Distribution patterns and dispersal of prosobranch gastropods along a seamount chain in the Atlantic Ocean

1991 ◽  
Vol 71 (1) ◽  
pp. 11-25 ◽  
Author(s):  
Josó H. Leal ◽  
Philippe Bouchet
Keyword(s):  
Distribution Patterns ◽  
Larval Transport ◽  
Eastern Coast ◽  
Similarity Coefficients ◽  
Specific Level ◽  
Trindade Island ◽  
Shallow Subtidal ◽  
Selection For ◽  
Seamount Chain ◽  
And Cluster Analysis

Based on qualitative data on prosobranch gastropods present at eight seamounts and islands of the Vitória-Trindade Seamount Chain off the eastern coast of Brazil, similarities at the species level are examined, and the effects of selection for different modes of development varying with increasing distance from the coast are investigated. Number of species decreases significantly from the continent towards easternmost localities. Similarity coefficients and cluster analysis suggest that similarities are greater among the western seamounts, followed by the eastern, most oceanic localities. Subtidal stations on Trindade Island show less similarity at specific level when compared with the remaining sublittoral stations. Percentages and absolute numbers of species with intracapsular metamorphosis decrease rapidly away from the coast in the sublittoral localities. However, there is little variation for the ratio planktotrophs/lecithotrophs among these localities, and their percentages remained constant over the entire Chain. In spite of the slightly wider range of distribution of planktotrophs within the Chain, the observations suggest that both planktotrophs and lecithotrophs can be effectively dispersed, probably by passive larval transport, in an ‘island-hopping’ pattern across the relatively small distances (100–250 km) that separate summits in the Chain. Notwithstanding shallow, subtidal conditions and intense isolation, percentages of planktotrophs and lecithotrophs also do not vary at the subtidal Trindade stations.

A prickly subject: innovative handling of a difficult prey

2018 ◽  
Vol 40 (2) ◽  
pp. 294
Author(s):  
Linda Behrendorff
Keyword(s):  
Canis Lupus ◽  
Eastern Coast ◽  
Island Ecosystems ◽  
Subtidal Area ◽  
Shallow Subtidal ◽  
Handling Technique ◽  
Prey Handling ◽  
Ambush Predators ◽  
Tachyglossus Aculeatus

Canids are generally considered to be ambush predators, but in island ecosystems adaptability and flexibility are essential for survival. Dingoes (Canis lupus dingo) attack and kill their prey in a variety of ways including utilising waterbodies. Here I document the drowning of an adult short-beaked echidna (Tachyglossus aculeatus) before consumption by a dingo using the coastal surf beach intertidal to shallow subtidal area on the eastern coast of Fraser Island (K’gari), highlighting an innovative prey-handling technique.

scholarly journals Genetic variation of Indian potato (Solanum tuberosum L.) genotypes using chromosomal and RAPD markers

2010 ◽  
Vol 10 (3) ◽  
pp. 238-246 ◽  
Author(s):  
Anath Bandhu Das ◽  
Iswar Chandra Mohanty ◽  
Dawanidhi Mahapatra ◽  
Suprava Mohanty ◽  
Ashutosh Ray
Keyword(s):  
Genetic Diversity ◽  
Rapd Markers ◽  
Solanum Tuberosum L ◽  
Chromosome Analysis ◽  
Genetic Distances ◽  
Chromosome Length ◽  
Similarity Coefficients ◽  
Varietal Improvement ◽  
And Cluster Analysis ◽  
4C Dna Content

Genetic diversity in thirty Indian potatoes were analyzed employing karyotype, genome size and RAPD markers. Chromosome analysis revealed 2n = 4x = 48 except cv. K. Chandramukhi (2n = 4x + 2 = 50). Total genomic chromosome length and chromosome volume varied from 21.14µm in cv. K. Pukhraj to 31.91µm in cv. MS/89-60 and 14.31µm³ in cv. MS/92-1090 to 33.16µm³ in cv. JW-160 respectively. 4C DNA content was significantly varied from 3.640 pg (~891 Mbp) in cv. MS/92-1090 to 11.12 pg (~2747 Mbp) in cv. K. Chandramukhi. RAPD revealed 131 amplified DNA fragments (300 to 2200 bp) with 79 unique bands (7 to 71% polymorphism) among the genotypes. Similarity coefficients (ranged from 0.29 to 0.93) and cluster analysis reflected the expected trends in relationships of the full and half-sib potato genotypes. Genetic distances obtained from a dendrogram could help breeders to choose the diverse parents for a breeding program aimed at varietal improvement.

Stratigraphy of the Upper Ordovician upper Vaureal and Ellis Bay formations, eastern Anticosti Island, Quebec

1987 ◽  
Vol 24 (9) ◽  
pp. 1807-1820 ◽  
Author(s):  
D. G. F. Long ◽  
Paul Copper
Keyword(s):  
Late Ordovician ◽  
Eastern Coast ◽  
Upper Ordovician ◽  
New Members ◽  
Patch Reefs ◽  
Accurate Definition ◽  
Central Regions ◽  
Shallow Subtidal ◽  
Anticosti Island ◽  
Definition Of

Marked facies changes occur in Late Ordovician strata, assigned to the uppermost Vaureal and Ellis Bay formations (Ashgill: Rawtheyan–Hirnantian) on Anticosti Island, Quebec. Western Anticosti features shales and carbonates, whereas outcrops along the eastern coast contain prominent, discontinuous, mixed siliciclastic–carbonate units. Detailed section measurement along the northeast coast allows, for the first time, accurate definition of seven new members within this uninterrupted sequence. Sands present in the upper Vaureal and lower Ellis Bay formations in the east appear to have deterred the growth of muddy-bottom brachiopod communities comparable to those in the western and central regions of Anticosti. Sand units within the upper Vaureal Formation contain 1 m diameter colonies of Paleofavosites; coeval small coral patch reefs are found in the central part of the island, where sands are absent. The uppermost Ellis Bay Formation of northeast Anticosti is marked by a shallow, subtidal, coral–algal oncolite bed or by small (2–4 m across, 1–2 m thick) local coral patch reefs, the tops of which have been used to define the Ordovician – Silurian boundary. No supratidal or intertidal sediments and faunas are evident in the Anticosti succession, suggesting that Late Ordovician sea-level drawdown was insufficient to provide shelf-emergent conditions in this region.

scholarly journals The Effects of Temporal Variation on Fitness, Functional Traits, and Species Distribution Patterns

2019 ◽  
Vol 59 (3) ◽  
pp. 503-516 ◽  
Author(s):  
Nancy C Emery ◽  
Raffica J La Rosa
Keyword(s):  
Soil Moisture ◽  
Phenotypic Plasticity ◽  
Temporal Variation ◽  
Functional Traits ◽  
Water Table ◽  
Species Distribution ◽  
Distribution Patterns ◽  
Vernal Pools ◽  
Bet Hedging ◽  
Selection For

AbstractTemporal variation is a powerful source of selection on life history strategies and functional traits in natural populations. Theory predicts that the rate and predictability of fluctuations should favor distinct strategies, ranging from phenotypic plasticity to bet-hedging, which are likely to have important consequences for species distribution patterns and their responses to environmental change. To date, we have few empirical studies that test those predictions in natural systems, and little is known about how genetic, environmental, and developmental factors interact to define the “fluctuation niche” of species in temporally variable environments. In this study, we evaluated the effects of hydrological variability on fitness and functional trait variation in three closely related plant species in the genus Lasthenia that occupy different microhabitats within vernal pool landscapes. Using a controlled greenhouse experiment, we manipulated the mean and variability in hydrological conditions by growing plants at different depths with respect to a shared water table and manipulating the magnitude of stochastic fluctuations in the water table over time. We found that all species had similarly high relative fitness above the water table, but differed in their sensitivities to water table fluctuations. Specifically, the two species from vernal pools basins, where soil moisture is controlled by a perched water table, were negatively affected by the stochasticity treatments. In contrast, a species from the upland habitat surrounding vernal pools, where stochastic precipitation events control soil moisture variation, was insensitive to experimental fluctuations in the water table. We found strong signatures of genetic, environmental (plastic), and developmental variation in four traits that can influence plant hydrological responses. Three of these traits varied across plant development and among experimental treatments in directions that aligned with constitutive differences among species, suggesting that multiple sources of variation align to facilitate phenotypic matching with the hydrological environment in Lasthenia. We found little evidence for predicted patterns of phenotypic plasticity and bet-hedging in species and traits from predictable and stochastic environments, respectively. We propose that selection for developmental shifts in the hydrological traits of Lasthenia species has reduced or modified selection for plasticity at any given stage of development. Collectively, these results suggest that variation in species’ sensitivities to hydrological stochasticity may explain why vernal pool Lasthenia species do not occur in upland habitat, and that all three species integrate genetic, environmental, and developmental information to manage the unique patterns of temporal hydrological variation in their respective microhabitats.

Nothria and Anchinothria (Annelida: Onuphidae) from eastern Australian waters, with a discussion of ontogenetic variation of diagnostic characters

2013 ◽  
Vol 93 (6) ◽  
pp. 1481-1502 ◽  
Author(s):  
Nataliya Budaeva ◽  
Hannelore Paxton
Keyword(s):  
New Species ◽  
First Record ◽  
Diagnostic Value ◽  
Wide Distribution ◽  
Eastern Coast ◽  
Ontogenetic Variation ◽  
Size Dependent ◽  
Antarctic Waters ◽  
Shallow Subtidal ◽  
Japanese Waters

Nothria and Anchinothria, two sister genera of onuphid worms were studied from eastern Australian waters. Nothria abyssia, with a wide distribution in Pacific and Antarctic waters is reported from slope depths south-east of Australia, while N. otsuchiensis, described from Japanese waters, was found along the eastern coast of Australia from shallow subtidal to deep slope areas. Anchinothria parvula sp. nov. is described, based on the presence of uni- and bidentate pseudocompound falcigers in the first three pairs of parapodia, absence of branchiae and appearance of limbate chaetae from chaetiger 2, subacicular hooks from chaetigers 6–8 and pectinate chaetae from chaetiger 14. The new species represents the first record of the genus in Australian waters. Ontogenetic variation of chaetal composition and morphology of parapodia was estimated in two Nothria species examined. Three size-related morphotypes with different chaetal composition and morphology of anterior falcigers were revealed in N. abyssia and N. otsuchiensis. The number of chaetigers with pseudocompound falcigers is the only character independent of size of the specimens in both examined species. Distribution of subacicular hooks and postchaetal lobes is shown to be size-dependent. The following characters are considered of diagnostic value only when scored in adults: presence/absence of simple falcigers in anterior parapodia; chaetiger of origin of limbate chaetae, pectinate chaetae, and subacicular hooks; and number of chaetigers with auricular prechaetal lobes and digitiform postchaetal lobes. The use of adult specimens with the final set of definitive morphological structures for diagnoses of Nothria species is suggested.

scholarly journals Movements and geographic distribution of juvenile bluefin tuna in the Northeast Atlantic, described through internal and satellite archival tags

2018 ◽  
Vol 75 (5) ◽  
pp. 1560-1572 ◽  
Author(s):  
Igor Arregui ◽  
Benjamin Galuardi ◽  
Nicolas Goñi ◽  
Chi Hin Lam ◽  
Igaratza Fraile ◽  
...  
Keyword(s):  
Distribution Patterns ◽  
Bluefin Tuna ◽  
The United States ◽  
Eastern Coast ◽  
Bay Of Biscay ◽  
Atlantic Bluefin Tuna ◽  
Archival Tags ◽  
Feeding Area ◽  
Spatio Temporal ◽  
Surrounding Areas

Abstract From 2005 to 2010, 136 internal archival tags and 29 pop-up satellite archival tags were used to track juvenile Atlantic bluefin tuna in the Bay of Biscay. Information from 15 pop-up and 5 internal archival tags was recovered. The analysis was adapted for a common treatment of both types of tag data, allowing classification of overwintering distribution patterns, fidelity to the Bay of Biscay feeding area, as well as of horizontal and vertical habitat utilization. Results show substantial geographic dispersion from autumn to spring, with high habitat concentration in the Bay of Biscay during summer, when bluefin tuna inhabit in the mixed layer. Of the individuals that left the Bay of Biscay towards the end of the year, a high percentage returned the next year, suggesting a strong fidelity to the area. Thirty-three percent of records during the overwintering periods revealed residency in the Bay of Biscay and surrounding areas. Half of the fish overwintered in the mid-Atlantic, near the Azores or Madeira Islands, while three (17%) made trans-Atlantic round trips, and one individual travelled to and remained off the eastern coast of the United States. These findings challenge previous assumptions regarding the seasonality and annual movements of bluefin tuna from the Bay of Biscay, while demonstrating extensive spatio-temporal dispersion.

scholarly journals Ecology, more than antibiotics consumption, is the major predictor for the global distribution of aminoglycoside-modifying enzymes

2022 ◽  
Author(s):  
Lea Pradier ◽  
Stephanie Bedhomme
Keyword(s):  
Antibiotic Resistance ◽  
Distribution Patterns ◽  
Antibiotic Use ◽  
Ecological Distribution ◽  
Aminoglycoside Resistance ◽  
Genomic Distribution ◽  
Genes Encoding ◽  
Major Predictor ◽  
Selection For ◽  
Terrestrial Biomes

Antibiotics consumption and its abuses have been historically and repeatedly pointed out as the major driver of antibiotic resistance emergence and propagation. However, several examples show that resistance may persist despite substantial reductions in antibiotic use, and that other factors are at stake. Here we study the temporal, spatial, and ecological distribution patterns of aminoglycoside resistance, by screening more than 160,000 publicly available genomes for 27 clusters of genes encoding aminoglycoside-modifying enzymes (AMEGs). We find that AMEGs are ubiquitous: about 25% of sequenced bacteria carry AMEGs. These bacteria were sequenced from all the continents and terrestrial biomes, and belong to a wide number of phyla. By focusing on several European countries between 1997 and 2018, we show that aminoglycoside consumption has little impact on the prevalence of AMEG-carrying bacteria, whereas most variation in prevalence is observed among biomes. We further analyze the resemblance of resistome compositions across biomes: soil, wildlife, and human samples appear to be central to understand the exchanges of AMEGs between different ecological contexts. Moreover, the genomic distribution of AMEGs suggests a selection for widening resistance spectra, mostly driven by mobile genetic elements. Together, these results support the idea that interventional strategies based on reducing antibiotic use should be complemented by a stronger control of exchanges, especially between ecosystems.

scholarly journals Effect of Flood Disaster and Long Term Changes during 2011 to 2018 on Community Structure of Zooplankton in the Inner Gulf of Thailand

2020 ◽  
Vol 11 (8) ◽  
pp. 383-389
Author(s):  
Porntep Punnarak ◽  
Pramot Sojisuporn ◽  
Hattaya Jitrapat ◽  
Ajcharaporn Piumsomboon
Keyword(s):  
Community Structure ◽  
Environmental Parameters ◽  
Distribution Patterns ◽  
Flood Disaster ◽  
Eastern Coast ◽  
Gulf Of Thailand ◽  
Calanoid Copepods ◽  
Data Set ◽  
Contour Maps

This study of community structure of zooplankton in the Inner Gulf of Thailand was initiated in late 2011 in response to a major flood disaster event and continued intermittently to 2018. Six cruises with 13-20 replicate stations/cruise, provided data for contour maps of zooplankton, nutrients, water hydrography, pigments and algae; this manuscript utilized this diverse data set to focus on mesozooplankton. Immediately after the flood, November 2011, mesozooplankton communities were dominated by calanoid copepods with contributions of about 78% of the total. This changed in 2012 to 2018 which the proportion of calanoid copepods was decreased while the other zooplankton such as hydromedusae, polychaete larvae, barnacle nauplii, pelagic shrimp (Lucifer sp. and protozoea) and chaetognaths were increased. The density of mesozooplankton varied between 1.70 x 104 to 1.26 x 106 ind./100 m3 with noticeably high densities near the four river mouths that flow into Inner Gulf. Distribution patterns of mesozooplankton emerged that are likely similar to the long-term patterns of this region which effected by water circulation in the Inner Gulf of Thailand. However, high density of zooplankton in November 2012 and October 2017 appeared along the north-eastern coast and may be related to the availability of food (i.g., algae). Zooplankton abundances in the Inner Gulf of Thailand were significantly correlated with environmental parameters mainly temperature, salinity and food supplies as represented by chlorophyll a concentrations.

scholarly journals SHAPE AND CLUSTER ANALYSIS FOR DIFFERENT DETECTER PATTERNS OF RHIZOPRIONODON POROSUS IN NORTHEAST COAST OF BRAZIL

2019 ◽  
Vol 37 (2) ◽  
pp. 258
Author(s):  
Leandro Ricardo Rodrigues de LUCENA ◽  
Rosângela Paula Teixeira LESSA
Keyword(s):  
Coastal Waters ◽  
Northeastern Brazil ◽  
Eastern Coast ◽  
Morphometric Study ◽  
Small Fish ◽  
Northern Coast ◽  
Anatomical Landmarks ◽  
And Cluster Analysis ◽  
Species Specific ◽  
Two Populations

The genus Rhizoprionodon comprises seven species of sharks occurring in the Atlantic, Pacific and Indian Oceans, the species are small and medium-sized animals attaining about 150 cm, inhabiting coastal waters, estuaries and brackish waters and feeding mainly on mollusks, crustaceans and small fish. In Brazil the two species are found Rhizoprionodon porosus and lalandi. The use of morphometric approaches has limitations for this group due to lack of anatomical landmarks, since they have a continuous form without angles. This study will analyze the chondrocranium a structure that is considered species-specific. The study aims to verify the hypothesis suggested in the literature of two populations of the species R. porosus off northeastern Brazil. One corresponds to the northern coast of the Northeast (RN) and the other to the eastern coast of this region (PE). For that we performed a comparative morphometric study of the chondrocranium of R. porosus between the indicated areas using shape and cluster analyses. Thus, there were differences both for adult and juvenile phases by regions of capture. In conclusion, there is indeed a difference between chondrocranium from Pernambuco and Rio Grande do Norte as showed by approaches used.

Sign in / Sign up

Export Citation Format

Share Document