Effect of WAF crude oil exposure to larvae development of the black-scar oyster Crasosstrea iredalei

Oil spills potentially effect exposed organisms at various stage of life. This work aimed to access health risk of crude oil to larva development of a sessile organism the Black scar oyster Crassostrea iredalei by using water accommodate fraction (WAF) of crude oil. Male and female gametes was collect and fertilized to obtained larvae at cleavage stage. The larvae were then incubate in various concentrations of WAF (0, 6.25, 12.5, 25, 50, and 100 %). After 24 hour of exposure, normal D-shaped veliger larva (D-larva) was observe. The result showed that WAF crude oil affected the development and the successful of D-larva development. Severity of WAF effect was increasing with dosages of exposure. The abnormal larva developments were increasing in the high concentrations. The information obtaining from current work is important for health risk assessment of crude oil contamination incident in marine ecosystem. This study will also contribute valuable knowledge needed for aquaculture to know effect of crude oil spill to oyster farming area.

Continuous tracking of gravistimulated roots in a chambered coverslip by confocal microscopy allows first glimpse on mechanoadaptation of cell files during curvature initiation

Plant cell properties are defined by its proteome and metabolome, which depend on the genetic background together with environmental conditions. Mechanical responses of individual cells to plant internal and external stimuli modulate organ movement and ensure thereby plant survival as sessile organism in a constantly changing environment. The root is a complex, three-dimensional object, which continuously modifies its growth path. Autonomous and paratonic root movements are both orchestrated by different signaling pathways, whereby auxin modulated directional growth adaptations, including gravitropic response, were already subject of manifold studies. But we still know very little about how cells adapt upon gravitropic stimulus to initiate curvature establishment, which is required to align root tip growth again along the gravitropic vector. This manuscript shows first insights into cell file movements upon gravitropic stimulus of Arabidopsis thaliana roots that initiate curvature establishment. The roots were grown shaded from light and without exogenous sucrose supplementation, both growth conditions that are known to negatively interfere with directed root growth, which allowed a more uniform tracking of root bending by using a confocal microscope with vertical stage.

The Early Cambrian tommotiid Micrina , a sessile bivalved stem group brachiopod

The tannuolinid Micrina belongs to the tommotiids—a common and widely distributed, but poorly understood, group of Early Cambrian fossil metazoans with multiple external organophosphatic sclerites. Recent findings of sessile articulated tommotiid scleritomes indicate that previous reconstructions of tommotiids as slug-like bilaterians with a dorsal cover of sclerites require detailed re-evaluation. Comparative ultrastructural work has already indicated that the tommotiids might be a sister group to the Brachiopoda, with Micrina representing the most derived and brachiopod-like bimembrate tommotiid. Here we further develop and strengthen this controversial phylogenetic model with a new reconstruction of Micrina , where the two types of sclerites—mitral and sellate—belong to a near bilaterally symmetrical bivalved sessile organism. This new scleritome configuration was tested by recreating an articulated bivalved Micrina from isolated mitral and sellate sclerites; both sclerites have muscles that would have enabled movement of the sclerites. The mitral and sellate sclerites of Micrina are considered to be homologous with the ventral and dorsal valves, respectively, of organophosphatic linguliform brachiopods, indicating that a simple type of filter-feeding within an enclosed bivalved shell had started to evolve in derived tannuolinids. The new reconstruction also indicates that the phylogenetic range of ‘bivalved’, sessile lophophorates is larger than previously suspected.

Research on Sessile Organism Removal from Metal Using the Underwater Shock Wave

The sessile organism of the oyster and the barnacle, etc. causes friction between the surface of the ship and the water. Friction causes the deterioration of fuel cost. In addition, dry dock operation with putting the ship on the land or the diving operation, are needed for the removal of the sessile organism. These works require a very high cost. Various techniques for reducing friction resistance have been proposed. On the other hand, the method for the practical use is not popular still now. Authors tried to perform an experiment to remove the sessile organism on surface of the metal by using the underwater shock wave.