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Genetic differentiation among Atlantic island populations of the brown spiny lobster Panulirus echinatus (Decapoda: Palinuridae)
Abstract
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.
... Population connectivity studies are a useful tool for this Frontiers in Genetics | www.frontiersin.org July 2022 | Volume 13 | Article 889672 2 purpose as they provide data on the resilience and sustainability of a species (Gaeta et al., 2020). By providing an overview of the connectivity of an emblematic species of the Mediterranean Sea, a key factor that must be considered for conservation plans and for decision-making on the design of marine protected areas (Holland et al., 2017), we hope to contribute to the persistence of this coral species. ...
... Given the status of C. caespitosa as an endangered species, efficient conservation management is necessary for its long-term survival. Population connectivity studies are a useful tool for this purpose as they provide data on the resilience and sustainability of a species (Gaeta et al., 2020). By providing an overview of the connectivity of an emblematic species of the Mediterranean Sea, a key factor that must be considered for conservation plans and for decision-making on the design of marine protected areas (Holland et al., 2017), we hope to contribute to the persistence of this coral species. ...
Population connectivity studies are a useful tool for species management and conservation planning, particular of highly threatened or endangered species. Here, we evaluated the genetic structure and connectivity pattern of the endangered coral Cladocora caespitosa across its entire distribution range in the Mediterranean Sea. Additionally, we examined the relative importance of sexual and asexual reproduction in the studied populations and their genetic diversity. A total of 541 individuals from 20 localities were sampled and analysed with 19 polymorphic microsatellite markers. Of the genotyped individuals, 482 (89%) had unique multilocus genotypes. Clonality percentages of the populations varied from 0% (in eight populations) to nearly 69% (in one population from Crete). A heterozygosity deficit and a high degree of inbreeding was the general trend in our data set. Population differentiation in C. caespitosa was characterised by significant pairwise F ST values with lower ones observed at an intraregional scale and higher ones, between populations from different biogeographic regions. Genetic structure analyses showed that the populations are divided according to the three main sub-basins of the Mediterranean Sea: the Western (Balearic, Ligurian and Tyrrhenian seas), the Central (Adriatic and Ionian seas) and the Eastern (Levantine and Aegean seas), coinciding with previously described gene flow barriers. However, the three easternmost populations were also clearly separated from one another, and a substructure was observed for the other studied areas. An isolation-by-distance pattern was found among, but not within, the three main population groups. This substructure is mediated mainly by dispersal along the coastline and some resistance to larval movement through the open sea. Despite the low dispersal ability and high self-recruitment rate of C. caespitosa, casual dispersive events between regions seem to be enough to maintain the species’ considerable genetic diversity. Understanding the population connectivity and structure of this endangered scleractinian coral allows for more informed conservation decision making.
... The majority of studies are in oceanic islands, such as São Pedro and São Paulo archipelago (Pinheiro et al. 2003, Pinheiro & Lins-Oliveira 2006, and Rocas Atoll (Silva et al. 2001, Gaeta &Cruz 2019a andb). Recently two different P. echinatus fishing stocks were genetically identified, indicating that this species needs to be managed according to the ecological factors and different pressures in each of these stocks (Gaeta et al. 2020). According to the identification key, P. echinatus differs from the congeners by the presence of a single pair of strong thorns in the antennular plate; the tail is covered by distinct rounded spots; the antennulae and legs are streaked with longitudinal lines; the membranous part of the telson and uropod are dark blue, and the pleopods are black with a white border (Holthuis 1991, Giraldes & Smyth 2016. ...
We are reporting a blue phenotype in the brown spiny lobster Panulirus echinatus captured in Alagoas, Brazil. In the blue phenotype, a dark blue color replaced the original brownish color throughout the body, and the peculiar lines and spots remained white.
... The genetic uniqueness of the TR population is corroborated by the larvae dispersal models, whose trajectories remain around the island (Figs. 8 and 9). Recent genetic studies with the spiny lobster Panulirus echinatus, with a 6 to 8 months PLD, showed a slight isolation of TR population (Gaeta et al., 2020). On the other hand, the coral Mussismilia hispida, with a 10 days PLD, has a single genetic population at RA, FN and TR, different from the mainland coastal reef populations, that could be explained if these sites acted as refugees in past low sea level stance (Peluso et al., 2018). ...
Grapsus grapsus and Grapsus adscensionis are supralittoral crabs that are known to inhabit oceanic islands and depend on surface currents to recruit in the rocky shores. The ornamentation of the cephalothorax is very distinct among species, but morphological differences are controversial, and integrative studies with different approaches are needed. This study investigated the genetic variation among the populations of G. grapsus from Saint Peter and Saint Paul Archipelago (SP), Fernando de Noronha (FN), Rocas Atoll (RA) and Trindade Island (TR) in the western Atlantic, and G. adscensionis from the islands of Ascension (AI) and Saint Helena (SH) in the mid-Atlantic. Morphology was assessed by geometric morphometric analyses of the carapace and chelae, and numerical analyses of tubercles in the frontal plate of SP, FN, RA, TR and AI populations. In addition, dispersal of the larvae in the Atlantic Ocean was simulated performing a Lagrangian analysis using HYCOM reanalysis dataset as the ocean surface velocity field. The data obtained for the mitochondrial D-loop gene confirmed the distinctness of the two putative species and demonstrated the connectivity between the populations of G. grapsus from the three equatorial islands. The TR population presented unique haplotypes, as well as AI and SH. The geometric morphometric analyses showed differentiation between the carapace shapes for G. grapsus and G. adscensionis, however, the chelae shape does not allow to distinguish between the species or the population. The morphometric and molecular results were consistent with the pattern of particles dispersion in the Atlantic ocean. The larvae of SP, FN and RA mix after two months of drift, while the larvae of TR, AI, SH circulate only around the respective islands. The results reinforce the validation of the two species and the isolation of populations of G. grapsus in TR and of G. adscensionis in AI and SH. The populations of these islands might be maintained by self-recruitment, through larval behavior associated with the local current system, and therefore should be the target of conservation measures.
... Over time, locally adapted populations may become genetically differentiated, giving rise to genetically structured populations across their geographic range. Local adaptation and genetic structure within widespread marine invertebrates have been documented for planktonic taxa (reviewed in Sanford & Kelly, 2011), spiny lobster (Gaeta et al., 2020;Lavery et al., 2014;Singh et al., 2018;Truelove et al., 2017), crabs (van Tienderen & van der Meij, 2017), oysters (Burford et al., 2014), and sea urchins (Carreras et al., 2020). Recent studies have shown that incorporating local adaptation and genetic structure in SDMs can be informative in predictive models of climate change effects (Cacciapaglia & van Woesik, 2018;Hällfors et al., 2016). ...
Aim
We incorporated genetic structure and life history phase in species distribution models (SDMs) constructed for a widespread spiny lobster, to reveal local adaptations specific to individual subspecies and predict future range shifts under the RCP 8.5 climate change scenario.
Location
Indo‐West Pacific.
Methods
MaxEnt was used to construct present‐day SDMs for the spiny lobster Panulirus homarus and individually for the three genetically distinct subspecies of which it comprises. SDMs incorporated both sea surface and benthic (seafloor) climate layers to recreate discrete influences of these habitats during the drifting larval and benthic juvenile and adult life history phases. Principle component analysis (PCA) was used to infer environmental variables to which individual subspecies were adapted. SDM projections of present‐day habitat suitability were compared with predictions for the year 2,100, under the RCP 8.5 climate change scenario.
Results
In the PCA, salinity best explained P. h. megasculptus habitat suitability, compared with current velocity in P. h. rubellus and sea surface temperature in P. h. homarus. Drifting and benthic life history phases were adapted to different combinations of sea surface and benthic environmental variables considered. Highly suitable habitats for benthic phases were spatially enveloped within more extensive sea surface habitats suitable for drifting larvae. SDMs predicted that present‐day highly suitable habitats for P. homarus will decrease by the year 2,100.
Main conclusions
Incorporating genetic structure in SDMs showed that individual spiny lobster subspecies had unique adaptations, which could not be resolved in species‐level models. The use of sea surface and benthic climate layers revealed the relative importance of environmental variables during drifting and benthic life history phases. SDMs that included genetic structure and life history were more informative in predictive models of climate change effects.
O PPCTA da UNIVALI foi implementado há 21 anos na região. Nesse período mais de 250 dissertações e teses de doutorado foram defendidas em temas que buscaram, de alguma forma, desvelar a estrutura e funcionamento do território deste setor costeiro. O PPCTA validou por meio do seu colegiado o uso dos 17 ODS para classificar suas dissertações e teses e esta tomada de decisão está integrada aos objetivos de formar recursos humanos para atuarem no ensino, gerenciamento, pesquisa e desenvolvimento da área ambiental, através do conhecimento ecológico interdisciplinar e do desenvolvimento de ferramentas e tecnologias passíveis de serem aplicadas no entendimento e na resolução dos problemas decorrentes da relação homem-natureza. Busca também desenvolver novos conhecimentos técnico-científicos que permitam um melhor gerenciamento das questões ambientais apresentadas pela sociedade (tanto pelo setor produtivo, quanto pela opinião pública), integrando a formação dos alunos a esse processo de busca do conhecimento novo, interdisciplinar e complexo. Constitui-se assim de um compromisso de promover a interconexão entre o saber acadêmico e a realidade social, permitindo que tanto o setor produtivo quanto a população em geral possam se beneficiar do avanço do conhecimento, novo, gerado pela fusão de saberes distintos, caracterizando uma inserção social inovadora e harmoniosa entre a sociedade e a ciência.
A obra traz, à luz da contemporaneidade, a relevância e significância que a ciência e a educação superior possuem, com destaque para Programas de Pós-Graduação da Área de Ciências Ambientais, enquanto promotores de conhecimento, formadores de talentos humanos altamente capacitados, e fomentadores de protagonismo para temas e questões de interesse da sociedade relacionados aos 17 Objetivos de Desenvolvimento Sustentável (ODS) da Agenda 2030 da Organização das Nações Unidas (ONU). Ao reunir experiências e reflexões teóricas, a obra demonstra contribuições dos programas para a formação de pesquisadores, docentes, estudantes de pós-graduação e graduação, profissionais e técnicos; para a incorporação dos ODS em pesquisas voltadas à aplicação em diversos setores da sociedade; bem como para o desenvolvimento de uma ciência cidadã. Os organizadores e os autores desta obra, enquanto orientadores e pesquisadores de pós-graduação em ciências ambientais, desenvolvem análises dos resultados de seus programas, aprofundando o reconhecimento de suas performances acadêmicas, científicas e socioambientais, indicando caminhos que possam contribuir para a divulgação e aplicação de seus achados junto dos setores públicos, empresariais e sociedade civil.
Peaks of the Southern Atlantic submarine ridge form the Fernando de Noronha Archipelago and Rocas Atoll off the coast of Brazil. They represent a large proportion of the island surface of the South Atlantic and their rich waters are extremely important for the breeding and feeding of tuna, shark, turtle and marine mammals. The islands are home to the largest concentration of tropical seabirds in the Western Atlantic. Baia de Golfinhos has an exceptional population of resident dolphin and at low tide the Rocas
Atoll provides a spectacular seascape of lagoons and tidal pools teeming with fish. © UNESCO
Genetic connectivity studies are essential to understand species diversity and genetic structure and to assess the role of potential factors affecting connectivity, thus enabling sound management and conservation strategies. Here, we analyzed the patterns of genetic variability in the marine snail Gibbula divaricata from five coastal locations in the central-south Adriatic Sea (central Mediterranean) and one in the adjacent northern Ionian Sea, using 21 described polymorphic microsatellite loci. Observed and expected heterozygosity varied from 0.582 to 0.635 and 0.684 to 0.780, respectively. AMOVA analyses showed that 97% of genetic variation was observed within populations. Nevertheless, significant, although small, genetic differentiation was found among nearly all of the pairwise FST comparisons. Over a general pattern of panmixia, three groups of populations were identified: eastern Adriatic populations, western Adriatic populations, and a third group represented by the single northern Ionian Sea population. Nonetheless, migration and gene flow were significant between these groups. Gibbula divaricata is thought to have a limited dispersal capacity related to its lecithotrophic trochophore larval stage. Our results indicated high levels of self-recruitment and gene flow that is mainly driven through coastline dispersion, with populations separated by the lack of suitable habitats or deep waters. This stepping-stone mode of dispersion together with the high levels of self-recruitment could lead to higher levels of population structuring and differentiation along the Adriatic Sea. Large effective population sizes and episodic events of long-distance dispersal might be responsible for the weak differentiation observed in the analyzed populations. In summary, the circulation system operating in this region creates natural barriers for dispersion that, together with life-history traits and habitat requirements, certainly affect connectivity in G. divaricata. However, this scenario of potential differentiation seems to be overridden by sporadic events of long-distance dispersal across barriers and large effective population sizes.
The isolation and characterization of 17 polymorphic
microsatellite loci from the spiny lobster Panulirus echina-
tus (Decapoda: Palinuridae) by Illumina MiSeq sequenc-
ing is described. The analysis of genetic variability was
performed in 42 individuals from 3 different populations
(Saint Peter and Saint Paul Rocks, The Rocas Atoll and
Cape Verde). The number of alleles ranged from 2 to 8, with
an average of 5.4 ± 1.4 alleles per locus. The values of allelic
richness varied from 1.8 to 6.2 (average of 3.9 ± 1.0), while
PIC values ranged between 0.173 and 0.811. Overall mean
observed and expected heterozygosity was estimated to be
0.418 ± 0.165 and 0.587 ± 0.173, respectively. These are
the first microsatellite markers characterized for P. echi-
natus and it is expected that these markers will help to
obtain the necessary information for developing conser-
vation and management strategies for this highly valuable
fishery species.
The presence of several actinopterygians species are reported based mainly on photographic
documents taken in various islands. Three tropical origin species are recorded for
the first time from the Canary Islands: Uraspis secunda, Cubiceps capensis and Cantherines
macrocerus. Also, the thermophilic Psettodes cf. bennettii and the Macaronesian anguilliform,
Paraconger cf. macrops are tentatively recorded for the first time. In addition,
the distribution range into the Canary archipelago of two previously stablished non-native
tropical species, Hippocampus algiricus and Microlipophrys velifer, is extended. The cases
of thermophilic species seem to respond to natural range spreading processes, probably related
to the sea water warming in the Atlantic, while P. macrops has probably passed unnoticed
until now. Biogeographic data are also included.
Background:
There is increasing recognition of the concordance between marine biogeographic and phylogeographic boundaries. However, it is still unclear how population-level divergence translates into species-level divergence, and what are the principal factors that first initiate that divergence, and then maintain reproductive isolation. This study examines the likely forces driving population and lineage divergences in the broadly-distributed Indo-Pacific spiny lobster Panulirus homarus, which has peripheral divergent lineages in the west and east. The study focuses particularly on the West Indian Ocean, which is emerging as a region of unexpected diversity. Mitochondrial control region (mtCR) and COI sequences as well as genotypes of 9 microsatellite loci were examined in 410 individuals from 17 locations grouped into 7 regions from South Africa in the west, and eastward across to Taiwan and the Marquesas Islands. Phylogenetic and population-level analyses were used to test the significance and timing of divergences and describe the genetic relationships among populations.
Results:
Analyses of the mtCR revealed high levels of divergence among the seven regions (ФST = 0.594, P < 0.001). Microsatellite analyses also revealed significant divergence among regions, but at a much lower level (FST = 0.066, P < 0.001). The results reveal different patterns of mtCR v. nDNA divergence between the two distinct peripheral lineages: a subspecies in South Africa and Madagascar, and a phylogeographically diverged population in the Marquesas. The results also expose a number of other more fine-scale population divergences, particularly in the Indian Ocean.
Conclusions:
The divergence of peripheral lineages in the west and east of the species' range appear to have been initiated and maintained by very different processes. The pattern of mitochondrial and nuclear divergence of the western lineage, implicates processes of parapatric isolation, secondary contact and introgression, and suggests possible maintenance through adaptation and behavioural reproductive isolation. In contrast, the eastern lineage appears to have diverged through a rare colonisation event, maintained through long-term isolation, and matches expectations of the core-periphery hypothesis. The process of active peripheral speciation may be a common force in the Indo-Pacific that helps drive some of the regions' recognized biogeographic boundaries.
Investigating the extent (or the existence) of local adaptation is crucial to understanding how populations adapt. When experiments or fitness measurements are difficult or impossible to perform in natural populations, genomic techniques allow us to investigate local adaptation through the comparison of allele frequencies and outlier loci along environmental clines. The thick-billed murre (Uria lomvia) is a highly philopatric colonial arctic seabird that occupies a significant environmental gradient, shows marked phenotypic differences among colonies, and has large effective population sizes. To test whether thick-billed murres from five colonies along the eastern Canadian Arctic coast show genomic signatures of local adaptation to their breeding grounds, we analyzed geographic variation in genome-wide markers mapped to a newly assembled thick-billed murre reference genome. We used outlier analyses to detect loci putatively under selection, and clustering analyses to investigate patterns of differentiation based on 2220 genomewide single nucleotide polymorphisms (SNPs) and 137 outlier SNPs. We found no evidence of population structure among colonies using all loci but found population structure based on outliers only, where birds from the two northernmost colonies (Minarets and Prince Leopold) grouped with birds from the southernmost colony (Gannet), and birds from Coats and Akpatok were distinct from all other colonies. Although results from our analyses did not support local adaptation along the latitudinal cline of breeding colonies, outlier loci grouped birds from different colonies according to their non-breeding distributions, suggesting that outliers may be informative about adaptation and/or demographic connectivity associated with their migration patterns or nonbreeding grounds.
Fourteen polymorphic microsatellites with perfect di-, tri-, and tetra-nucleotide repeats were identified for Panulirus homarus using Roche 454 whole-genome sequencing method. Microsatellites were efficiently co-amplified in four multiplexes and a singleplex, providing consistent and easily interpretable genotypes. The number of alleles per locus ranged from 2 to 11 with the observed and expected heterozygosity ranging between 0.000-0.532 and 0.031-0.836, respectively. A significant deviation from Hardy-Weinberg equilibrium was observed for majority of the loci, probably due to homozygote excess. Genetic linkage disequilibrium analysis between all the possible pairs of the loci showed significant departure from the null hypothesis in the loci pairs Pho-G11-Pho-G33 and Pho-G33-Pho-G57. High success in primer cross-species amplification of these microsatellite markers indicates their utility for genetic studies of different Panulirus species.
Background:
The distribution of genetic variability from the interior towards the periphery of a species' range is of great interest to evolutionary biologists. Although it has been long presumed that population genetic variation should decrease as a species' range is approached, results of empirical investigations still remain ambiguous. Knowledge regarding patterns of genetic variability as well as affected factors is particularly not conclusive in plants.
Methodology/principal findings:
To determine genetic divergence in peripheral populations of the wild rice Oryza rufipogon Griff. from China, genetic diversity and population structure were studied in five northern & northeastern peripheral and 16 central populations using six microsatellite loci. We found that populations resided at peripheries of the species possessed markedly decreased microsatellite diversity than those located in its center. Population size was observed to be positively correlated with microsatellite diversity. Moreover, there are significantly positive correlations between levels of microsatellite diversity and distances from the northern and northeastern periphery of this species. To investigate genetic structure and heterozygosity variation between generations of O. rufipogon, a total of 2382 progeny seeds from 186 maternal families were further assayed from three peripheral and central populations, respectively. Peripheral populations exhibited significantly lower levels of heterozygosities than central populations for both seed and maternal generations. In comparisons with maternal samples, significantly low observed heterozygosity (HO) and high heterozygote deficit within populations (FIS) values were detected in seed samples from both peripheral and central populations. Significantly lower observed heterozygosity (HO) and higher FIS values were further observed in peripheral populations than those in central populations for seed samples. The results indicate an excess of homozygotes and thus high inbreeding depression in peripheral populations.
Conclusions/significance:
Our results together suggest that historical contraction of geographical range, demographic changes, and environmental conditions near the northern and northeastern margins of O. rufipogon favor inbreeding and possibly selfing, leading to the rapidly decreased effective population size. Genetic drift, reduced gene flow, and possible local selection, consequently lead to lowered gene diversity, accelerated genetic divergence and increased inbreeding depression found in peripheral populations of O. rufipogon. Given these characteristics observed, northern and northeastern peripheral populations deserve relatively different conservation strategies for either germplasm sampling of ex situ conservation or setting in situ reserves for the adaptation to possible environmental changes and the future germplasm utilization of wild rice.
To resolve phylogeographical partitions in the pronghorn spiny lobster, Panulirus penicillatus, which has a nine-month pelagic larval phase and the broadest distribution among spiny lobsters. With samples from the Red Sea to the East Pacific, we test genetic partitions across two-thirds of the planet, in a species with one of the longest pelagic phases. Red Sea, Indian and Pacific Oceans. A fragment of the mtDNA cytochrome c oxidase subunit I gene (COI) was resolved in 774 individuals from 28 locations, plus 55 sequences (10 locations) from public databases. Portions of COI, 12S and 16S mtDNA regions were resolved for phylogenetic analyses on a subset of individuals. Phylogenetic and population-level analyses were used to detect evolutionary partitions and dispersal barriers. Significant population structuring was detected (overall ΦST = 0.310, P < 0.001). Samples from the Red Sea and East Pacific Provinces (western and eastern range edges) comprise distinct phylogenetic lineages, divergent at d = 1.1% and 1.8%, respectively, from the Indo-Pacific. Coalescent analyses indicate a Pleistocene isolation for the Red Sea (0.71 Ma) and East Pacific (1.52 Ma). Excluding the Red Sea and East Pacific, structure across the rest of the range was comparatively low, but significant (ΦST = 0.018, P < 0.001). The Red Sea and East Pacific populations are phylogenetically distinct from populations elsewhere in the range. The East Pacific population diverged earliest, and may represent a distinct subspecies. Phylogeographical divisions align with the major Indo-Pacific biogeographical barriers, and with subsets of provincial designations from two frameworks: one based on levels of endemism and one on species composition. Tropical and temperate regions in the Pacific are significantly differentiated, potentially indicating an ecological partition. Isolation at eastern and western peripheral provinces may serve as a starting point for evolutionary diversification within this group.
The aim of this study is to update the list of spiny lobsters in the Abrolhos Archipelago. The data were obtained by scuba diving during diurnal (8am to 5pm) and nocturnal (7pm to 11pm) visual censuses, from 2 to 12 meters depth. This work presents the first record of Panulirus laevicauda on the Abrolhos Archipelago, confirm the previous unique record of Panulirus echinatus and reinforce the occurrence of Panulirus argus. All the spiny lobster species of the genus Panulirus registered in the Brazilian coast are now registered for the Abrolhos National Marine Park reinforcing the importance of this marine protected area. RESUMO Este trabalho pretende atualizar a lista de espécies de lagostas de espinho para o Arquipélago de Abrolhos. Os dados foram obtidos através de mergulhos autônomos (SCUBA) durante censos visuais diurnos (8am a 5pm) e noturnos (7pm a 11 pm), em profundidades de 2 a 12 metros. Neste estudo apresenta-se o primeiro registro de Panulirus laevicauda no Arquipélago de Abrolhos, confirma-se a presença de Panulirus echinatus e reforça-se a ocorrência de Panulirus argus. Todas as espécies de lagostas do gênero Panulirus registradas na costa brasileira estão presentes no Parque Nacional Marinho dos Abrolhos, reforçando a importância dessa área marinha protegida.
This study is an update of list of lobster species from Rocas Atoll Marine Reserve, Brazil. The data were obtained trough visual censuses and photographic registers during expeditions since 1997 until 2014. It represents the first record of Enoplometopus antillensis Lütken, 1865, Palinurellus gundlachi Von Martens, 1878, and Panulirus laevicauda (Latreille, 1817) and reinforces the occurrence of Panulirus argus (Latreille, 1804), Panulirus echinatus Smith, 1869, and Parribacus antarticus (Lund, 1793) from Rocas Atoll. The presence of different lobster species shows us the importance of Rocas Atoll Reserve in relation to number of species and abundance of lobsters.
Few traits are shared by all species of animals and plants. Movement is a noteworthy exception. Although many species seem permanently locked to a particular place, they inevitably move at some stage of their life cycles. The mobile phase can be adults, juveniles, or gametes. Species move for many reasons. Some move to seek food. Others move to avoid becoming food for someone else. Some move to seek favorable conditions. Others move to find a mate or an egg to
fertilize. When these forms of movement occur over relatively short distances, they can play important roles in a wide range of ecological and evolutionary processes (Davidson et al., 2004). Much of marine
ecology has focused on the dynamics and consequences of such local interactions.
Here we utilize a combination of genetic data, oceanographic data, and local ecological knowledge to assess connectivity patterns of the ornate spiny lobster Panulirus ornatus (Fabricius, 1798) in the South-East Asian archipelago from Vietnam to Australia. Partial mitochondrial DNA control region and 10 polymorphic microsatellites did not detect genetic structure of 216 wild P. ornatus samples from Australia, Indonesia and Vietnam. Analyses show no evidence for genetic differentiation among populations (mtDNA control region sequences ΦST = -0.008; microsatellite loci FST = 0.003). A lack of evidence for regional or localized mtDNA haplotype clusters, or geographic clusters of microsatellite genotypes, reveals a pattern of high gene flow in P. ornatus throughout the South-East Asian Archipelago. This lack of genetic structure may be due to the oceanography-driven connectivity of the pelagic lobster larvae between spawning grounds in Papua New Guinea, the Philippines and, possibly, Indonesia. The connectivity cycle necessitates three generations. The lack of genetic structure of P. ornatus population in the South-East Asian archipelago has important implications for the sustainable management of this lobster in that the species within the region needs to be managed as one genetic stock.
Behavior such as ontogenetic vertical migration (OVM) limits the transport of marine larvae with short pelagic larval durations (PLDs), but its effect on the supposed long-distance dispersal of larvae with long PLDs is unknown. We conducted laboratory tests of ontogenetic change in larval phototaxis and examined size-specific patterns of larval distribution in the plankton to characterize OVM in the Caribbean spiny lobster Panulirus argus during its long (6 mo) PLD. We then used a coupled biophysical model to explore the consequences of OVM and hydrodynamics on larval P. argus dispersal in the Caribbean Sea. Larvae reared in the laboratory were positively phototatic for the first 2 mo and then avoided light thereafter, similar that seen in the planktonic distribution of same-sized larvae. Simulations of larval dispersal from 13 spawning sites in the Caribbean Sea predicted that twice as many larvae would recruit to nurseries if they displayed OVM compared with passive dispersers. Larvae with OVM typically settled <400 km from where they were spawned, while passive dispersers often settled >1000 km away. OVM also produced an asymmetrical bimodal pattern of dispersal dominated by larvae that settled near their origin (similar to 60%), but showed a second peak of larvae that dispersed over long distances (similar to 20%). Hydrodynamics created subregional differences in the potential for self-recruitment. Our findings suggest that (1) larval behavior constrains the dispersal of even long-lived larvae, particularly in tandem with retentive oceanographic environments, and (2) larval sources of P. argus in the Caribbean Sea cannot be estimated from passive transport and surface circulation.
As additional results of marine wildlife checklists carried out within different research projects in Canary Islands, an updated systematic list of the 132 species of decapods and 5 stomatopods observed is provided, all illustrated with specimens fotographed alive. Among the species listed, 11 are new records from the archipelago (9 decapods: Penaeus kerathurus (Forskål, 1775), Pestarella candida (Olivi, 1792), Pisidia longimana (Risso, 1816), Merocryptus boletifer A. Milne-Edwards & Bouvier, 1894, Liocarcinus pusillus (Leach, 1816),
Macropipus tuberculatus (Roux, 1830), Xaiva mcleayi (Barnard, 1947), Brachynotus sexdentatus (Risso, 1827) and Pinnotheres pisum (Linnaeus, 1767); 2 stomatopods: Pseudosquilla ciliata (Fabricius, 1787) y Rissoides pallidus (Giesbrecht, 1910)), and several species whose presence in the archipelago was uncertain or which it had few records.
A checklist of the decapod crustacean species from the infraorders Astacidea, Thalassinidea, Polychelida, Palinura, and Anomura from the northern and northeastern (N/NE) Brazilian coast based on literature and material deposited in the carcinological collection of the Universidade Federal de Pernambuco, Recife, Brazil, is provided. The list includes marine and estuarine species reported at least once to each of the studied area, including the oceanic islands and banks along the N/NE Brazil. A total of 146 species is reported, corresponding to an increase of 32.7% when compared to the data published in Paulo Young’s Catalogue (1998). The most representative infraorder concerning number of species is Anomura, represented in N/NE Brazil by 90 species and 10 families, followed by Thalassinidea, with 36 species and 6
families, Palinura, with 14 species and 4 families and, finally, Astacidea, which comprises 6 species and 2 families. Families with highest species richness were Porcellanidae (20), Diogenidae (19), Paguridae (18) and Galatheidae (15), all of them included in the infraorder Anomura. Zoogeographic affinities regarding the species are briefly discussed.
The pronghorn spiny lobster Panulirus penicillatus is a highly valuable species which is widely distributed in Indo-West Pacific and Eastern Pacific regions. Mitochondrial DNA control region sequences (566-571 bp) were determined to investigate the population genetic structure of this species in the Indian Ocean. In total, 236 adult individuals of Panulirus penicillatus were collected from five locations in the Indian Ocean region. Almost all individuals had a unique haplotype. Intrapopulation haplotype (h) and nucleotide (π) diversities were high for each locality, ranging from h = 0.9986-1.0000 and π = 0.031593-0.043441. We observed distinct genetic isolation of population located at the northwestern and southwestern edge of the species range. Gene flow was found within localities in the central and eastern region of the Indian Ocean, probably resulting from an extended planktonic larval stage and prevailing ocean currents.
We compare mitochondrial genetic data for two spiny lobsters in Hawai'i with different
geographic ranges and histories of fishing pressure. Panulirus marginatus (Quoy and Gaimard,
1825) is endemic to Hawai'i, and experienced a short, intense fishery in the Northwestern
Hawaiian Islands (NWHI) and long-term, less intense exploitation in the Main Hawaiian Islands
(MHI). Populations show significant overall structure (FST = 0.0037, P = 0.007; Dest_Chao = 0.137), with regional differentiation (FCT = 0.002, P = 0.047) between the MHI and the NWHI.
Haplotype diversity did not differ significantly between regions (F2, 8 = 3.740, P = 0.071);
however, nucleotide diversity is significantly higher at the primary NWHI fishery banks (0.030)
than in the MHI (0.026, Tukey’s P = 0.013). In contrast, Panulirus penicillatus (Olivier, 1791),
found across the tropical Indo-West Pacific region, was not targeted by the NWHI fishery, but
has experienced long-term exploitation in the MHI. Panulirus penicillatus has no significant
overall population structure in Hawai'i (FST = 0.0083, P = 0.063; Dest_Chao = 0.278), although
regional differentiation (FCT = 0.0076, P = 0.0083) between the MHI and the NHWI is
significant. Neither haplotype nor nucleotide diversity differed significantly between regions for
P. penicillatus. While neither species has suffered a loss of genetic diversity from fishing, our
results highlight that only by incorporating knowledge of fishing history with genetic
connectivity data can we understand the most beneficial management strategy for each species.
Neither exemplar species nor specific suites of traits are reliable predictors of the spatial scales
of management.
Delineating regions is an important first step in understanding the evolution and biogeography of faunas. However, quantitative approaches are often limited at a global scale, particularly in the marine realm. Reef fishes are the most diversified group of marine fishes, and compared to most other phyla, their taxonomy and geographical distributions are relatively well known. Based on 169 checklists spread across all tropical oceans, the present work aims to quantitatively delineate biogeographical entities for reef fishes at a global scale. Four different classifications were used to account for uncertainty related to species identification and the quality of checklists. The four classifications delivered converging results, with biogeographical entities that can be hierarchically delineated into realms, regions and provinces. All classifications indicated that the Indo-Pacific has a weak internal structure, with a high similarity from east to west. In contrast, the Atlantic and the Eastern Tropical Pacific were more strongly structured, which may be related to the higher levels of endemism in these two realms. The "Coral Triangle", an area of the Indo-Pacific which contains the highest species diversity for reef fishes, was not clearly delineated by its species composition. Our results show a global concordance with recent works based upon endemism, environmental factors, expert knowledge, or their combination. Our quantitative delineation of biogeographical entities, however, tests the robustness of the results and yields easily replicated patterns. The similarity between our results and those from other phyla, such as corals, suggests that our approach may be of broad utility in describing and understanding global marine biodiversity patterns.
Panulirus argus (Latreille in Ann Mus Hist Nat Paris 3:388–395, 1804) is the lobster of greatest economic importance throughout its distribution. In this study, mitochondrial (Cytochrome Oxidase I and 16S ribosomal genes) and nuclear (Adenine Nucleotide Transporter gene) sequences were used to evaluate the taxonomic status of P. argus sampled from five sites in the Caribbean Sea and nine sites in the Southwest Atlantic. Phylogenetic analyses indicate that lobsters from the two regions form two monophyletic groups with a molecular divergence similar to that observed between distinct congeneric lobster species and much larger than that found between conspecific lobster populations. Therefore, the Caribbean and the Southwest Atlantic lobster populations originally attributed to P. argus belong to different species, with an estimated time of isolation of around 16 Million years. An important consequence of these findings is that the fisheries of spiny lobsters from the Caribbean and the Southwest Atlantic species must be managed separately.
Seven coastal fish species are newly reported for the remote north Atlantic archipelago of the Azores: Mediterranean sand eel Gymnammodytes cicerelus, bar jack Caranx ruber, two-banded seabream Diplodus vulgaris, bastard grunt Pomadasys incisus, unicorn leatherjacket filefish Aluterus scriptus and longspined porcupinefish Diodon holacanthus. The occurrence is also confirmed for 19 species that had been hitherto cited occasionally for the region, totalling a list of two elasmobranchs and 23 teleosts. Diplodus vulgaris, which appears to have recently colonized the islands, as well as roughtail stingray Dasyatis centroura and golden grey mullet Liza aurata, re-cited based on new records, are frequent or common coastal species in the Azores. The remaining 22 species, exceptional or rare in the region, are of tropical or subtropical affinity and find their northernmost distribution limit within the central and north-east Atlantic Ocean precisely in the Azores. This biogeographical pattern contrasts with that of the Azorean coastal fish community and suggests a tropicalization process in the region in line with previous findings of similar patterns across the north-east Atlantic Ocean and the Mediterranean Sea. These novel data from the most isolated archipelago of the North Atlantic Ocean, located in a biogeographic boundary area where colonization opportunities are reduced, reinforce the need for long-term monitoring programmes of coastal fish communities and, in particular, of indicator species groups to improve understanding of the effects of climate change on marine communities.
Many marine organisms are sedentary as adults and are redistributed between generations by the oceanic transport of planktonic larvae. In order to assess interactions among oceanographic and biological processes that determine larval dispersal patterns, we introduce a Lagrangian (or water-parcel-following) description of larval transport. This formalism is used to determine larval dispersal kernels (larval settlement probability distributions) for a range of ocean flows, planktonic larval durations and settlement pre-competency/competency periods. Paths of individual planktonic larval releases are modeled statistically and, by averaging over many individuals, ensemble estimates of larval dispersal are determined. Typical dispersal scales vary from a few km to >400 km. Modeled dispersal kernels are well explained using only a few readily available biological and oceanographic parameters, and derived dispersal scales agree well with population-genetic estimates, suggesting that the model has reasonable predictive power. An index for regional-scale self-seeding is presented, and is used as a tool to evaluate the efficiency of marine conservation areas. Finally, settlement patterns resulting from larval releases made over short times (days to months) should be comprised of a small number of discrete samples taken from the long-term averaged dispersal kernel. The resulting larval dispersal patterns will be quasi-random in both space and time, which will have important implications for the interpretation of settlement time series and the prediction of recruitment of sessile organisms.
The common approach to the multiplicity problem calls for controlling the familywise error rate (FWER). This approach, though, has faults, and we point out a few. A different approach to problems of multiple significance testing is presented. It calls for controlling the expected proportion of falsely rejected hypotheses — the false discovery rate. This error rate is equivalent to the FWER when all hypotheses are true but is smaller otherwise. Therefore, in problems where the control of the false discovery rate rather than that of the FWER is desired, there is potential for a gain in power. A simple sequential Bonferronitype procedure is proved to control the false discovery rate for independent test statistics, and a simulation study shows that the gain in power is substantial. The use of the new procedure and the appropriateness of the criterion are illustrated with examples.
Coastal lobsters support important fisheries all over the world, but there is evidence that climate-induced changes may jeopardize some stocks. Here we present the first global forecasts of changes in coastal lobster species distribution under climate change, using an ensemble of ecological niche models (ENMs). Global changes in richness were projected for 125 coastal lobster species for the end of the century, using a stabilization scenario (4.5 RCP). We compared projected changes in diversity with lobster fisheries data and found that losses in suitable habitat for coastal lobster species were mainly projected in areas with high commercial fishing interest, with species projected to contract their climatic envelope between 40 and 100%. Higher losses of spiny lobsters are projected in the coasts of wider Caribbean/Brazil, eastern Africa and Indo-Pacific region, areas with several directed fisheries and aquacultures, while clawed lobsters are projected to shifts their envelope to northern latitudes likely affecting the North European, North American and Canadian fisheries. Fisheries represent an important resource for local and global economies and understanding how they might be affected by climate change scenarios is paramount when developing specific or regional management strategies.
Rising ocean temperatures as consequence of climate change has led to increased populations of species with tropical affinities, generating a tropicalization process of the biota. In this sense, an increase in populations of the zoanthids Palythoa canariensis and Zoanthus sp. is expected for the Canary Islands being able to change local habitats and biodiversity. Within this study the potential of these species to modify the composition of their associated fauna in intertidal pools of the Canaries was assessed. The composition and biodiversity of communities in intertidal habitats dominated by P. canariensis and Zoanthus sp. were compared with habitats dominated by macroalgae. Samples were collected in order to quantify the mesofauna, and coverage of algae and zoanthids colonies were assessed. Results showed significant differences in the composition of the associated fauna between both kind of habitats, as well as an increase in species diversity and richness in habitats dominated by colonies of both zoanthids. The high potential of P. canariensis and especially of Zoanthus sp. to transform the habitat and associated communities of invertebrates in intertidal environments of the Canary Islands was demonstrated. Given the expected climate change scenario for the future that will benefit the expansion of these key zoanthids, important changes in the biodiversity and potential alterations in natural ecosystems are expected for the Archipelago.
Using high-throughput sequencing technology 17 polymorphic microsatellites with perfect tetranucleotide repeats were identified for the brown spiny lobster Panulirus echinatus Smith, 1869. Two to ten alleles were detected per locus across 30 samples analysed from the Canary Archipelago. Observed and expected heterozygosities per locus ranged between 0.100 and 0.867 and 0.095 and 0.799, respectively. No significant linkage disequilibrium was found between pairs of loci, and only one locus (Pe-L43) deviated from Hardy-Weinberg equilibrium, likely due to the presence of null alleles. Despite its economic importance and the threat of overfishing, population genetics studies of this species are lacking. Therefore, these 17 novel microsatellites markers will be a useful genetic resource for future conservation studies of P. echinatus.
We describe a model-based clustering method for using multilocus genotype data to infer population structure and assign individuals to populations. We assume a model in which there are K populations (where K may be unknown), each of which is characterized by a set of allele frequencies at each locus. Individuals in the sample are assigned (probabilistically) to populations, or jointly to two or more populations if their genotypes indicate that they are admixed. Our model does not assume a particular mutation process, and it can be applied to most of the commonly used genetic markers, provided that they are not closely linked. Applications of our method include demonstrating the presence of population structure, assigning individuals to populations, studying hybrid zones, and identifying migrants and admixed individuals. We show that the method can produce highly accurate assignments using modest numbers of loci—e.g., seven microsatellite loci in an example using genotype data from an endangered bird species. The software used for this article is available from http://www.stats.ox.ac.uk/~pritch/home.html.
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Franklin noted on his frequent trips between the United States and Europe that some trips were considerably quicker than others. He decided that this was due to a strong ocean current flowing from the west to the east. He observed marked changes in surface conditions and reasoned that this ocean current might be marked by a change in sea surface temperature. Franklin began making measurements of the ocean surface temperature during his travels. Using a simple mercury-in-glass thermometer, he was able to determine the position of the current.
This study compiled available information on the dispersal distance of the propagules of benthic marine organisms and used this information in the development of criteria for the design of marine reserves. Many benthic marine organisms release propagules that spend time in the water column before settlement. During this period, ocean currents transport or disperse the propagules. When considering the size of a marine reserve and the spacing between reserves, one must consider the distance which propagules disperse. We could find estimates of dispersal distance,for 32 taxa; for 25 of these, we were also able to find data on the time the propagules spent dispersing. Dispersal distance ranged from meters to thousands of kilometers, and time in the plankton ranged from minutes to months. A significant positive correlation was found between the log-transformed duration in the plankton and the log-transformed dispersal distance (r =. 0.7776, r(2) = 0.60, df = 1, 25, P = 0.000); the more time propagules spend in the water column the further they tend to be dispersed. The frequency distribution of the log-transformed dispersal distance is bimodal (kurtosis = -1.29, t = -4.062, P < 0.001) with a gap between 1 and 20 km. Propagules that dispersed <1 km spent less time in the plankton (<100 h), or if they remained in the plankton for a longer period, they tended to remain in the waters near the bottom. Propagules that dispersed >20 km spent more than 300 h in the plankton. The bimodal. nature of the distribution suggests that evolutionary constraints may reduce the likelihood of evolving mid-range dispersal strategies (i.e., dispersal between 1 and 20 km) resulting in two evolutionarily stable dispersal strategies: dispersal <1 km or >similar to20 km. We suggest that reserves be designed large enough to contain the short-distance dispersing propagules and be spaced far enough apart that long-distance dispersing propagules released from one reserve can settle in adjacent reserves. A reserve 4-6 km in diameter should be large enough to contain the larvae of short-distance dispersers, and reserves spaced 1020 km apart should be close enough to capture. propagules released from adjacent reserves.
The 6e of Descriptive Physical Oceanography provides an introduction to descriptive physical oceanography for advanced undergraduates and graduate students. The emphasis is on large-scale oceanography, based mainly in observations, with some topics from waves and coastal oceanography also included. Topics include the physical properties of seawater, heat and salt budgets, instrumentation, data analysis methods, introductory dynamics, oceanography and climate variability of each of the oceans and of the global ocean, and brief introductions to the physical setting, waves, and coastal oceanography.
A comparison of the documented ecology and behaviour of the separate phases in the life cycles is presented. Data gathered during the review show that during the evolution of the family from deeper-water habitats to the more rapidly fluctuating shallower waters, there have been many biological adjustments at each phase in their life cycles. In the more ancient Stridentes genera, like Puerulus, the larvae are found well below the surface waters and the pueruli often settle at greater depths than those of the adults. Long incubation times, few larval instars, and year-round spawning are probably their life cycle characteristics. As an "intermediate-evolved" genus of Stridentes, Palinurus lives along the outer shelf, grows slowly, matures late, and breeds seasonally once a year. Incubation time is long, the larvae live at depth, the number of larval instars is limited, and the puerulus is a weak swimmer. Settlement is often downstream of the breeding stock. Incubation times are short for the more recently evolved Stridentes Panulirus, the larvae pass through many instars in the surface waters to c. 200 m. Some pueruli settle in special coastal habitats, others settle in the same habitat as the adult. Breeding in the cooler water First Major Lineage species is seasonal, one or two broods being produced. Most of the species in the tropical Second Major Lineage are faster growing, breed repetitively over a long breeding season, and have a shorter larval life. For the Silentes, the trend in biological changes from deep to shallower water is comparable with that of Stridentes. Incubation is probably long in the more ancient Projasus, the larvae are rare in surface waters and the pueruli settle at depths similar to those of the adults. Sagmariasus and Jasus breed once during a defined season, incubation time is moderate, and the larvae pass through many instars. The pueruli of Sagmariasus settle downstream and exhibit contranatant migration whereas the pueruli of Jasus swim strongly to their shallow habitats. In each life cycle phase, migration methods range from vertical paddling in phyllosomata, horizontal swimming in pueruli, and horizontal walking when juveniles move to adult habitats. Adult movements are associated with foraging, searching for shelter, avoiding adverse seasonal conditions, or walking to preferred offshore locations for moulting and reproduction.
We examine the hypothesis that reef fish larvae have some direct influence on their own dispersal and ability to recruit to their natal reef by tracking cohorts of bicolor damselfish (Stegastes partitus) from hatching to settlement onto the reef, about 30 d later. We conducted high-resolution sampling during two consecutive years in a small area (15 km x 20 km) off the west coast of Barbados, extending from depths of 0 to 100 m. Observations of discrete stage-specific larval patches of mean size of 29.4 and 13.2 km2 for preflexion (>5-d old) and flexion/postflexion (>5-d old) stages extending ca. 30 m in the vertical indicated that larvae initially dispersing as patches tend to stay in coherent patches throughout their pelagic duration. Highest concentrations of preflexion larvae within a patch were in the upper 20 m, while those of older larvae were always deeper. Downward migration of about 60 m throughout ontogeny within stratified currents represented a retention mechanism for locally spawned larvae. Most of the variability in estimated retention rates between daily cohorts occurred during the earliest stages as a result of the dynamic nature of surface currents experienced by larvae prior to the onset of vertical migration. Differences in residence time between experiments were consistent with observed intermonthly variability in recruitment strength, implying that pelagic processes can explain recruitment rates. These results provide empirical evidence for larval retention of coral reef fishes and stress the role of active behavior in larval transport.
The most important populations of the spiny lobster (Panulirus argus (Latreille, 1804)) in the Atlantic are found in the Caribbean and along the Brazilian coast. Field studies covering the waters off the Cuban archipelago and Brazil have improved our understanding of the importance of oceanic circulation to larval recruitment. South of Cuba, puerulus settlement is intensive in October and November when the coastal reefs (83°W) are impacted by a cyclone-anticyclone pair, suggesting this area is the main source of retention and supply of surviving larvae, thus of self-recruitment. On the continental shelf of Brazil, puerulus settlement takes place throughout the year, but two annual peaks have been identified: one in March-April and one in July-September, when retroflection eddies of the North Brazil Current are more intense and feed into the eastward-flowing North Equatorial Countercurrent. Conceivably, Brazilian spiny lobster larvae are trapped in this oceanic system, leading to self-recruitment. On the continental shelf of Brazil the larval period lasts 6-7 months, depending on the season and spawning date. In the Caribbean the period is reported to be 6-8 months. Information on the relative abundance of early-stage spiny lobster larvae makes it possible to predict patterns of recruitment of pueruli and juveniles and the timing of their life cycle. However, further research on seasonal variations in local currents, current retroflection and ring formation is needed to clarify important aspects of larval transport, puerulus settlement and recruitment
We investigated population genetic structure within and between ocean basins in the common mesopelagic copepod, Haloptilus longicornis, using the mitochondrial marker cytochrome oxidase subunit II (mtCOII, 43 locations, n = 1059). We found highly significant genetic divergence among ocean basins (global FST = 0.20; p < 0.00001), with the exception of relatively weak genetic divergence between the South Atlantic and Indian oceans. Strong genetic breaks also were observed between populations in the northern and southern subtropical gyres of both the Atlantic and Pacific oceans (Atlantic: FCT = 0.21, Pacific: FCT = 0.15, AMOVA, p < 0.00001 for both oceans; where FCT measures genetic divergence among groups). In the Atlantic, a region of low abundance for H. longicornis in equatorial waters coincided with the location of the observed genetic break (∼ 0-12°N), suggesting the presence of a physical or bio-physical barrier that effectively limits migration among subtropical gyre systems for this species. Using oceanographic data from a basin-scale transect, we provide the first environmental portrait of an open-ocean dispersal barrier for the marine plankton. Within all four Atlantic and Pacific subtropical gyres, we found a general lack of genetic subdivision among sites, as has been observed in a few other globally distributed plankton species.
This study compiled available information on the dispersal distance of the propagules of benthic marine organisms and used this information in the development of criteria for the design of marine reserves. Many benthic marine organisms release propagules that spend time in the water column before settlement. During this period, ocean currents transport or disperse the propagules. When considering the size of a marine reserve and the spacing between reserves, one must consider the distance which propagules disperse. We could find estimates of dispersal distance for 32 taxa; for 25 of these, we were also able to find data on the time the propagules spent dispersing. Dispersal distance ranged from meters to thousands of kilometers, and time in the plankton ranged from minutes to months. A significant positive correlation was found between the log-transformed duration in the plankton and the log-transformed dispersal distance (r 5 0.7776, r 2 5 0.60, df 5 1, 25, P 5 0.000); the more time propagules spend in the water column the further they tend to be dispersed. The frequency distribution of the log-transformed dispersal distance is bimodal (kurtosis 52 1.29, t 52 4.062, P , 0.001) with a gap between 1 and 20 km. Propagules that dispersed ,1 km spent less time in the plankton (,100 h), or if they remained in the plankton for a longer period, they tended to remain in the waters near the bottom. Propagules that dispersed .20 km spent more than 300 h in the plankton. The bimodal nature of the distribution suggests that evolutionary constraints may reduce the likelihood of evolving mid-range dispersal strategies (i.e., dispersal between 1 and 20 km) resulting in two evolutionarily stable dispersal strategies: dispersal , 1k m or.;20 km. We suggest that reserves be designed large enough to contain the short-distance dispersing propagules and be spaced far enough apart that long-distance dispersing propagules released from one reserve can settle in adjacent reserves. A reserve 4-6 km in diameter should be large enough to contain the larvae of short-distance dispersers, and reserves spaced 10- 20 km apart should be close enough to capture propagules released from adjacent reserves.
A composite of the phylogenetic relationships of the species of Panulirus, based on morphological and genetic comparisons is presented. Data on the timing of the longitudinal break up of the Tethys Sea into the separate major oceans (and the resulting ecosystem changes) allow a review of the isolating mechanisms that may have resulted in the present day species distribution. These scenarios have been supplemented by personal visits to most of the regions inhabited by the various species of Panulirus. Two major phylogenetic lineages are recognized, the first emerging earlier and exhibiting a habitat preference for clear waters associated with continents or volcanic islands, the second major lineage emerging a little later and showing a distinct preference for the turbid waters of coastal habitats. The genus originated in the broad Tethys Sea and the Panulirus stock was initially divided longitudinally by the collision of Africa with Eurasia, isolating the Indo-west Pacific element; the final separation of the east Pacific from the Atlantic elements occurred with the Pliocene closure of the Panama Seaway. New habitats for incipient species were formed by these geological events as well as by the emergence of oceanic islands, climatic changes, and the formation of more discrete current systems.
[Une grande serie de la langouste d'eau peu profonde Panulirus echinatus Smith de la cote orientale du Bresil et des iles oceaniques a ete obtenue. Les etudes en plongee des habitats preferes ont montre que le sex-ratio variait fortement avec la profondeur, les femelles etant rarement trouvees au dela de 5 m. La variation a ete etudiee a travers l'aire de distribution bresilienne. Les dimorphismes entre mâles adultes et juveniles ont ete analyses et la correlation des types de disposition des taches avec les habitats observee. L'espece comprend deux formes de base en ce qui concerne cette disposition, laquelle n'est pas une reponse phenotypique aux conditions de l'environnement, mais ne presente pas des differences caracteristiques suffisantes pour justifier une separation subspecifique. Ces differences s'observent dans les memes aires geographiques, mais habituellement dans des habitats distincts., Une grande serie de la langouste d'eau peu profonde Panulirus echinatus Smith de la cote orientale du Bresil et des iles oceaniques a ete obtenue. Les etudes en plongee des habitats preferes ont montre que le sex-ratio variait fortement avec la profondeur, les femelles etant rarement trouvees au dela de 5 m. La variation a ete etudiee a travers l'aire de distribution bresilienne. Les dimorphismes entre mâles adultes et juveniles ont ete analyses et la correlation des types de disposition des taches avec les habitats observee. L'espece comprend deux formes de base en ce qui concerne cette disposition, laquelle n'est pas une reponse phenotypique aux conditions de l'environnement, mais ne presente pas des differences caracteristiques suffisantes pour justifier une separation subspecifique. Ces differences s'observent dans les memes aires geographiques, mais habituellement dans des habitats distincts.]
Spiny (rock) lobsters are the basis of important fisheries in all of the world's major oceans. We synthesize current information on their early life history from a variety of biological disciplines and draw conclusions about the significance of this phase in the ecology of the group. Larval behaviour is still poorly understood and the scale of larval dispersal conjectural. However, recruitment processes in some shallow-water species, including effects of the environment on these processes, are becoming clearer. Field and laboratory studies have increased our understanding of phyllosoma larval development and behaviour. Our knowledge of the puerulus stage has increased dramatically, particularly concerning behaviour from studies using collectors to measure settlement and through laboratory experiment. Discovery of the habitat of young juveniles has led to examination of relationships between puerulus abundance at sea, levels of puerulus settlement, and the abundance of juveniles and recruits.
Jasus is at least as old as early Miocene (20 Ma).
Genetic differentiation between J. verreauxi in
Australia and New Zealand indicates larval isolation across the northern
Tasman Sea following a northward retreat of a strong south-flowing warm
current. After South Africa and Australia separated from Antarctica, stocks of
the temperate J. lalandii subgroup of three species
became genetically isolated because of reduced larval exchange by tracking of
local environments. Once the full strength of the Antarctic Circumpolar
Current was established, a series of subantarctic islands and seamounts
provided new habitats for four species of the
J. frontalis subgroup, and their larvae responded to
local circulation systems. Speciation of nine species or subspecies of
Indo–West Pacific Panulirus probably occurred
between 9 and 3.5 Ma (late Miocene to early Pliocene) as a result of the
formation of new habitats after collisions of India and Australia with the
Asian plate. Major mountain chains resulted in high continental run-off,
produced regular tropical monsoon systems, enhanced regional upwelling,
altered oceanographic circulation patterns and restricted larval transport
between the Pacific and Indian Oceans.