LivingNautilusEmbryos: Preliminary Observations

Science ◽  
1986 ◽  
Vol 232 (4746) ◽  
pp. 73-76 ◽  
Author(s):  
JOHN M. ARNOLD ◽  
BRUCE A. CARLSON
Keyword(s):  
Surface Morphology ◽  
Larval Stages ◽  
Molluscan Evolution ◽  
Insight Into ◽  
Circulatory Pattern

Nautilus, long recognized as the most primitive living cephalopod, provides insight into molluscan evolution. Despite many attempts, embryos have not been observed until now. This report details the surface morphology and extraembryonic circulatory pattern. It was found that development, as in other extant cephalopods, is direct, without larval stages. There appears to be no embryonic protoconch associated with shell ontogeny.

The community structure of larval fish populations in an area of the Celtic Sea in 1998

2002 ◽  
Vol 82 (4) ◽  
pp. 641-648 ◽  
Author(s):  
S. Acevedo ◽  
O. Dwane ◽  
J.M. Fives
Keyword(s):  
Community Structure ◽  
Fish Species ◽  
Larval Fish ◽  
Single Species ◽  
Coastal Fish ◽  
Larval Stages ◽  
Celtic Sea ◽  
Sea Area ◽  
Insight Into ◽  
Fish Distributions

Ichthyoplankton from an area in the Celtic Sea was studied to provide an insight into the fish larval community structure in March, May and June 1998. Three station groups were defined each month, Neritic, Transition and Oceanic. The Neritic assemblages included larval stages of coastal fish species and the Oceanic assemblages included mesopelagic and high-oceanic fish species which were not recorded from any of the Neritic stations. The Transition stations usually contained species characteristic of both the Neritic and Oceanic assemblages. It is suggested that these broad patterns of larval fish distributions are constant features of the Celtic Sea area, probably related to the spawning location of the adults. The area is, in general, species poor, with the Oceanic stations usually dominated by a single species, indicating the presence of a large spawning school of fish.

Nano Co 3 O 4 as Anode Material for Li–Ion and Na‐Ion Batteries: An Insight into Surface Morphology

2018 ◽  
Vol 3 (18) ◽  
pp. 5040-5049 ◽  
Author(s):  
Palani Subalakshmi ◽  
Arumugam Sivashanmugam
Keyword(s):  
Surface Morphology ◽  
Anode Material ◽  
Li Ion ◽  
Insight Into

scholarly journals Insight into Magnetite’s Redox Catalysis from Observing Surface Morphology during Oxidation

2013 ◽  
Vol 135 (27) ◽  
pp. 10091-10098 ◽  
Author(s):  
Shu Nie ◽  
Elena Starodub ◽  
Matteo Monti ◽  
David A. Siegel ◽  
Lucía Vergara ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Redox Catalysis ◽  
Insight Into

scholarly journals Eye development in the four-eyed fish Anableps anableps : cranial and retinal adaptations to simultaneous aerial and aquatic vision

2017 ◽  
Vol 284 (1852) ◽  
pp. 20170157 ◽  
Author(s):  
Louise N. Perez ◽  
Jamily Lorena ◽  
Carinne M. Costa ◽  
Maysa S. Araujo ◽  
Gabriela N. Frota-Lima ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Proliferation ◽  
Cell Layer ◽  
Eye Development ◽  
Frontal Bone ◽  
Larval Stages ◽  
Layer Density ◽  
Key Features ◽  
Insight Into ◽  
Shed Light

The unique eyes of the four-eyed fish Anableps anableps have long intrigued biologists. Key features associated with the bulging eye of Anableps include the expanded frontal bone and the duplicated pupils and cornea. Furthermore, the Anableps retina expresses different photoreceptor genes in dorsal and ventral regions, potentially associated with distinct aerial and aquatic stimuli. To gain insight into the developmental basis of the Anableps unique eye, we examined neurocranium and eye ontogeny, as well as photoreceptor gene expression during larval stages. First, we described six larval stages during which duplication of eye structures occurs. Our osteological analysis of neurocranium ontogeny revealed another distinctive Anablepid feature: an ossified interorbital septum partially separating the orbital cavities. Furthermore, we identified the onset of differences in cell proliferation and cell layer density between dorsal and ventral regions of the retina. Finally, we show that differential photoreceptor gene expression in the retina initiates during development, suggesting that it is inherited and not environmentally determined. In sum, our results shed light on the ontogenetic steps leading to the highly derived Anableps eye.

scholarly journals Electrical Potentials of Protoscoleces of the Cestode  Echinococcus granulosus from Bovine Origin

2021 ◽  
Author(s):  
Monica PA Carabajal ◽  
Marcos A Durán ◽  
Santiago Olivera ◽  
María José Fernández Salom ◽  
Horacio F Cantiello
Keyword(s):  
Electrical Activity ◽  
Echinococcus Granulosus ◽  
Time Course ◽  
Saline Solution ◽  
Electrical Potential ◽  
Transport Mechanisms ◽  
Peak Potential ◽  
Larval Stages ◽  
Electrical Potentials ◽  
Insight Into

Larval stages of the tenia Echinococcus granulosus are the infective forms of cystic echinococcosis or hydatidosis, a worldwide zoonosis. The protoscolex that develops into the adult form in the definitive host is enveloped by a complex cellular syncytial tegument, where all metabolic interchange takes place. Little information is available as to the electrical activity of the parasite in this developmental stage. To gain insight into the electrical activity of the parasite at the larval stage, here we conducted microelectrode impalements of bovine lung protoscoleces (PSCs) of Echinococcus granulosus in normal saline solution. We observed two distinct intra-parasitic potentials, a transient peak potential and a stable second potential, most likely representing tegumental and intra-parasitic extracellular space electrical potential differences, respectively. These values changed upon the developmental status of the parasite, its anatomical regions, or time course after harvesting. Changes in electrical potential differences of the parasite provide an accessible and useful parameter for the study of transport mechanisms and potential targets for the development of novel antiparasitic therapeutics .

Scanning electron microscope study of the development of mandibular structure and the molar surface morphology of Branchinella maduraiensis and Streptocephalus dichotomus (Crustacea, Anostraca)

2006 ◽  
Vol 84 (9) ◽  
pp. 1248-1262 ◽  
Author(s):  
Chinavenmeni S. Velu ◽  
Natesan Munuswamy
Keyword(s):  
Surface Morphology ◽  
Developmental Stages ◽  
Gradual Transition ◽  
Mandibular Movement ◽  
Scanning Electron Microscope Study ◽  
Larval Stages ◽  
Ephemeral Pools ◽  
Molar Morphology ◽  
Further Development ◽  
Scanning Electron

In the present study, the molar surface morphology of Streptocephalus dichotomus Baird, 1860 and Branchinella maduraiensis Raj, 1961 is analyzed and correlated with the distribution of these species in ephemeral pools. The larval stages of S. dichotomus are characterized by scanning electron microscopy in relation to their feeding physiology, which shows their morphological complexity during developmental stages. The larval mandible consists of a coxa with a three-segmented palp, and further development leads to its gradual transition into the adult mandible. Muscles involved in mandibular movement exhibit rotatory and counter-rotatory movement, which enhances the grinding of food materials. Analysis of the molar surface morphology of B. maduraiensis and S. dichotomus reveals that the mandibles are asymmetrical. Detailed analysis of the topography of the molar illustrates specific structural differences between the species. Gut content analysis also perfectly matches the molar morphology of these species, confirming that B. maduraiensis handles zooplankton more preferentially than S. dichotomus. Our investigation of these fairy shrimps provides information on their molar surface morphology and feeding biology, which increases the understanding of their coexistence.

scholarly journals Surface morphology enhances deposition efficiency in biomimetic, wind-driven fog collection

2020 ◽  
Vol 17 (166) ◽  
pp. 20200038
Author(s):  
A. Shahrokhian ◽  
J. Feng ◽  
H. King
Keyword(s):  
Surface Morphology ◽  
Deposition Efficiency ◽  
Droplet Deposition ◽  
Surface Transport ◽  
Fog Collection ◽  
Biological Surface ◽  
3D Geometry ◽  
Separation Devices ◽  
Insight Into

Passive interception of fog from the wind is an effective solution for accessing water in regions where fog is frequent and other sources scarce. A Namib Desert beetle is often cited as bioinspiration for further advancement, in a narrative which focuses on patterned wettability of its bumpy elytra as a means of transporting accumulated water from its back to its mouth. However, surface transport in fog collection is secondary to the role of the fluid dynamics of droplet deposition, in which inertial droplets migrate across diverging streamlines approaching an obstruction. 3D geometry of biological surface features inevitably affect this process, but its specific role in flow physics of fog collection has not previously been explored. Here, we report experimental measurements of deposition efficiency of targets with identical surface chemistry but varying surface morphology. We find a nearly threefold increase in collection upon addition of millimetric bumps to a spherical target, and provide insight into the micromechanics underlying the performance. Modifying surface morphology can be easier than overall geometry for both manufactured structures and evolved organisms and should therefore be both considered in the design of separation devices and expected in other biological systems for which extraction of particles from flow is important.

Calibration problems in hydrogen luminosities

1966 ◽  
Vol 24 ◽  
pp. 322-330
Author(s):  
A. Beer
Keyword(s):  
Galactic Structure ◽  
B Stars ◽  
Insight Into

The investigations which I should like to summarize in this paper concern recent photo-electric luminosity determinations of O and B stars. Their final aim has been the derivation of new stellar distances, and some insight into certain patterns of galactic structure.

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