scholarly journals Defecation by the ctenophore Mnemiopsis leidyi occurs with an ultradian rhythm through a single transient anal pore

2019 ◽  
Vol 138 (1) ◽  
pp. 3-16 ◽  
Author(s):  
Sidney L. Tamm
Keyword(s):  
Mnemiopsis Leidyi ◽  
Ultradian Rhythm

scholarly journals Defecation by the ctenophore Mnemiopsis leidyi occurs with an ultradian rhythm through a single transient anal pore

2019 ◽  
Author(s):  
Sidney L. Tamm
Keyword(s):  
Scientific Literature ◽  
Mirror Image ◽  
Mnemiopsis Leidyi ◽  
Ultradian Rhythm ◽  
Tissue Fusion ◽  
Time Intervals ◽  
Opening And Closing ◽  
Shed Light ◽  
Permanent Structure ◽  
Gastrovascular System

AbstractDefecation in the ctenophore Mnemiopsis leidyi is a stereotyped sequence of effector responses that occur with a regular ultradian rhythm. Time intervals between repeated defecations of individual animals depend on body size, ranging from ~10 min in small larvae to ~1 hr in large adults. New features and corrections of previous reports of the gastrovascular system during and between defecations are described in detail by video microscopy. Contrary to the scientific literature, the defecating organ of the excretory complex is just one of the two anal canals which possesses the animal’s only anal pore. The anal pore is not visible as a permanent structure as depicted in textbooks, but appears at defecation and disappears afterward. DIC microscopy reveals that opening and closing of the anal pore resemble a reversible ring of tissue fusion between apposed endodermal and ectodermal layers at the aboral end. Mnemiopsis thus appears to have an intermittent anus and therefore an intermittent through-gut that reoccur at regular intervals. The temporality of a visible anal pore in Mnemiopsis is novel, and may shed light on the evolution of a permanent anus and through-gut in animals. In addition, mirror image dimorphism of the diagonal anal complex occurs in larval ctenophores but not in adults, indicating developmental flexibility in diagonal symmetry of the anal complex.

Peculiarities of the Biology of Mnemiopsis leidyi (A. Agassiz) under Conditions of the Black Sea

2001 ◽  
Vol 37 (4) ◽  
pp. 9
Author(s):  
A. N. Grishin
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Mnemiopsis Leidyi

scholarly journals Scyphomedusae and Ctenophora of the Eastern Adriatic: Historical Overview and New Data

Diversity ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 186
Author(s):  
Branka Pestorić ◽  
Davor Lučić ◽  
Natalia Bojanić ◽  
Martin Vodopivec ◽  
Tjaša Kogovšek ◽  
...  
Keyword(s):  
Adriatic Sea ◽  
Seasonal Pattern ◽  
Geographical Location ◽  
Distribution Patterns ◽  
Mnemiopsis Leidyi ◽  
Future Studies ◽  
Phenological Data ◽  
Pelagia Noctiluca ◽  
Regional Trends ◽  
Clear Seasonal Pattern

One of the obstacles to detecting regional trends in jellyfish populations is the lack of a defined baseline. In the Adriatic Sea, the jellyfish fauna (Scyphozoa and Ctenophora) is poorly studied compared to other taxa. Therefore, our goal was to collect and systematize all available data and provide a baseline for future studies. Here we present phenological data and relative abundances of jellyfish based on 2010–2019 scientific surveys and a “citizen science” sighting program along the eastern Adriatic. Inter-annual variability, seasonality and spatial distribution patterns of Scyphomedusae and Ctenophore species were described and compared with existing historical literature. Mass occurrences with a clear seasonal pattern and related to the geographical location were observed for meroplanktonic Scyphomedusae Aurelia solida, Rhizostoma pulmo, and to a lesser extent Chrysaora hysoscella, Cotylorhiza tuberculata and Discomedusa lobata. Holoplanktonic Pelagia noctiluca also formed large aggregations, which were seasonally less predictable and restricted to the central and southern Adriatic. Four species of Ctenophora produced blooms limited to a few areas: Bolinopsis vitrea, Leucothea multicornis, Cestum veneris and the non-native Mnemiopsis leidyi. However, differences between Adriatic subregions have become less pronounced since 2014. Our results suggest that gelatinous organisms are assuming an increasingly important role in the Adriatic ecosystem, which may alter the balance of the food web and lead to harmful and undesirable effects.

scholarly journals The Ctenophore Mnemiopsis leidyi Has a Flow-Through System for Digestion with Three Consecutive Phases of Extracellular Digestion

1997 ◽  
Vol 70 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Dirk Bumann ◽  
Gabriela Puls
Keyword(s):  
Mnemiopsis Leidyi ◽  
Flow Through

Inductive interactions and embryonic equivalence groups in a basal metazoan, the ctenophore Mnemiopsis leidyi

2004 ◽  
Vol 6 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Jonathan Q. Henry ◽  
Mark Q. Martindale
Keyword(s):  
Mnemiopsis Leidyi ◽  
Basal Metazoan

Population development of the invader ctenophore Mnemiopsis leidyi , in the Black Sea and in other seas of the Mediterranean basin

2001 ◽  
Vol 139 (3) ◽  
pp. 431-445 ◽  
Author(s):  
Shiganova T. ◽  
Mirzoyan Z. ◽  
Studenikina E. ◽  
Volovik S. ◽  
Siokou-Frangou I. ◽  
...  
Keyword(s):  
Black Sea ◽  
Mediterranean Basin ◽  
The Black Sea ◽  
Mnemiopsis Leidyi ◽  
Population Development ◽  
The Mediterranean ◽  
The Mediterranean Basin

scholarly journals Evidence of Diel Vertical Migration in Mnemiopsis leidyi

PLoS ONE ◽  
2014 ◽  
Vol 9 (1) ◽  
pp. e86595 ◽  
Author(s):  
Matilda Haraldsson ◽  
Ulf Båmstedt ◽  
Peter Tiselius ◽  
Josefin Titelman ◽  
Dag L. Aksnes
Keyword(s):  
Vertical Migration ◽  
Diel Vertical Migration ◽  
Mnemiopsis Leidyi

scholarly journals Stealth predation and the predatory success of the invasive ctenophore Mnemiopsis leidyi

2010 ◽  
Vol 107 (40) ◽  
pp. 17223-17227 ◽  
Author(s):  
S. P. Colin ◽  
J. H. Costello ◽  
L. J. Hansson ◽  
J. Titelman ◽  
J. O. Dabiri
Keyword(s):  
Mnemiopsis Leidyi

The role of aerobic metabolism and intragel oxygen in hypoxia tolerance of three ctenophores: Pleurobrachia bachei, Bolinopsis infundibulum and Mnemiopsis leidyi

2005 ◽  
Vol 85 (3) ◽  
pp. 627-633 ◽  
Author(s):  
Erik V. Thuesen ◽  
Ladd D. Rutherford ◽  
Patricia L. Brommer
Keyword(s):  
Aerobic Metabolism ◽  
Hypoxia Tolerance ◽  
Mnemiopsis Leidyi ◽  
Survival Times ◽  
Partial Pressures ◽  
Pleurobrachia Bachei ◽  
Oxygen Measurements ◽  
Surrounding Seawater ◽  
Planktonic Communities

Ctenophores are important members of planktonic communities that are often abundant in dysaerobic environments. Previous studies have shown that ctenophores are not adversely affected by extended periods of hypoxia. The three species used in this study, Pleurobrachia bachei, Bolinopsis infundibulum, and Mnemiopsis leidyi, were all able to oxyregulate to very low partial pressures of oxygen (PO2s). These species were found to have mean critical oxygen tensions of 7.7, 10.6, and 7.2 hPa respectively. In general, ctenophores are better oxyregulators than medusae and many species of shrimps, fish and squid. Intragel oxygen was measured using a fibre optic oxygen optode. All these ctenophores have intragel subsurface [O2]s of 5–10% below that of the surrounding seawater. Intragel oxygen measurements of P. bachei showed a gradient of decreasing PO2 from surface tissues to the gut. Specimens of P. bachei over 14 mm in diameter had anaerobic guts. Survival times in anoxia ranged from 0 h for M. leidyi to up to 6 h for P. bachei. Ctenophores rely on aerobic metabolism to tolerate hypoxia.

scholarly journals Discovery, Prevalence, and Persistence of Novel Circular Single-Stranded DNA Viruses in the Ctenophores Mnemiopsis leidyi and Beroe ovata

2015 ◽  
Vol 6 ◽  
Author(s):  
Mya Breitbart ◽  
Bayleigh E. Benner ◽  
Parker E. Jernigan ◽  
Karyna Rosario ◽  
Laura M. Birsa ◽  
...  
Keyword(s):  
Mnemiopsis Leidyi ◽  
Single Stranded Dna ◽  
Dna Viruses ◽  
Beroe Ovata
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