440 research outputs found
FIGURE 1 in Key to the currently recognized species of Limnias Schrank, 1803 (Rotifera, Monogononta, Gnesiotrocha, Flosculariidae)
No full textFIGURE 1. Representative morphology of two species of Limnias. (A) Limnias melicerta in ventral view. (NB: Ventral antennae on the opposite side obscured.) Inset: Region of dorsal nodules: (3 rows: 2,3,2). (B) L. melicerta in 3/4th ventral view. (C) Limnias ceratophylli in 3/4th ventral view. Symbols: a = algae and debris; b = adult body; c = corona; dn = dorsal nodules; e = amictic embryo; f = foot; rt = ringed tube; s = substratum; st = stucco-like tube (with adhering epiphytes and debris); va = ventral antennae; bars ~100 µm. (Photomicrographs B and C are courtesy of Michael Plewka.)Published as part of Wallace, Robert Lee, Kordbacheh, Azar & Walsh, Elizabeth J., 2018, Key to the currently recognized species of Limnias Schrank, 1803 (Rotifera, Monogononta, Gnesiotrocha, Flosculariidae), pp. 307-318 in Zootaxa 4442 (2) on page 308, DOI: 10.11646/zootaxa.4442.2.7, http://zenodo.org/record/130316
FIGURE 3 in Key to the currently recognized species of Limnias Schrank, 1803 (Rotifera, Monogononta, Gnesiotrocha, Flosculariidae)
No full textFIGURE 3. Two rare Limnias species. (A) Limnias myriophylli. (B) Limnias shiawasseensis (Line art as indicated; photomicrograph of Specimen Preparation ANSP 486 [collected by C.F. Rousselet] courtesy of C. Jersabek; The Academy of Natural Sciences of Drexel University). Symbols: ctb = clear tube base; f = foot; s = substratum; bar = 100 µm.Published as part of Wallace, Robert Lee, Kordbacheh, Azar & Walsh, Elizabeth J., 2018, Key to the currently recognized species of Limnias Schrank, 1803 (Rotifera, Monogononta, Gnesiotrocha, Flosculariidae), pp. 307-318 in Zootaxa 4442 (2) on page 313, DOI: 10.11646/zootaxa.4442.2.7, http://zenodo.org/record/130316
Interview with Azar Nafisi
No full textIranian author Azar Nafisi speaks about her experiences and the themes of women's rights and struggle that motivate her work including her famous memior Reading Lolita in Tehran. She also shares her thoughts and feelings on the 40 year fight for women's rights in Iran
Azar Nafisi, 39th Annual ODU Literary Festival
No full textAzar Nafisi is the author of numerous books including Reading Lolita in Tehran: A Memoir in Books, which has been translated in 32 languages; Anti-Terra: A Critical Study of Vladimir Nabokov’s Novels; and The Republic of Imagination: America in Three Books. Her work has been published in The New York Times, The Washington Post, and New Republic. She has received many literary and humanitarian awards including the Prix du Meilleur Livre Étranger; an American Immigration Law Foundation achievement award; a Persian Golden Lioness Award for Literature from the World Academy of Arts, Literature, and Media; and a Cristóbal Gabarrón Foundation International Thought and Humanities Award. She currently is a visiting fellow at the Foreign Policy Institute of Johns Hopkins University in Washington, DC
Limnioides cornuella Rousselet 1889
No full text<i>Limnias</i> <i>cornuella</i> Rousselet, 1889 <p>Fig. 2A</p> <p> <b>Types:</b> None designated</p> <p> <b>Type locality:</b> Hot-house tank; Gardens of the Royal Botanic Society, Regent’s Park (U.K).</p> <p> <b>Diagnosis.</b> Tube ringed as in <i>melicerta</i> species group, smaller (1/ 2x) in size then either <i>L. ceratophylli</i> (≤1500 µm) or <i>L. melicerta</i> (≤500 µm); curved or twisted; transparent at base and top and opaque between. Ventral antennae long. Dorsal gap in corona unknown. Koste (1978) reports dorsal nodules as either 4 or 10.</p> <p> <b>Comments.</b> The etymon of this species (L., <i>cornu</i>, horn + L., <i>ella</i>, diminutive) is in reference to the shape of the tube. Trophi: no available information. Amictic, male, and diapausing embryos undescribed. Apparently this species has not been reported since the original description of Rousselet (1889). Placed as a subspecific taxon within the <i>L. melicerta</i> species group by Koste (1978). Although this species was presented as <i>species inquirenda</i> by Segers (2007), it may be distinguished from other members of the <i>L. melicerta</i> species complex by its long ventral antennae and the number of dorsal nodules (n=4).</p>Published as part of <i>Wallace, Robert Lee, Kordbacheh, Azar & Walsh, Elizabeth J., 2018, Key to the currently recognized species of Limnias Schrank, 1803 (Rotifera, Monogononta, Gnesiotrocha, Flosculariidae), pp. 307-318 in Zootaxa 4442 (2)</i> on page 310, DOI: 10.11646/zootaxa.4442.2.7, <a href="http://zenodo.org/record/1303168">http://zenodo.org/record/1303168</a>
Limnioides melicerta Weisse 1848
No full textLimnias melicerta Weisse, 1848 Figs 1A,B; 4C Cephalosiphon limnias Ehrenberg, 1853 Limnias corniculata Ehrenberg, 1853 Limnias annulatus Bailey, 1855; name amended to annulata to agree with feminine genus name Limnias doliolum Schoch, 1868 Melicerta cubitti Cubitt, 1871; text refers to M. annulata, but plate 98 labels as M. cubitti Limnias granulosa Weber, 1888 Limnias melicerta melicerta: Koste, 1978 Types: None designated Type locality: Afrossimov Estate, St. Petersburg, Russia. Other material: Specimen Preparation ANSP 1527. Diagnosis. Base of tube clear, switching abruptly to a series of clear, stacked rings. Ventral antennae short; dorsal nodules present (n = 7 in 3 rows: 2,3,2). Dorsal gap in corona ciliation approximately equal to neck width. Trophi: rami asymmetrical; uncus with 3 strong main teeth. Measurements: Total body length, ≤1550 µm; corona width, 160 µm; height, 70 µm; tube width (at top), =100 µm; amictic egg, 130–242 x 40 –98 µm. See also Koste (1978). Geographic range: Apparently cosmopolitan: Africa (Democratic Republic of the Congo), Australia, Europe (France, Germany, Ireland, Russia, U.K.), India, North America (Canada, U.S.A., Mexico), South America (Brazil, Ecuador), Thailand. Ecology: pH, 4.1–8.9; bicarbonate, 57–305 mg /L; calcium, 5–38 mg /L; magnesium, ≤ 20 mg /L, conductivity, 81–686 µS/cm2, temperature, 18–32 °C; colonizes a wide variety of substrata such as glass, charophyte algae (Chara, Nitella), aquatic mosses (Fontinalis, Sphagnum), and vascular hydrophytes including Ceratophyllum, Elodea, Eriocaulon, Lemna, Ludwigia, Myriophyllum, Nuphar, Nymphaea, Potamogeton, Ranunculus, and Utricularia (Bailey 1855; Francez 1984b; Kellicott 1888; Koste, 1978; Sarma et al. 2017; Wallace 1977; Yang & Hochberg 2018; pers. obs.). Edmondson (1944) suggests that flat surfaces provide suitable substrata. Comments. The etymon of this species (G., meli, honey + G., keras, horn) is apparently in reference to the color that the tube of this species may take. Male and diapausing embryos undescribed. Construction of the ringed tube (rings ~5-10 µm in height) is by an elaborate behavior of the animal (Wright 1954).Published as part of Wallace, Robert Lee, Kordbacheh, Azar & Walsh, Elizabeth J., 2018, Key to the currently recognized species of Limnias Schrank, 1803 (Rotifera, Monogononta, Gnesiotrocha, Flosculariidae), pp. 307-318 in Zootaxa 4442 (2) on page 312, DOI: 10.11646/zootaxa.4442.2.7, http://zenodo.org/record/130316
Limnioides shiawasseensis Kellicott 1888
No full textLimnias shiawasseensis Kellicott, 1888 Fig. 3B Limnias Shiawasseënsis Kellicott, 1888 Limnias shiawasseensis Kellicott: Hudson & Gosse, 1889 Limnias shiawasseensis Kellicott: Harring, 1913 Limnias melicerta shiawasseensis Kellicott: Koste, 1978 Types: None designated. Type locality: Shiawassee River, Shiawassee Co., Michigan, (U.S.A.). Other material: Specimen Preparation ANSP 486 Diagnosis. Tube surface covered by transverse, parallel rows of tiny raised points. Ventral antennae long. Dorsal nodules n = 7 in 4 rows: 1 [bifurcate], 2,2,2). Dorsal gap present, undefined. Amictic, male, and diapausing embryos undescribed. Measurements: None reported. Geographic range: Very rare: Scotland (U.K.), Florida, and Michigan (U.S.A.). Ecology: pH, 6.9–7.6; bicarbonate, 21.4–38.4 mg /L. Sessile on Myriophyllum and Ranunculus. Comments. The etymon of this species refers to its poorly defined type location “… at the border of the …” Shiawassee River, Shiawassee Co. (Michigan, U.S.A.). Edmondson (1944) reported this species from a lake in Connecticut (U.S.A.); Ahlstrom (1934) listed this species as present in Florida (U.S.A.). Additionally, there is a mounted adult specimen (collected by C.F. Rousselet (1912.08.07), pond near Glasgow, Scotland and prepared by L. M. Dorsey: see Other material, above). Kellicott’s (1888) description offers ratios of certain features, but no dimensions are provided. To our knowledge the seven dorsal nodules have never been illustrated adequately. The original description of this species notes that specimens were found attached to Myriophyllum along with two congeners L. ceratophylli and L. melicerta, both of which were more common. Edmondson (1944) notes the occurrence of this species on hydrophytes that had the characteristics of “… predominantly flat or very gently convex leaves, whether finely divided or not” and certain other species that did not fit this categorization (e.g., Ranunculus). Kellicott (1888) noted two interesting behaviors. (1) The animals are said to pack flocculent debris against the rugose tube wall. Except for the placement of formed debris pellets in some Floscularia and fecal pellets in some Ptygura, no other sessile species actively augments their tubes. (2) The coronal discs are held in a near vertical position with the ventral antennae held at a sharp angle to the tube. An additional taxon, Limnias sphagnicola Zacharias, 1886 has not been included in the present treatment of the genus as it is considered an unrecognizable species inquirenda (Segers 2007; Jersabek & Leitner 2013). In addition the name is included on the list of names to be removed from zoological nomenclature in the candidate part Phylum Rotifera of the List of Available Names in Zoology (see Segers et al. 2012).Published as part of Wallace, Robert Lee, Kordbacheh, Azar & Walsh, Elizabeth J., 2018, Key to the currently recognized species of Limnias Schrank, 1803 (Rotifera, Monogononta, Gnesiotrocha, Flosculariidae), pp. 307-318 in Zootaxa 4442 (2) on pages 314-315, DOI: 10.11646/zootaxa.4442.2.7, http://zenodo.org/record/130316
Inlet patch: The under-explored island
No full text[No abstract available]Azar C, 2007, J CLIN GASTROENTEROL, V41, P468, DOI 10.1097-01.mcg.0000225519.59030.8d; GRAY SW, 1972, EMBRYOLOGY SURGEONS; Gutierrez O, 2003, AM J GASTROENTEROL, V98, P1266, DOI 10.1016-S0002-9270(03)00267-3; Jacobs E, 1997, ENDOSCOPY, V29, P710, DOI 10.1055-s-2007-1004294; Klaase JM, 2001, GASTROINTEST ENDOSC, V53, P101, DOI 10.1067-mge.2001.111394; Lauwers GY, 1998, DIGEST DIS SCI, V43, P901, DOI 10.1023-A:1018855223225; Maconi G, 2000, EUR J GASTROEN HEPAT, V12, P745, DOI 10.1097-00042737-200012070-00005; RATTNER HM, 1986, GASTROENTEROLOGY, V90, P130911
Hidden Diversity in Aquatic Habitats: Lessons from Cryptic Species in Microscopic Invertebrates (Rotifera)
No full textSpeciation is a continuous and adaptive process by which lineages are diverged into multiple groups, and species are the product of this process. Taxonomy is the study of relationship between organisms, classifying and naming them, and one of the taxonomical challenges is delimiting species boundaries. Species delimitation can be controversial because biologists do not agree on species concepts and approaches for defining species boundaries. One of the well-known species concepts is the Biological Species Concept that requires studying reproductive barriers among populations. Investigating strength of reproductive isolation among populations is not always practical in the wild. Therefore, many biologists have used morphological traits as an indicator of reproductive isolation and for delineating species. Yet, morphological methods are not fully effective in defining species boundaries and detecting species diversity, since some species are morphologically identical. Molecular analyses have contributed to species delimitation for morphologically indistinguishable groups (cryptic species). Species that are delimited based on molecular methods have been further tested using multiple complementary approaches (integrative taxonomy) such as ecological, behavioral and morphological differentiation especially for groups such as microorganisms that show high morphological uniformity. Rotifers, similar to other microorganisms, have drought-resistance propagules that are efficient for long distance dispersal. Therefore, they are assumed to have high rates of gene flow among habitats even across large geographic scales. As a result of high population connectivity, little genetic variation in population structure within rotifer morphospecies is expected. Moreover, rotifers do not have a lot of recognizable morphological characteristics and there has not been enough effort to resolve the taxonomical controversies resulted from morphological plasticity and cryptic species; morphologically similar species (cryptic species) are often not distinguished. However, high genetic structure has been reported among populations of many rotifer morphospecies suggesting they are species complexes with multiple cryptic species. Thus, rotifers are a good model organism for the application of molecular methods for species delimitation and to test the DNA based species boundaries using an integrative taxonomy. Integrating multiple approaches has been successfully used to delimit species boundaries in some rotifer species complexes such as Epiphanes senta and Brachionus calicyflorus. In Chapters 1 and 2, I used COI gene and ITS region sequences to study genetic structure and to delimit cryptic species in a littoral rotifer morphospecies, Euchlanis dilatata (62 populations), and four sessile morphospecies (Limnias melicerta [29 populations]; L. ceratophylli [20 populations]; Collotheca campanulata [19 populations]; C. ornata [45 populations]). Using Bayesian species delimitation (BSD), I found seven putative cryptic species for E. dilatata based on the ITS region sequence analysis. Based on COI gene sequences analyzed by BSD, nine putative cryptic species within L. melicerta, four putative cryptic species within L. ceratophylli, seven putative cryptic species for C. campanulata and eight putative cryptic species for C. ornata were detected. The relationship between genetic and geographic distance was weak or lacking within the examined morphospecies. Moreover, geographic distributions of cryptic species varied from occurring in a single locality, broadly, or even overlapping suggesting that they may differ in their capabilities to disperse, colonize, and persist in new habitats. Geometric and morphometric analyses did not show significant variation in trophi (rotifer’s jaws) shape and size among cryptic species of L. melicerta and L. ceratophylli. The lack of morphological variation can be a case of morphological stasis 1) through stabilizing selection because of niche conservationism, or 2) a result of speciation mediated by ecological and/or mating signals differentiation without morphological changes. I studied cryptic diversity within Euchlanis dilatata and for the first time, for four sessile morphospecies. I used DNA-based taxonomy to delimit species boundaries for morphologically similar lineages within five rotifer morphospecies. Integrative taxonomy has been suggested for species delimitation in especially in groups with limited morphological characteristics such as microorganisms. Here, I used integrative approach for more reliable species delimitation within Euchlanis dilatata and I found that those cryptic species are reproductively isolated and ecologically differentiated. On the other hand, I showed that genetic diversity within each morphospecies has weak correlation with geographic isolation. This may indicate that speciation in rotifers is not necessarily caused by geographic isolation. On the other hand, genetic variation among cryptic species is potentially associated to differentiation in ecological adaptation. Therefore, cryptic species of rotifers are likely to show variation in their adaptive range resulting in genetic variation and reproductive isolation among them. This mode of speciation is not necessarily accompanied by morphological divergence. (Abstract shortened by ProQuest.
Limnioides ceratophylli Schrank 1803
No full text<i>Limnias</i> <i>ceratophylli</i> Schrank, 1803 <p>Fig. 1C</p> <p> <i>Melicerta biloba</i> Ehrenberg, 1832</p> <p> <i>Limnias socialis</i> Leidy, 1874</p> <p> <b>Types:</b> None designated</p> <p> <b>Type locality:</b> Bayern (Germany).</p> <p> <b>Other material:</b> Specimen Preparation ANSP 793.</p> <p> <b>Diagnosis.</b> Base of tube straight or slightly curved, clear at base, abruptly changing to stucco-like granular surface to the top; tube may be light to dark brown (opaque), depending on water conditions. Solitary or colonial. Ventral antennae short. Dorsal nodules absent. Dorsal gap in corona less than neck width. Tube length ≤1500 µm. Trophi: unci longest tooth ~14 µm; 3 (4?) pairs of main teeth. Amictic embryos: ca. 257 x 88 µm. Males known; diapausing embryos not described. Considered to have a cosmopolitan distribution.</p> <p> <b>Measurements:</b> Total length, ≤1500 µm; corona width, 125–183 µm; tube length, ≤800, tube width (at top), =80 µm; amictic egg, 40– 50 x 100–110 µm. See also Koste (1978). Putative male poorly described by Hudson and Gosse (1886: 76).</p> <p> <b>Geographic range:</b> Apparently cosmopolitan: Africa (Senegal), Australia, Europe (France, Russia, U.K.), North America (Canada, U.S.A., Mexico), South America (Brazil, Ecuador, Panama), Thailand.</p> <p> <b>Ecology:</b> pH, 6–9.6; bicarbonate, 7.3–396 mg /L, conductivity, 77–663 µS/cm2, temperature, 13–30 °C; colonizes inert materials (glass and stones), submerged logs, algae, aquatic moss (<i>Fontinalis</i>), several vascular hydrophytes, including <i>Ceratophyllum, Elodea, Myriophyllum, Potamogeton, Ranunculus, Utricularia</i>), and an animal (crocodile) (Edmondson 1944; Koste 1978; Magnusson 1985; Meksuwan <i>et al</i>. 2011; Nilsen and Larimore 1973; Sarma <i>et al</i>. 2017; Tiefenbacher 1972; pers. obs.). It sometimes forms moderately sized allorecruitive colonies, but its propensity to form colonies has not been studied. A planktonic population has been reported (see below).</p> <p> <b>Comments.</b> The etymon of this genus is apparently a reference to the plant substratum on which Schrank (1803) found specimens. See Koste (1978) for additional synonyms. Tiefenbacher (1972) reported that he did not see the periodical production of tube material, as in the way that <i>Limnias melicerta</i> deposits its tube in rings (Wright 1954), and that colony formation occurred at high population levels.</p> <p> Four curious habitats have been reported for <i>L. ceratophylli</i>: three sessile and one planktonic. (1) Leidy (1874) reported a population attached to stones in an undefined region of the Schuylkill River (Philadelphia, Pennsylvania, U.S.A.) where colonies of up to 50 individuals occurred. (2) Nilsen and Larimore (1973) reported population densities reaching 17 inds/cm2 on submerged, bark-less logs. (3) Magnusson (1985) noted <i>L. ceratophylli</i> to be an epizootic on an Amazonian crocodile. (4) Although <i>L. ceratophylli</i> has always been considered to be sessile, Beach (1960) reported abundant planktonic populations in two lakes out of approximately 25 lotic and lentic habitats examined in the Ocqueoc River system, Presque Isle Co. (Michigan, U.S.A.). Regrettably Beach did not state whether he examine hydrophytes for sessile individuals, but he implied that: <i>L. ceratophylli</i> “… was always present and always free-swimming.” In one lake the mean population level over three summers was ~900 inds/L. Beach suggested that his findings of <i>L. ceratophylli</i> as an “adventitiously planktonic” was not from the animals being dislodged from their sessile attachment by water movements, but rather that local factors of lake morphology and water chemistry accounted for this unusual condition. Unfortunately, no drawings or photomicrographs were provided to substantiate these observations. Without that level of documentation the possibility remains that Beach was mistaken and that the organisms he observed were tintinnids or another small, encapsulated planktonic organism. However, apparently Beach was familiar with tintinnids, such as <i>Codonella</i> sp., which he reported being present in the freshwater system he studied. Thus, while his report may be in error, it cannot simply be dismissed.</p>Published as part of <i>Wallace, Robert Lee, Kordbacheh, Azar & Walsh, Elizabeth J., 2018, Key to the currently recognized species of Limnias Schrank, 1803 (Rotifera, Monogononta, Gnesiotrocha, Flosculariidae), pp. 307-318 in Zootaxa 4442 (2)</i> on pages 309-310, DOI: 10.11646/zootaxa.4442.2.7, <a href="http://zenodo.org/record/1303168">http://zenodo.org/record/1303168</a>
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