community encompassed an important impact in the estuarine trophic chain, which was essential to fish juveniles, such as sea bass and flat fish.

Respiratory responses to salinity, temperature and hypoxia of six caridean shrimps from different aquatic habitats

The respiratory response of six caridean shrimp species under different salinity and dissolved oxygen concentrations (DO) has been carried out at 20 and 25°C. The lowest mean specific oxygen consumption rates (MO2) were found for the less active benthic crangonids Crangon crangon and Philocheras monacanthus; whereas the highest ones corresponded to the two more mobile native palaemonids Palaemon longirostris and Palaemonetes varians. The level of oxygen regulation displayed by the different native species was mainly related with environmental characteristics of their common habitats: species with temporal (C. crangon) or permanent (P. varians) estuarine habitats tended to be more tolerant of salinity changes and/or hypoxia, than are fully marine (P. monacanthus) or freshwater (Atyaephyra desmarestii) species. The estuarine P. longirostris showed moderate oxygen independence, but rather independent of salinity and temperature fluctuations. The exotic shrimp P. macrodactylus seemed to have higher tolerance to hypoxia that its native counterpart P. longirostris at brackish waters, but only under moderate temperature (at 20°C). Results of this study suggest that a simultaneous evaluation of respiration rates and their dependence on DO could be an integrative way of determining the potential effects of increased salinity, temperature and hypoxia on aquatic species with different mobility and/or from different habitats.

Long-Term Changes in Population Dynamics of the Shrimp Palaemon longirostris in the Gironde Estuary

Spanning 20 years (1979–2007), this study is the longest time series pertaining to the resident shrimp species Palaemon longirostris in a European estuary. Data from monthly faunal surveys undertaken across the middle part of the Gironde estuary from April 1979 along with data from a statistical analysis of the commercial catches throughout the entire estuary and river were considered in order to explore their inter and intra-annual variability and long-term trends. Long-term densities series as well as environmental series (salinity, discharge, temperature and NAO) were decomposed and the effects of environmental variables were also examined using statistical models (GAMs). This revealed important spatio-temporal variability and a significant overall decrease in abundance of this species in the Gironde estuary since the beginning of the 1980s. This long-term decrease in abundance corresponded significantly to long-term decreases in both discharge and the NAO index, as well a long-term increase in temperature and salinity in the middle part of the estuary. However, models showed that environmental factors explained only a small part of the variability. The upstream shift of the population highlighted in this study, probably due to the intrusion of marine waters into the middle section of the estuary, may also have contributed to its decrease in abundance. Inter-annual variability of densities was also significantly linked with inter-annual fecundity fluctuations, and a significant decrease in both mean female size and fecundity was shown for preserved samples from 1992. Moreover, the breeding period has been temporally stretched out and began earlier in more recent years, potentially due to the increase in spring temperature.

Growth Modeling and Spatio-Temporal Variability in the Body Condition of the Estuarine Shrimp Palaemon longirostris in the Gironde (Sw France)

Abstract Growth and morphometric characteristics of the caridean Palaemon longirostris Milne Edwards, 1837, were studied in the Gironde estuary population. Their first comparison with earlier studies in this estuary and in the Mira River provided the first step towards developing environmental indicators using a species represented at the European scale. Mean individual growth was modelled for each sex using the classical von Bertalanffy growth model and the seasonal model that integrates periods of lower growth. Morphometric relationships, in particular the spatio-temporal variability in the relative weight of individuals, were explored according to sex and physical parameters of the environment. Females grew to larger size than males. Growth estimates showed the importance of accounting for the seasonal variations to evaluate non-biased growth. Sex and the presence of eggs for females showed significant interaction within the carapace length – total length relation as well as for the carapace length – w...

Reproductive Biology of Palaemon longirostris (Decapoda: Palaemonidae) from Gironde Estuary (France), with a Comparison with Other European Populations

Our study details key parameters of the reproductive biology of the shrimp Palaemon longirostris, e.g., spatio-temporal variation of the sex-ratio, migration pattern, breeding period, fecundity, size at the onset of maturity, and egg volume. While P. longirostris population was very little studied in its distribution area, our fist aim was to complete that lack of knowledge and to provide a basis for understanding its population dynamic. Finally, our results were also compared with those reported from different studies on this species within Europe, in order to test the reported latitudinal cline of reproductive parameters in decapods. During a one-year survey, P. longirostris have been collected monthly across a large part of the Gironde estuary (France). Biometric measurements and determination of sex and maturation stages were carried out on preserved subsamples. Eggs were counted and measured for ovigerous females. In the Gironde, the breeding period was restricted from March to July, and related to water temperature. The size of the ovigerous females ranged between 7.1 and 14.6 mm cephalothorax length; according to their size, these females brought between 78 and 1391 eggs (547 on average). These results were compared with available data from the literature on French or foreign populations. For two reproductive parameters a latitudinal cline was noticed: e.g., an increase of the maximum females size and a restriction of the breeding period with latitude. Due to the weakness of available data on the reproductive biology of P. longirostris, it was very difficult to compare fecundity (number of eggs brought per female) and egg volume between localities. As expected fecundity could decrease with latitude, but this trend remains to be confirmed by more extensive studies on the species populations.

Assessment of the interaction between the white shrimp, Palaemon longirostris, and the exotic oriental shrimp, Palaemon macrodactylus, in a European estuary (SW Spain)

Results of field surveys, stomach content analysis, and laboratory measurements of oxygen consumption at different salinities in the exotic shrimp Palaemon macrodactylus and its native counterpart P. longirostris from the Guadalquivir estuary (SW Spain) were used to assess interaction between both species. After its first record in this estuary in 1998, P. macrodactylus has shown a gradual increase in density and its estuarine population has been clearly dominated by juveniles. Feeding habits of both shrimps indicated a strong trophic overlap between them, with mysids as main prey. Their salinity-related and spatial distribution patterns show that maximal inter-specific overlap between the two populations occurs in the inner, less saline part of the estuary. Specific oxygen consumption rates under different salinities and water oxygen concentrations suggest a more efficient metabolism and a higher tolerance to hypoxic conditions in brackish waters by P. macrodactylus than by P. longirostris. Such inter-specific physiological differences could have made it possible for the exotic P. macrodactylus to invade an estuarine stretch that, prior to its arrival, was infra-utilized by native species.

Exoskeletal deformities in Palaemonidae: Are they a threat to survival?

Shrimps of the Palaemon genus have been affected for over 15 years by a problem of exoskeletal deformities, particularly in the Gironde estuary (France). Given the large numbers of individuals affected, this study focus on a better description of the phenomenon to estimate its impact on shrimps. This study, on Palaemon longirostris and Palaemon macrodactylus, is based on samples collected from 1992 to 2007 in the Gironde estuary with particular focus on the year 2007, and on a 4-month rearing of adult shrimps in experimental system. The different approaches reveal the relative persistence of the phenomenon since 1992 (with on average more than 58% of ovigerous females affected) and its persistence during shrimp life cycle, even after several moults. Important consequences associated with deformities at the individual level were demonstrated: a higher mortality, a lighter egg mass and a lower weight for a given size. The presence of exoskeletal deformities is now a major phenomenon, with profound effects on individual shrimps, and which may in turn have an important impact on the survival of the P. longirostris population in particular.