Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Proc Natl Acad Sci U S A ; 117(6): 2824-2834, 2020 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-31988128

RESUMO

A conceptual model connecting seasonal loss of Arctic sea ice to midlatitude extreme weather events is applied to the 21st-century intensification of Central Pacific trade winds, emergence of Central Pacific El Nino events, and weakening of the North Pacific Aleutian Low Circulation. According to the model, Arctic Ocean warming following the summer sea-ice melt drives vertical convection that perturbs the upper troposphere. Static stability calculations show that upward convection occurs in annual 40- to 45-d episodes over the seasonally ice-free areas of the Beaufort-to-Kara Sea arc. The episodes generate planetary waves and higher-frequency wave trains that transport momentum and heat southward in the upper troposphere. Regression of upper tropospheric circulation data on September sea-ice area indicates that convection episodes produce wave-mediated teleconnections between the maximum ice-loss region north of the Siberian Arctic coast and the Intertropical Convergence Zone (ITCZ). These teleconnections generate oppositely directed trade-wind anomalies in the Central and Eastern Pacific during boreal winter. The interaction of upper troposphere waves with the ITCZ air-sea column may also trigger Central Pacific El Nino events. Finally, waves reflected northward from the ITCZ air column and/or generated by triggered El Nino events may be responsible for the late winter weakening of the Aleutian Low Circulation in recent years.

2.
Microb Ecol ; 77(2): 333-342, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30610255

RESUMO

Synechococcus is one of the most widely distributed and abundant picocyanobacteria in the global oceans. Although latitudinal variation of Synechococcus assemblage in marine surface waters has been observed, few studies compared Synechococcus assemblage composition in surface and subsurface waters at the basin scale. Here, we report marine Synechococcus diversity in the surface and deep chlorophyll maximum (DCM) layers along 170° W from the South Pacific to the Arctic Ocean in summer. Along the transect, spatial niche partitioning of Synechococcus lineages in the surface waters was clearly observed. Species richness of surface Synechococcus assemblage was positively correlated with water temperature. Clade CRD1 was dominant in the areas (15° S-10° N and 35-40° N) associated with upwelling, and there were 3 different subclades with distinct distribution. CRD1-A was restricted in the North Equatorial Current (5-10° N), CRD1-B dominated in the equatorial upwelling region (15° S-0.17° N), and CRD1-C was only distributed in the North Pacific Current (35-40° N). Similarities between the Synechococcus assemblages in the surface and DCM layers were high at the upwelling regions and areas where the mixed layer was deep, while low in the Subtropical Gyres with strong stratification. Clade I, CRD1-B, and CRD1-C were major Synechococcus lineages in the DCM layer. In particular, clade I, which is composed of 7 subclades with distinct thermal niches, was widely distributed in the DCM layer. Overall, our results provide new insights into not only the latitudinal distribution of Synechococcus assemblages, but also their vertical variation in the central Pacific.


Assuntos
Água do Mar/microbiologia , Synechococcus/classificação , Synechococcus/isolamento & purificação , Regiões Árticas , Biodiversidade , Oceano Pacífico , Filogenia , Água do Mar/química , Synechococcus/genética , Temperatura
3.
Mol Ecol ; 27(23): 4657-4679, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30378207

RESUMO

The abyssal demosponge Plenaster craigi inhabits the Clarion-Clipperton Zone (CCZ) in the northeast Pacific, a region with abundant seafloor polymetallic nodules with potential mining interest. Since P. craigi is a very abundant encrusting sponge on nodules, understanding its genetic diversity and connectivity could provide important insights into extinction risks and design of marine protected areas. Our main aim was to assess the effectiveness of the Area of Particular Environmental Interest 6 (APEI-6) as a potential genetic reservoir for three adjacent mining exploration contract areas (UK-1A, UK-1B and OMS-1A). As in many other sponges, COI showed extremely low variability even for samples ~900 km apart. Conversely, the 168 individuals of P. craigi, genotyped for 11 microsatellite markers, provided strong genetic structure at large geographical scales not explained by isolation by distance (IBD). Interestingly, we detected molecular affinities between samples from APEI-6 and UK-1A, despite being separated ~800 km. Although our migration analysis inferred very little progeny dispersal of individuals between areas, the major differentiation of OMS-1A from the other areas might be explained by the occurrence of predominantly northeasterly transport predicted by the HYCOM hydrodynamic model. Our study suggests that although APEI-6 does serve a conservation role, with species connectivity to the exploration areas, it is on its own inadequate as a propagule source for P. craigi for the entire eastern portion of the CCZ. Our new data suggest that an APEI located to the east and/or the south of the UK-1, OMS-1, BGR, TOML and NORI areas would be highly valuable.


Assuntos
Distribuição Animal , Conservação dos Recursos Naturais , Genética Populacional , Poríferos/genética , Animais , DNA Mitocondrial/genética , Genótipo , Repetições de Microssatélites , Mineração , Oceano Pacífico , Movimentos da Água
4.
J Fish Biol ; 88(2): 735-40, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26511767

RESUMO

The capture of a rarely encountered Randall's snapper Randallichthys filamentosus (female, 587 mm fork length) from the upper continental slope (c. 350 m) off the south coast of Western Australia (c. 34·5° S; 122·5° E) in January 2014 represents its first record from the temperate Indian Ocean and a southern range extension. This record suggests that spawning of this predominantly tropical species may probably be occurring in the eastern Indian Ocean, considering the extensive, and unlikely, distance the progeny would have otherwise travelled from its typical distribution in the western and central Pacific Ocean.


Assuntos
Perciformes/classificação , Filogenia , Animais , Complexo IV da Cadeia de Transporte de Elétrons/genética , Feminino , Oceano Índico , Oceano Pacífico , Análise de Sequência de DNA , Austrália Ocidental
5.
Glob Chang Biol ; 21(12): 4401-14, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26220498

RESUMO

The zooplankton of the northern California Current are typically characterized by an abundance of lipid-rich copepods that support rapid growth and survival of ecologically, commercially, and recreationally valued fish, birds, and mammals. Disruption of this food chain and reduced ecosystem productivity are often associated with climatic variability such as El Niño events. We examined the variability in timing, magnitude, and duration of positive temperature anomalies and changes in copepod species composition in the northern California Current in relation to 10 tropical El Niño events. Measurable impacts on mesozooplankton of the northern California Current were observed during seven of 10 of these events. The occurrence of anomalously warm water and the response of the copepod community was rapid (lag of zero to 2 months) following the initiation of canonical Eastern Pacific (EP) events, but delayed (lag of 2-8 months) following 'Modoki' Central Pacific (CP) events. The variable lags in the timing of a physical and biological response led to impacts in the northern California Current peaking in winter during EP events and in the spring during CP events. The magnitude and duration of the temperature and copepod anomalies were strongly and positively related to the magnitude and duration of El Niño events, but were also sensitive to the phase of the lower frequency Pacific Decadal Oscillation. When fisheries managers and biological oceanographers are faced with the prospect of a future El Niño event, prudent management and observation will require consideration of the background oceanographic conditions, the type of event, and both the magnitude and duration of the event when assessing the potential physical and biological impacts on the northern California Current.


Assuntos
Biodiversidade , Copépodes/fisiologia , El Niño Oscilação Sul , Cadeia Alimentar , Animais , California , Temperatura Alta , Oceano Pacífico , Estações do Ano , Zooplâncton/fisiologia
6.
Heliyon ; 10(18): e38099, 2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-39347404

RESUMO

Understanding the spatial fishing activity distribution characteristics is important for the sustainable development of fisheries. Spatial nonstationarity is always present, especially in marine ecosystems. To explore how marine environmental factors affect the fishing effort of tuna purse seine vessels, data from 2015 to 2020 on the fishing activities of these fleets and environmental variables in the Western and Central Pacific Ocean (WCPO) were analyzed. A Generalized Additive Model (GAM), Geographically Weighted Regression model (GWR), and Multi-Scale Geographically Weighted Regression (MGWR) model were applied to explore the drivers of fishing activity and the impacts of environmental factors on spatial heterogeneity. The results indicate that: (1) The MGWR models has the highest prediction accuracy and effectively reflects the spatial heterogeneity and multi-scale effects of environmental factors in a year. (2) Environmental factors exhibit significant multi-scale effects and spatial heterogeneity on the fishing activities of purse seine tuna vessels. Sea floor depth, salinity at 200 m depth and sea surface temperature show the greatest spatial heterogeneity in their impact on fishing activities. (3) Sea surface temperature, distance to port, and primary productivity and salinity at 200 m depth are key variables influencing the fishing activities of purse seine tuna vessels. These findings are expected to provide scientific and effective guidance for fishery management and sustainable development by assessing the spatial variations in fishing activities at multiple scales.

7.
Heliyon ; 10(12): e33298, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-39022052

RESUMO

To investigate the spatial and temporal patterns of environmental factors influencing the activity of purse seine tuna fishing vessels, data on fishing efforts of purse seine tuna fleets and environmental factors in the Western and Central Pacific Ocean (WCPO) from 2015 to 2020 were utilized to develop a geographically weighted regression (GWR) model. The results showed that fishing activity was primarily concentrated in the area between 140°E and 175°W, and between 10°S and 5°N. The GWR model showed excellent fitting performance and was suitable for correlation analysis. The environmental factors had a significant spatially heterogeneous effect on the fishing activity of purse seine tuna fishing vessels. The sea surface temperature, primary productivity at 200 m depth, and dissolved oxygen below the surface had the greatest spatially heterogeneous effect and are important environmental variables influencing the activity of purse seine tuna vessels in the WCPO. This study provides new methods for exploring the spatial distribution of fishing vessel activity to support science-based conservation and management.

8.
Environ Sci Pollut Res Int ; 28(18): 22679-22692, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33423198

RESUMO

Given their predatory characteristics, long life, and high trophic levels, sharks can have a remarkable ability to bioaccumulate and/or biomagnify trace elements (TE). In the present study, 13 TE (Hg, Pb, Cd, Cu, As, Se, Zn, Cr, V, Fe, Ni, Co, and Mn) were analyzed in the muscle tissue of three shark species (Prionace glauca, Carcharhinus falciformis, and Alopias pelagicus) using high-resolution mass spectrometry inductively coupled to a plasma generator (HR-ICP-MS); 30 shark specimens of each specie were obtained during commercial fish landings in the port of Manzanillo, Mexico. The morphometric characteristics and sex of the sharks were recorded. Shark A. pelagicus accumulated higher concentrations of TE, especially for Hg and Cd, than the other species. Significant differences in the TE levels were detected between sexes in P. glauca and A. pelagicus; in all cases, the highest concentrations were found in female muscle tissue. The ability of sharks to bioaccumulate ETs depends of the metals (essentials higher than non-essential) but is explained mainly by feeding habits associated to sexes (population segregation) and size (ontogeny). The association between TE in shark specimens was related to the essentiality, their antagonistic action, and origin. The Se/Hg ratio was significantly higher than 1, evidence of the protective role of dietary Se against Hg uptake and toxicity in all specimens of the three shark species. Also, the elevate inverse correlation of As and Cd versus Se could indicate a protective action of Se against these toxic metals, but the mechanism must be investigated.


Assuntos
Tubarões , Oligoelementos , Poluentes Químicos da Água , Animais , Monitoramento Ambiental , Feminino , México , Músculos/química , Poluentes Químicos da Água/análise
9.
Zootaxa ; 4903(1): zootaxa.4903.1.3, 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33757105

RESUMO

A new palaemonid shrimp genus, Opaepupu gen. nov., is established to accommodate a new species of bivalve-associated shrimp, Opaepupu huna sp. nov. from Hawaii. A single mated pair, the female holotype and the male allotype, were found inside the trapezid bivalve Trapezium oblongum (Linnaeus, 1758) at a depth of 14 m in Kâne'ohe Bay, Hawai'i. The new genus is characterised by the rostrum being proximally broad, distally pointed, mid-dorsally carinate, and non-dentate; the anterolateral margin of the carapace without supraorbital, hepatic or epigastric teeth, but with a strong sharp antennal tooth; the sixth pleonite posteriorly unarmed; the telson medially depressed, with the dorsal surface armed with two pairs of submarginal cuspidate setae and with the posterior margin armed with two pairs of spiniform setae; the distolateral angle of the first article of the antennular peduncle without a sharp tooth; the mandible without a palp; the maxillular palp furnished with one long stiff seta dorsal to a small tooth-like extension; the first maxilliped without a palp; the third maxilliped not being operculate; the second pereiopods moderately robust, relatively slender, subequal, subsymmetrical, with simple teeth on the cutting edges of the fingers; the ambulatory pereiopods being slender, each ending in an elongate biunguiculate dactylus; and the uropodal exopod with a faint diaeresis and greatly reduced distolateral spiniform seta. The phylogenetic position of Opaepupu gen. nov. remains unclear, although it does not appear to be closely related to other bivalve-associated palaemonid genera.


Assuntos
Bivalves , Decápodes , Palaemonidae , Distribuição Animal , Estruturas Animais , Animais , Feminino , Havaí , Masculino , Filogenia
10.
PeerJ ; 8: e9051, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32391203

RESUMO

The occurrence and diversity of elasmobranchs from the Oligocene-Miocene boundary from Tropical America is poorly known in comparison with the paleodiversity from younger Neogene intervals of the region. Here we describe a new elasmobranch assemblage from the rich fossil site of Montañita-Olón (Dos Bocas Formation, Santa Elena, Ecuador), where other vertebrates have already been described: for example, sea turtles and cetaceans. We report a total of 27 elasmobranch taxa, 19 of which are new fossil records for Ecuador, 10 new records for the Central Eastern Pacific and four new records for South America. Additionally, in order to reconstruct the environment where these marine remains were deposited, we performed abundance, paleobathymetric and habitat preference analyses, concluding that they were likely deposited in an outer neritic (open shelf) environment. The study of Oligocene and early Miocene marine elasmobranchs faunas in Tropical America is key to addressing the issues in the evolutionary history of this group.

11.
Zootaxa ; 4885(3): zootaxa.4885.3.5, 2020 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-33311270

RESUMO

The polynoid genus Chaetacanthus Seidler, 1922 currently includes three nominal species provided with parapodial branchiae. Members of this taxon have palps with longitudinal rows of papillae, notochaetae abundant and neurochaetae spinulose. Most Chaetacanthus species were originally described as belonging to Lepidonotus Leach, 1816, and some of them were later regarded as subjective synonyms of Iphione magnifica Grube, 1876, the type species for Chaetacanthus. This species was described from the Caribbean Sea and later recorded for the tropical Eastern Pacific. After the supposed Amphi-American distribution, a revision of all available material was performed in order to clarify the generic delineation, and to improve the understanding of species systematics. Further, some non-type specimens collected in Panama allowed us to have a better understanding of the variation of elytral shape and ornamentation along the body. The type material of Polynoe brasiliensis de Quatrefages, 1866 was examined and despite its poor condition, it shows parapodial branchial filaments which were overlooked in the original description; these branchiae are also present in the holotype of I. magnifica. We identify that there are no relevant difference between both species, and they are regarded as synonyms, and Chaetacanthus brasiliensis (de Quatrefages, 1866) is newly combined and is the senior synonym. On the other hand, Chaetacanthus pilosus (Treadwell, 1937), from the Eastern Pacific, and C. pomareae (Kinberg, 1856) from the South Central Pacific are redescribed, and C. harrisae n. sp., and C. ornatus n. sp. are both newly described from the Eastern Pacific. A key to identify all species of Chaetacanthus of the World, together with an appendix for the reversal of precedence of Lepidonotus Leach, 1816 over Eumolpe Oken, 1807 are also included.


Assuntos
Anelídeos , Poliquetos , Animais
12.
Folia Parasitol (Praha) ; 672020 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-33108763

RESUMO

The parasite communities of predatory fish can be species rich and diverse, making them effective models for studying the factors influencing temporal and spatial variation in these communities. Over a ten-year period an initial study was done on the metazoan parasite communities of Scomberomorus sierra (Jordan et Starks) from four locations on the south-central Pacific coast of Mexico. Twenty-four metazoan parasite taxa were identified from 674 S. sierra specimens: three species of Monogenea, eight Digenea, one Cestoda, one Acanthocephala, four Nematoda, five Copepoda, and two Isopoda. The parasite communities were characterised by high ectoparasite species richness, with monogeneans and some didymozoid species being numerically dominant. Community structure and species composition varied between locations, seasons and sampling years. Similarity between the component parasite communities was generally low, despite the occurrence of a distinctive set of host-specialist parasites. Interannual or local variations in some biotic and abiotic environmental factors are possible causes of the observed variations in the structure and species composition of the parasite community of S. sierra. Ecological factors were therefore considered to have more influence than phylogenetic aspects (host phylogeny) on parasite community structure.


Assuntos
Copépodes/fisiologia , Doenças dos Peixes/epidemiologia , Peixes , Helmintíase Animal/epidemiologia , Helmintos/fisiologia , Interações Hospedeiro-Parasita , Animais , Biodiversidade , Doenças dos Peixes/parasitologia , Helmintíase Animal/parasitologia , México/epidemiologia , Oceano Pacífico/epidemiologia , Prevalência
13.
Mar Pollut Bull ; 160: 111584, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32896714

RESUMO

In the South Pacific (SP) pearl farming atolls, wind is the main driver of lagoon water circulation, affecting dispersal and survival of pearl oyster larvae. To characterize typical wind conditions in the SP, wind regime classifications are performed from regional climate simulations using the WRF model, for present-day and for the end of the 21st century under RCP8.5 scenario conditions. At the daily time-scale, 4 regimes are identified: a trade-wind, a north-easterly, and two easterly regimes. Their characteristics are driven by large-scale circulation and climate modes of variability. In future projection, all regimes are characterized by a ~15% wind speed increase, while directions and occurrence frequencies undergo marginal changes. At the monthly time-scale that corresponds to pearl oyster pelagic larval duration, nine wind regimes are determined including three regimes with wind reversals. These regimes can be used to model typical lagoon conditions during larval dispersal.


Assuntos
Modelos Teóricos , Vento , Agricultura , Animais , Clima , Oceano Pacífico
14.
Sci Total Environ ; 740: 140109, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-32569913

RESUMO

This study investigated the connection between interannual variations in winter haze frequency over Beijing and different flavors of the El Niño-Southern Oscillation (ENSO). The results showed that the haze frequency was highest during eastern-Pacific (EP) El Niño winters and lowest during EP La Niña winters. No below-normal winter haze frequency years were observed during EP El Niño winters, and no above-normal years were observed during EP La Niña winters. However, the relationship between winter haze frequency and central-Pacific (CP) ENSO conditions was more complex, i.e., both above- and below-normal haze frequency years were equally probable during CP El Niño and CP La Niña winters, and the difference in the number of mean haze days associated with these flavors was exceptionally small. The nearly opposite atmospheric circulation patterns between EP El Niño and EP La Niña winters were responsible for the substantial difference in local winter haze frequency, as these patterns established favorable and unfavorable local meteorological conditions for haze formation, respectively. However, the diverse in situ haze frequency situations during CP El Niño and CP La Niña winters and the small relative differences between such winters could reflect the complexity of the CP ENSO's impacts on haze-related circulation anomalies. The results of this study may help improve winter haze frequency forecasts for Beijing through more accurate climatic predictions.

15.
Zootaxa ; 4758(3): zootaxa.4758.3.3, 2020 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-32230129

RESUMO

This study describes a new genus and two new species of Tanaidacea that were collected from the Singaporean exploratory area (OMS) of the polymetallic nodule fields in the eastern end of the Clarion-Clipperton Fracture Zone, Pacific Ocean. The descriptions are based on material collected during the research cruise ABYSSLINE II, which was conducted in the year 2015, covering abyssal depths of 4041-4227 m. These new species are paratanaoideans belonging to the genera Unispinosus n. gen. and Portaratrum Guerrero-Kommritz, 2003 of the family incertae sedis.


Assuntos
Crustáceos , Animais
16.
Sci Total Environ ; 655: 766-780, 2019 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-30476857

RESUMO

El Niño is a strong signal of interannual climate variability. The occurrence of an El Niño event may have an important impact on atmospheric pollutant concentrations in China through changes to the regional climate. This study quantitatively examines the differences among the effects of different types and intensities of El Niño events on winter mean aerosol concentration and severe haze days in China. It is found that Central Pacific (CP) El Niño events lead to larger increases in the aerosol burden over southern China relative to the same intensity of Eastern Pacific (EP) events. For El Niño events of the same type but with different intensities, moderate events induce large increases in surface aerosol concentrations over the entire eastern China, while strong and weak events lead to obvious decreases in the surface aerosol concentration over northern China. These differences are mainly attributed to changes in atmospheric circulation, with the resulting changes in aerosol mass transport occurring in response to the different types of El Niño event. Except for moderate CP events, all kinds of El Niño events lead to an increase in severe haze days in winter over northern China. Strong and weak EP El Niño events and weak CP El Niño events lead to an increase in severe haze days in winter over southern China. A change in the south-north transport of aerosols caused by El Niño events also play a dominate role in changing the occurrence of winter haze days in China.

17.
Zootaxa ; 4646(1): zootaxa.4646.1.5, 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31717028

RESUMO

The alpheid shrimp Nennalpheus Banner Banner, 1981, hitherto known only from a few records in the tropical western Pacific, is recorded for the first time from the tropical eastern Atlantic, as well as from the Indian Ocean. Nennalpheus gabonensis sp. nov. is described based on a single but complete male specimen collected in mediocre visibility conditions at 11 m depth on a rocky reef north of Libreville, Gabon. The new species presents a substantial number of morphological differences from the two other species of Nennalpheus, especially in the armature of the cheliped fingers. The previously known distribution range of Nennalpheus sibogae (De Man, 1910), the type species of the genus, is extended significantly to include the Central Pacific (Hawaiian Archipelago) and the Indian Ocean (Glorioso Islands in the Scattered Islands group, and Mayotte Island in the Comoro Archipelago). In addition, new illustrations of N. sibogae are provided, including the previously not figured mouthparts and high-quality, contrasting background colour photographs. Field observations indicate that Nennalpheus is able to produce a weak snapping sound by rapidly closing one or both chelipeds, a previously suspected, but never observed behaviour.


Assuntos
Decápodes , Distribuição Animal , Estruturas Animais , Animais , Comores , Gabão , Havaí , Oceano Índico , Ilhas , Masculino
18.
Zootaxa ; 4413(3): 531-540, 2018 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-29690100

RESUMO

Parmaturus nigripalatum, a new species of catshark of the genus Parmaturus is described from a single specimen collected from a deep-water shark longliner operating in south Sumbawa waters, Indonesia. This new species is distinguished from its closest geographic congener P. lanatus by having prominent enlarged caudal crests, well-developed labial furrows with the uppers and lowers of equal lengths, mouth roof blackish with dark pores, first dorsal fin origin more posteriorly positioned on body trunk, and much lower tooth counts than all other known Parmaturus species. This is the second Parmaturus species recorded from Indonesian waters.


Assuntos
Tubarões , Distribuição Animal , Animais , Peixes , Indonésia
19.
PeerJ ; 6: e5313, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30042900

RESUMO

We present the first comprehensive review of the present and past shark and ray diversity in marine waters of Tropical America, examining the patterns of distribution in the Eastern Central Pacific (EP) and Western Central Atlantic (WA) realms. We identified the major regions of diversity and of endemism, and explored the relations to physical variables. We found a strong relationship between shark and ray diversity with area and coastal length of each province. The Tropical Northwestern Atlantic Province is characterized by high diversity and greater occurrence of endemic species, suggesting this province as the hotspot of sharks and rays in Tropical America. The historical background for the current biogeography is explored and analyzed. Referential data from 67 geological units in 17 countries, from both shallow and deep-water habitats, across five time-clusters from the Miocene to the Pleistocene were studied. New data include 20 new assemblages from six countries. The most diverse Neogene and extant groups of shark and ray are Carcharhiniformes and Myliobatiformes, respectively. The differentiation between Pacific and Atlantic faunas goes to at least the middle Miocene, probably related with the increasing closure of the Central American Seaway acting as a barrier. The highest faunal similarity between the assemblages from the EP and the WA at the early Miocene could be related to the lack of a barrier back then, but increased sampling is needed to substantiate this hypothesis.

20.
Rev. biol. trop ; 71abr. 2023.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1449486

RESUMO

Introducción: El mantenimiento de las comunidades coralinas depende directamente de la capacidad de los individuos para crecer como colonia. Dado que el crecimiento forma la base de la estructura física del arrecife, determinar la tasa de crecimiento de las especies de corales constructores y su respuesta a las variaciones ambientales nos permitirá identificar su potencial particular para implementar estrategias de restauración más efectivas. Objetivo: Determinar la tasa de crecimiento del coral constructor de arrecifes Pocillopora en todo el Pacífico Central Mexicano (PCM) y su relación con las fluctuaciones en las condiciones ambientales. Métodos: De agosto de 2019 a octubre de 2020, se monitorearon y trasplantaron un total de 153 fragmentos de coral ramificado del género Pocillopora como parte del programa de restauración en diferentes sitios de la PCM: Parque Nacional Islas Marietas y en la Caleta de Cuastecomates. Se calculó el crecimiento del coral (cm·año-1) y sobrevivencia (%), y se correlacionó con la temperatura, PAR y Kd490 para cada localidad. Resultados: Patrones similares en los parámetros examinados entre los fragmentos de coral fueron encontrados para todos los sitios, con un rango de sobrevivencia de 61.6 - 68 %, cuya mortalidad estuvo relacionada principalmente con huracanes y tormentas que afectaron la región. Sin embargo, la tasa de crecimiento oscila entre 2.0 - 8.0 cm·año-1, sin diferencias significativas entre localidades. Además, no se registraron diferencias en las condiciones ambientales entre las localidades. Conclusiones: Los corales ramificados del género Pocillopora presentan una tasa de crecimiento similar en sitios insulares y costeros de la PCM, por lo que se podría esperar que la implementación de un programa de restauración en toda esta región del Pacífico Mexicano sería potencialmente exitoso, ya que, las condiciones ambientales locales no son factores limitantes.


Introduction: The maintenance of the coral communities depends directly on the capacity of the individuals to grow as a whole colony. Since growth shapes the basis of the physical structure of the reef, determining the growth rate of builder coral-species and their response to environmental variations will allow us to identify their particular potential to implement more effective restoration strategies. Objective: To determine the growth rate of the reef-building coral Pocillopora throughout the Mexican Central Pacific (PCM) and its relationship with fluctuations in environmental conditions. Methods: From August 2019 - October 2020, a total of 153 branched coral fragments of the genus Pocillopora were monitored and transplanted as part of the restoration program in different PCM locations: Islas Marietas National Park and in the Caleta de Cuastecomates. Coral growth (cm·year-1) and survival rate (%), was calculated and correlated with temperature, PAR and Kd490 for each locality. Results: The results show similar patterns in the parameters examined among the coral fragments were found for all sites, with a survival range of 61.6 - 68 %, whose mortality was mainly related to hurricanes and storms that affected the region. However, growth rate range from 2.0 - 8.0 cm·year-1, with no significant differences between locations. Also, no differences in environmental conditions between locations were recorded. Conclusions: The branching corals of the genus Pocillopora present a similar growth rate in insular and coastal sites of the PCM, so it could be expected that the implementation of a restoration program throughout this region of the Mexican Pacific would be potentially successful, since local environmental conditions are not limiting factors.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA