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Bryozoan epibiosis on lobster hosts is rarely reported. Here we document bryozoan fouling of the spiny rock lobster Jasus edwardsii from the Hauraki Gulf, North Island of New Zealand. The 92 lobste...

Panulirus argus virus 1 (PaV1) (Family Mininucleoviridae) causes chronic and systemic infection in wild juvenile spiny lobsters Panulirus argus (Latreille, 1804), ending in death by starvation and metabolic wasting. In marine decapods, the antennal gland is involved in osmoregulation and excretion. In this compact organ, fluid is filtered from the hemolymph, and ions are reabsorbed to produce a hypotonic urine. Although PaV1 is released with the urine in infected individuals, little is known regarding the metabolic effect of PaV1 in the antennal gland. The objective of this study was to perform a comparative evaluation of the metabolic profile of the antennal gland of clinically PaV1-infected lobsters versus those with no clinical signs of infection, using proton nuclear magnetic resonance analysis. Overall, 48 compounds were identified, and the most represented metabolites were those involved in carbohydrate, amino acid, energy, and nucleotide metabolism. Most of the metabolites that were down-regulated in the infected group were essential and non-essential amino acids. Some metabolites involved in the urea cycle and carbohydrate metabolism were also altered. This study represents a first approach to the metabolic evaluation of the antennal gland. We broadly discuss alterations in the content of several proteinogenic and non-proteinogenic amino acids and other key metabolites involved in energetic and nucleotide metabolism.

The Caribbean spiny lobster, Panulirus argus (Latreille, 1804), is an important resource in the Western Atlantic Ocean, Caribbean Sea, and Gulf of Mexico. A nemertean egg predator of P. argus, Carcinonemertes conanobrieniSimpson, Ambrosio & Baeza, 2017, was recorded in Florida in 2017 and Colombia in 2018. This study sought to investigate the presence of C. conanobrieni in P. argus in Saint Kitts and Nevis, eastern Caribbean Sea. Nemerteans were observed in the brood masses of P. argus. Molecular techniques confirmed its presence in the P. argus population on Saint Kitts. Egg, juvenile, and adult stages of C. conanobrieni and of an undescribed Carcinonemertes sp. were found in the brood masses of 27 of 31 (87%) ovigerous P. argus. Differences in the shape of the nemertean egg masses (string versus spherical arrangement) were confirmed as two distinct species of Carcinonemertes Coe, 1902 using molecular analyses. The juvenile stage of the undescribed Carcinonemertes sp. was detected in the gills of 72 of 320 (23%) of the P. argus individuals from Saint Kitts. The prevalence of branchial nemertean infestation was not significantly different among male and female P. argus. Female lobsters with ovaries in early stages of gonadal maturation were more likely to have branchial nemerteans relative to those with ovaries in late stages of maturation, suggestive of nemertean migration from gills to egg mass once the host oviposits. This is the first report of C. conanobrieni in the Caribbean spiny lobster from the eastern Caribbean, which is approximately 1,300 miles from Florida and 1,000 miles from Colombia. This is also the first report of an undescribed nemertean worm in P. argus. The high prevalence of Carcinonemertes spp. in P. argus raises concern for the extent to which these egg predators may be impacting P. argus in Saint Kitts, an important fishery on the island.

The review explores the current diversity of methods used to determine the nutritional condition of crustaceans and to provide evidence that standardization is needed to make results comparable among the increasing number of studies in this field. The advantages and disadvantages of inexpensive and wide-ranging indices are discussed with respect to the blood refractive index (BRI) and the effectiveness of the total weight/carapace length relationship based on their application to the spiny lobster Panulirus argus (Latreille, 1804). Also reviewed are the environmental factors that impact metabolism based on the nutritional condition concept and the nutritional condition itself. Ocean acidification, temperature, salinity, dissolved oxygen, and noise have been the most studied factors impacting nutritional condition in crustaceans, usually under controlled (laboratory) conditions. Methodological aspect could be nevertheless one of the most important factors affecting nutritional condition estimations. More than twenty methods have been applied to determine nutritional variations in crustaceans, all then following different techniques, procedures, and instrumentation. These differences make results almost impossible to compare. BRI determined by a hand-held refractometer, usually inexpensive, is a good option to standardize studies so that the results from different species and different regions can be comparable; other methodologies could nevertheless be used in combination. Laboratory studies, which typically use few individuals that are exposed to extreme and usually non-natural conditions, show limited results. Emphasis should be placed on field studies that integrate the effects of several environmental factors.

The Caribbean spiny lobster Panulirus argus supports a large and valuable fishery in the Caribbean Sea. In 2007-2008, a rare microsporidian parasite with spore characteristics typical of the Ameson genus was detected in 2 spiny lobsters from southeast Florida (FL). However, the parasite species was not confirmed by molecular analyses. To address this deficiency, reported here are structural and molecular data on single lobsters displaying comparable 'cotton-like' abdominal muscle containing ovoid microsporidian spores found at different locations in FL in 2014 and 2018 and in Saint Kitts and Nevis Islands in 2017. In the lobster from 2014, multiple life stages consistent with an Ameson-like monokaryotic microsporidian were detected by transmission electron microscopy. A partial (1228 bp) small subunit (SSU) rRNA gene sequence showed each microsporidia to be identical and positioned it closest phylogenetically to Ameson pulvis in a highly supported clade also containing A. michaelis, A. metacarcini, A. portunus, and Nadelspora canceri. Using ecological, pathological, ultrastructural, and molecular data, the P. argus microsporidian has been assigned to a distinct species: Ameson herrnkindi.

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 × 104 V. 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 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.

There is little information on the early life history of the spotted spiny lobster Panulirus guttatus (Latreille, 1804), an obligate reef resident, despite its growing importance as a fishery resource in the Caribbean and as a significant predator. We cultured newly-hatched P. guttatus larvae (phyllosomata) in the laboratory for the first time, and the growth, survival, and morphological descriptions are reported through 324 days after hatch (DAH). Phyllosomata were cultured at 25 °C in a flow-through seawater system within a series of custom 80 l plankton-kreisel tanks and provided with ongrown Artemia and mussel gonad. Mean body length (BL) of phyllosomata was 1.70 mm (N = 10) at hatch and increased linearly to 22.20 mm at 226 DAH (N = 3). Morphological characters from a total of 164 sampled phyllosomata were ascribed to nine distinct developmental stages (stages I-IX), and described and illustrated. Although no final stage phyllosomata (stage X) were obtained, the BL in the final stage was extrapolated at 39.6 mm using a Gompertz function, expressing the relationship between phyllosoma stages and BL. The total duration of phyllosomata for P. guttatus was estimated at 410 d, with the 5th and 95th percentiles at 334 and 526 d, respectively. Our data suggest that P. guttatus has a larger body size in the final larval stage and a substantial pelagic larval duration compared with other related panulirid lobsters in its geographic range. The described morphological and biological attributes associated with the early-life history for this species can inform future studies, and add value to models of distribution and population connectivity.

The two spiny lobster fisheries targeting Panulirus argus (Latreille, 1804) and Panulirus laevicauda (Latreille, 1817) have made an important marine resource in Northeast Brazil since 1955. The Von Bertalanffy age and growth parameters of the spiny lobster started being studied in 1960 and the last assessment was performed over 20 years ago. The objective of this review is to analyse the type of input data and the methods historically used to assess age and growth of the spiny lobster stock in Northeast Brazil. Our study reviews and updates the research on the subject and proposes relative values for the Von Bertalanffy growth parameters for P. argus and P. laevicauda as provisional reference. We recommend further age and growth research on spiny lobsters to create a new and updated growth function for commercial lobsters in Northeast Brazil.

The Caribbean spiny lobster Panulirus argus (Latreille, 1804) is an important species in shallow-water coral reefs and target of the most lucrative fishery in the Caribbean Sea. We explored historical demography in P. argus inferred using single nucleotide polymorphisms (SNPs). We expected an increase in population size of P. argus from Florida, USA starting ~18,000-24,000 years ago, after the Last Glacial Maximum, when ice sheets started to retreat and sub-tropical/tropical shallow coastal waters warmed up. A total of 10 lobsters were collected from shallow reefs in the Florida Keys, Florida, USA. One microgram of gDNA extracted from each specimen was used for RAD library construction using established protocols. A panel of 1643 SNPs obtained after interrogation of RAD-tags was used to calculate a site frequency spectrum (SFS). The observed SFS for the Florida population of P. argus exhibited a non-normal distribution peaking at singleton SNPs. The expected SFS in a total of six different candidate demographic models with dissimilar population size changes through time (i.e., standard neutral, exponential growth, bottleneck, bottleneck + growth, two epochs, and three epochs) were numerically computed in the software A i and a model selection approach was implemented to test which expected model(s) best fitted the empirical SFS. The model selection approach indicated that the bottleneck + growth model most closely matched the observed SFS; P. argus experienced a population decline at about 1.9 (0.75-5.7) mya, to then recover and growth exponentially until present time. In disagreement with expectations, population expansion started much earlier than ~18,000-24,000 years ago. Fisheries and conservation studies are expected to profit from the evaluation of genomic and population variability in this species using demographic models, as shown here. Studies exploring population connectivity and locality-specific demographic history of P. argus are underway. © 2019 The Author(s) 2019. Published by Oxford University Press on behalf of The Crustacean Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com. La langosta espinosa del Caribe Panulirus argus (Latreille, 1804) es una especie importante en los arrecifes de coral de aguas poco profundas y objetivo de la pesquería más lucrativa del Mar Caribe. Exploramos la demografía histórica en P. argus inferida mediante polimorfismos de un solo nucleótido (SNP). Esperábamos un aumento en el tamaño de la población de P. argus de Florida, EE. UU., Comenzando hace ~ 18.000-24.000 años, después del Último Máximo Glacial, cuando las capas de hielo comenzaron a retirarse y las aguas costeras poco profundas subtropicales / tropicales se calentaron. Se recolectaron un total de 10 langostas de arrecifes poco profundos en los Cayos de Florida, Florida, EE. UU. Se utilizó un microgramo de ADNg extraído de cada muestra para la construcción de la biblioteca RAD utilizando protocolos establecidos. Se utilizó un panel de 1643 SNP obtenidos después de la interrogación de etiquetas RAD para calcular un espectro de frecuencia de sitio (SFS). El SFS observado para la población de Florida de P. argus exhibió una distribución no normal con un pico en los SNP únicos. El SFS esperado en un total de seis modelos demográficos candidatos diferentes con cambios de tamaño de población diferentes a lo largo del tiempo (es decir, estándar neutral, crecimiento exponencial, cuello de botella, cuello de botella + crecimiento, dos épocas y tres épocas) se calcularon numéricamente en el software A i y Se implementó un enfoque de selección de modelos para probar qué modelo (s) esperado (s) se ajustaba mejor al SFS empírico. El enfoque de selección del modelo indicó que el modelo de cuello de botella + crecimiento coincidía más estrechamente con el SFS observado; P. argus experimentó una disminución de la población de aproximadamente 1,9 (0,75-5,7) millones de años, para luego recuperarse y crecer exponencialmente hasta la actualidad. En desacuerdo con las expectativas, la expansión de la población comenzó mucho antes que hace ~ 18.000-24.000 años. Se espera que los estudios de pesca y conservación se beneficien de la evaluación de la variabilidad genómica y poblacional de esta especie utilizando modelos demográficos, como se muestra aquí. Se están realizando estudios que exploran la conectividad de la población y la historia demográfica específica de la localidad de P. argus. Department of Biological Sciences, 132 Long Hall, Clemson University, Clemson, SC, United States Smithsonian Marine Station at Fort Pierce, 701 Seaway Drive, Fort Pierce, FL, United States Departamento de Biología Marina, Facultad de Ciencias Del Mar, Universidad Católica Del Norte, Coquimbo,Larrondo, Chile Laboratorio de Análisis Genómico (LAGEN), Escuela de Ciencias Biológicas, Universidad Nacional, Heredia, Costa Rica Laboratorio de Bioespeleología y Carcinología, División de Desarrollo Sustentable, Universidad de Quintana Roo, Quintana Roo, Mexico Universidad Nacional, Costa Rica Escuela de Ciencias Biológicas

Lobsters are fished world-wide due to their status as a high value, luxury seafood. A large proportion of the product is sold via live export, with lobsters subject to a range of stressors during holding post-capture. Improving the current understanding of the immune response to these stressors assists in improving efficiency and reducing loss in the chain between capture and consumption. In this study, the immune status of four treatment groups of Southern Rock Lobster (Jasus edwardsii) were studied: controls recently landed from a fishing boat, lobsters displaying advanced shell necrosis, lobsters in an unexplained moribund state and lobsters held in a processing facility for 10 weeks in standard conditions (i.e. high density, fasted). A total of 15 immune parameters and 19 haemolymph biochemical parameters were assayed. Phenoloxidase activity was only sporadically observed in haemocyte lysate and was consistently observed at a low level in the plasma with no difference between treatments for either. Haemocyte lysate prophenoloxidase activity was detected in most individuals, with no differences found between treatments. Prophenoloxidase in the plasma showed the highest level of activity, with the shell necrosis treatment demonstrating an elevated activity level relative to the other three treatments. Cell viability was not affected in any treatment. Lobsters with shell necrosis had a reduced capacity for phagocytosis, a significantly higher total haemocyte count, fewer hyalinocytes and more granulocytes and semigranulocytes. Fasted lobsters showed an opposite shift, with significantly more hyalinocytes compared to the other treatments and very few granulocytes and semigranulocytes. The balance of a range electrolytes, minerals metabolites and enzymes were affected in shell necrosis and fasted treatments, raising them as potential markers for immunocompromised lobsters. Multivariate analysis of all assayed parameters showed that all individuals in the necrosis treatment showed a similar, distinct immune response and that the fasted treatment, along with one control and one moribund individual, showed a separate intermediate response. The remainder of the control and moribund lobsters demonstrated a distinct "non-response" in comparison. These results offer a characterisation of the physiological response to common challenges during post-capture holding of rock lobsters, demonstrating the differential response to pathogenic bacterial infection, long term fasting, non-specific moribundity and the stress of capture and transport.

A specific study has been carried out for the first time to investigate the homing capability and daily home range of the spiny lobster Palinurus elephas by means of ultrasonic telemetry. Nine lobsters collected in the Capo Gallo — Isola delle Femmine marine protected area (northwestern Sicily, central Mediterranean) were tagged with miniaturized transmitters and released at a single site inside the protected area. The lobsters were monitored with the purpose of calculating their horizontal and vertical positions, analysing their movement patterns to assess their homing capability, and calculating their daily home range. Five lobsters moved back close to the capture sites within the first 20 hours after release (‘homed’). The remaining four lobsters ‘relocated’ to a different refuge. Homed lobsters had a larger home range than relocated lobsters. This study provides the first description of a homing pattern with high spatial resolution in the wild European spiny lobster as inferred by ultrasonic telemetry.

The anaesthetic isoeugenol has been used as metabolic suppressant for commercial transport of live lobsters in order to decrease energy expenditure and improve survival. Given the central role of mitochondria in metabolism and structural similarities of isoeugenol to the mitochondrial electron carrier coenzyme Q, we explored the influence on mitochondrial function of isoeugenol. Mitochondrial function was measured using high-resolution respirometry and saponin-permeabilised heart fibres from the Australasian red spiny lobster, Jasus edwardsii. Relative to vehicle (polysorbate), isoeugenol inhibited respiration supported by complex I (CI) and cytochrome c oxidase (CCO). While complex II (CII), which also reduces coenzyme Q, was largely unaffected by isoeugenol, respiration supported by CII when uncoupled was depressed. Titration of isoeugenol indicates that respiration through CI has a half-maximal inhibitory concentration (IC50) of 2.4±0.1 µmol l−1, and a full-maximal inhibitory concentration (IC100­) of approximately 6.3 µmol l−1. These concentrations are consistent with those used for transport and euthanasia of J. edwardsii and indicate that CI is a possible target of isoeugenol, like many other anaesthetics with quinone-like structures.

Determining the drivers of key ecological processes of commercial marine species is important to acquire basic and essential knowledge for fisheries management and conservation. Here we report on a long-term monitoring of the settlement of the European spiny lobster, Palinurus elephas, the most commercially important spiny lobster species in the Mediterranean and north-eastern Atlantic. Densities of recently settled individuals (early benthic juveniles –EBJs) were recorded annually, as an approximation to annual settlement, from 2000 to 2016 (17 years) in three zones of the north-western Mediterranean: Catalonia (CAT), the Columbretes Islands (COL), and the Balearic Islands (BAL). Settlement, the end point that integrate most of the variability occurred during dispersion, is a complex ecological process governed by the interaction of biotic and abiotic factors that can be in turn influenced by the atmospheric and oceanographic conditions. Using linear regression of the size structure of EBJs, we demonstrate that settlement occurs synchronously in the three study zones. Densities of EBJs were handled as time series, and regression analysis revealed that CAT and COL covaried significantly, but none of them with BAL. Therefore, CAT and COL were analysed together using generalized linear model and much of their joint variability was explained by the mesoscale oceanographic index IDEA. Settlement in BAL showed a different pattern, explained by the joint effect of the atmospheric oscillations NAO and WEMO. Complexity of P. elephas settlement cannot be fully accounted neither for CAT-COL nor for BAL because settlement seems be driven by more complex unknown multi-factorial processes. Therefore, further studies are necessary to gain insight into other factors that allow short-or medium-term predictions of settlement. Expanding the study area across the Mediterranean would also allow establishing a complete knowledge of the ecology of the species applicable to the management of the fishery., RECMARE, Recuperación de una poblacion explotada en una nueva area protegida adyacente a una reserva marina efectiva, SI

The spiny lobster, Panulirus argus, is an ecologically relevant species in shallow water coral reefs and a target of the most lucrative fishery in the greater Caribbean region. This study reports, for the first time, the heart + hemolymph transcriptome of the Caribbean spiny lobster Panulirus argus assembled from short Illumina 150bp PE raw reads. A total of 80,152,094 raw reads were assembled using the Oyster River Protocol pipeline. The assembly resulted in a total of 254,773 transcripts. Functional gene annotation was conducted using the software package 'dammit'. Lastly, gene enrichment analyses were conducted using the Gene Ontology (GO) and KEGG pathway (Kaas) databases. This resource will be of utmost importance in future research aiming at exploring the effect of local and regional anthropogenic disturbances, as well as global climate change on the molecular physiology of this overexploited species.

Declines in Panulirus echinatus Smith, 1869 populations along their wide distribution in the Atlantic Ocean have spurred efforts to improve their fisheries management and conservation. In this study, the genetic structure of these populations is reported for the first time. In a survey of 18 species-specific polymorphic microsatellite markers, 152 individuals were genotyped from five Atlantic oceanic islands, covering most of the insular distribution range of the species. The analyses revealed that P. echinatus is genetically partitioned into two stocks in the Atlantic Ocean. A highly significant genetic structure was observed between north-east and south-west Atlantic populations based on fixation index, discriminant analysis of principal components, and structure and barrier analysis. We suggest that the Equatorial Circulation System represents a biophysical barrier that effectively limits migration among Atlantic subtropical gyre systems, as has been described for other species. Other physical and ecological barriers, such as the Mid-Atlantic Ridge itself, the distance between the eastern and western sides of the Atlantic (Mid-Atlantic Barrier) and water mass differences, as well as other biological aspects, may also influence larval dispersal and modulate the insular distribution of this species. The results show the existence of two distinct genetic stocks of P. echinatus and have implications for fisheries management in the Atlantic Ocean, including their independent management according to their individual status. The Cabo Verde and the Canarian populations (north-east Atlantic) showed the lowest level of genetic variability in comparison with the south-western populations. A combination of factors that have occurred or are occurring in the Canary Islands, such as overfishing and volcanic eruptions, is likely to explain the reduced abundance of this lobster species in the area., This study forms part of the doctoral thesis of the first author JCG, who was supported by a grant from Coordenaçao de Aperfeiçoamento de Pessoal de Nível Superior (CAPES – process no. 88881.132819/2016-01), Brazil. This work was also supported by Aquawork, S.L., Elittoral, S.L.N.E., the Division for the Protection of the Sea of the Ministry of Agriculture and Fisheries, Food and Environment for the service contract “Genetic analysis of the species Panulirus echinatus” (grant reference: 28-5249) and “Ejecución de acciones de conservación de la langosta herreña (Panulirus echinatus) y redacción del plan de recuperación”, and partially by a project of the Spanish Ministry of Economy and Competitiveness (CTM2014-57949-R).

The Caribbean spiny lobster Panulirus argus supports important fisheries throughout the greater Caribbean and is also the only known host for the pathogenic virus Panulirus argus virus 1 (PaV1). While discovered nearly 2 decades ago, gaps still exist in our knowledge of PaV1, such as the dose required to establish infection and its viability outside of the host. To help answer such questions and to enhance diagnostic capabilities, we developed a TaqMan real-time quantitative polymerase chain reaction (qPCR) assay for PaV1. Of the advantages offered by qPCR, one of the most important benefits is its ability to accurately quantify viral DNA copies in a clinical sample. The qPCR assay was found to be efficient (mean ± SD: 99.19 ± 4.67%) and sensitive, detecting as few as 10 copies of PaV1 plasmid DNA. Its diagnostic sensitivity and specificity determined using a set of 165 lobster samples (138 from Florida, USA, and 27 from across the Caribbean) were 100 and 84%, respectively. The qPCR assay should thus prove useful as a research tool and for detecting and quantifying PaV1 infection severity in Caribbean spiny lobsters.

While the California spiny lobster (Panulirus interruptus) is an important commercial and recreational fishery species in California, there is a lack of data on bioaccumulation for the species. This study examined pollutant tissue concentrations in lobsters from San Diego Bay, California. Observed lobster pollutant tissue concentrations in tail muscle were compared to State of California pollutant advisory levels. Concentrations were then used to conduct risk assessment using catch data from the California Department of Fish and Wildlife. Study results found little bioaccumulation of organic pollutants in tail tissue, likely due to low observed lipids. Mercury was present, predominantly in methyl form, at concentrations above advisory levels. Recreational catch data for San Diego Bay showed increased non-cancer risk for fishers at the 90th percentile or greater of reported annual catch. Further studies should focus on non-tail tissues, as exploratory whole lobster samples (n = 2) showed elevated organic pollutants and metals.

We found 158 juvenile Caribbean spiny lobsters (Panulirus argus) recruiting over a year into 10 artificial shelters in shallow (2-3 m) seagrass beds, but none recruiting into 10 shelters on deeper (approximately 10 m) hard bottom. Spiny lobster juveniles were observed at 10 m or greater depth in submerged fish cages. They may have been strained out by currents rather than naturally recruiting. A large number of these cages inshore could impede natural lobster recruitment. One of the shallow shelters recruited most (85/158) of the juveniles and two shelters recruited most of all (118/158). With no discernable natural habitat difference, we assume that early recruitment into those shelters and the “guide effect” may have been responsible for these preferences. Previous Caribbean studies found the maximum settling periods of juveniles in August to December. Our results were similar with the exception of having more recruits one month later (August to January). Shelters with covers had more juveniles than those without covers; however, this result was largely due to the preponderance of juveniles in one shelter.

The Rio Grande Rise (RGR) is a volcanic topographic structure of the Southwest Atlantic basin that rises over 3000 m from the seafloor and is located half way between the Brazilian continental margin (~ 30°S latitude) and the Mid-Atlantic Ridge. Previous records of decapods at the RGR are uncertain or non-existent. The observations and material examined here were collected by the manned submersible Shinkai 6500 during two dives to the plateau of the RGR main topographic feature, known as Alpha. Additional records were determined by analysing high-definition photos and videos obtained by the Shinkai 6500. Five species of deep-sea decapods were found: a Solenoceridae, Hymenopenaeus debilis Smith, 1882 previously sampled at the Brazilian slope; a Nematocarcinidae, Nematocarcinus parvus Burukovsky, 2000 previously unknown from the Atlantic Ocean; a Parapaguridae, Strobopagurus gracilipes (Milne-Edwards, 1891); a rare Palinuridae, Projasus parkeri (Stebbing, 1902); and the brachyuran Chaceon sanctaehelenae Manning & Holthuis, 1989 that were never sampled in the western Atlantic Ocean. The results show that the RGR decapod fauna is rare, unknown and, in its great majority, distinct, at the species level, from that found at the South American slope. At the genus and family levels, however, we can observe similarities between the RGR decapod fauna and that recorded on the South American slope. Unique exploration initiatives such as this can improve significantly the knowledge on western Atlantic deep-sea biodiversity and contribute to the understanding of deep-sea biogeography.

There is a critical knowledge gap regarding the impacts of seismic air gun signals on the physiology of adult crustaceans. We conducted four controlled field experiments to examine the impact of seismic acoustic signals on spiny lobster, Jasus edwardsii. Seismic air gun exposure suppressed total haemocyte count (THC) for up to 120 days post-exposure, suggesting a chronic negative impact of immune competency. THC levels after 365 days post-exposure, were elevated two fold, potentially indicating an immune response to infection. Haemolymph refractive index was reduced after 120 days post exposure in one experiment, suggesting a chronic impairment of nutritional condition. There was no effect of air gun exposure on 24 haemolymph biochemical parameters, hepatopancreas index or survival. Collectively these results indicate that the biochemical haematological homeostasis of J. edwardsii is reasonably resilient to seismic acoustic signals, however, air gun exposure may negatively influence the lobster's nutritional condition and immunological capacity.

The literature on late-stage larval and puerulus settlement of tropical spiny lobsters suggests that a broad range of visually-assessed variables may play a role in the selection of settlement substrates. These variables include light level, luminosity, degree of exposure, and the availability of edges, crevices and clefts. A fishery has developed in Indonesia, that captures pueruli for grow-out purposes, along the entire southern coastline from Java to Sumbawa. The present study builds on knowledge gained on the behaviour and substrate preferences of settling pueruli by examining aspects of collector design and substrate surface characteristics in regard to catch rates. A series of tank-based experiments were used to examine preferences for various attributes of collector materials, and preferred material characteristics were then tested in a field experiment to verify the laboratory results. In the tank experiment the most preferred substrate was cement bag paper, followed by insect mesh, weed netting, PVC rubber and cement bag plastic. Crevice angles of 10° and 20° were significantly preferred over 30°. The substrate level and other substrates had less influence on settlement. However, both the lunar phase and type of materials tested in the field had a significant effect on settlement. Significantly greater numbers of pueruli were caught at the time of the new moon than at other moon phases. Cement bag paper was the most preferred material in the field, followed by cement bag plastic, insect mesh, weed fabric, and PVC rubber.

The spiny lobster Panulirus pascuensis stands out among the endemic species of Easter Island, due to its cultural and economic importance. A total of 16 microsatellite loci were characterized in 18 individuals, 9 of which were polymorphic. The mean number of alleles per locus was 3.44 (2-6) and the observed heterozygosity ranged from 0.11 to 0.93. None of the loci exhibited significant linkage disequilibrium or departures from HWE. These new microsatellites will be used to obtain information about migration, population structure and genetic diversity of P. pascuensis in order to improve the future sustainable management and conservation plans.

Panulirus argus virus 1 (PaV1) affects wild populations of Caribbean spiny lobsters. PaV1 can be lethal but shows predilection for juvenile lobsters. Because P. argus is one of the most valuable fisheries around the wider Caribbean region, monitoring disease prevalence in local populations is desirable. Diseased lobsters are easily recognized by their milky hemolymph, but this sign only becomes evident in advanced stages of infection. Other methods have been developed to detect PaV1, but are less practical for long-term monitoring of patterns of infection in populations. A previous study estimated the validity measures (sensitivity and specificity) of detection of PaV1 infection by observed clinical signs against endpoint PCR assays, using a representative sample of lobsters comprising mainly subadults and adults from a commercial fishing area. In the present study, these validity measures were estimated in a similar manner for a different population comprising mainly juveniles from a protected nursery area. We obtained virtually the same sensitivity and specificity values (0.48 and 1, respectively) for observed clinical signs as in the previous study (0.51 and 1, respectively), confirming the validity of applying a simple 2× correction factor to monitor the patterns of PaV1 infection over time based on more easily conducted visual assessments of a representative sample of the population.

The Caribbean spiny lobster Panulirus argus (Latreille, 1804), previously considered to range from North Carolina, USA, to Rio de Janeiro, Brazil, and throughout the wider Caribbean region, was recently divided into two species based on morphology and coloration: Panulirus meripurpuratus Giraldes & Smyth, 2016 in Brazil, and P. argus north of the Amazon-Orinoco River plume. Here we report on the presence of two individuals of P. meripurpuratus and four of Panulirus laevicauda (Latreille, 1804), another species typical of Brazil, in Bahia de la Ascension, Mexico. This bay is located in the area where the Caribbean current - the main route by which South Atlantic water can reach this coast after entering the Caribbean basin through the Lesser Antillean passages - impinges the Mexican Caribbean coast before turning north to give rise to the Yucatan Current. The potential for larval retention is increased in this area, potentially explaining the episodic occurrence of Brazilian spiny lobster species in Bahia de la Ascension.

International audience; Spiny lobsters (Palinuridae) are capable of emitting sounds called antennal rasps. In the bioacoustics literature, such broadband sounds have mostly been characterized from tank recordings where reverberation and resonant frequencies might strongly distort their features. Hence, in this study, we compared antennal rasps produced by European spiny lobsters Palinurus elephas in both tank and in situ conditions. We found significant differences in all sound features (temporal, intensity and spectral features) between tank and in situ recordings, confirming that antennal rasps-and broadband sounds generally -cannot be accurately characterized in tanks if sound reverberation is ignored. In recordings of antennal rasps made in situ, we show that the main acoustic power is located in the low frequency band (below 1 kHz), which was missed by all earlier studies done in tanks where such low frequencies cannot be properly measured. The hearing capacities of crustaceans suggest roles for intra-specific communication of these sounds, and their high levels indicate they could be heard above noise. Indeed, we outline that antennal rasps are among the loudest sounds known in the marine animal kingdom, with peak-to-peak sound pressure levels (calculated at 20 cm from the source) above 175.7 dB re 1 mu Pa-2, and peak-to-peak source levels (estimated at 1 m from the source) ranging from 154.2 to 160.6 dB re 1 mu Pa-2. These acoustic properties imply they could be detected in situ during passive acoustic monitoring. This study also highlights the importance of using appropriate measurement methods when characterizing sounds produced by marine invertebrates.

Este artículo contiene 8 páginas, 4 figuras, 2 tablas., The phyllosoma larva of spiny and slipper lobsters (Palinuridae and Scyllaridae respectively) can disperse during several months before metamorphosing into a decapodid stage, which is the key phase for a successful settlement. The largest Scyllarus decapodid known to date was recently collected near the Canary Islands and identified by DNA analysis as Scyllarus subarctus. This species had never been previously reported from the area, and the decapodid stage is described here for the first time. The examination of further museum specimens has now significantly expanded the current distribution of S. subarctus, including much of the NW African coast, St Helena and Canary Islands. These results highlight the importance of combining molecular analysis of recently collected specimens with historical collections., This research was funded by projects CETOBAPH (CGL2009-1311218) and POPCOMICS (CTM2017-88080) of the Spanish Government and EU-Synthesys grants (DK-TAF-4873: Morphological study of Achelata lobsters and phyllosoma larvae from Danish collections; DE-TAF-7058: Achelata lobsters from the Museum für Naturkunde and FR-TAF-5980: Description of phyllosoma stages of West-African lobster species). FP acknowledges project FP7 Marie Curie IAPP #324475 ‘Colbics’ of the European Union and a post-doctoral contract funded by the Beatriu de Pinos Programme of the Generalitat de Catalunya.

Fishery landings composition in tropical developing countries is formed of high diversity of species and some of them are not well-reported in landings or national fisheries statistics. This is particularly the case of the endemic red spiny lobster Panulirus penicillatus (Olivier, 1791) on the Pacific coast of Costa Rica. The red spiny lobster is a circumtropical species which has the most extensive global distribution of all the species of spiny lobsters. In order to fill the gap of knowledge regarding the spatial distribution of this species in the eastern Pacific Ocean and highlight its importance to fishing communities, this study focused on data collected from a dive-based bentho-demersal fishery on the northern Pacific coast of Costa Rica. Environmental and fishing effort data were recorded as an input for fitting site-occupancy models to get estimates of occurrence and probability of detection. The most parsimonious model structure for detection suggested that the covariates of diving time and water column visibility had an important effect on detection probability. For the occupancy part of the model, the depth gradient had the strongest effect, with high probability of lobster encounters in shallow rocky reefs near the coastline. These findings point towards an enlargement of the area of occurrence of the endemic sub-population of P. penicillatus to which sampled animals belong. Further, it is discussed potential ecological and fishery factors that explain the low occurrence of the red spiny lobster at this restricted area of the eastern Pacific continental shelf. As a result, a set of research guidelines and management recommendations are suggested for promoting the conservation and sustainable use of this endemic species within the region.

This study presents results on the collection of Panulirus inflatus pueruli in seaweed (GuSi; set at the surface) and crevice (Booth: set on the bottom) collectors from April to December 1998 in waters of the southeastern Gulf of California, Mexico. The collectors were deployed at two sites in Mazatlán Bay. A total of 15 pueruli and 26 post-pueruli were collected, of which 4 postpueruli were found in crevice collectors from 10 inspections. Examination of the crevice collectors was difficult because weather conditions made sampling problematic during the year in this zone. Seaweed collectors caught 37 pueruli in 91 observations. Most of the pueruli from these collectors were caught between April and June, with a peak settlement in May (19) and a mean surface water temperature of 24.4°C. The highest catch per unit of effort was 1.36 pueruli per collector per week in May, followed by April (0.33) and June (0.31). Statistical tests showed no significant differences among the moon phases, although the number of pueruli was higher during the first quarter. This is the first record of P. inflatus pueruli in the southeastern Gulf of California on specifically designed collectors.

The deep-sea lobster Palinustus unicornutus Berry, 1979 is reported for the first time from Taiwan, with the largest male and female ever recorded for the species. Additional material of this rare species showed that many distinguishing characters previously suggested for this species are actually variable and its characteristics are re-diagnosed.

Indonesia has a unique opportunity to establish the world's largest lobster aquaculture industry, based on a significant natural resource of settling puerulus. These seed lobsters can be captured and on-grown to generate high value, consumption size lobsters. However, existing fisheries regulation prohibits fishing of these seed lobsters in Indonesia. Nevertheless, seed fishing occurs widely, and the seed are smuggled into Vietnam, where the Vietnamese gain most of the commercial benefit. By removing access to pueruli and grow-out opportunities, these regulations have diminished the capacity of Indonesian lobster farmers to develop a sustainable grow-out industry. Although the new policies were introduced as a management intervention to protect adult lobster stocks, they have had the unintended consequence of preventing development of lobster aquaculture while having no known benefit on abundance of adult lobsters. This study collected data on the puerulus available in Indonesia, species composition, seasonality, and capture methods. A census of seed capture determined that 5,243,887 pueruli were fished from two bays in the southeast of Lombok in 2014, representing 64,787 pueruli per km2. Surveys beyond Lombok determined there was high abundance of seed in areas with similar environmental characteristics, where local communities had also engaged in seed fishing. The locations identified as having substantial puerulus abundance comprised the southern coast of Java, Bali, Lombok and Sumbawa covering a distance of 1500 km. Puerulus abundance is highest in enclosed bays with distinct currents, relatively high turbidity attributable to terrestrial inflows, and muddy/sandy substrates. Satellite imaging identified all such suitable locations for puerulus settlement, enabling an estimate of total puerulus catch of 103,480,283 per year. The composition of puerulus fished consisted of two species, Panulirus homarus and P. ornatus. P. homarus was most abundant representing between 63 and 87%, while P. ornatus represented 37 to 13%. Seasonality of catch was unclear, with low catch between December and March and higher catches from April to November. The magnitude of the estimated puerulus resource of Indonesia is >20 times greater than that of Vietnam. If used for aquaculture, the seed available can support an industry generating >12,500 t of market size lobster, and provide social and economic benefit to many thousands of households. To achieve this, fisheries policies could be revised and a regulatory framework established to manage the puerulus fishery and support lobster farming. Tropical marine rock lobster aquaculture is a major opportunity for high-value aquaculture production for the Indonesian economy.

Spiny lobster post-larvae undertake an extensive migration from the open ocean to the coast, during which time their swimming is fueled solely by energy reserves accumulated through their preceding larval phase. We assessed the influence of future ocean temperatures on the swimming behavior and energy use of migrating post-larvae of Sagmariasus verreauxi, by experimentally swimming post-larvae for up to 6 days at three temperatures and measuring the lipid and protein used, and observing their time spent actively swimming. Increasing the temperature from 17 °C to 23 °C doubled the energy utilized by post-larvae while swimming, while also reducing the time they spent swimming by three times. Therefore, increasing ocean temperatures appear to greatly affect the energetic cost and efficiency of shoreward migration of post-larvae in this lobster species, with the potential to markedly impact post-larval recruitment into coastal populations under future scenarios of ocean warming.

Tail fan necrosis (TFN) is a common condition found in commercially exploited spiny lobsters that greatly diminishes their commercial value. Bacteria possessing proteolytic, chitinolytic and lipolytic capabilities were associated with TFN in spiny lobsters, Jasus edwardsii. In this study, 69 bacterial isolates exhibiting all the three enzymatic capabilities from the haemolymph and tail fans of J. edwardsii with and without TFN were further characterized and compared, including morphology, biofilm formation, antimicrobial activity, antimicrobial resistance, and production of siderophores, melanin and ammonia. The genomic patterns of the most common Vibrio crassostreae isolates were also compared between TFN-affected and unaffected lobsters. Biofilm formation was stronger in bacterial isolates from both haemolymph and tail fans of TFN-affected lobsters compared to those from the unaffected lobsters, while melanin production and siderophore production were stronger in the isolates from tail fans of lobsters with TFN. By contrast, the other characteristics of isolates were similar in lobsters with and without TFN. The Vib. crassostreae isolates from the affected lobsters had similar genomic patterns. Overall, the results indicate that in addition to proteolytic, chitinolytic and lipolytic activities, the bacteria associated with TFN commonly have enhanced activity of important virulence factors, including biofilm formation, melanin production and siderophore production.

Bacteriocins are ribosomally synthesized antimicrobial peptides, which have been found in diverse bacterial species of terrestrial origins and some from the sea. New bacteriocins with new characteristics, new origins and new applications are likely still awaiting discovery. The present study screened bacteria isolated from marine animals of interest to the aquaculture industry for antimicrobial and bacteriocin-like activities in order to uncover biodiversity of bacteriocin producers, and explore the potential application in aquaculture. In total, 24 of 100 screened isolates showed antimicrobial activities and 7 of these exerted bacteriocin-like activities. Sequencing of 16S rRNA genes identified the isolates as members of the six genera Proteus, Providencia, Klebsiella, Alcaligenes, Bacillus and Enterococcus. In some cases, further analysis of housekeeping genes, rpoB for Proteus and recA for Klebsiella, as well as biochemical tests was necessary for identification to species level, and some of the Proteus isolates may represent novel species. The seven bacteriocinogenic isolates showed a wide antimicrobial spectrum against foodborne and animal pathogens, which opens the way to their potential use as marine drugs and probiotics in food, aquaculture, livestock and clinical settings. As a case study, the protective effect of shortlisted bacteriocinogenic isolates were tested in aquaculture-raised spiny lobster (Panulirus ornatus) juveniles. A single-strain (Bacillus pumilus B3.10.2B) and a three-strain (B. pumilus B3.10.2B, Bacillus cereus D9, Lactobacillus plantarum T13) probiotic preparation were added to the feed of Panulirus ornatus juveniles, which were subsequently challenged with the pathogen Vibrio owensii DY05. Juveniles in the probiotic treatments displayed increased growth and reduced feed conversion rates after 60 days, and increased survival rate after pathogen challenge relative to the control. This study represents the first evidence of bacteriocin production by bacteria associated with lobster, tiger shrimp, snubnose pompano and cobia and the first description of V. owensii as a pathogen in P. ornatus juveniles.

Dietary supplementation with mannan oligosaccharide (MOS) has been demonstrated to provide significant benefits to growth and health of many species of fish and crustaceans. An investigation was made to assess the effect of MOS supplementation on the diet of the tropical lobster Panulirus homarus. The aim of the study was to test the effect of various dietary inclusion levels of MOS on growth, survival rate, intestinal morphology and bacterial abundance, haemocyte make-up, and tissue composition of P. homarus lobsters. A manufactured, semi-moist diet was used as a basal diet and supplemented with 0.2%, 0.4%, 0.6% and 0.8% MOS inclusion, and fed to lobsters with an initial mean weight of 0.16 g for 56 days. A typical fishery bycatch mixture was used as a reference control diet. Growth rate of lobsters was significantly higher for those fed diets supplemented with 0.4 and 0.6% MOS than those fed an un-supplemented diet or bycatch. Survival rates of lobsters ranged from 68 to 78%. The survival rate was significantly higher in lobsters fed diets with 0.2% and 0.4% MOS supplementation and bycatch, compared with those fed the basal or 0.6% MOS diet. There was no significant difference in differential haemocyte count of lobsters fed with various MOS levels or bycatch. The mid-gut surface area of lobsters fed diets supplemented with 0.2%, 0.4% and 0.6% MOS was significantly higher than that of lobsters fed on control, 0.8% MOS or bycatch. The total Vibrio count in the mid-gut of lobsters fed any MOS diet was significantly lower than that of lobsters fed either the control or the bycatch diet. There was no significant difference in protein, lipid or ash content in lobsters fed the different diets. There were significant correlations between concentrations of MOS in diets and lobster growth rates. Optimal MOS concentration was estimated to be 0.69% at day 14 (R2 = 76.79%), 0.55% at day 28 (R2 = 88.18%), 0.48% at day 42 (R2 = 97.72%) and 0.47% at day 56 (R2 = 94.42%), demonstrating a decreasing requirement for MOS with increasing lobster size. In conclusion, mannan oligosaccharide supplementation appears to be effective for improving growth, survival and gastro-intestinal health of the lobster, P. homarus.

Many marine species are predicted to shift their ranges poleward due to rising ocean temperatures driven by climate change. For benthic marine species with pelagic larval stages, poleward range shifts are often facilitated through pelagic larval transport via western boundary currents (WBC). By surveying pelagic larval distributions within WBCs, species advected poleward of their known distributions can be identified and monitored. Palinurid and scyllarid lobster larvae (phyllosoma) have long pelagic larval durations, providing high potential for poleward advection. We surveyed spatial distribution of phyllosoma within the western-boundary East Australian Current. Due to difficulties morphologically identifying phyllosoma, we tested the utility of molecular identification using cytochrome c oxidase I (COI). From COI sequences of 56 phyllosoma and one postlarva, 65% of sequences consisted of good-quality mitochondrial DNA. Across water types sampled, scyllarid phyllosoma exhibited relatively homogeneous distribution, whereas palinurid phyllosoma exhibited heterogeneous distribution with greatest abundance inside a warm core eddy on the south coast of eastern Australia. Two tropical and one subtropical palinurid species were detected ~75–1800km to the south or south-west of their known species distribution. Our results indicate tropical lobster species are reaching temperate regions, providing these species the opportunity to establish in temperate regions if or when environmental conditions become amenable to settlement.

In Bahia de la Ascension in Mexico, the Caribbean spiny lobster Panulirus argus fish- ery is based on extensive use of artificial shelters (casitas) that can harbor both juveniles and adults of this highly gregarious species. There is concern that the use of casitas might increase contact transmission of Panulirus argus virus 1 (PaV1). However, a previous study found no evi- dence for lobster crowding within casitas influencing the prevalence of clinical PaV1 disease, although differences in clinical prevalence were noted between different bay environments. To investigate this more closely, 683 lobsters were sampled from casitas in 2 zones in this bay (Vigia Chico, a shallow low-vegetation zone, and Punta Allen, a deeper dense-vegetation zone) previ- ously found to have the lowest and highest prevalence, respectively, of observed clinical signs. When hemolymph collected from these lobsters was tested by PCR, the prevalence of PaV1 infec- tion was found to be significantly lower in Vigia Chico relative to Punta Allen irrespective of sea- son or the size, sex, or presence of shell injuries on lobsters. Among 714 large commercial-catch lobsters collected throughout the bay, the prevalence of infection was low irrespective of year or sex. For all lobsters tested, the sensitivity (0.510) at which PaV1 infection was detected by observed clinical signs was about half that determined by PCR, but the specificity of clinical signs was absolute (1), indicating that a simple 2× correction factor can be used to accurately estimate PaV1 infection prevalence based on more easily conducted visual assessments of lobsters.

The morphometric relationship of carapace length (CL) to tail width (TW) of southern rock lobster (Jasus edwardsii) was determined to assist enforcement of existing minimum size limits and also to enable the development of an upper size limit in Tasmania. Data were collected from southern rock lobsters in the wild and at processors and used to develop a system for measuring TW which reduces measurement error. Linear regression was used to define the relationship between CL and TW for males (TW = 0.4107x+14.058, R2=.9236, n=1003) and females (TW=0.5756x+2.2884, R2=.9323, n=503). Logistic regressions provide the TWs associated with the probability (0.5, 50 and 95%) of a lobster having a carapace equal to or more than the theoretical size limits. Regional differences in the morphometric relationship were evident but would not prevent the use of size limit based on TW if a conservative probability value were used.

The ability of lobsters to recover from stress is an important factor influencing growth and survival in aquaculture; however, there is limited information on the metabolic responses of spiny lobsters to stress. This study determined oxygen consumption rate ( M ˙ O 2 ) and ammonia-N excretion of juvenile spiny lobsters Sagmariasus verreauxi in response to handling, anaesthesia, anaesthesia then force feeding, and exercising to exhaustion in order to determine the recovery time and amount of oxygen required to recover from common sources of stress in aquaculture. Lobsters required 0.29 ± 0.24 mg O2 g DM− 1 over a period of 2.5 ± 1.40 h to recover from handling. Anaesthesia with 2-phenoxyethanol immobilised lobsters but they required 0.72 ± 0.36 mg O2 g DM− 1 over a period of 4.5 ± 1.77 h to recover, indicating that 2-phenoxyethanol causes substantial stress. Force feeding lobsters anaesthetised with 2-phenoxyethanol or clove oil did not result in a higher increase of M ˙ O 2 compared to 2-phenoxyethanol anaesthesia alone. Recovery from exercise to exhaustion required 1.84 mg O2 g DM− 1 over a period of 10.17 ± 0.70 h. Ammonia-N excretion, measured 24 h post-treatment, and atomic O:N ratios were not significantly different between treatments and indicated lobsters in all groups had reached the same level of recovery 24 h post-treatment. Overall, the study demonstrated that lobsters recover rapidly from handling. Conversely, the increase in M ˙ O 2 induced by 2-phenoxyethanol demonstrated this is not an effective anaesthetic for reducing recovery periods and physiological stress associated with handling. However, 2-phenoxyethanol and clove oil eliminated further stress associated with force feeding, indicative of an invasive research procedure. Exercise to exhaustion resulted in the largest magnitude increase in M ˙ O 2 and longest recovery period. It is therefore recommended that aquaculture handling procedures take precautions to limit activity and are carried out without anaesthesia to facilitate more rapid recovery of lobsters.

The pathogenic virus Panulirus argus virus 1 (PaV1) was first discovered in Caribbean spiny lobsters Panulirus argus from the Florida Keys (USA) in 1999 and has since been reported in Belize, Mexico, and Cuba; its distribution in the wider Caribbean is unknown. We col- lected tissue samples from adult spiny lobsters from 30 locations in 14 countries bordering the Caribbean Sea and used molecular diagnostics to assay for the presence of PaV1. PaV1 occurred primarily in the northern areas of the Caribbean, where its prevalence was highest. The virus was not found in lobsters from the southeastern Caribbean, and its prevalence was lowest in the south- western Caribbean. DNA sequence analysis was performed on a fragment of the viral DNA to examine the genetic diversity of PaV1 on a Caribbean-wide scale. Sequence variation in the viral DNA fragment was high, with 61 unique alleles identified from 9 areas. The sharing of viral alleles in lobsters from distant locations supports the hypothesis of a strong genetic connectivity among lobsters within the Caribbean, and further supports the hypothesis that postlarvae infected with PaV1 may serve to disperse the virus over long distances.

Mass propagation of spiny lobster phyllosoma is a critical bottleneck for the development of spiny lobster aquaculture. Eastern spiny lobster Sagmariasus verreauxi has been identified as a good candidate for temperate culture with a relatively short life cycle lasting 6 to 8 months and 17 stages. We investigated the development and functionality of the filter-press of S. verreauxi phyllosoma to better understand the size and quantity of dietary particles ingested over the entire larval cycle. Filter-press morphometrics were obtained from live phyllosoma larvae throughout development, and filtration capacity was ascertained using fluorescent microspheres and the rare earth metal markers yttrium oxide and ytterbium oxide. The filter-press of phyllosoma larvae was fully functional from stage 3, fully developed from stage 4, and the numbers (8 to 50), lengths (79 to 384 μm), and widths (14.8 to 20.3 μm) of food grooves increased with the development stage to accommodate a larger volume of ingested food. In contrast, there was no change in the widths of the lower ampullary setae (1.28 ± 0.16 μm) or the widths of the gap between these setae (0.91 ± 0.07 μm). Lower ampullary setae were arranged in a single layer perpendicular to the food grooves and restricted the entry of food particles into the digestive gland. From stage 3, the filter-press selectively excluded more than 99% of particles of > 1 μm from reaching the digestive gland and demonstrated that only particles of ≤ 1 μm are available for digestion. In the absence of a gastric mill, phyllosoma larvae have no obvious structure for internally grinding prey and the present study shows that phyllosoma larvae are well adapted to feed from the body fluids of wild preys over their entire larval cycle. The results have important practical applications for the development of formulated feeds for spiny lobster larvae.

The seasonal brood size of the spiny lobster Panulirus gracilis in Mexican waters (southeastern Gulf of California) was estimated for 259 ovigerous females caught in commercial tangle nets at depths ranging from 8-25 m during spring, summer, fall, and winter between March 1993 and March 1994. The number of eggs per individual ranged from 76,727 eggs for a 60.0-mm carapace length (CL; 250 g total weight (TW)) female to 1,115,060 for a 80-mm CL (510 g TW) female. A brood size (BS) value was estimated from replicate counts and was found to vary with CL and TW according to the relationships BS ¼ 0.6803CL 3.1007 (R 2 ¼ 0.5203) and BS ¼ 1236.7TW - 35548.9 (R 2 ¼ 0.5781), respectively. The smallest egg-bearing female was 50.3 mm in CL. Significant differences were found in seasonal brood sizes, with lower values during the winter than during the remaining seasons. Egg loss during the incubation period was estimated at 7.9%.

The Caribbean spiny lobster, Panulirus argus, is a migratory crustacean that uses Earth's magnetic field as a navigational cue, but how lobsters detect magnetic fields is not known. Magnetic material thought to be magnetite has previously been detected in spiny lobsters, but its role in magnetoreception, if any, remains unclear. As a first step toward investigating whether lobsters might have magnetite-based magnetoreceptors, we subjected lobsters to strong, pulsed magnetic fields capable of reversing the magnetic dipole moment of biogenic magnetite crystals. Lobsters were subjected to a single pulse directed from posterior to anterior and either: (1) parallel to the horizontal component of the geomagnetic field (i.e., toward magnetic north); or (2) antiparallel to the horizontal field (i.e., toward magnetic south). An additional control group was handled but not subjected to a magnetic pulse. After treatment, each lobster was tethered in a water-filled arena located within 200 m of the capture location and allowed to walk in any direction. Control lobsters walked in seemingly random directions and were not significantly oriented as a group. In contrast, the two groups exposed to pulsed fields were significantly oriented in approximately opposite directions. Lobsters subjected to a magnetic pulse applied parallel to the geomagnetic horizontal component walked westward; those subjected to a pulse directed antiparallel to the geomagnetic horizontal component oriented approximately northeast. The finding that a magnetic pulse alters subsequent orientation behavior is consistent with the hypothesis that magnetoreception in spiny lobsters is based at least partly on magnetite-based magnetoreceptors.

The present study compares 13 physiological and immunological variables between a group of healthy Panulirus argus lobsters and a group of lobsters naturally infected with Pan- ulirus argus Virus 1 (PaV1). Viral infection was determined through histopathology and PCR. Ten of the 13 variables differed significantly between the 2 groups. Using these variables, a principal component analysis yielded 2 separate clusters: one corresponding to the healthy group and the other corresponding to the infected group. In particular, infected lobsters exhibited significantly lower levels of osmotic pressure, total hemocyte counts, plasmatic proteins, and total phenoloxi- dase (PO) activity in plasma, as well as significantly higher levels of cholesterol and acylglyc- erides. These features are consistent with metabolic wasting, hyperlipidemia, and presumed immune suppression. Infection with PaV1 appears to increase the susceptibility of lobsters to some other opportunistic pathogens, as 61.1% of infected lobsters presented infestations of ciliate epibionts (Epystilis and Zoothamniun) in the gill chamber compared with 11.5% lobsters in the healthy group. Infected lobsters also showed significantly higher levels of total PO activity in degranulated hemocytes and trypsin inhibitor activity, potentially indicating activation of immune response by the PO system during the systemic infection with PaV1.