Prawn Palaemon Elegans Research Articles

Impacts of the Invasive Seaweed Asparagopsis armata Exudate on Energetic Metabolism of Rock Pool Invertebrates.

The marine red algae Asparagopsis armata is an invasive species gaining competitive advantage by releasing large amounts of toxic compounds to the surrounding invaded area. The main objective of this study was to evaluate the effects of this invasive seaweed on marine invertebrates by exposing the common prawn Palaemon elegans and the marine snail Gibbula umbilicalis to the exudate of this seaweed. The seaweed was collected and placed in a tank for 12 h in the dark in a 1:10 ratio. Afterwards the seawater medium containing the released secondary metabolites was collected for further testing. Lethal and sublethal effects of A. armata were investigated. Biochemical biomarker responses associated with energy metabolism (lactate dehydrogenase, LDH; electron transport system activity, ETS; lipid, protein and carbohydrate content) were analysed. The biomarker responses showed physiological status impairment of invertebrates after exposure to low concentrations of this algal exudate. The highest concentrations of exudate significantly increased lipid content in both organisms. In the shrimp, protein content, ETS, and LDH were also significantly increased. By contrast, these parameters were significantly decreased in G. umbilicalis. A behavioural impairment was also observed in G. umbilicalis exposed to A. armata exudate, reducing feeding consumption. These results represent an important step in the research of natural toxic exudates released to the environment and prospective effects of this seaweed in invaded communities under increasing global change scenarios.

Escape trajectories of the rockpool prawn (Palaemon elegans) in response to visual and mechanosensory stimuli

Small crustaceans, such as the rockpool prawn Palaemon elegans Rathke, respond to the approach of predators by executing a version of the crustacean tail-flip response, known as the ‘jack-knife’. We used two types of stimulus to investigate the escape behaviour of P. elegans, specifically the escape trajectories taken by individual prawns. The first stimulus consisted of mechanosensory cues, while the second stimulus included visual and mechanosensory cues. Responses to the two stimulus types differed, with the combined cues from the second stimulus type resulting in escapes over longer distances, and with greater directionality, compared to those following purely mechanosensory stimulation. Altering the direction of approach of the ‘predator’ affected the proportion of escapes that were to the side opposite from the eliciting stimulus and strongly influenced escape trajectories. Such unpredictability in the escape direction of P. elegans may be an example of so-called ‘Protean’ behaviour.

Trophic interactions between native and alien palaemonid prawns and an alien gammarid in a brackish water ecosystem

Macroalgae are an important habitat for small mobile invertebrates such as gammarid amphipods and palaemonid prawns. Gammarid amphipods are important grazers of micro- and macroalgae whereas palaemonid prawns are feeding on macroalgae and small aquatic invertebrates including gammarids. Recently the invasive palaemonid prawn Palaemon elegans established in the Baltic Sea. As P. elegans occurs within the same habitats as the native Palaemon adspersus, it is expected that this invasion modifies the existing trophic interactions. To address this question, we experimentally investigated the feeding of the native P. adspersus and the invasive P. elegans on the benthic macroalga Cladophora glomerata and on the invasive gammarid amphipod Gammarus tigrinus. In the course of the experiment neither G. tigrinus nor Palaemon spp. had effects on filamentous macroalgae. The presence of prawns drastically increased the mortality of amphipods with no difference in the feeding efficiency between the two prawn species. To conclude, the alien prawn does not add an extra function to the trophic system of the coastal ecosystem of the Baltic Sea. Nevertheless, due to its progressively increasing densities and wide habitat range, P. elegans is expected to exert stronger predation pressure on gammarid amphipods as compared to P. adspersus alone.

Trophic position and basal energy sources of the invasive prawn Palaemon elegans in the exposed littoral of the SE Baltic Sea

We investigated the abundance, trophic position, and linkages to basal energy sources of the non-indigenous prawn Palaemon elegans in shallow (0.5–1.6 m) stony habitats of the exposed coast of the SE Baltic Sea. Prawn abundance at the site with artificial stone was higher than that in the natural stony habitats. Stable isotope analysis (SIA) suggested similarity in feeding between different size classes of P. elegans. However, SIA of stomach contents showed greater variability of ingested food among large individuals (body length > 25 mm). Trophic position was estimated at 3.0 ± 0.8 suggesting the prevalence of animal prey in the assimilated diet of P. elegans. However, filamentous green algae was also consumed by large-sized individuals, as indicated by their isotopic signature and the elemental (C:N) ratio of their stomach contents. Modeling of the contribution of Cladophora and particulate organic matter, as basal food sources, to the diet of P. elegans (two end-member mixing model) revealed that only 40% of the assimilated biomass was derived from macroalgae, either directly or through intermediate consumers. This finding suggests that pelagic production was the main carbon source supporting prawn’s nutrition. In an experimental study, P. elegans readily consumed mysids, suggesting that this prey may be the prawn’s link to the pelagic food chain.

Sex and the Syndrome: Individual and Population Consistency in Behaviour in Rock Pool Prawn Palaemon elegans

Animal personality has been widely documented across a range of species. The concept of personality is composed of individual behavioural consistency across time and between situations, and also behavioural trait correlations known as behavioural syndromes. Whilst many studies have now investigated the stability of individual personality traits, few have analysed the stability over time of entire behavioural syndromes. Here we present data from a behavioural study of rock pool prawns. We show that prawns are temporally consistent in a range of behaviours, including activity, exploration and boldness, and also that a behavioural syndrome is evident in this population. We find correlations between many behavioural traits (activity, boldness, shoaling and exploration). In addition, behavioural syndrome structure was consistent over time. Finally, few studies have explicitly studied the role of sex differences in personality traits, behavioural consistency and syndrome structure. We report behavioural differences between male and female prawns but no differences in patterns of consistency. Our study adds to the growing literature on animal personality, and provides evidence showing that syndromes themselves can exhibit temporal consistency.

Palaemon elegans Rathke, 1837 in the food of Baltic cod (Gadus morhua callarias L., 1758) from the Gulf of Gdańsk

Analysis of stomach contents of 52 cod (Gadus morhua callarias) individuals (TL 37.0–58.0 cm) caught in November 2003 in the coastal waters of the Gulf of Gdańsk showed the presence of the prawn Palaemon elegans, a malacostracan species that has been recently reported as abundant in various parts of the Baltic Sea. This is the first observation of P. elegans as a cod food item in the Baltic Sea. The prawns were found in 88.5% of the stomachs analysed, accounting for 17% and almost 7% of food weight of cod <45.0 cm and ≥45.0 cm, respectively. The prawns consumed by the cod measured from 20 to 48 mm (average±SD: 31.7±5.3 mm), the prawn length increasing slightly with the cod length. Although P. elegans seems to be the most important invertebrate food item, diet in the cod was still dominated by fish. Neogobius melanostomus and Zoarces viviparus were the most important fish species found in the cod stomachs examined. In addition, the contents of some of the cod stomachs featured other malacostracan species, mainly Crangon crangon, as well as other invertebrates; however, these were of lesser importance. The significance of P. elegans as food of the cod fished commercially in the coastal waters of the Gulf of Gdańsk in comparison with other species preyed upon by cod there is discussed.

Marine biogeographic boundaries and human introduction along the European coast revealed by phylogeography of the prawn Palaemon elegans

A phylogeographic analysis is carried out for the widely distributed European littoral prawn Palaemon elegans in order to test for potential genetic differentiation and geographic structure. Mitochondrial sequences were obtained from 283 specimens from the northeastern Atlantic, the Baltic, Mediterranean, Black and Caspian Seas. Our study revealed a surprisingly complex population structure. Three main haplogroups can be separated: one from the Atlantic (Type I) and two from the Mediterranean (Types II and III). While the Mediterranean types occur in sympatry, a clear phylogeographic break was observed along the Almería-Oran Front separating Type I and giving evidence for a genetic isolation of Atlantic and Mediterranean populations. Type III represents the most distinct haplogroup with high levels of nucleotide divergence, indicating the occurrence of a cryptic species with a Messinian origin. The colonization of the southeastern Baltic Sea is most likely due to human introduction.

Seasonal and temperature effects on osmoregulation by the invasive prawn Palaemon elegans Rathke, 1837 in the Baltic Sea

The effect of season and acclimation temperature on the osmoregulatory ability of the invasive prawn Palaemon elegans in the Baltic Sea was investigated. There was a significant seasonal effect that could be attributed largely to temperature. Decreasing environmental temperature increased haemolymph osmolality (i.e. improved osmoregulatory ability) in field-sampled hyper-regulating prawns. This effect of temperature was confirmed in the laboratory for individuals acclimated to different salinity and temperature regimes. When compared with an English Channel population of P. elegans, individuals of the Baltic population were better at maintaining hyper-osmoregulatory capacity at the lowest temperature tested (2°C), but individuals of the English Channel population were better at maintaining hypo-osmoregulatory capacity at the highest temperature tested (12°C). It is concluded that the low environmental temperatures encountered by P. elegans invading the Baltic will not compromise but may actually further their range expansion in this area.

Does the effect of low temperature on osmoregulation by the prawn Palaemon elegans Rathke, 1837 explain winter migration offshore?

Osmoregulation by the European glass prawn Palaemon elegans Rathke, 1837 was impaired at low temperature (2°C) and high salinities (full strength sea water 35 PSU). Under these conditions, small individuals showed stronger osmoregulatory ability than larger individuals. This observation could partially explain differences in winter migrations off the UK coast where mainly large P. elegans go offshore, leaving smaller individuals in high shore rock pools, a finding consistent with winter experiments in situ.

Can high-frequency sound affect gas-bubble dynamics? A study in the intact prawn Palaemon elegans

Underwater sound beacons (pingers) are employed in professional and scientific diving for location and navigation. Previous studies have demonstrated that exposure to acoustic fields may lead to the emergence of bubbles and cavities in tissues by rectified diffusion. However, this issue was studied mainly in vitro in various gels and isolated tissues. In the present study, we used the intact prawn Palaemon elegans, whose transparent shell makes it possible to conduct continuous microscopic observation of gas-bubble dynamics in the intact living prawn, to study the effect of high-frequency sound. In a crossover designed experiment, prawns were exposed to hyperbaric pressure of 203 kPa for 10 min, followed by decompression at 40 m/min (control). This procedure was carried out in the study group during transmission of a 37-kHz, 0.25-W, 10-ms pulse width, 1 pulse/s pulse interval. A significant increase was found in the mean volume of bubbles present for a longer period of time, in a higher percentage of the high-frequency sound-exposed prawns. We suggest that this sound exposure causes more gaseous micronuclei to grow into bubbles, and more of the dissolved gas to shift into the gas phase.

The Effect of Protein Source On the Growth of the Prawn Palaemon Elegans Rathke, 1837 (Decapoda, Caridea)

Des crevettes Palaemon elegans Rathke, 1837, ont grandi en laboratoire, soumises a quatre regimes a 35% de proteine provenant de differentes sources: chair de crevette, farine de soja, broyat de Glycimeris seche, et melange egal des trois. Les observations ont porte sur la survie, la croissance a la mue, la periode d'intermue et la consommation de nourriture. La survie a ete de 100% sous tous les regimes. Les crevettes et les melanges ont produit de plus courts intermues et de plus grands accroissements que les autres regimes. La croissance globale etait, dans l'ordre: crevettes > melange > soja = Glycimeris. La croissance la plus forte, sous le regime crevettes, correspondait a la consommation de nourriture la plus elevee et la meilleure efficacite alimentaire, 31 %, au regime mixte.

Effects of Food and Feeding Regime On the Growth and Survival of the Prawn Palaemon Elegans Rathke, 1837 (Decapoda, Caridea)

[La survie et la croissance de la crevette Palaemon elegans Rathke, 1837, ont ete etudiees sous des conditions constantes (20°C; 24‰; 12/12 JN). Deux nourritures ont ete utilisees: muscle de l'abdomen de Nephrops et boulettes de crevettes commerciales, avec deux frequences d'alimentation : quotidiennement et tous les cinq jours. La survie etait meilleure avec les boulettes, ceci etant attribue a leurs effets sur la qualite de l'eau plutot qu'a leur valeur nutritionelle. Avec l'alimentation quotidienne, la croissance etait similaire sous les deux regimes, en depit de larges differences dans la composition proteiniques et les autres composants. Avec l'alimentation tous les cinq jours, la periode d'intermue etait plus longue et le pourcentage d'accroissement a la mue plus faible, en comparaison avec l'alimentation journaliere. Les effets etaient plus grands avec le regime Nephrops qu'avec le regime boulettes., La survie et la croissance de la crevette Palaemon elegans Rathke, 1837, ont ete etudiees sous des conditions constantes (20°C; 24‰; 12/12 JN). Deux nourritures ont ete utilisees: muscle de l'abdomen de Nephrops et boulettes de crevettes commerciales, avec deux frequences d'alimentation : quotidiennement et tous les cinq jours. La survie etait meilleure avec les boulettes, ceci etant attribue a leurs effets sur la qualite de l'eau plutot qu'a leur valeur nutritionelle. Avec l'alimentation quotidienne, la croissance etait similaire sous les deux regimes, en depit de larges differences dans la composition proteiniques et les autres composants. Avec l'alimentation tous les cinq jours, la periode d'intermue etait plus longue et le pourcentage d'accroissement a la mue plus faible, en comparaison avec l'alimentation journaliere. Les effets etaient plus grands avec le regime Nephrops qu'avec le regime boulettes.]

Functional significance of a partial-emersion response in the intertidal prawn Palaemon elegans (Crustacea: Palaemonidae) during environmental hypoxia

Functional significance of a partial-emersion response in the intertidal prawn Palaemon elegans (Crustacea: Palaemonidae) during environmental hypoxia

Response of haemolymph oxygen affinity to simultaneous salinity and oxygen stress in the intertidal prawn, Palaemon elegans (rathke)

1. 1. Specimens of the intertidal prawn Palaemon elegans were acclimated to nine different combinations of salinity and oxygen availability. The conditions ranged from hyposaline (15%o) to hypersaline (40%o) and from hypoxia (50 Torr) to hyperoxia (500 Torr). 2. 2. P. elegans was able to regulate haemolymph Ca 2+, Mg 2+ and Cl −, independent of the oxygen tension of the water. 3. 3. The oxygen affinity and pH sensitivity of oxygen binding by the haemocyanin both increased when the acclimation salinity was highest at 40%, but were unaffected by the acclimation oxygen tension. 4. 4. The dependence of oxygen affinity on the concentration of l-lactate was relatively low (Alog P 50/Alog[lac −] ranged from −0.10 to −0.23) but was independent of the acclimation salinity and oxygen tension. 5. 5. It was concluded that acclimation to the conditions used influenced oxygen affinity primarily via altered concentrations of Ca 2+ and Mg 2+ in the haemolymph.

Formula omitted][formula omitted]31P NMR in crustacean muscles: Fatigue and recovery in the tail musculature from the prawn [formula omitted][formula omitted

31P NMR has been used to observe the in vivo phosphometabolite concentrations in the tail musculature from the prawn Palaemon elegans , at rest and after escape swimming and subsequent recovery. Muscular fatigue corresponds to a 60 % breakdown of phosphoarginine, and a 45 % increase of sugar phosphates. The pHi fell from 7.10 to 6.86. During recovery, the sugar phosphates and arginine phosphate are replenished after 20 minutes. The ATP concentration did not change throughout the experiment. The pHi was restored within 20 minutes.

The effect of temperature on zinc regulation by the decapod crustaceanPalaemon elegansRathke

Abstract The littoral prawn Palaemon elegans Rathke regulates the body concentration of the essential metal zinc to a constant level over a wide range of dissolved zinc concentrations, until regulation breaks down at a threshold external zinc concentration. The body zinc concentration at which zinc is regulated in Palaemon elegans increases with increase in temperature. These changed regulated body concentrations are reached after an acclimation period of greater than 3 and less than 24 days. Breakdown of zinc regulation in prawns takes place at lower external zinc concentrations at higher temperatures. Net accumulation of zinc by Palaemon elegans after breakdown in zinc regulation, is increased at higher temperatures. The rate at which this net accumulation takes place has a Q10 of 1.8 from 10 to 20 °C for an exposure concentration of 562 µg Zn · I-1. The frequency of moulting increases at higher temperatures and this may have a significant effect on zinc regulation, the total body zinc concentration bei...

The relationship between osmoregulation and nitrogen metabolism in the intertidal prawn, Palaemon elegans (Rathke)

1. 1. The relationship between nitrogen metabolism and osmoregulation has been studied in the prawn Palaemon elegans (Rathke) following sudden exposure to hyper- and hyposaline conditions. 2. 2. Animals acclimated to a salinity of 30‰ showed a pronounced increase in the rates of ammonia excretion during the first 2 hr after transfer to lower salinities. These gradually declined during the next 6 hr to rates that were significantly higher than that of control animals (30‰) and were maintained throughout the rest of the experiment. 3. 3. Rates of ammonia excretion in animals transferred to hypersaline conditions (40‰) fluctuated considerably during the experiment. It was consistently observed, however, that there were two periods during the experiments when ammonia excretion rates had negative values indicating that NH + 4 ions were being taken up by the prawns. 4. 4. Experiments in which small quantities of (NH 4) 2SO 4 containing the stable isotope 15N were added to the sea-water confirmed that P. elegans was able to take NH + 4 ions from the sea-water. 5. 5. Changes in the Na + ion concentration in the blood and the changes in free amino acid concentration in the blood and in the muscle after exposure to differing salinities were also determined. Their significance and relationship to the observed changes in the rates of ammonia excretion are discussed.

Modulation of haemocyanin oxygen affinity in the prawn, Palaemon elegans (Rathke) under environmental salinity stress

The effects of salinity acclimation on the oxygen-transporting properties of the blood of the intertidal prawn Palaemon elegans (Rathke) have been examined. Although there was considerable variation in the haemocyanin content of the haemolymph between individual animals, an inverse relationship was obtained between the haemocyanin content of the blood and the salinity to which the animals were acclimated. This resulted in an increase in the oxygen-carrying capacity of the haemocyanin from 1.2 mmol · 1 ∮-1 to 1.48 mmol · 1 −1 in prawns acclimated to salinities of 30 and 10%., respectively. No significant differences were observed in either the oxygen affinity ( P 50 = 31.3–34.0 Torr, pH = 7.8, temperature = 10 °C) or in the size of the Bohr effect (mean value of Φ = −0.74) of the haemocyanin in animals maintained in salinities of 10, 20, and 30%., but blood from animals kept in water having a salinity of 40%. had both a higher oxygen affinity ( P 50 = 11.8 Torr, pH = 7.8) and a higher Bohr value (Φ = −1.26). These increases were primarily due to changes in the concentration of ions (mainly Mg 2+) in the blood of these animals. The co-operativity of the haemocyanin, however, did not differ significantly between the four groups of prawns. Similarly, the effect of l-lactate on the modulation of haemocyanin oxygen affinity was found to be unaffected by changes in the ionic composition of the blood associated with acclimation to differing salinities.

The respiratory response of the intertidal prawn Palaemon elegans (Rathke) to hypoxia and hyperoxia

1. 1. Palaemon elegans behaves as a strong oxyregulator under hyperoxic and hypoxic conditions. Oxygen consumption and heart rate were maintained down to a P c of approximately 15 Torr. 2. 2. Ventilation rate increased progressively when the environmental PO 2 was reduced from 500 to 20 Torr, but at lower oxygen tensions ventilation rate decreased rapidly to zero. 3. 3. At oxygen tensions below 15 Torr the prawns became torpid but could survive 6 hours of anoxia. 4. 4. Under normoxic conditions P. elegans exhibited periods of cardiac arrest and cessation of ventilatory activity, the duration of which increased as the ambient oxygen tension increased. 5. 5. The respiratory responses of P. elegans to hypoxia and hyperoxia are interpreted in relation to the environmental conditions in the intertidal rock pools which this species inhabits.

Modulation of haemocyanin oxygen affinity in the intertidal prawn Palaemon elegans (rathke)

The modulation of haemocyanin oxygen affinity was studied at 10°C in the blood of the intertidal prawn Palaemon elegans. On increasing the L-lactate concentation in dialysed blood from 0 to 9.1 mM, P 50 decreased from 27 to 11 torr at pH 7.8. Undialysed blood exhibited a higher oxygen affinity than dialysed blood with the same lactate concentration indicating the presence of an unidentified factor which increased oxygen affinity. After dialysis both winter and summer blood exhibited the same intrinsic oxygen affinity and response to lactate. The response of oxygen affinity to lactate was exponential, low concentrations of lactate (0–5 mM) markedly increasing oxygen affinity. The lactate effect in dialysed blood expressed as Δ logP 50 δ log[L-lactate was −0.56 at pH 7.8 and −0.63 at pH 7.4. The effect of lactate on oxygen affinity, ΔP 50, was similar in dialysed and whole blood. The effect of the unidentified factor (ΔP 50, between dialysed and undialysed blood) at the same lactate concentration was 13.1 and 15.1 torr at pH 7.8 in winter and summer blood, respectively. At pH 7.4 the ΔP 50 was 38 torr for both summer and winter blood. Differences in oxygen affinity between blood collected in summer and winte cloud be explained by difference in blood lactate concentrations.