scholarly journals Role of depleted initial energy reserves in early benthic phase mortality of six marine invertebrate species

2021 ◽  
Author(s):  
Shannon R. Mendt ◽  
Louis A. Gosselin
Keyword(s):  
Marine Invertebrate ◽  
Initial Energy ◽  
Energy Reserves ◽  
Invertebrate Species

scholarly journals More Than Names: The role of updated taxonomy in palaeontology collections

2019 ◽  
Vol 3 ◽  
Author(s):  
Ricardo Paredes
Keyword(s):  
Fossil Record ◽  
Marine Invertebrate ◽  
Research Community ◽  
Type Material ◽  
Museum Collections ◽  
Web Based ◽  
2D Imaging ◽  
Visual Impact ◽  
Fossil Data

The accuracy on taxonomic determinations of palaeontology collections may have significant consequences in estimations of organism diversity through time. This justifies the need of taxonomic standardization of palaeontological collections. The perception of palaeodiversity through Phanerozoic time has significantly improved since the Sepkoski showed the marine invertebrate taxonomic data in diversity graphs, organized in orders (Sepkoski 1978) and families (Sepkoski 1979, Sepkoski 1984). The visual impact of these graphs engaged palaeontologists into gathering quantitative macroevolution in order to better understand marine palaeodiversity. Alroy et al. (2008) presented a rebuilt diversity curve based on genus-level in a large sample record. These and other statistically sound and standardized datasets of fossil occurrences have combined sources as literature, databases, and museum collections data as a foundation. Integration of these datasets with the entire fossil record based on individual specimens in space and time would be the ideal approach to species-level taxonomy standards determinations. An example showing how this approach may be achieved is the use of initiatives such as the Web-based data facility Palaeontology Database (PdB) which includes a large amount of fossil record data from throughout the world. The major advantage of that is to gather institucional and also private palaeontological collections with taxonomy experts validation. The core of these datasets is the taxon, with the species as the expected most reliable unit. Taxonomy is therefore the discipline enrolled in the process with the taxonomist at the centre of the process. Updated taxonomy is crucial to create reliable datasets and a careful approach should prevent biased data due to under- or overestimation of diversity. Palaeontological museum collections are known to be one of the largest repositories of fossil data. Taxonomic standardization of palaeontology collections in the context of a museum should: Engage taxonomists in revising fossil clades of the museum material; Promote networking and museum researcher peers involved in similar collections activities; Avoid replication of errors in taxonomic determinations (e.g. exclusive use of Web-based databases sources of taxonomy); Use type material to compare with the collection specimens; Critically analyse previous taxonomic determinations on old labels and associated specimen information; Promote the accessibility of the collection to the research community; Emphasize digitisation of specimen catalogue records as well as 2D imaging of the specimens. Engage taxonomists in revising fossil clades of the museum material; Promote networking and museum researcher peers involved in similar collections activities; Avoid replication of errors in taxonomic determinations (e.g. exclusive use of Web-based databases sources of taxonomy); Use type material to compare with the collection specimens; Critically analyse previous taxonomic determinations on old labels and associated specimen information; Promote the accessibility of the collection to the research community; Emphasize digitisation of specimen catalogue records as well as 2D imaging of the specimens. These practices are valuable complements to current methodologies adopted to improve the taxonomy of collections, resulting in more reliable data which further enables museum-based research focusing on palaeodiversity estimations.

scholarly journals The Endocannabinoid System and Invertebrate Neurodevelopment and Regeneration

2021 ◽  
Author(s):  
Tristyn L. Clarke ◽  
Rachael L. Johnson ◽  
Jonathan J. Simone ◽  
Robert L. Carlone
Keyword(s):  
Endocannabinoid System ◽  
Invertebrate Species ◽  
Medicinal Cannabis

Cannabis has long been used for its medicinal and psychoactive properties. With the relatively new adoption of formal medicinal cannabis regulations worldwide, the study of cannabinoids, both endogenous and exogenous, has similarly flourished in more recent decades. In particular, research investigating the role of cannabinoids in regeneration and neurodevelopment has yielded promising results in vertebrate models. However, regeneration-competent vertebrates are few, whereas a myriad of invertebrate species have been established as superb models for regeneration. As such, this review aims to provide a comprehensive summary of the endocannabinoid system, with a focus on current advances in the area of endocannabinoid system contributions to invertebrate neurodevelopment and regeneration.

The Distribution of Settled Larvae of the Bryozoans Alcyonidium Hirsutum (Fleming) and Alcyonidium Polyoum (Hassall) on Fucus Serratus L.

1974 ◽  
Vol 54 (3) ◽  
pp. 665-676 ◽  
Author(s):  
P. J. Hayward ◽  
Paul H. Harvey
Keyword(s):  
Aquatic Invertebrates ◽  
Marine Invertebrate ◽  
Substrate Selection ◽  
Sessile Invertebrates ◽  
Fucus Serratus ◽  
The Subject ◽  
Invertebrate Larvae ◽  
Experi Mental Result ◽  
Selection Of

The spatial settlement of marine invertebrate larvae is not a random process. The distribution of the adults of a particular species is influenced by the behavioural responses of the animal to a range of environmental stimuli which, in the case of many sessile invertebrates, result in the display of clear substrate selection. The role of habitat selection in determining the distribution of aquatic invertebrates has been the subject of a review by Meadows & Campbell (1972). The selection of algal substrata by the larvae of various intertidal species of Bryozoa has been demonstrated by Ryland (1959); among these, the ctenostomatous bryozoans Alcyonidium hirsutum and A. polyoum were shown to exhibit a strong preference for fronds of the alga Fucus serratus, an experi-mental result which accorded well with the distribution of the two species on the shore (Ryland, 1962).

scholarly journals Magnetically driven jets and winds from weakly magnetized accretion discs

2019 ◽  
Vol 490 (3) ◽  
pp. 3112-3133 ◽  
Author(s):  
J Jacquemin-Ide ◽  
J Ferreira ◽  
G Lesur
Keyword(s):  
Numerical Simulations ◽  
Energy Content ◽  
Initial Energy ◽  
Accretion Discs ◽  
Analytical Models ◽  
Magnetorotational Instability ◽  
New Class ◽  
Analytical Criterion ◽  
First Time

Abstract Semi-analytical models of disc outflows have successfully described magnetically driven, self-confined super-Alfvénic jets from near-Keplerian accretion discs. These jet-emitting discs (JEDs) are possible for high levels of disc magnetization μ defined as μ = 2/β, where beta is the usual plasma parameter. In near-equipartition JEDs, accretion is supersonic and jets carry away most of the disc angular momentum. However, these solutions prove difficult to compare with cutting-edge numerical simulations, for the reason that numerical simulations show wind-like outflows but in the domain of small magnetization. In this work, we present for the first time self-similar isothermal solutions for accretion–ejection structures at small magnetization levels. We elucidate the role of magnetorotational instability-like (MRI) structures in the acceleration processes that drive this new class of solutions. The disc magnetization μ is the main control parameter: Massive outflows driven by the pressure of the toroidal magnetic field are obtained up to μ ∼ 10−2, while more tenuous centrifugally driven outflows are obtained at larger μ values. The generalized parameter space and the astrophysical consequences are discussed. We believe that these new solutions could be a stepping stone in understanding the way astrophysical discs drive either winds or jets. Defining jets as self-confined outflows and winds as uncollimated outflows, we propose a simple analytical criterion based on the initial energy content of the outflow, to discriminate jets from winds. We show that jet solution is achieved at all magnetization levels, while winds could be obtained only in weakly magnetized discs that feature heating.

scholarly journals EXCESS POTASSIUM INDUCES LARVAL METAMORPHOSIS IN FOUR MARINE INVERTEBRATE SPECIES

1986 ◽  
Vol 170 (2) ◽  
pp. 255-266 ◽  
Author(s):  
ANDREA J. YOOL ◽  
SUSAN M. GRAU ◽  
MICHAEL G. HADFIELD ◽  
REBECCA A. JENSEN ◽  
DOUGLAS A. MARKELL ◽  
...  
Keyword(s):  
Marine Invertebrate ◽  
Larval Metamorphosis ◽  
Invertebrate Species

scholarly journals The Fetal Allograft Revisited: Does the Study of an Ancient Invertebrate Species Shed Light on the Role of Natural Killer Cells at the Maternal-Fetal Interface?

2008 ◽  
Vol 2008 ◽  
pp. 1-10 ◽  
Author(s):  
Amy Lightner ◽  
Danny J. Schust ◽  
Yi-Bin A. Chen ◽  
Breton F. Barrier
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Vascular System ◽  
Marine Invertebrate ◽  
Cell Types ◽  
Primary Origin ◽  
Uterine Nk Cells ◽  
Missing Self ◽  
Fresh Insight

Human pregnancy poses a fundamental immunological problem because the placenta and fetus are genetically different from the host mother. Classical transplantation theory has not provided a plausible solution to this problem. Study of naturally occurring allogeneic chimeras in the colonial marine invertebrate, Botryllus schlosseri, has yielded fresh insight into the primitive development of allorecognition, especially regarding the role of natural killer (NK) cells. Uterine NK cells have a unique phenotype that appears to parallel aspects of the NK-like cells in the allorecognition system of B. schlosseri. Most notably, both cell types recognize and reject “missing self” and both are involved in the generation of a common vascular system between two individuals. Chimeric combination in B. schlosseri results in vascular fusion between two individual colonies; uterine NK cells appear essential to the establishment of adequate maternal-fetal circulation. Since human uterine NK cells appear to de-emphasize primary immunological function, it is proposed that they may share the same evolutionary roots as the B. schlosseri allorecognition system rather than a primary origin in immunity.

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