155,755 research outputs found
Detection and distribution of Craspedacusta sowerbii: Observations of medusae are not enough
No full textThe freshwater cnidarian Craspedacusta sowerbii, native to the Yangtze valley, has invaded lakes and ponds throughout the world. Most distribution records have to date been based on observations of the medusa (jellyfish) stage, including numerous recent publications. We aimed to determine whether polyps are widespread in lakes, and geographical areas, outside of where medusae have been observed, and whether constructed waters are more easily invaded than natural waters. Our results show that C. sowerbii is more common and widespread than is apparent from observations of medusae. We argue that observed occurrences of medusae provide little useful information regarding the distribution of this species, and that published records of new jellyfish occurrences provide unreliable estimates of the timing of introduction, establishment or spread of C. sowerbii in new regions. We found no evidence that constructed waters were more readily invaded than natural waters. Overall, accurate determination of Craspedacusta occurrence and distribution requires systematic surveys of the polyp stages
Craspedacusta Lankester 1880
No full textGenus <i>Craspedacusta</i> Lankester, 1880 <p> <i>Craspedacusta</i> Lankester, 1880: 147.</p> <p> <b>Type species.</b> <i>Craspedacusta sowerbii</i> Lankester, 1880, by monotypy.</p> <p> <b>Diagnosis.</b> Olindiid polyps solitary or primitively colonial. Hydranths atentaculate, athecate, club-shaped to cylindrical; distal end a knob-shaped capitulum, bearing an apical mouth surrounded by nematocysts; hydranth base with attachment region surrounded by thin perisarc; asexual reproduction by frustulation, cyst formation, or fission.</p> <p>Gonophores medusae, arising from gastric column of hydranth. Medusae hemispherical to dome-shaped, with marginal nematocyst ring; radial canals four; centripetal canals absent; manubrium quadrate, moderately short, gastric peduncle absent; tentacles evenly spaced, of one type, lacking adhesive disks; statocysts in vesicles on velum; gonads sac-shaped, on radial canals.</p> <p> <b>Remarks.</b> Bouillon <i>et al</i>. (2006) listed eight nominal species in <i>Craspedacusta</i> Lankester, 1880, but speculated that they might all be conspecific with <i>C. sowerbii</i> Lankester, 1880. Earlier, He <i>et al</i>. (2000) had recognized six species, while Dumont (1994) reported that four species were considered valid by most workers. Jankowski (2001) and Jankowski <i>et al</i>. (2008) believed there were as many as four species endemic to the Yangtze River Basin in China, the likely origin of the genus. Several species of the genus appear valid from molecular data (Collins <i>et al.</i> 2008; Zhang <i>et al</i>. 2009). The species taxonomy of this enigmatic fresh water genus remains unsettled.</p>Published as part of <i>Calder, Dale R., 2010, Some anthoathecate hydroids and limnopolyps (Cnidaria, Hydrozoa) from the Hawaiian archipelago 2590, pp. 1-91 in Zootaxa 2590 (1)</i> on pages 73-74, DOI: 10.11646/zootaxa.2590.1.1, <a href="http://zenodo.org/record/10834110">http://zenodo.org/record/10834110</a>
La medusa Craspedacusta sowerbii Lankester, 1880: nuova osservazione nei laghi trentini e distribuzione in Italia
No full textNell’agosto del 2015 sono stati osservati esemplari della medusa Craspedacusta sowerbii Lankester nel Lago di Levico
(Trentino). La specie era già stata trovata in altri laghi della provincia a partire dagli anni ’90 (Lago Santo di Cembra, Lago
di Lavarone, Lago dei Poiani, Lago di Garda). Allo stato attuale questa medusa risulta segnalata in 40 ambienti di acque
ferme e correnti in Italia. Le segnalazioni, basate sulla osservazione dello stadio pelagico (medusa) e non sulla ricerca dello
stadio bentonico (polipo), probabilmente sottostimano la distribuzione della specie in Italia.The first documented sighting of the jellyfi sh Craspedacusta sowerbii Lankester from Lake Levico (Trentino, Northern
Italy) was in August 2015, but records of this species in other lakes of the province (Lago Santo di Cembra, Lago di Lavarone,
Lago dei Poiani, Lago di Garda) go back to the early 1990s. C. sowerbii has a relatively wide distribution in Italy, with
records from 40 freshwater ecosystems. These sightings, based on the observation of the pelagic stage (medusa) and not
on the benthic stage (polyp), probably underestimates the real distribution in Ital
Craspedacusta sowerbii Lankester 1880
No full text<i>Craspedacusta sowerbii</i> Lankester, 1880 <p>Fig. 48</p> <p> <i>Craspedacusta sowerbii</i> Lankester, 1880: 148.</p> <p> <i>Craspedacusta sowerbyi</i>.— Edmondson, 1940: 314 [medusa only].— Matthews, 1963: 18, figs. 1, 2; 1966: 246, figs. 1–5.</p> <p> <b>Type locality.</b> UK: London, Regent’s Park, “…in the tank in the water-lily house…” (Lankester 1880: 147).</p> <p> <b>Material examined.</b> None.</p> <p> <b>Description.</b> As for diagnosis of genus.</p> <p> <b>Remarks.</b> <i>Craspedacusta sowerbii</i> Lankester, 1880 is a well-known freshwater species with a wide geographic range (Kramp 1961; Dumont 1994). Edmondson (1940) first reported the species from Hawaii, based on medusae found at Maliko Gulch, Maui. Both medusa and polyp stages were later reported from Honolulu in aquaria by Matthews (1963, 1966). No specimens of the hydroid were found in collections at the Bishop Museum, and it is not currently known to occur in limnic aquaria and culture systems at the Waikiki Aquarium (Gerald Crow & Kelley Lam, pers. comm., 30 July 2009).</p> <p> A review of the global distribution, dispersal, and feeding ecology of <i>C. sowerbii</i> and other freshwater medusae is given by Dumont (1994).</p> <p> <b>Reported distribution.</b> Hawaii. Maui: Maliko Gulch [medusa only] (Edmondson 1940).–Oahu: Honolulu, in aquaria (Matthews 1963, 1966).</p> <p> Worldwide. All continents except Antarctica, in shallow subtropical and temperate fresh waters (Kramp 1961; Dumont 1994; Jankowski 2001; Jankowski <i>et al.</i> 2008; Zhang <i>et al</i>. 2009).</p>Published as part of <i>Calder, Dale R., 2010, Some anthoathecate hydroids and limnopolyps (Cnidaria, Hydrozoa) from the Hawaiian archipelago 2590, pp. 1-91 in Zootaxa 2590 (1)</i> on page 74, DOI: 10.11646/zootaxa.2590.1.1, <a href="http://zenodo.org/record/10834110">http://zenodo.org/record/10834110</a>
Zoological articles contributed to the "Encyclopaedia Britannica" / by E. Ray Lankester, to which are added kindred articles by W. Johnson Sollas ... [et al.].
No full textA new record of the freshwater jellyfish Craspedacusta sowerbii Lankester, 1880 (Hydrozoa) in Southeastern Anatolia (Turkey)
No full textWe report the first record of the invasive freshwater jellyfish Craspedacusta sowerbii Lankester in Kralkizi Dam Lake, Southeastern Anatolia, Turkey. The medusa was found only in August, 2008 when average surface water temperatures were 26.9 degrees C
A new yellow-flowered Chiloschista (Orchidaceae: Aeridinae) from Thailand
No full textA new species of Chiloschista Lindl. from western Thailand is described and illustrated with a line drawing and photographs. It is compared with the sympatric C. parishii Seidenf., from which it differs in having larger flowers, which are 11–12 mm across versus 8–10 mm across for C. parishii. The new species also distinctly differs in having widely spreading rostellum lobes and a viscidium that is as broad as the length of the stipe, as opposed to downward directed rostellum lobes and a viscidium that is distinctly narrower than the length of the stipe for C. parishii. The same distinguishing features separate the new species from the similarly colored C. trudelii Seidenf., which has inward-directed rostellum lobes and a viscidium that is distinctly narrower than the length of the stipe
O. A. C. Review Volume XLVI Issue 5, February 1934
No full textThe focus of this issue is the preparation for College Royal and recognizing its tenth anniversary. This month's agricultural article is a report from the Dominion Parasite Laboratory on the biological control of pests. Other articles provide an account of the activities of a stage manager and the development of the field of home economics at Macdonald College in Quebec. Campus news addresses the success of the 1934 Conversazione, the commemorating of the sixtieth anniversary of the founding of O. A. C., the attendance at the Canadian Author Lecture, and the successful productions of "The Apple Cart" and "Iolanthe". The Macdonald Institute column comments on the Conversat and women's athletics activities in basketball and the rifle club. The Alumni Record supplies alumni updates.EditorialTen Years of the RoyalRamblings on the RoyalBlame it on the stage managerBiological control of insect pests in CanadaNot for girls onlyCollege lifeLiterary sectionO. A. C. sportsfolioAlumni recordMacdonald newsLetters to the editoradvertisin
O. A. C. Review Volume XXXVI Issue 12, August 1924
No full textThis slim summer issue contains the address given by the agricultural section of the British Association for the Advancement of Science, and a report on the visit of this association to the O. A. C. Other articles include instructions on increasing strawberry production and a biography of the author John Masefield. The editorial comments on Rhodes Scholars. The Alumni column provides an update of alumni activities. This issue does not contain a Macdonald column.JoyPresent-day problems in crop productionAfter the strawberry harvestJohn MasefieldVisit of the Agricultural Section of the British Association for the Advancement of ScienceEditorialCollege lifeAlumniadvertisin
Craspedacusta Sowerbii, Lankester : an annotated bibliography of its distribution and biology
No full textCitations for the published literature on Craspedacusta sowerbii Lankester are presented in alphabetical order. These begin with the discovery of the animal in 1880, and are believed to be complete through 1997. An overview of the history, biology and ecology of C. sowerbii is included. Following is a bibliography in which examined citations are briefly annotated. Topics emphasized include historical overviews, distribution notes, polyp and medusae development, ecology and physiology.Thesis (M.A.)Department of Biolog
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