Spiny Lobster Species Research Articles

Occurrence of Panulirus meripurpuratus and Panulirus laevicauda (Decapoda: Achelata: Palinuridae) in Bahia de la Ascension, Mexico

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.

Genetic biodiversity of spiny lobsters (Panulirus spp.) from coastal waters of Southern Java, Indonesia

Abstract. Haryono FED, Ambariyanto. 2018. Genetic biodiversity of spiny lobsters (Panulirus spp.) from coastal waters of Southern Java, Indonesia. Ocean Life 2: 73-78. Spiny lobsters of the genus Panulirus inhabit the southern Java, however, species identification of early life-stages based on morphological features analysis is equivocal. The condition as result of differences in morphology of the larval stage and the adult, a long period of larval life cycle, impact of oceanographic currents inhibit and restrict the route and direction of larval dispersal that causes genetic changes. However, genetic biodiversity of spiny lobsters from this area has not been investigated. The aim of this/our study was to identified genetic diversity of lobsters in Southern Java waters. The research was conducted from January through to August 2015. A total of 1137 lobsters were collected from seven different locations for morphological analyses and 40 lobsters were taken randomly for genetic analysis. Observations nuclear and mitochondrial DNA, and the relationships of genetic in phylogenetic using Codon of code and MEGA 5.0, and dendogram using Primer_e software. Morphological analysis obtained 6 species of spiny lobsters: P. homarus, P. versicolor, P. ornatus, P. penicillatus, P. polyphagus and P. longipes. Phylogenetic analysis obtained two clades and morphological identification results obtained P. penicillatus (spiny rock lobster), but the identification genetically acquired included in a group of genetic P. homarus (spiny sand lobster). Such discrepancies are possibly due to a long period of larval life, adult in low light of intensity environment and an extreme of oceanographic conditions with marine oil spill.

The influence of flesh ingredients format and krill meal on growth and feeding behaviour of juvenile tropical spiny lobster Panulirus ornatus

One of the main challenges for spiny lobster aquaculture is the successful development of formulated feeds that are attractive, readily consumed by lobsters and promote optimal growth and survival. In a 54-day growth trial, we investigated the performance of four moist formulated feeds containing A) non-homogenised flesh ingredients; B) fish meal only; C) 10% krill meal; or D) homogenised flesh ingredients; and a reference diet of shucked blue mussel (Mytilus galloprovincialis) flesh, on growth, nutritional condition and feeding behaviour of juvenile tropical spiny lobster (Panulirus ornatus) reared either communally or individually. Growth and survival achieved by lobsters fed mussel were significantly higher than all other treatments. However, lobsters fed the formulated feed containing 10% krill meal (treatment C) and reared communally had a significantly higher growth, survival and feeding performance when compared to the formulated feeds with inclusion of non-homogenised and homogenised flesh ingredients (treatments A and D). The highest levels of feed interaction and pellet consumption among the formulated feeds were also recorded for treatment C. We demonstrated that the inclusion of krill meal in formulated feeds provides a benefit when compared to the inclusion of the flesh ingredients. Flesh ingredient format (homogenised or non-homogenised) had no effect on growth performance of lobsters, suggesting that the process of homogenisation of flesh ingredients does not provide any benefit in promoting feed consumption. Furthermore, time-series photography analysis trials showed that all the formulated feeds only promoted a feeding response within the first 2–3 h post-feeding, whereas mussel retained its attractiveness throughout the feeding period. These results suggest that the prolonged attractiveness remains an impediment for formulated feed performance in lobster culture. The present study also showed that growth performance and feeding response were higher in lobsters reared communally than individually. As observed in other spiny lobster species, it is likely that social interactions in communal housing may have provided cues that stimulated feeding responses and promoted higher growth rates.

Can metamorphosis survival during larval development in spiny lobster Sagmariasus verreauxi be improved through quantitative genetic inheritance?

BackgroundOne of the major impediments to spiny lobster aquaculture is the high cost of hatchery production due to the long and complex larval cycle and poor survival during the many moult stages, especially at metamorphosis. We examined if the key trait of larval survival can be improved through selection by determining if genetic variance exists for this trait. Specifically, we report, for the first time, genetic parameters (heritability and correlations) for early survival rates recorded at five larval phases; early-phyllosoma stages (instars 1–6; S1), mid-phyllosoma stages (instars; 7–12; S2), late-phyllosoma stages (instars 13–17; S3), metamorphosis (S4) and puerulus stage (S5) in hatchery-reared spiny lobster Sagmariasus verreauxi.ResultsThe data were collected from a total of 235,060 larvae produced from 18 sires and 30 dams over nine years (2006 to 2014). Parentage of the offspring and full-sib families was verified using ten microsatellite markers. Analysis of variance components showed that the estimates of heritability for all the five phases of larval survival obtained from linear mixed model were generally similar to those obtained from threshold logistic generalised models (0.03–0.47 vs. 0.01–0.50). The heritability estimates for survival traits recorded in the early larval phases (S1 and S2) were higher than those estimated in later phases (S3, S4 and S5). The existence of the additive genetic component in larval survival traits indicate that they could be improved through selection. Both phenotypic and genetic correlations among the five survival measures studied were moderate to high and positive. The genetic associations between successive rearing periods were stronger than those that are further apart.ConclusionsOur estimates of heritability and genetic correlations reported here in a spiny lobster species indicate that improvement in the early survival especially during metamorphosis can be achieved through genetic selection in this highly economic value species.

Efficiency of ddRAD target enriched sequencing across spiny rock lobster species (Palinuridae: Jasus)

Double digest restriction site-associated DNA sequencing (ddRADseq) and target capture sequencing methods are used to explore population and phylogenetic questions in non-model organisms. ddRADseq offers a simple and reliable protocol for population genomic studies, however it can result in a large amount of missing data due to allelic dropout. Target capture sequencing offers an opportunity to increase sequencing coverage with little missing data and consistent orthologous loci across samples, although this approach has generally been applied to conserved markers for deeper evolutionary questions. Here, we combine both methods to generate high quality sequencing data for population genomic studies of all marine lobster species from the genus Jasus. We designed probes based on ddRADseq libraries of two lobster species (Jasus edwardsii and Sagmariasus verreauxi) and evaluated the captured sequencing data in five other Jasus species. We validated 4,465 polymorphic loci amongst these species using a cost effective sequencing protocol, of which 1,730 were recovered from all species, and 4,026 were present in at least three species. The method was also successfully applied to DNA samples obtained from museum specimens. This data will be further used to assess spatial-temporal genetic variation in Jasus species found in the Southern Hemisphere.

Dietary partitioning between sympatric species of spiny lobster in a coral reef system

Throughout the Wider Caribbean Region, the spotted spiny lobster, Panulirus guttatus (Latreille, 1804), dwells and forages exclusively in coral reef habitat after post-larval settlement, whereas its sympatric species, the Caribbean spiny lobster, Panulirus argus (Latreille, 1804), undergoes ontogenetic habitat shifts, with smaller individuals dwelling in reef lagoon habitats and larger individuals dwelling in reef habitats, but exhibiting broad foraging ranges. Stomach content, and carbon and nitrogen stable isotopes analyses were used to examine dietary partitioning between co-occurring P. guttatus and reef-dwelling P. argus in a coral reef system off Mexico. Both species fed on a wide variety of invertebrates, but mollusks contributed more to the diet of P. guttatus and crustaceans to the diet of P. argus. The two species had different ranges of isotopic composition and each filled a unique trophic position within the local food web. A Bayesian mixing model revealed a distinct contribution of different food sources to the diet of these lobsters. Reef herbivores were the primary food source for P. argus and an important food source for P. guttatus, but the latter also consumed more carnivores, resulting in a higher trophic position relative to P. argus. The isotopic niche space, delineated by means of bivariate ellipses, exhibited no overlap between species, and P. argus exhibited a significantly larger niche area than P. guttatus. These results suggest that, in addition to a differential use of habitat resources, a differential use of food resources facilitates the local coexistence of these two congeners.

Identification of taxonomic status of spiny lobster species in Sri Lanka Using DNA barcoding and its implications on fisheries and conservation programs

Lobster fishery is one of the most economically important marine coastal fishing activities. However, genetic identification and taxonomic status of available lobster species are poorly understood in Sri Lanka. The DNA barcoding based on the amplification of partial mitochondrial Cytochrome oxidase I (COI) gene region provides an effective approach for the rapid identification of species status and evaluation of species richness. The present study attempted to collect genetic information of barcoding region for five spiny lobster species that are available in the southern coast of Sri Lanka and to estimate the phylogenetic relationships with the data available for relevant spiny lobsters of other geographic locations. For this purpose, additional sequences were downloaded from the NCBI Genbank and phylogenetic trees were constructed using Maximum Parsimony, Maximum Likelihood and Neighbour Joining methods. Identical tree topologies were resulted from the three methods, and three major clades could be identified. The first clade consisted of Panulirus penicillatus + P. longipes. Panulirus homarus + P. versicolor + P. ornatus were grouped into the second clade whereas the third clade included P. homarus + P. penicillatus + P. longipes. It is important to observe that P. homarus samples collected from southern Sri Lanka grouped with both sub species P. h. homarus and P. h. megasculpta indicating their availability in the sampling regions. Although three subspecies are available in P. longipes the samples from southern Sri Lankan grouped only with P. l. longipes. High intra-specific nucleotide diversity was reported in for Sri Lankan samples. This indicates that habitats around southern coast of Sri Lanka possess suitable environmental conditions to inhabit diverse Panulirus populations. These results would be highly useful to plan management and conservation strategies for Panulirus populations in Sri Lanka. Tropical Agricultural Research Vol. 25 (1): 96-108 (2013)

Abnormal reproductive morphology in two species of spiny lobster: Jasus edwardsii and Jasus paulensis

Jasus edwardsiiandJasus paulensisare two species of spiny lobster that are distributed across south-eastern Australia and isolated islands of the southern Indian Ocean, respectively. We present rare examples of abnormal reproductive morphology in both species. ForJasus edwardsii, this included a female lobster captured in South Australia, which, in addition to the normal pair of gonopores at the base of the third pair of pereiopods, also exhibited a second a pair of gonopores on the coxopodites of the fourth pair of pereiopods. In Tasmania, a male individual exhibited the specialized pincer on the right propopodite, normally only observed in females. The frequency of abnormal morphological reproductive characteristics appeared higher inJasus paulensis. This included 14 individuals that exhibited a range of additional and abnormal gonopore locations in both males and females. We discuss the findings in relation to rare cases of gynandromorphism in crustaceans.

Isolation, characterization, and multiplexing of novel microsatellite markers for the tropical scalloped spiny lobster (Panulirus homarus)

Of the various spiny lobster species in the tropical and subtropical Indo-West Pacific region, the tropical scalloped spiny lobster (Panulirus homarus) supports one of the most commercially valuable fishery resources in many coastal African and Asian countries. The last decade has witnessed a serious decline in the wild populations of this species. Knowledge of the genetic basis of spiny lobster population structure is a prerequisite to achieve a sustainable fisheries management for this species. Here, we describe 13 novel polymorphic microsatellite markers developed for P. homarus, using a cross-species primer design strategy based on P. ornatus Roche 454 shot-gun generated sequencing. Microsatellite polymorphisms were assessed in 96 unrelated P. homarus individuals of a natural population, with the number of alleles per locus varying from 2 to 14, the observed and expected heterozygosity from 0.00 to 0.78 and from 0.03 to 0.79, respectively, and with only four loci (Pho-G27, Pho-G32, Pho-G36, and Pho-G58) deviating from Hardy- Weinberg equilibrium. Genetic linkage disequilibrium analysis between all pairs of the loci showed significant departure from the null hypothesis between loci Pho-G22 - Pho-G30, and Pho-G30 - Pho-G35. The successful cross amplification of these microsatellites highlights the potential of the developed microsatellites for future population genetic research within the different Panulirus species.

Mate choice in temperate and tropical spiny lobsters with contrasting reproductive systems

Abstract Sperm limitation of reproductive success is common in decapod crustaceans, favouring mating systems in which females compete for large males of high reproductive value. We investigated these phenomena in two species of spiny lobsters—one temperate, one tropical—with contrasting reproductive systems: the Southern Rock Lobster (Jasus edwardsii) and the Caribbean Spiny Lobster (Panulirus argus). We hypothesized that female mate selection should be more pronounced in the temperate J. edwardsii than in the tropical P. argus because J. edwardsii matures later, has a shorter mating season, and produces just one clutch of eggs per year that benefit from significant maternal investment of resources. As hypothesized, experiments conducted in large mesocosms revealed that female J. edwardsii cohabited with large males more often than expected by chance during their receptive period, but not at other times. Large male J. edwardsii cohabited in dens with the largest unmated females, whereas small males exhibited no mate size preference. In contrast, the proportion of female and male P. argus that co-occupied dens with the opposite sex was no more than expected by chance. Cohabitation patterns in the wild supported these laboratory findings for both species. Our results demonstrate the tight connection between contrasting reproductive strategies and the specificity of mate choice in spiny lobsters that are consistent with predictions based on environmental seasonality in temperate vs. tropical ecosystems.

Agonistic behaviour in juvenile southern rock lobster, Jasusedwardsii (Decapoda, Palinuridae): implications for developing aquaculture.

The Southern rock lobster, Jasus edwardsii, is a temperate species of spiny lobster with established well managed fisheries in Australia and New Zealand. It has also been under consideration as a species with aquaculture potential. Agonistic behaviour has important consequences under aquaculture conditions that encompass direct effects, such as damage or death of protagonists, and indirect effects on growth that relate to resource access, principally food and refuge. This study aimed to identify and characterize behaviours and to make a preliminary investigation of their occurrence under tank culture. Juvenile Jasus edwardsii were examined in a flow-through seawater system using a remote video camera system. Twenty-nine behaviours were divided into three sub-groups: aggressive (11), avoidance (6) and others (12). Aggressive behaviours included attacks, pushing, lifting, clasping and carrying an opponent. Avoidance behaviours included moving away in a backwards-, forwards- or side-stepping motion as well as with more vigorous tail flips. These behaviours were components of twelve behavioural groups that described contact, attack and displacement between individuals. Activity was crepuscular with two clear peaks, one in the morning and the other in the evening. The occurrence of behavioural groups was not different between the morning and evening. The frequency of aggressive behaviours was not affected by changes made to stocking density or access to food. The implications of agonistic behaviours are discussed further in relation to developing aquaculture.

Differences in life-history and ecological traits between co-occurring Panulirus spiny lobsters (Decapoda, Palinuridae).

Coexistence of closely related species may be promoted by niche differentiation or result from interspecific trade-offs in life history and ecological traits that influence relative fitness differences and contribute to competitive inequalities. Although insufficient to prove coexistence, trait comparisons provide a first step to identify functional differences between co-occurring congeneric species in relation to mechanisms of coexistence. Here, a comparative review on life history and ecological traits is presented for two pairs of co-occurring species of spiny lobsters in the genus Panulirus: Panulirus gracilis and Panulirus inflatus from the Eastern Central Pacific region, and Panulirus argus and Panulirus guttatus from the Caribbean region. Panulirus gracilis and Panulirus inflatus have similar larval, postlarval, and adult sizes and a similar diet, but differ in degree of habitat specialization, fecundity, and growth rate. However, little is known on behavioral traits of these two species that may influence their competitive abilities and susceptibility to predators. The more abundant information on Panulirus argus and Panulirus guttatus shows that these two species differ more broadly in degree of habitat specialization, larval, postlarval and adult sizes, diet, fecundity, growth rate, degree of sociality, defense mechanisms, susceptibility to predators, and chemical ecology, suggesting a greater degree of niche differentiation between Panulirus argus and Panulirus guttatus than between Panulirus gracilis and Panulirus inflatus. Whether the substantial niche differentiation and apparent interspecific trade-offs between Panulirus argus and Panulirus guttatus relative to Panulirus gracilis and Panulirus inflatus reflect an earlier divergence of the former pair of species in the evolution of the genus constitutes an intriguing hypothesis. However, whether or not post-divergence evolution of each species pair occurred in sympatry remains uncertain.

Species composition and distributional characteristics of Panulirus White, 1847 (Palinuridae) in Cu Lao Cham marine protected area, Quang Nam province

Among total 22 specimens of spiny lobster collected from two fieldtrips in the Cu Lao Cham marine protected area (MPA), Quang Nam province on May and November 2012, we have identified six species belong to genus Panulirus: Panulirus longipes, P. stimpsoni, P. versicolor, P. ornatus, P. penicillatus and P. homarus. At present, the species of genus Panulirus have recorded for Cu Lao Cham MPA estimates 75.0% of spiny lobster species reported for Vietnam. Five of which are listed in the 2007 Red Data Book of Vietnam as Endangered (Panulirus longipes), Vulnerable (P. ornatus, P. versicolor and P. homarus) and Data Deficient (P. stimpsoni and P. penicillatus). The Panulirus species popularly found in the Cu Lao Cham MPA, most of dominant areas are Hon Lao, Hon Mo, Hon Dai and Hon La island. Spiny lobsters of Cu Lao Cham MPA were found at different habitats, the sites may with mud, sand and gravel, coral reefs, caves, or rocks at a depth from 0.5 to 30 meters. Annually, they were frequently recorded from March to July and rarely seen in the remaining time of the year. This time is also the breeding season of most spiny lobster species in Cu Lao Cham MPA.

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.

Analysis of the central nervous system transcriptome of the eastern rock lobster Sagmariasus verreauxi reveals its putative neuropeptidome.

Neuropeptides have been discovered in many arthropod species including crustaceans. The nature of their biological function is well studied and varies from behavior modulation to physiological regulation of complex biochemical processes such as metabolism, molt and reproduction. Due to their key role in these fundamental processes, neuropeptides are often targeted for modulating these processes to align with market demands in commercially important species. We generated a comprehensive transcriptome of the eyestalk and brain of one of the few commercially important spiny lobster species in the southern Hemisphere, the Eastern rock lobster Sagmariasus verreauxi and mined it for novel neuropeptide and protein hormone-encoding transcripts. We then characterized the predicted mature hormones to verify their validity based on conserved motifs and features known from previously reported hormones. Overall, 37 transcripts which are predicted to encode mature full-length/partial peptides/proteins were identified, representing 21 peptide/protein families/subfamilies. All transcripts had high similarity to hormones that were previously characterized in other decapod crustacean species or, where absent in crustaceans, in other arthropod species. These included, in addition to other proteins previously described in crustaceans, prohormone-3 and prohormone-4 which were previously identified only in insects. A homolog of the crustacean female sex hormone (CFSH), recently found to be female-specific in brachyuran crabs was found to have the same levels of expression in both male and female eyestalks, suggesting that the CFSH female specificity is not conserved throughout decapod crustaceans. Digital gene expression showed that 24 out of the 37 transcripts presented in this study have significant changes in expression between eyestalk and brain. In some cases a trend of difference between males and females could be seen. Taken together, this study provides a comprehensive neuropeptidome of a commercially important crustacean species with novel peptides and protein hormones identified for the first time in decapods.

Effects of predation upon the long-spined sea urchin Diadema antillarum by the spotted spiny lobster Panulirus guttatus

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 495:185-191 (2014) - DOI: https://doi.org/10.3354/meps10568 Effects of predation upon the long-spined sea urchin Diadema antillarum by the spotted spiny lobster Panulirus guttatus Meredith D. Kintzing1,2, Mark J. Butler IV1,* 1Department of Biological Sciences, Old Dominion University, Norfolk, Virginia 23529, USA 2Present address: University of North Carolina at Chapel Hill, Department of Marine Sciences, Chapel Hill, North Carolina 27599, USA *Corresponding author: mbutler@odu.edu ABSTRACT: Sea urchins, important herbivores in marine ecosystems, are strongly impacted by both the direct and indirect effects of predation, and the long-spined sea urchin Diadema antillarum is no exception. Once abundant on Caribbean coral reefs, D. antillarum populations were decimated by disease in the early 1980s, and only where their natural predators have been overfished has D. antillarum recovery been observed. Spiny lobsters (Palinuridae) are predators of sea urchins, and although there are several species of spiny lobster in the Caribbean, only the spotted spiny lobster Panulirus guttatus is restricted to coral reefs where D. antillarum dwells. We investigated the direct and indirect impacts of P. guttatus on D. antillarum mortality, foraging, and behavior in a series of laboratory experiments. We found that P. guttatus prey on D. antillarum, especially small urchins. D. antillarum also consumed significantly less algae in the presence of P. guttatus and fled when exposed to the odor of P. guttatus but apparently not the scent of the Caribbean spiny lobster P. argus. The altered foraging and avoidance behaviors displayed by D. antillarum are strong evidence that predation by P. guttatus has played an important, but underappreciated, role in the evolutionary history of D. antillarum and perhaps its recovery on Caribbean coral reefs. KEY WORDS: Diadema antillarum · Panulirus guttatus · Florida Keys · Predation · Trait-mediated interactions · Coral reefs Full text in pdf format PreviousNextCite this article as: Kintzing MD, Butler IV MJ (2014) Effects of predation upon the long-spined sea urchin Diadema antillarum by the spotted spiny lobster Panulirus guttatus. Mar Ecol Prog Ser 495:185-191. https://doi.org/10.3354/meps10568 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 495. Online publication date: January 09, 2014 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2014 Inter-Research.

Palinurid lobster aquaculture: nutritional progress and considerations for successful larval rearing

AbstractThe closed‐cycle rearing of palinurid lobsters in commercially relevant quantities currently represents one of the most difficult challenges facing modern‐day aquaculture. The length and complexity of the larval life cycle exacerbate the problem, comprising the major bottleneck to their successful aquaculture. The general consensus is that developments in the key research area of nutrition will provide the necessary breakthroughs to make the closed‐cycle rearing of lobster a reality. Due to the cryptic nature of feeding preferences and complex larval morphology, a commercially formulated feed for their culture does currently not exist. Nevertheless, there has been a wealth of research conducted to elucidate many of the unknowns concerning larval nutritional requirements. This review presents a synthesis of this information, ranging from investigations of larval morphology and feeding behaviour, hatchery nutrition practices, the elucidation of wild prey items and the nutritional content of wild‐caught larval species. Based on the information available, this review culminates with a ‘best guess’ formulation for a larval spiny lobster diet, taking aspects concerning both the physical and chemical attributes of formulation into consideration. It is concluded that larval spiny lobsters are likely comparatively low in relation to other larval species with respect to their quantitative dietary requirements. Ultimately, the overall success of the larval cycle appears to be dictated by the stockpiling of lipids to fuel an energy‐demanding metamorphosis and a subsequent nonfeeding puerulus phase. These insights provide valuable direction for the formulation of nutritionally complete feeds to permit the closed‐loop culture of spiny lobster species.

Strong preference for decapod prey by the western rock lobster Panulirus cygnus

Western rock lobsters, Panulirus cygnus are an abundant benthic consumer distributed along the temperate west coast of Australia and constitute the largest single species fishery in Australia. As a dominant consumer, it is important to understand their predator–prey interactions as they can potentially exert strong trophic effects, and may influence ecosystem function as seen in other spiny lobster species. While previous field studies have focused on the diet composition of P. cygnus, this study investigated their preference for various benthic invertebrate prey to better understand the likely predator–prey interactions of P. cygnus. Prey preferences of small sub-legal juvenile lobsters, as well as medium and large legal-sized mature lobsters were investigated using laboratory feeding trials to identify size-associated differences in lobster prey preference. Handling time and diet quality were investigated to estimate energetic cost and gain from consuming different prey which may explain prey choice by lobsters. It was found that large lobsters preferred crabs and mussels while medium and small lobsters preferred crabs over mussels, gastropods, and sea urchins. This suggests that strong predator–prey interactions between P. cygnus and crabs may occur in the wild.

High connectivity and lack of mtDNA differentiation among two previously recognized spiny lobster species in the southern Atlantic and Indian Oceans

Adult spiny lobsters Jasus paulensis and J. tristani inhabit non-emergent seamounts and remote islands in the southern mid-latitude (30–45°S) Indian and Atlantic Oceans. Populations are often thousands of kilometres apart, and metapopulation genetic structure relies on successful exchange of long-lived drifting larvae. Genetic population structure and connectivity were investigated by sequencing the mitochondrial cytochrome oxidase I gene from lobsters collected at two Indian Ocean sites (Seamount 150 and St Paul/Amsterdam Islands) and two Atlantic sites (Vema Seamount and Gough/Inaccessible Islands) between 2006 and 2011. Jasus paulensis and J. tristani individuals share identical haplotypes across the distribution range and Bayesian phylogenetic analyses strongly support the monophyly of all individuals sampled, to the exclusion of all other recognized Jasus species. Analyses of molecular variance revealed no significant population genetic differentiation between sites, and Fu's F s and a mismatch distribution suggested demographic expansion, which was estimated to have occurred between 14,000 and 118,000 years ago. The results show an apparent lack of barriers to dispersal and gene flow over thousands of kilometres of the southern Indian and Atlantic Oceans, and suggest that J. paulensis and J. tristani should be synonymized as J. paulensis (Heller, 1862).

Spatially explicit mortality of California spiny lobster (Panulirus interruptus) across a marine reserve network

SUMMARYStudies of marine reserves typically focus upon differences in the size and abundance of target organisms inside versus outside reserve borders, but they seldom provide spatially explicit measurements of how reserves influence mortality rates. This study investigated mortality rates for female California spiny lobster (Panulirus interruptus) at multiple sites inside and outside of three marine reserves at the Santa Barbara Channel Islands, California, USA. Mean total mortality (Z) of female lobsters was lower at sites inside reserves (Z = 0.22 [± 0.05 SE]) than at sites outside reserves (Z = 0.59 [± 0.02 SE]). Mean mortality at all sites inside reserves, and among sites near reserve centres (where Z = 0.17 [± 0.05 SE]), was similar to estimates of natural mortality for other temperate spiny lobster species. Among sites inside reserves, there was a positive relationship between mortality and proximity to reserve borders, but this relationship was absent among sites outside reserves. Mortality estimates were much more variable among sites inside reserves than at sites in fished areas. This variation is probably due to differential emigration rates from the three reserves, as well as site-specific ecological factors that influence population structure, demonstrating the importance of spatially explicit reserve sampling and understanding how ecological heterogeneity influences fisheries models.