Effect of morphine and naloxone on a defensive response of the mantis shrimp (Squilla mantis)

Summary The mantis shrimpSquilla mantis responds to an electrical shock with a quick and violent flexure of its body (Fig. 1 and 2). The reaction time of this defensive response was measured for each experimental shrimp and the minimal current that elicited a reaction time equal to or lesser than 0.22 s was considered as its intensity threshold (Fig. 3). Different doses of morphine-HCl were injected and results showed that this drug produces a dose-related analgesia by increasing the intensity threshold. A concentration of morphine equal to 30.0 g/mm of animal length (about 91.0 g/g) causes a 50% inhibition in the sensitivity to the electrical stimulus, but the effect is fully blocked by naloxone (Table 2).The present study represents the first behavioral analysis of opiate effects in invertebrates. However, the effective dose reported in this experiment is far greater than that used with vertebrates. Some speculative arguments are mentioned in order to account for a such large difference.     

Adaptive Mechanisms in the compound eye of Squilla mantis (Crustacea,Stomatopoda)

Summary Light and dark adaptations were studied in the eye of Squilla mantis. Light adaptation is characterized by (1) a proximal shift of the distal pigment sheath (DPS) surrounding the proximal portion of the crystalline cone above its zone of contact with the rhabdom; (2) flattening of the distal pigment sheath; (3) lengthening of the crystalline cone correlated with shortening of the rhabdom; (4) a migration of screening pigment granules in retinula cells in the protoplasmic bridges crossing the perirhabdomal space. In animals kept in constant darkness, longitudinal displacements of the distal pigment sheath were found to be subject to a circadian rhythm characterized by a maximal light adaptation state at about 5 p.m. and a minimal one at 5 a.m. Screening pigment granule translocation in retinula cells does not show such rhythmic activity.Abbreviations a, b maximal incidence angles in L.A., and D.A., respectively - Cc crystalline cone - Dps distal pigment sheath - I extreme incident light beam - Prs perirhabdomal space - Rh rhabdom - Rp reflecting pigment This research has been supported by grant 3.012-76 of the Swiss National Science Foundation     

Insight on cellular and humoral components of innate immunity in Squilla mantis (Crustacea, Stomatopoda)

For deeper insights into the function of crustacean haemocytes in immune responses, we studied the morphology and enzyme content of circulating cells of the mantis shrimp Squilla mantis from the North Adriatic Sea, together with their ability to phagocytose foreign cells. We also assayed the enzyme content and the agglutinating and haemolytic activities of cell-free haemolymph. Three haemocyte types, i.e., hyalinocytes, semigranulocytes and granulocytes, can be distinguished, according to cell and nuclear morphology and the presence of cytoplasmic granules. All of them share the same patterns of enzyme activities and are recognised by the same lectins. Spreading cells (hyalinocytes and semigranulocytes) can ingest foreign cells; granules of semigranular and granular cells have similar cytochemical properties. Injection of Micrococcus luteus into the heart sinus results in an increase in the frequency of hyaline cells and a decrease in the frequency of granulocytes. After 24 h from the injection, a decrease in the number of phagocytosing hyalinocytes, and a general decrease in the frequency of acid phosphatase-positive cells was reported. Our data match previous results and suggest the existence of a single differentiation pathway for Squilla haemocytes with the three haemocyte morphs as different stages of cell differentiation. Results also indicate that Squilla haemolymph performs immunosurveillance, through rapid changes in haemocyte distribution, increase of antimicrobial and antioxidant enzymes and secretion of lectins stimulating agglutination, phagocytosis and encapsulation.     

Evidence for hemocyanin formation in the compound eye of Squilla mantis (Crustacea,Stomatopoda)

Summary In the retina and in the subretinal space of the compound eye of Squilla mantis a special kind of pigment cell is present. The crystalline inclusions of this cell have been identified as hemocyanin, as determined (i) by the dimensional congruence of the crystalline substructure with the dimensions of isolated, purified hemocyanin, and (ii) by the immunofluorescence reaction using anti-hemicyanin antibodies. The ultrastructure of these cells, their location and the presence of crystalline bodies in their cytoplasm suggest that they are sites of hemocyanin synthesis and homologous to the cyanocytes or cyanoblasts of Limulus.Supported by grant No. 3,012-0.76 of the Swiss National Science Foundation     

Population structure and genetic analysis of narrow-clawed crayfish (Astacus leptodactylus) populations in Turkey

The genetic differentiation among Turkish populations of the narrow-clawed crayfish was investigated using a partial sequence of cytochrome oxidase subunit I gene (585 bp) of 183 specimens from 17 different crayfish populations. Median joining network and all phylogenetic analyses disclosed a strong haplotype structure with three prominent clades diverged by a range between 20 and 50 mutations and substantial inter-group pairwise sequence divergence (5.19–6.95 %), suggesting the presence of three distinct clades within the Anatolian populations of Astacus leptodactylus. The divergence times among the three clades of Turkish A. leptodactylus are estimated to be 4.96–3.70 Mya using a molecular clock of 1.4 % sequence divergence per million years, pointing to a lower Pliocene separation. The high level of genetic variability (H _d  = 95.8 %, π = 4.17 %) and numerous private haplotypes suggest the presence of refugial populations in Anatolia unaffected by Pleistocene habitat restrictions. The pattern of genetic variation among Turkish A. leptodactylus populations, therefore, suggests that the unrevealed intraspecific genetic structure is independent of geographic tendency and congruent with the previously reported geographic distribution and number of subspecies (A. l. leptodactylus and A. l. salinus) of A. leptodactylus.     

Ontogeny of the antennal glands in the crayfish Astacus leptodactylus (Crustacea, Decapoda): anatomical and cell differentiation

The ontogeny of the antennal glands was studied during the embryonic and post-embryonic development of Astacus leptodactylus. The future glands arising from undifferentiated columnar cells were detectable at the metanauplius stage EI 150 m (EI: eye index; approximately 440 m at hatching). The tubule and labyrinth differentiated in embryos at EI 190 m, and the bladder and coelomosac at EI 250 m. At EI 350 m, the tubule lengthened and divided into proximal and distal sub-regions. In later stages, the gland retained the same morpho-anatomy but the differentiation and size of each part increased. The cells of the coelomosac displayed the cytological features of podocytes in late embryonic development at EI 440 m. Only small apical microvilli and a few mitochondria were observable in the labyrinth cells at EI 250 m; by EI 440 m, these cells presented well-shaped apical microvilli, formed bodies, basal infoldings and mitochondria. In the cells of the tubules and bladder, mitochondria and basal infoldings occurred at EI 440 m and EI 250 m, respectively. The differentiation of the tubules and bladder cells suggested that they were involved in active transport at EI 440 m. Following hatching, the differentiation of the cells and the size of the glands increased. The ontogeny of the antennal glands thus starts in early embryos, the specific cellular functional features being differentiated in the various parts of the glands by EI 440 m. The antennal glands are probably functional just before hatching, i.e., before the juveniles are confronted with the low osmolality of freshwater.Thanks are due to the University of Tarbiat Modarres and Ministry of Science, Research and Technology, Islamic Republic of Iran, for financial aid and support. Special thanks are also extended to the Société Française dExportation des Ressources Educatives (SFERE) for a scholarship to S.K.     

Kinetics of reaction between hemocyanin and CN: a comparative study on the hemocyanin of five species of crustacea (Carcinus maenas, Maja squinado, Squilla mantis, Eriphia spinifrons, Calappa calappa)

This paper presents a comparative study of five hemocyanins from different species of crustacea, such as Carcinus maenas, Squilla mantis, Eriphia spinifrons, Calappa calappa, and Maja squinado. The aim of the paper is to compare the data of kinetics of reaction between CN^- with several hemocyanins of Crustacea.     

Synergistic and Antagonistic Effects of Thermal Shock,Air Exposure,and Fishing Capture on the Physiological Stress of Squilla mantis (Stomatopoda)

This study is aimed at assessing the effects of multiple stressors (thermal shock, fishing capture, and exposure to air) on the benthic stomatopod Squilla mantis, a burrowing crustacean quite widespread in the Mediterranean Sea. Laboratory analyses were carried out to explore the physiological impairment onset over time, based on emersion and thermal shocks, on farmed individuals. Parallel field-based studies were carried out to also investigate the role of fishing (i.e., otter trawling) in inducing physiological imbalance in different seasonal conditions. The dynamics of physiological recovery from physiological disruption were also studied. Physiological stress was assessed by analysing hemolymph metabolites (L-Lactate, D-glucose, ammonia, and H⁺), as well as glycogen concentration in muscle tissues. The experiments were carried out according to a factorial scheme considering the three factors (thermal shock, fishing capture, and exposure to air) at two fixed levels in order to explore possible synergistic, additive, or antagonistic effects among factors. Additive effects on physiological parameters were mainly detected when the three factors interacted together while synergistic effects were found as effect of the combination of two factors. This finding highlights that the physiological adaptive and maladaptive processes induced by the stressors result in a dynamic response that may encounter physiological limits when high stress levels are sustained. Thus, a further increase in the physiological parameters due to synergies cannot be reached. Moreover, when critical limits are encountered, mortality occurs and physiological parameters reflect the response of the last survivors. In the light of our mortality studies, thermal shock and exposure to air have the main effect on the survival of S. mantis only on trawled individuals, while lab-farmed individuals did not show any mortality during exposure to air until after 2 hours.     

Differences in the crista dentata structure of the ischium of the third maxilliped in Astacus leptodactylus (Eschscholtz, 1823)

The differences in the crista dentata structure of the ischium of third maxilliped in different size Astacus leptodactylus (36-80 mm carapace length) were investigated. The results showed that four different types of crista dentata structure and teeth number occur in the third maxillipeds of A. leptodactylus. These are: (1) same number of teeth in the crista dentata of right and left third maxilliped, but not in the same structure, (2) different number and structure of teeth in the crista dentata of right and left third maxilliped, (3) same number and structure ofteeth in the crista dentata of right and left third maxilliped, (4) same sturucture of teeth in the crista dentata of right and left third maxilliped, but not same number of irregular teeth. In conclusion, it is believed that the differences in the crista dentata structure and different tooth number of the ischium of maxilliped cause a different cutting edge and variations in the food choice of A. leptodactylus.     

Biomonitoring of Trace Metals in the Keban Dam Reservoir (Turkey) Using Mussels (Unio elongatulus eucirrus) and Crayfish (Astacus leptodactylus)

Biological Trace Element Research - Freshwater mussels and crayfish are commonly used as biomonitors of trace metals. In the present study, the concentrations of ten metals were determined in...     

A comparison of the spermatozoa of OratosquiMa stephensoni and Squilla mantis (Crustacea, Stomatopoda) with comments on the phylogeny of the Malacostraca

Each stomatopod sperm, aflagellate and obovoid, is surrounded by an electron dense coat. A spermatophore is absent. The discus-shaped acrosome vesicle is penetrated and underlain by a straight, slender acrosome rod (perforatorium) ensheathed, below the vesicle, in subacrosomal material. Feulgen-positive granular material, indicating chromatin, fills most of the length of the cell but there is no certain nuclear membrane. Two centrioles, consisting of doublets each with a radial “foot” as in decapods and peracarids, occur near the acrosome and like it are embedded in the chromatin. Myelin-like membranes are associated with degenerating mitochondria in the posterior region of the cell. Thiéry-positive granules are aggregated as a glycogen body posteriorly in the cell. Spermatozoa1 ultrastructure confirms monophyly of the mysid–amphipod–isopod– cumacean section of the Peracarida but affinities of the tanaids are uncertain. A closer phylogenetic relationship of Phyllocarida to the Branchiopoda than to the Malacostraca is suggested. A weak similarity (synapomorphy?) of syncarids and peracarids is the filiform perforatorium bipassing the nucleus. Stomatopods resemble decapods in their diffuse sperm chromatin but are placed below the syncarid–peracarid–decapod assemblage.     

Firing properties of the soma and axon of the abdominal stretch receptor neurons in the crayfish (Astacus leptodactylus)

Action potentials (APs) and impulse responses in the soma and axon of the rapidly and slowly adapting (SA) abdominal stretch receptor neurons of the crayfish (Astacus leptodactylus) were recorded with single microelectrode current-clamp technique. Impulse frequency response to constant current injection was almost constant in the SA neuron while the response decayed completely in the rapidly adapting (RA) neuron. Mean impulse frequency responses to current stimulations were similar in the receptor neuron pairs. In the RA neuron additional current steps evoked additional impulses while a sudden drop in the current amplitude caused adaptation. Impulse duration was dependent on the rate of rise when current ramps were used. Adaptation was facilitated when calculated receptor current was used. Exposing the neuron to 3 mmol/l TEA or scorpion venom resulted in partly elongated impulse responses. SA neuron could continuously convert the current input into impulse frequency irrespective of previous stimulation conditions. Exposing the SA neuron to 3 mmol/l TEA or 1 mmol/l Lidocaine reduced impulse duration to large current stimulations. The SA neuron fired spontaneously if it was exposed to 5-10 mmol/l Lidocaine or 10(-2) mg/ml Leiurus quinquestriatus venom. The action potential (AP) amplitudes in the RA soma, RA axon, SA soma, and SA axon were significantly different between components of all pairs. Duration of the AP in the axon of the RA neuron was significantly shorter than those in the RA soma, SA soma, and SA axon. Diameter of the RA axon was larger than that of the SA axon. Non-adapting impulse responses were promptly observed only in the SA axons. The results indicate that the RA neuron is a sort of rate receptor transducing the rapid length changes in the receptor muscle while the SA neuron is capable of transducing the maintained length changes in the receptor muscle. The differences in firing properties mainly originate from the differences in the active and passive properties of the receptor neurons.     

Localization of crustacean hyperglycemic hormone (CHH) in the X-Organ sinus gland complex in the eyestalk of the crayfish,Astacus leptodactylus (Nordmann, 1842)

The eyestalk of Astacus leptodactylus is investigated immunocytochemically by light, fluorescence, and electron microscopy, using an antiserum raised against purified crustacean hyperglycemic hormone (CHH). CHH can be visualized in a group of neurosecretory perikarya on the medualla terminalis (medulla terminalis ganglionic X-organ: MTGX), in fibers forming part of the MTGX-sinus gland tractus, and in a considerable part of the axon terminals composing the sinus gland. Immunocytochemical combined with ultrastructural investigations led to the identification of the CHH-producing cells and the CHH-containing neurosecretory granule type.     

Experimental study of the combined effects of pH and salinity on the bioaccumulation of inorganic mercury in the crayfish Astacus leptodactylus

ABSTRACT

The combined effects of pH and salinity were investigated on the bioaccumulation of inorganic mercury in the Turkish crayfish Astacus leptodactylus, at the whole organism and organ levels. Effects on the ionic balance were also analysed during the acclimatization phase and after 3 and 15 days of exposure, via the direct route. The experimental protocol, based on a complete factorial design, took into account nine experimental conditions, resulting from the combination of three levels for pH (6, 7.5 and 9) and for salinity (1, 10 and 100 mM Cl-). The results showed an important Hg accumulation in the organs or tissues in direct contact with the surrounding medium, e.g. gills and carapace. The effects of the nine pH and salinity conditions were complex and variable from one organ to another. Correlations were studied between chemical species concentrations in the water (HgCl₂, HgOHCl, HgCl₃-,HgCl₄², Hg(OH)₂) and amounts of metal accumulated in the different organs. A positive correlation was found between the neutral species HgCl₂ and metal accumulated in the gills and in the carapace. Perturbations of the haemolymph ionic concentrations were no significant, except for Na⁺ after 3 days of exposure.     

Ontogeny of the antennal glands in the crayfish Astacus leptodactylus (Crustacea, Decapoda): immunolocalization of Na+,K+-ATPase

The involvement of the antennal urinary glands in the ontogeny of osmoregulatory functions was investigated during the development of Astacus leptodactylus by measurements of hemolymph and urine osmolality in juvenile and adult crayfish and by the immunodetection of the enzyme Na⁺,K⁺-ATPase. In stage II juveniles, 1-year-old juveniles, and adults, all of which were maintained in freshwater, urine was significantly hypotonic to hemolymph. In adults, chloride and sodium concentrations were much lower in urine than in hemolymph. During embryonic development, Na⁺,K⁺-ATPase was detected by immunocytochemistry in ionocytes lining the tubule and the bladder, at an eye index (EI) of 220–250 m, and in the labyrinth, at EI 350 m. In all regions, immunofluorescence was mainly located at the basolateral side of the cells. No immunofluorescence was detected at any stage in the coelomosac. In late embryonic stages (EI 410–440 m), in stage I juveniles, and in adults, strong positive immunofluorescence was found from the labyrinth up to and including the bladder. These results show that, as early as hatching, juvenile crayfish are able to produce dilute urine hypotonic to hemolymph. This ability originates from the presence of Na⁺,K⁺-ATPase in ion-transporting cells located in the labyrinth, the tubule, and the bladder of the antennal glands and constitutes one of the main adaptations of crayfish to freshwater.We thank the University of Tarbiat Modarres and Ministry of Science, Research and Technology, Islamic Republic of Iran for financial aid and support. Special thanks are also due to the Société Française dExportation des Ressources Educatives (SFERE) for the scholarship to S.K.     

Correction to: Biomonitoring of Trace Metals in the Keban Dam Reservoir (Turkey) Using Mussels (Unio elongatulus eucirrus) and Crayfish (Astacus leptodactylus)

Biological Trace Element Research - The original version of this article contained mistakes: the units mg/kg-1 and μg/kg-1 found on tables 1, 2, 4, 5 and 6 should be mg kg−1 and μg...     

Cilia-driven rotational behavior in gastropod (Physa elliptica) embryos induced by serotonin and putative serotonin reuptake inhibitors (SSRIs)

We characterized the serotonin (5-hydroxytryptamine; 5-HT) receptor mediating cilia-driven rotational movement in embryos of the freshwater gastropod Physa elliptica. In addition, putative serotonin reuptake inhibitors (SSRIs), previously shown to induce other 5-HT-mediated processes in molluscs, were tested for their ability to induce rotation. As in previous studies with other freshwater gastropods, 5-HT induced a significant dose-dependent increase in rotation from 10(-6) to 10(-4) M. The 5-HT(1A) agonist 8-OH-DPAT produced a similar dose-dependent increase in rotation. However, the 5-HT(2) agonist alpha-CH3-serotonin evoked a significant rotational response only at the highest concentration of 10(-4) M. The 5-HT(2) receptor antagonist mianserin not only blocked 5-HT-induced rotation, it reduced rotation rate below that of baseline. However, two other antagonists, cyproheptadine (5-HT(2)) and propranolol (5-HT(1)), caused similar responses that consisted of an initial rotational surge followed by reduced rotation. Thus, these drugs appear to act as partial agonists. The putative SSRI fluvoxamine exhibited a significant dose-dependent increase in positive rotation as that seen with 5-HT. The SSRIs paroxetine and fluoxetine both caused an increase in rotation at 10(-6) and 10(-5) M but reduced rotation rate below that of baseline at 10(-4) M. These results agree with other studies on aquatic molluscs, suggest a 5-HT receptor with a mixed 5-HT(1)/5-HT(2) pharmacological profile and add to a now growing body of literature on the pharmacology of molluscan 5-HT receptors. In addition, all the tested putative SSRIs induced cilia-driven rotation in Physa embryos, indicating either the presence of 5-HT reuptake transporters or that these compounds act as 5-HT receptor ligands. J. Exp. Zool. 286:414-421, 2000.