Detection and diagnosis of Panulirus argus virus 1 in captive spiny lobsters using qPCR in conjunction with histopathology and transmission electron microscopy.

Panulirus argus virus 1 (PaV1) is the first and only naturally occurring pathogenic virus described in the Caribbean spiny lobster, Panulirus argus. PaV1 infection in decapod species that commonly co-occur with P. argus, including the spotted spiny lobster Panulirus guttatus, has not been previously described. In 2016, 14 Caribbean and 5 spotted spiny lobsters were collected near Summerland Key, Florida, to supplement the resident population of the Audubon Aquarium of the Americas in New Orleans, Louisiana. After 5 months in quarantine, Caribbean and spotted spiny lobsters began to exhibit clinical signs of lethargy and dying in the molt. Initial histologic evaluation revealed intranuclear inclusion bodies in circulating hemocytes in the spongy connective tissue of the epidermis, suggesting a viral infection. Samples of hepatopancreas and hemolymph from deceased Caribbean and spotted spiny lobsters tested negative for white spot syndrome virus and positive for PaV1 using real-time quantitative polymerase chain reaction (qPCR). Intranuclear, eosinophilic to amphophilic, Cowdry type A inclusion bodies observed primarily within fixed phagocytes and circulating hemocytes in the hepatopancreas of freshly euthanized Caribbean spiny lobsters were consistent with PaV1 infection. Transmission electron microscopy revealed that hemocytes associated with hepatopancreatic tubules contained viral inclusions with location, size, and morphology consistent with previously described PaV1 infection. These findings highlight the significance of using molecular diagnostics in conjunction with histopathology and electron microscopy in the investigation and diagnosis of PaV1 in spiny lobsters. Further study is required to investigate the relationship of PaV1-associated mortality events and microscopic lesions in the spotted spiny lobster.

Predatory bacteria in the haemolymph of the cultured spiny lobster Panulirus ornatus.

Bdellovibrio and like organisms (BALOs) are Gram-negative obligate predators of other bacteria in a range of environments. The recent discovery of BALOs in the circulatory system of cultured spiny lobster P. ornatus warrants more investigation. We used a combination of co-culture agar and broth assays and transmission electron microscopy to show a Halobacteriovorax sp. strain Hbv preyed upon the model prey bacterium Vibrio sp. strain Vib. The haemolymph microbiome of juvenile P. ornatus was characterised following injection of phosphate buffered saline (control) or prey and/or predator bacteria for 3 d. The predator Hbv had no effect on survival compared to the control after 3 d. However, when compared to the prey only treatment group, lobsters injected with both prey and predator showed significantly lower abundance of genus Vibrio in the haemolymph bacterial community composition. This study indicates that predatory bacteria are not pathogenic and may assist in controlling microbial population growth in the haemolymph of lobsters.

Single cell transcriptomes reveal expression patterns of chemoreceptor genes in olfactory sensory neurons of the Caribbean spiny lobster, Panulirus argus.

BACKGROUND: Crustaceans express several classes of receptor genes in their antennules, which house olfactory sensory neurons (OSNs) and non-olfactory chemosensory neurons. Transcriptomics studies reveal that candidate chemoreceptor proteins include variant Ionotropic Receptors (IRs) including both co-receptor IRs and tuning IRs, Transient Receptor Potential (TRP) channels, Gustatory Receptors, epithelial sodium channels, and class A G-protein coupled receptors (GPCRs). The Caribbean spiny lobster, Panulirus argus, expresses in its antennules nearly 600 IRs, 17 TRP channels, 1 Gustatory Receptor, 7 epithelial sodium channels, 81 GPCRs, 6 G proteins, and dozens of enzymes in signaling pathways. However, the specific combinatorial expression patterns of these proteins in single sensory neurons are not known for any crustacean, limiting our understanding of how their chemosensory systems encode chemical quality. RESULTS: The goal of this study was to use transcriptomics to describe expression patterns of chemoreceptor genes in OSNs of P. argus. We generated and analyzed transcriptomes from 7 single OSNs, some of which were shown to respond to a food odor, as well as an additional 7 multicell transcriptomes from preparations containing few (2-4), several (ca. 15), or many (ca. 400) OSNs. We found that each OSN expressed the same 2 co-receptor IRs (IR25a, IR93a) but not the other 2 antennular coIRs (IR8a, IR76b), 9-53 tuning IRs but only one to a few in high abundance, the same 5 TRP channels plus up to 5 additional TRPs, 12-17 GPCRs including the same 5 expressed in every single cell transcriptome, the same 3 G proteins plus others, many enzymes in the signaling pathways, but no Gustatory Receptors or epithelial sodium channels. The greatest difference in receptor expression among the OSNs was the identity of the tuning IRs. CONCLUSIONS: Our results provide an initial view of the combinatorial expression patterns of receptor molecules in single OSNs in one species of decapod crustacean, including receptors directly involved in olfactory transduction and others likely involved in modulation. Our results also suggest differences in receptor expression in OSNs vs. other chemosensory neurons.

Seismic air guns damage rock lobster mechanosensory organs and impair righting reflex.

The effects of anthropogenic aquatic noise on marine invertebrates are poorly understood. We investigated the impact of seismic surveys on the righting reflex and statocyst morphology of the palinurid rock lobster, Jasus edwardsii, using field-based exposure to air gun signals. Following exposure equivalent to a full-scale commercial assay passing within 100-500 m, lobsters showed impaired righting and significant damage to the sensory hairs of the statocyst. Reflex impairment and statocyst damage persisted over the course of the experiments-up to 365 days post-exposure and did not improved following moulting. These results indicate that exposure to air gun signals caused morphological damage to the statocyst of rock lobsters, which can in turn impair complex reflexes. This damage and impairment adds further evidence that anthropogenic aquatic noise has the potential to harm invertebrates, necessitating a better understanding of possible ecological and economic impacts.

Effects of chronic hypercapnia and elevated temperature on the immune response of the spiny lobster, Jasus lalandii.

The West Coast rock lobster (WCRL), Jasus lalandii, inhabits highly variable environments frequented by upwelling events, episodes of hypercapnia and large temperature variations. Coupled with the predicted threat of ocean acidification and temperature change for the coming centuries, the immune response in this crustacean will most likely be affected. We therefore tested the hypothesis that chronic exposure to hypercapnia and elevated seawater temperature will alter immune function of the WCRL. The chronic effects of four combinations of two stressors (seawater pCO2 and temperature) on the total number of circulating haemocytes (THC) as well as on the lobsters' ability to clear (inactivate) an injected dose of Vibrio anguillarum from haemolymph circulation were assessed. Juvenile lobsters were held in normocapnic (pH 8.01) or hypercapnic (pH 7.34) conditions at two temperatures (15.6 and 18.9 °C) for 48 weeks (n = 30 lobster per treatment), after which a subsample of lobsters (n = 8/treatment), all at a similar moult stage, were selected from each treatment for the immune challenge. Baseline levels of haemocytes (THC ml-1) and bacteria (CFU ml-1) in their haemolymph were quantified 24 h prior to bacterial challenge. Lobsters were then challenged by injecting 4 × 104V. anguillarum per g body weight directly into the cardiac region of each lobster and circulating haemocyte and culturable bacteria were measured at 20 min post challenge. No significant differences in THC ml-1 (p < 0.05) were observed between any of the treatment groups prior to the bacterial challenge. However lobsters chronically exposed to a combination of hypercapnia and low temperature had significantly higher (p < 0.05) THCs post-challenge in comparison with lobsters chronically exposed to hypercapnia and high temperature. A significant interactive effect was recorded between temperature and pH for the post-challenge THC data (two-way ANOVA, p = 0.0025). Lobster were very efficient at rendering an injected dose of bacteria non-culturable, with more than 83% of the theoretical challenge dose (∼1.7 × 105Vibrio ml-1 haemolymph) inactivated within the first 10 min following injection. Although differences in the inactivation of V. anguillarum were observed between treatment groups, none of these differences were significant. Clearance efficiency was in the following order: Hypercapnia/low temperature > normocapnia/high temperature > normocapnia/low temperature > hypercapnia/high temperature. This study demonstrated that despite chronic exposure to combinations of reduced seawater pH and high temperature, the WCRL was still capable of rapidly rendering an injected dose of bacteria non-culturable.

Genome-wide SNP analyses reveal high gene flow and signatures of local adaptation among the scalloped spiny lobster (Panulirus homarus) along the Omani coastline.

BACKGROUND: The scalloped spiny lobster (Panulirus homarus) is a popular seafood commodity worldwide and an important export item from Oman. Annual catches in commercial fisheries are in serious decline, which has resulted in calls for the development of an integrated stock management approach. In Oman, the scalloped spiny lobster is currently treated as a single management unit (MU) or stock and there is an absence of information on the genetic population structure of the species that can inform management decisions, particularly at a fine-scale level. This work is the first to identify genome-wide single nucleotide polymorphisms (SNPs) for P. homarus using Diversity Arrays Technology sequencing (DArT-seq) and to elucidate any stock structure in the species. RESULTS: After stringent filtering, 7988 high utility SNPs were discovered and used to assess the genetic diversity, connectivity and structure of P. homarus populations from Al Ashkharah, Masirah Island, Duqm, Ras Madrakah, Haitam, Ashuwaymiyah, Mirbat and Dhalkut landing sites. Pairwise FST estimates revealed low differentiation among populations (pairwise FST range = - 0.0008 - 0.0021). Analysis of genetic variation using putatively directional FST outliers (504 SNPs) revealed higher and significant pairwise differentiation (p < 0.01) for all locations, with Ashuwaymiyah being the most diverged population (Ashuwaymiyah pairwise FST range = 0.0288-0.0736). Analysis of population structure using Discriminant Analysis of Principal Components (DAPC) revealed a broad admixture among P. homarus, however, Ashuwaymiyah stock appeared to be potentially under local adaptive pressures. Fine scale analysis using Netview R provided further support for the general admixture of P. homarus. CONCLUSIONS: Findings here suggested that stocks of P. homarus along the Omani coastline are admixed. Yet, fishery managers need to treat the lobster stock from Ashuwaymiyah with caution as it might be subject to local adaptive pressures. We emphasize further study with larger number of samples to confirm the genetic status of the Ashuwaymiyah stock. The approach utilised in this study has high transferability in conservation and management of other marine stocks with similar biological and ecological attributes.

The cost of decompression illness: the case of lobster and sea cucumber fishery in Yucatan, Mexico.

Diving fisheries are an important source of income and protein for many coastal communities around the world. However, these fisheries are also the cause of both fatal and non-fatal injuries. The aim of this study is to estimate the costs of decompression sickness (DCS) in the diving small-scale fisheries that target benthic resources in the Yucatan, Mexico. The DCS cases that occurred during three fishing seasons for sea cucumber (Isostichopus badionotus) and one for spiny lobster (Panulirus argus) were used to calculate the direct medical costs. The catch data during the same fishing seasons were used to calculate the potential losses caused by disability as indirect costs. In the three years (from 2013 to 2016) the total number of fishermen treated in the region numbered 282; 116 during lobster fishing and 166 during sea cucumber season. The direct medical costs were estimated to be USD $120,269; the temporary loss of income in USD $724,377; and the permanent loss of income was USD $737,053. Considering the direct and indirect costs, the social costs of diving in both small-scale fisheries was USD $1,614,121. This is a first approach to estimate the cost of the use of diving in fisheries for the health services but for the fishing communities as well. Furthermore, this is an important first step on the road to a full economic evaluation of the benthic fisheries in order to improve their management.

Production of recombinant insulin-like androgenic gland hormones from three decapod species: In vitro testicular phosphorylation and activation of a newly identified tyrosine kinase receptor from the Eastern spiny lobster, Sagmariasus verreauxi.

In crustaceans the insulin-like androgenic gland hormone (IAG) is responsible for male sexual differentiation. To date, the biochemical pathways through which IAG exerts its effects are poorly understood and could be elucidated through the production of a functional recombinant IAG (rIAG). We have successfully expressed glycosylated, biologically active IAG using the Pichia pastoris yeast expression system. We co-expressed recombinant single-chain precursor molecules consisting of the B and A chains (the mature hormone) tethered by a flexible linker, producing rIAGs of the following commercially important species: Eastern spiny lobster Sagmariasus verreauxi (Sv), redclaw crayfish Cherax quadricarinatus (Cq) and giant freshwater prawn Macrobrachium rosenbergii (Mr). We then tested the biological activity of each, through the ability to increase phosphorylation in the testis; both Sv and Cq rIAGs significantly elevated phosphorylation specific to their species, and in a dose-dependent manner. Mr rIAG was tested on Macrobrachium australiense (Ma), eliciting a similar response. Moreover, using bioinformatics analyses of the de novo assembled spiny lobster transcriptome, we identified a spiny lobster tyrosine kinase insulin receptor (Sv-TKIR). We validated this discovery with a receptor activation assay in COS-7 cells expressing Sv-TKIR, using a reporter SRE-LUC system designed for RTKs, with each of the rIAG proteins acting as the activation ligand. Using recombinant proteins, we aim to develop specific tools to control sexual development through the administration of IAG within the critical sexual differentiation time window. The biologically active rIAGs generated might facilitate commercially feasible solutions for the long sought techniques for sex-change induction and monosex population culture in crustaceans and shed new light on the physiological mode of action of IAG in crustaceans.

Novel Polymorphic Microsatellite Markers for Panulirus ornatus and their Cross-species Primer Amplification in Panulirus homarus.

Polymorphic microsatellite loci were isolated for Panulirus ornatus using 454 GS-FLX Titanium pyrosequencing. Fifteen markers containing perfect di-, tri-, tetra-, and penta-nucleotide motifs were consistently co-amplified in five multiplexes in a panel of 91 randomly selected samples. Observed number of alleles varied from 2 to 14 per locus. Observed and expected heterozygosity ranged from 0.090 to 0.79 and 0.08 to 0.87, respectively. Ten loci deviated from Hardy-Weinberg equilibrium after sequential Bonferroni correction. Genetic linkage disequilibrium analysis between all pairs of the loci showed significant departure from the null hypothesis between 11 loci. The microsatellite markers were also amplified successfully in related Panulirus homarus species with adequate level of polymorphism. The successful cross-species primer amplification of the 15 microsatellites indicates the potential of the developed markers to be transferred to other Panulirus species. The 15 novel microsatellite markers reported in this work add to the previously characterized markers by our group, exhibit adequate levels of polymorphism for wide range of future studies investigating population structure, genetic diversity, and evolutionary relationships among Panulirus species.

Identification and characterization of androgenic gland specific insulin-like peptide-encoding transcripts in two spiny lobster species: Sagmariasus verreauxi and Jasus edwardsii.

In this study we describe, for the first time in spiny lobsters, the androgenic gland and its putative hormone. The androgenic gland in crustaceans is the key regulator of crustacean masculinity. The transcript encoding the insulin-like androgenic gland specific factor has recently been identified and characterized in a number of decapod crustacean species including commercially important crabs, crayfish, prawns and shrimps. This insulin-like factor has proven to be the androgenic gland masculinizing hormone, and is absent in females. While the androgenic gland and its putative hormone have been identified in all other commercially valuable groups, none had been identified in lobsters. We identified and characterized the androgenic glands of two spiny lobster species (Sagmariasus verreauxi and Jasus edwardsii) and conducted a transcriptomic analysis of the S. verreauxi androgenic gland. Bioinformatics analysis led to the discovery and characterization of the insulin-like androgenic gland specific factors in both species studied. Changes in androgenic gland cell size and quantity between sub-adult and sexually mature males were evident. The transcriptomic database established for the S. verreauxi androgenic gland might enable to elucidate the mechanisms through which the insulin-like factor is secreted, transported to the target cells and how it triggers the physiological effects of sexual differentiation towards maleness and maintenance of the male gonad.

Complete genome of Vibrio harveyi isolate K2014767 from the hepatopancreas of captive Caribbean spiny lobster (Panulirus argus).

The complete genome sequence is reported for Vibrio harveyi isolate K2014767, isolated from a captive Caribbean spiny lobster (Panulirus argus) during a species-specific mortality event in a public display aquarium in the United States.

Discontinuous, biphasic, ontogenetic shifts in the metabolic allometry of aquatic animals?

Several investigations in recent years have reported patterns of discontinuous, biphasic, loglinear variation in the metabolic allometry of aquatic animals. These putative shifts in pattern of allometry have been attributed to changes in the primary site for gas exchange from cutaneous to branchial as animals undergo ontogenetic changes in size, shape, and surface area. Because of the important implications of the earlier research with regard to both physiology and evolution, I re-examined data that purportedly support claims of discontinuous, biphasic allometry in oxygen consumption versus body size of American eels (Anguilla rostrata) and spiny lobsters (Sagmariasus verreauxi). I used ANCOVA to fit three different statistical models to each set of logarithmic transformations and then assessed the fits by Akaike's Information Criterion. The observations for both species were described better by a single straight line fitted to the full distribution than by a biphasic model. Eels, lobsters, and other aquatic animals undergo changes in shape and surface area as they grow, but such changes are not necessarily accompanied by changes in the pattern of metabolic allometry.

Effect of body mass and activity on the metabolic rate and ammonia-N excretion of the spiny lobster Sagmariasus verreauxi during ontogeny.

Intraspecific analyses of the relationship between metabolic rate and mass have rarely been considered during complete ontogeny. Spiny lobsters are fascinating candidates to examine metabolic changes during ontogeny because their life cycle includes an extended planktonic, nektonic, and benthic life stages. The effect of body mass on metabolic rates, aerobic scope, and ammonia-N excretion of Sagmariasus verreauxi juveniles were examined to determine energetic demands through juvenile development. Mass-independent routine oxygen consumption increased allometrically during juvenile development with a mass scaling exponent of 0.83. The mass scaling exponent of active metabolism (0.81) was reduced compared to standard metabolism (0.91) of juvenile lobsters. The aerobic scope of juvenile lobsters decreased with larger body mass. To examine if the mass scaling exponent varies with ontogeny, we compared our data with previous measurements made with larvae of the same species. Comparison between mass scaling exponents showed they were higher for phyllosoma (0.97) compared to juvenile (0.83) development. Higher scaling exponents for phyllosoma may be attributed to increased growth rates of phyllosoma compared to juveniles, which increase oxygen consumption due to the higher energy cost of growth. The mass scaling exponent for complete ontogeny (0.91) of S. verreauxi was larger than the commonly cited 0.67 (1/3) and 0.75 (3/4) mass scaling exponents, indicating that species-specific differences can be a large factor affecting allometric relationships of animals.

MPs and NPs intake and heavy metals accumulation in tissues of Palinurus elephas (J.C. Fabricius, 1787), from NW Aegean sea, Greece.

European marine waters are infested with plastic, with an average density of 1 plastic item in every four square-meters. Research relevant to MPs-NPs ingestion by wild decapods in European waters is limited, none of which regards the European spiny lobster. Totally 4102 plastic particles were extracted from the spiny lobster stomach tissues of both sexes. Out of the 63 samples analysed only three (4.8%) of them were found with no plastic particles. The range of number of MPs in stomachs was from 20 to 273 MPs individual-1. The 98.3% were fragments. In total 3833 plastic particles were extracted from the gill tissues of both sexes. MPs were found in all samples (n = 50),99.2% of the detected particles were fragments. The MPs detected in gills ranged from 11 to 339 MPs individual-1. The DLS method was used in order to evaluate the NPs presence. Nanoplastics were detected in 22.6% of stomachs and in the 48.1% of gills. A total of 43 polymer types were identified in both tissues. Also, our study assessed the accumulation of heavy metals at the edible tail muscle. Certain elements were detected above the EU's Maximum Residue Level, including arsenic. The present results are alarming and the potential human health implications could be serious.

Movement patterns analysis as a tool in Fully Protected Areas design: Influence of relocations on travelled distances of Palinurus elephas (Fabr. 1787) in Sardinian FPAs (central-western Mediterranean).

Effectiveness of restocking programs in Marine Fully Protected Areas' (FPAs) can be highly affected by the movement behavior of the species to protect. We analyzed the data of 744 Palinurus elephas specimens tagged, relocated inside 12 FPAs, established in the seas surrounding Sardinia (central-western Mediterranean), and then recaptured. The overall aims were to characterize the individuals' movements after the relocation and to discuss strengths and weaknesses of the current FPAs' design. Almost 80% of tagged individuals travelled progressively increasing distances, as a function of the release distance, up to a maximum value of 11,500 m. Then, for larger release distances, individuals' mobility appeared reduced and more chaotic. A similar trend was found analyzing the distances travelled with respect to the FPAs with the highest number of recaptured individuals and to the size. These results allow to establish a threshold limit of the release distance, to take into account when designing FPAs, as a useful tool to keep a portion of the individuals into FPAs' borders, in order to both preserve the species and guarantee a spillover of individuals in the commercial areas.

Characterization of spiny lobsters from Bangladesh waters using morphology, COI and 16S rRNA sequences.

This study aims to taxonomically identify and characterise the phylogenetic relationships of spiny lobsters based on mitochondrial cytochrome c oxidase I (COI) and 16S rRNA genes from Bangladesh waters. A total of 19 barcode sequences (10 partial COI sequences and 9 partial 16S rRNA) were successfully generated from 12 collected spiny lobster samples representing four species belonging to the family Palinuridae. The average genetic distances within and between species were 0.834 ± 0.427 and 17.810 ± 0.830, respectively, in COI and 0.107 ± 0.255 and 8.401 ± 2.547, respectively, in 16S rRNA genes. The successful amplification rate of 16S rRNA was higher than that of the COI marker. In the maximum likelihood (ML) tree, the sequences of the same species were clustered together under a single clade for both COI and 16S rRNA, which supports the efficacy of both marker genes in differentiating lobster species.

The Use of Reproductive Indicators for Conservation Purposes: The Case Study of Palinurus elephas in Two Fully Protected Areas and Their Surrounding Zones (Central-Western Mediterranean).

In 1990s, the European spiny lobster Palinurus elephas, one of the most commercially important species in the Mediterranean, exhibited a population decline. For this reason, fully protected areas (FPAs) appeared effective in re-establishing natural populations and supporting fishery-management objectives. Here, the reproductive parameters of P. elephas populations in two different FPAs (Su Pallosu and Buggerru, central-western Mediterranean), where a restocking programme was carried out, and in their surrounding commercial zones, were investigated from quantitative and qualitative perspectives. The comparison of fecundity between females collected inside and outside FPAs did not show statistical differences as well as the vitellogenin concentration, which did not vary among eggs of different size classes of females caught inside and outside the FPAs, indicating the same reproductive potential. The study demonstrated a benefit of overexploited populations in terms of enhancement of egg production overtime (15 years for Su Pallosu and 6 years for Buggerru) with a mean egg production 4.25-5.5 times higher at the end of the study than that observed at the beginning of the study. The main driver of eggs production appeared to be size, with larger lobsters more present inside the FPAs than outside. Given these results, the dominant contribution of the two studied FPAs to the regional lobster reproduction is remarkable.

A new record of the spiny lobster, Panulirusfemoristriga (von Martens, 1872) from the coastal waters of Malaysia, with revision of global distribution.

BACKGROUND: Spiny lobsters of the family Palinuridae Latreille, 1802 are known to be industrial crustaceans in the global fishing market amongst other crustacean marine species. Panulirusfemoristriga has been reported in the Maldives, Japan, Taiwan, Vietnam, the Philippines, Indonesia (Ambon, Irian Jaya, Celebes Island, Seram Island), the Polynesian Islands, Solomon Islands, New Hebrides, Wallis and Futuna and off the coast of northern Australia, but there is uncertainty about their distributions due to the morphological similarity with Panulirusfemoristriga, Panuliruslongipesbispinosus and Panulirusbrunneiflagellum. However, the identification on P.femoristiga can only be confirmed if the morphological descriptions are mentioned in literature. NEW INFORMATION: A specimen of the spiny lobster Panulirusfemoristriga Von Martens, 1872 was discovered in Semporna, located on the west coast of Sabah State, Malaysia Borneo. While the status of P.femoristriga has been classified as "least concern" on the International Union for Conservation of Nature Red List, studies on the species' population size, habitat and distribution are still inadequate. This study adopted both morphological and molecular approaches for species delimitation.The phylogenetic position of the Sabah P.femoristriga was revealed by the mitochondrial cytochrome c oxidase gene (COI) marker. This represents the first record of the species in the coastal waters of Sabah, despite its wide geographical distribution in the Indo-West Pacific. A revision on the species global distribution was also conducted by harvesting all literature with species named Panuliruslongipesfemoristriga and Panulirusfemoristriga which were available online including those prior to year 2001 before the presence of P.femoristriga is confirmed. Due to the uncertainties on the morphological distribution in previous literature, further studies are required to fill in the missing data for confirmation.

Accumulation of paralytic shellfish toxins by Southern Rock lobster Jasus edwardsii causes minimal impact on lobster health.

Recurrent dinoflagellate blooms of Alexandrium catenella expose the economically and ecologically important Southern Rock Lobster in Tasmania to paralytic shellfish toxins (PST), and it is unknown if PST accumulation adversely affects lobster performance, health and catchability. In a controlled aquaculture setting, lobsters were fed highly contaminated mussels to accumulate toxin levels in the hepatopancreas (mean of 6.65 mg STX.2HCl equiv. kg-1), comparable to those observed in nature. Physiological impact of PST accumulation was comprehensively assessed by a range of behavioural (vitality score, righting ability and reflex impairment score), health (haemocyte count, bacteriology, gill necrosis and parasite load), nutritional (hepatopancreas index and haemolymph refractive index) and haemolymph biochemical (21 parameters including electrolytes, metabolites, and enzymes) parameters during a 63 day period of uptake and depuration of toxins. Exposure to PST did not result in mortality nor significant changes in the behavioural, health, or nutritional measures suggesting limited gross impact on lobster performance. Furthermore, most haemolymph biochemical parameters measured exhibited no significant difference between control and exposed animals. However, the concentration of potassium in the haemolymph increased with PST, whilst the concentration of lactate and the sodium:potassium ratio decreased with PST. In addition, exposed lobsters showed a hyperglycaemic response to PST exposure, indicative of stress. These findings suggest that PST accumulation results in some measurable indicators of stress for lobsters. However, these changes are likely within the adaptive range for Jasus edwardsii and do not result in a significant impairment of gross performance. Our findings support previous conclusions that crustaceans are relatively tolerant to PST and the implications for the lobster fishery are discussed.

Nutritional Quality of the European Spiny Lobster Palinurus elephas (J.C. Fabricius, 1787) (Achelata, Palinuridae) and the Non-Indigenous Northern Brown Shrimp Penaeus aztecus Ives, 1891 (Dendrobranchiata, Penaeidae).

The European spiny lobster is a species of great commercial value, yet a limited scientific knowledge exists on its biology, ecology, and physiology, especially for the stocks from east Mediterranean waters. The northern brown shrimp, a non-indigenous established species, is commercially exploited in regions of the Mediterranean Sea. Both species' proximate composition and fatty acid profile were assessed for the first time in the Mediterranean region, exhibiting an overall significant statistical difference. Protein, fat, and energy contents were significantly higher in the northern brown shrimp, whereas moisture and ash contents were significantly higher in the European spiny lobster. The proximate composition for both species was well within the reported range for other lobster and prawn species in the Mediterranean Sea.