scholarly journals Inconclusive evidence of sexual reproduction of invasive Halophila stipulacea: a new field guide to encourage investigation of flower and fruit production throughout its invasive range

2020 ◽  
Vol 63 (6) ◽  
pp. 537-540
Author(s):  
Fee O.H. Smulders ◽  
Kelcie L. Chiquillo ◽  
Demian A. Willette ◽  
Paul H. Barber ◽  
Marjolijn J.A. Christianen
Keyword(s):  
Sexual Reproduction ◽  
Clonal Growth ◽  
Large Scale ◽  
Fruit Production ◽  
Morphological Evidence ◽  
Invasive Range ◽  
Reproductive Structures ◽  
Halophila Stipulacea ◽  
The Caribbean ◽  
Low Rate

AbstractThe dioecious seagrass species Halophila stipulacea reproduces mainly through fast clonal growth, underlying its invasive behavior. Here, we provide morphological evidence to show that the first findings of fruits in the Caribbean were misidentified. Consequently, H. stipulacea reproduction is likely still only asexual in the Caribbean. Therefore, we introduce an identification key of H. stipulacea reproductive structures to encourage careful identification and quantification throughout its invasive range. Until large-scale seed production in invaded habitats is reported, the apparent low rate of sexual reproduction needs to be considered in current studies investigating the invasion capacity of this species.

Fruits and flowers of the invasive seagrass Halophila stipulacea in the Caribbean Sea

2019 ◽  
Vol 62 (2) ◽  
pp. 109-112 ◽  
Author(s):  
Kelcie L. Chiquillo ◽  
Paul H. Barber ◽  
Demian A. Willette
Keyword(s):  
Caribbean Sea ◽  
Native Range ◽  
Native Population ◽  
Western Atlantic ◽  
Invasive Range ◽  
First Report ◽  
Halophila Stipulacea ◽  
The Caribbean ◽  
The Mediterranean ◽  
Survey Effort

Abstract While the seagrass Halophila stipulacea reproduces both sexually and asexually in its native range, reproduction is largely asexual in its invasive range in the Mediterranean and the Caribbean Seas. Here we make the first report of fruit-bearing H. stipulacea in the Caribbean. Although the lack of reports of H. stipulacea fruit could be the consequence of past survey effort, multiple recent reports of both flowers and fruit across the invasive range strongly suggest that introductions of H. stipulacea in the tropical western Atlantic and Caribbean included both sexes of this dioecious seagrass. This finding may have important implications for the future dispersal, survival, and maintenance of the non-native population.

The development characteristics of the discontinuous leader under the positive switching impulse with low rate of voltage rising

2018 ◽  
Vol 83 (2) ◽  
pp. 20802 ◽  
Author(s):  
Yaoheng Xie ◽  
Yue Yishi ◽  
Huisheng Ye ◽  
Liu Yun ◽  
Yongheng Zhong ◽  
...  
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Unit Length ◽  
Leader Development ◽  
Air Gap ◽  
Discharge Process ◽  
Temperature Changes ◽  
Channel Temperature ◽  
Impulse Voltage ◽  
Low Rate

Discontinuous leader development is the most important discharge process under the application of the switching impulse voltage with the low rate of voltage rising, which is of great significance to study the external insulation characteristics of ultra-high voltage (UHV) large scale air gap. Based on the CMOS high-speed camera, a discharge test with different operating impulse voltage is carried out by constructing a comprehensive observation platform of rod-plate air gap discharge, and a clear discontinuous leader development process picture is captured. Moreover, the leader current, injection charge and leader channel unit length charge, and their characteristics of the change trend are also obtained. Further analysis based on the experimental results shows that the discontinuous leader development under the action of the impulse voltage with low rate of voltage rising has two different laws. Finally, this paper uses the thermodynamic equation, combined with the test results, the channel temperature changes in the discontinuous leader development stagnation stage were calculated. The results show that the leader channel temperature is still greater than 1500 K in the hundreds of microsecond time scales in the leader stagnation stage, and the subsequent leader can continue to develop on the original leader channel.

scholarly journals Multigene phylogeny of the family Cordycipitaceae (Hypocreales): new taxa and the new systematic position of the Chinese cordycipitoid fungus Paecilomyces hepiali

2020 ◽  
Vol 103 (1) ◽  
pp. 1-46
Author(s):  
Yuan-Bing Wang ◽  
Yao Wang ◽  
Qi Fan ◽  
Dong-E Duan ◽  
Guo-Dong Zhang ◽  
...  
Keyword(s):  
New Species ◽  
Large Scale ◽  
Sequence Data ◽  
Systematic Position ◽  
New Combination ◽  
Morphological Evidence ◽  
New Combinations ◽  
Asexual Morph ◽  
The Family ◽  
Paecilomyces Hepiali

Abstract The phylogeny and systematics of cordycipitoid fungi have been extensively studied in the last two decades. However, systematic positions of some taxa in the family Cordycipitaceae have not yet been thoroughly resolved. In this study, a new phylogenetic framework of Cordycipitaceae is reconstructed using multigene (nrSSU, nrLSU, tef-1α, rpb1 and rpb2) sequence data with large-scale taxon sampling. In addition, ITS sequence data of species belonging to the Lecanicillium lineage in the family Cordycipitaceae are used to further determine their phylogenetic placements. Based on molecular phylogenetic data together with morphological evidence, two new genera (Flavocillium and Liangia), 16 new species and four new combinations are introduced. In the new genus Flavocillium, one new species F. bifurcatum and three new combinations previously described as Lecanicillium, namely F. acerosium, F. primulinium and F. subprimulinium, are proposed. The genus Liangia is built by the new species Lia. sinensis with Lecanicillium-like asexual morph, isolated from an entomopathogenic fungus Beauveria yunnanensis. Due to the absence of Paecilomyces hepiali, an economically and medically significant fungus, in the earlier phylogenetic analyses, its systematic position has been puzzling in both business and academic communities for a long time. Here, P. hepiali is recharacterized using the holotype material along with seven additional samples. It is assigned to the genus Samsoniella (Cordycipitaceae, Hypocreales) possessing Cordyceps-like sexual morph and Isaria-like asexual morph, and thus a new combination, namely S. hepiali is proposed. An additional nine new species in Samsoniella are described: S. alpina, S. antleroides, S. cardinalis, S. cristata, S. lanmaoa, S. kunmingensis, S. ramosa, S. tortricidae and S. yunnanensis. Four new species in Cordyceps are described: C. chaetoclavata, C. cocoonihabita, C. shuifuensis and C. subtenuipes. Simplicillium yunnanense, isolated from synnemata of Akanthomyces waltergamsii, is described as a new species.

Rapport des sexes, effort et succès de reproduction chez Rubus chamaemorus, plante herbacée vivace dioïque de distribution subarctique

1987 ◽  
Vol 65 (12) ◽  
pp. 2628-2639 ◽  
Author(s):  
Pascale Dumas ◽  
Lucie Maillette
Keyword(s):  
Reproductive Success ◽  
Sexual Reproduction ◽  
Sex Ratios ◽  
Female Flower ◽  
Fruit Production ◽  
Climatic Conditions ◽  
Total Biomass ◽  
Dioecious Species ◽  
Pollinator Behaviour ◽  
Rubus Chamaemorus

Studies published on the reproductive success of dioecious species concentrate on the role of sex ratios and pollinator behaviour. In the case of Rubus chamaemorus L., a circumboreal dioecious species, we hypothesized that flower survival and biomass allocation to reproductive tissues, which are climate dependent, also influence fruit production. Only 0.05% of total biomass is allocated to reproduction, whereas 94% goes to underground organs responsible for vegetative propagation. Many male (28 – 51%) and female flower buds (35 – 54%) and young fruits (24–51%) die prematurely mainly because of the climate; fruit production then becomes independent from initial female flower density. The scarcity of female flowers at most sites (except near open water) limits fruit production. The limited sexual reproduction would allow cloudberry to maintain somatic resources, thereby increasing the longevity of individuals and their chance of encountering the climatic conditions required for reproductive success. Such a strategy is adaptive in a variable climate like that of the subarctic. Furthermore, the reduced importance of sexual reproduction would diminish the need to optimize sex ratios. Other selective pressures (e.g., competition) would then favour male clones in most sites, in spite of the unproductive pollen excess.

The Spanish Caribbean, 1492–1550

2018 ◽  
Author(s):  
Ida Altman
Keyword(s):  
Native Americans ◽  
Large Scale ◽  
Institutional Development ◽  
Indigenous Communities ◽  
16Th Century ◽  
Christopher Columbus ◽  
Spanish Caribbean ◽  
African Slaves ◽  
The Caribbean ◽  
Diverse Groups

The arrival of Christopher Columbus in the northern Caribbean with three Spanish ships in October 1492 marked the beginning of continuing European contact with the Americas. With his second voyage of 1493 permanent European occupation of the Caribbean began, with enormous consequences for the peoples and ecology of the region. Failing to encounter the wealthy trading societies that Columbus had hoped to find by reaching Asia, Europeans in the Caribbean soon realized that they would have to involve themselves directly in organizing profitable enterprises. Gold mining in the northern islands and pearl fishing in the islands off the coast of Tierra Firme (present-day Venezuela) for some years proved enormously profitable but depended on Spaniards’ ability to exploit indigenous labor on a large scale. The imposition of the Spanish encomienda system, which required indigenous communities to provide labor for mining and commercial agriculture, and the large-scale capture and transportation of Native Americans from one locale to another wrought havoc among the indigenous peoples of the Caribbean and circum-Caribbean, resulting in high mortality and flight. Spaniards in the islands soon sought to supplement indigenous labor by importing African slaves who, in the early 16th century, became a significant if not always easily controlled presence in the region. From the earliest years the Spanish Caribbean was a complex, dynamic, and volatile region characterized by extensive interaction and conflict among diverse groups of people and by rapid economic and institutional development. Although the islands became the launching grounds for subsequent Spanish moves to the nearby mainland, throughout the 16th century and beyond they played a crucial role in sustaining Spain’s overseas empire and integrating it into the larger Atlantic system.

Iospilids (Polychaeta: Iospilidae) from the northwest Caribbean Sea, with observations on reproductive structures

Zootaxa ◽  
2006 ◽  
Vol 1211 (1) ◽  
pp. 53 ◽  
Author(s):  
SOLEDAD JIMÉNEZ-CUETO ◽  
EDUARDO SUÁREZ-MORALES ◽  
SERGIO I. SALAZAR-VALLEJO
Keyword(s):  
Caribbean Sea ◽  
Common Species ◽  
Eastern Coast ◽  
Reproductive Process ◽  
Morphological Variations ◽  
Reproductive Structures ◽  
Morphological Adaptations ◽  
The Family ◽  
Mode Of Life ◽  
The Caribbean

Iospilids are a small, inconspicuous group of holopelagic polychaetes that dwell in the upper layers of tropical, temperate, and cold waters of the world. Representatives of this interesting and infrequent group were collected during four oceanographic cruises off the eastern coast of the Yucatan Peninsula, northwest Caribbean Sea. Three of the four species currently known in the family were recorded: Iospilus phalacroides Viguier, 1886, Phalacrophorus pictus Greeff, 1879, and P. uniformis Reibisch, 1895. The latter was the most common species in the area; it occurred during the four cruises and represented more than 92% of the total iospilid specimens caught; it was slightly more abundant in nighttime samples. New observations of reproduction-related morphological variations and sexual dimorphism are presented for P. uniformis. These may be regarded as morphological adaptations to the planktic mode of life thus favouring the efficiency of the reproductive process in the water column. These are the first records of the family Iospilidae in the Caribbean Basin. Revised generic and species diagnoses, taxonomic illustrations and notes, and an identification key are given here for the species recorded in the Caribbean.

IX. Report on the eruptions of the soufrière, St. Vincent, 1902, and on a visit to Montagne Pelèe, in Martinique. -Part I.

1903 ◽  
Vol 200 (321-330) ◽  
pp. 353-553 ◽  
Author(s):  
Tempest Anderson ◽  
John Smith Flett
Keyword(s):  
Tropical Forest ◽  
Sugar Cane ◽  
Large Scale ◽  
Main Axis ◽  
The Caribbean ◽  
Geological Work ◽  
Steep Slopes

The islands of the Caribbean chain have been occupied by European colonists for several hundred years, yet they cannot even at the present day be said to be thoroughly known or sufficiently explored. Though small, they are for the most part moun­tainous, and present usually a ridge or backbone of high land forming the main axis of each island, with sharp spurs on each side running down to the sea. Cul­tivation is practically confined to the lower grounds, where alone there are goodroads, and the interior is covered with dense tropical forest, the aspect of which varies greatly with the altitude, and through which there are only rough bush paths. The valleys are usually very deep and narrow, and the steep slopes are covered with plantations of arrowroot, limes, cocoa, coffee, banana or plantain, while most of the level alluvial ground in the valley bottoms is given up to the growth of sugar cane. In all the British islands, at any rate, the principal peaks and ridges have been ascended, and the main features of the country are delineated on the Admiralty charts, which are the best, and in fact the only available maps. As regards the coast-lines and the lower grounds generally, they are very accurate; but in theinterior only the more important points, the principal mountain summits and the like, have had their position sufficiently determined. The rest of the country has apparently been sketched in more or less carefully—but many of the details as, for example, the courses of the smaller streams, and the number of their branches, cannot be relied on. The want of a good map on a fairly large scale is a great drawback in geological work, and prevents the structure of the country being laid down with anyapproach to minuteness.

An evaluation of the genus Kincaidiana Altman, 1936, with the designation of Altmanella n. gen. (Annelida, Clitellata, Lumbriculidae)

Zootaxa ◽  
2009 ◽  
Vol 2077 (1) ◽  
pp. 1-30 ◽  
Author(s):  
STEVEN V. FEND
Keyword(s):  
North America ◽  
Large Scale ◽  
New Genus ◽  
Pacific Coast ◽  
Morphological Characters ◽  
Reproductive Organs ◽  
Regional Patterns ◽  
Reproductive Structures ◽  
New Material ◽  
Morphological Differences

A review of morphological characters for the western Nearctic genus Kincaidiana indicated that the two described species should be assigned to separate genera. Kincaidiana freidris Cook was transferred to a new genus, Altmanella. New material resembling A. freidris was obtained from many sites throughout western North America. Morphology of the male reproductive structures varied among populations, and the most distinctive morphological differences were accounted for by splitting the taxon into two species, which roughly corresponded to large scale regional patterns. Typical A. freidris occurred in several Pacific Coast drainages. Altmanella idahoensis n. sp., mostly associated with the Snake River drainage, was distinguished from A. freidris by shorter and less muscular atria and penial structures. A second new lumbriculid species with the same basic arrangement of reproductive organs was collected in southeastern North America, and was provisionally assigned to Altmanella. However, in contrast to the petiolate atria and large penial structures of A. freidris and A. idahoensis, Altmanella lenati n. sp. has tubular atria and simple male porophores.

scholarly journals An Analysis of Moisture Fluxes into the Gulf of California

2009 ◽  
Vol 22 (8) ◽  
pp. 2216-2239 ◽  
Author(s):  
Man-Li C. Wu ◽  
Siegfried D. Schubert ◽  
Max J. Suarez ◽  
Norden E. Huang
Keyword(s):  
Time Scales ◽  
Time Scale ◽  
Gulf Of California ◽  
Large Scale ◽  
Moisture Flux ◽  
Easterly Waves ◽  
Low Level ◽  
Moisture Fluxes ◽  
The Caribbean ◽  
The U.S

Abstract This study examines the nature of episodes of enhanced warm-season moisture flux into the Gulf of California. Both spatial structure and primary time scales of the fluxes are examined using the 40-yr ECMWF Re-Analysis data for the period 1980–2001. The analysis approach consists of a compositing technique that is keyed on the low-level moisture fluxes into the Gulf of California. The results show that the fluxes have a rich spectrum of temporal variability, with periods of enhanced transport over the gulf linked to African easterly waves on subweekly (3–8 day) time scales, the Madden–Julian oscillation (MJO) at intraseasonal time scales (20–90 day), and intermediate (10–15 day) time-scale disturbances that appear to originate primarily in the Caribbean Sea–western Atlantic Ocean. In the case of the MJO, enhanced low-level westerlies and large-scale rising motion provide an environment that favors large-scale cyclonic development near the west coast of Central America that, over the course of about 2 weeks, expands northward along the coast eventually reaching the mouth of the Gulf of California where it acts to enhance the southerly moisture flux in that region. On a larger scale, the development includes a northward shift in the eastern Pacific ITCZ, enhanced precipitation over much of Mexico and the southwestern United States, and enhanced southerly/southeasterly fluxes from the Gulf of Mexico into Mexico and the southwestern and central United States. In the case of the easterly waves, the systems that reach Mexico appear to redevelop/reorganize on the Pacific coast and then move rapidly to the northwest to contribute to the moisture flux into the Gulf of California. The most intense fluxes into the gulf on these time scales appear to be synchronized with a midlatitude short-wave trough over the U.S. West Coast and enhanced low-level southerly fluxes over the U.S. Great Plains. The intermediate (10–15 day) time-scale systems have zonal wavelengths roughly twice that of the easterly waves, and their initiation appears to be linked to an extratropical U.S. East Coast ridge and associated northeasterly winds that extend well into the Caribbean Sea during their development phase. The short (3–8 day) and, to a lesser extent, the intermediate (10–15 day) time-scale fluxes tend to be enhanced when the convectively active phase of the MJO is situated over the Americas.

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