Effects of Temperature, Salinity and Oxygen on the Survival of the American Lobster

1956 ◽  
Vol 13 (2) ◽  
pp. 247-272 ◽  
Author(s):  
D. W. McLeese

Thermal acclimation for lobsters transferred from 14.5 °C. to 23.0 °C. is complete in 22 days. Substantial acclimation to low salinity and to low oxygen occurs within one week. Lethal levels of these three factors are not altered by differences in size within the range 16–34 cm., by difference in the areas where lobsters were caught, or by starvation for up to 57 days. Moulting lobsters are less resistant to high temperature, low salinity and low oxygen conditions than hard-shelled lobsters.Upper lethal temperature levels and lower lethal salinity and oxygen levels were investigated for hard-shelled lobsters acclimated to each of the 27 combinations of three levels of temperature (5, 15 and 25 °C.), salinity (20, 25 and 30‰), and oxygen (2.9, 4.3 and 6.4 mg./l.). The upper lethal temperature is raised by an increase in thermal acclimation, and is lowered by a decrease in the salinity and oxygen acclimation levels. The lower lethal salinity is raised by an increase in the level of thermal acclimation and a decrease in the level of oxygen acclimation. It is lowered by acclimation to reduced salinity. The effect of salinity acclimation is not always the same, but depends on the temperature acclimation. The lower lethal oxygen is raised by either an increase in the temperature acclimation level of a decrease in the salinity acclimation.The lower lethal temperature is 1.8 °C. for 17° acclimated lobsters, and 5.0° for 27.5° acclimated lobsters.Ultimate and maximum or minimum lethal levels of temperature, salinity and oxygen—the highest and lowest lethal levels that can be attained by acclimation—were interpolated from the results. These measures were used to integrate the lethal levels of the three factors into a single three-dimensional graph which describes the boundary of lethal conditions for lobsters exposed to the three factors operating together (Fig. 7).


2021 ◽  
Vol 11 ◽  
Author(s):  
Irum Mukhtar ◽  
Siyi Wu ◽  
Shurong Wei ◽  
Ruanni Chen ◽  
Yunying Cheng ◽  
...  

Adaptation to life at different oxygen tensions plays a role in protozoan ecology and controls the distribution of different species in anoxic habitats. The ciliate genus Spirostomum inhabiting fresh or low salinity water globally where these species are considered as bioindicators. Under anaerobic or low oxygen conditions, the rhodoquinol-dependent pathway has been reported in the species from the class Heterotrichea. With the help of RNA sequencing (RNAseq) data, Spirostomum spp., are suitable for deep molecular investigations on rquA for rhodoquinone (RQ) biosynthesis. In this study, Spirostomum ambiguum, Spirostomum subtilis, and Spirostomum teres collected from densely vegetated freshwater habitat in Fuzhou, China, explored the evidence of rquA. Based on transcriptome analysis, two to three RquA proteins were identified in S. ambiguum, S. teres, and S. subtilis, respectively. The presence of a key Motif-I of RquA and mitochondrial targeting signals (MTS), also confirmed the identity of these as RquA. Furthermore, Spirostomum RquA proteins could be sorted into two groups based on their conserved amino acid (CAA) residues. Phylogenetic analysis also exhibited RquA division into two subclades contained RquA1 and RquA2/RquA3 and supports two to three paralogs of rquA genes in the genomes Spirostomum spp. Additional transcriptomes and genomes analysis of Blepharisma spp., and Stentor spp., respectively, also revealed at least two paralogs of rquA in members of the class Heterotrichea. The present study provides evidence for the presence of RquA and rhodoquinol dependent fumarate reduction pathway in Spirostomum species potentially use to respire in the oxygen-depleted habitats and two to three diverse rquA genes.



Author(s):  
Eamon J. Sheehy ◽  
Tatiana Vinardell ◽  
Conor T. Buckley ◽  
Daniel J. Kelly

Tissue engineering applications aim to replace or regenerate damaged tissues through a combination of cells, three-dimensional scaffolds, and signaling molecules [1]. The endochondral approach to bone tissue engineering [2], which involves remodeling of an intermittent hypertrophic cartilaginous template, may be superior to the traditional intramembranous approach. Naturally derived hydrogels have been used extensively in tissue engineering applications [3]. Mesenchymal stem cell (MSC) seeded hydrogels may be a particularly powerful tool in scaling-up engineered endochondral bone grafts as the low oxygen conditions that develop within large constructs enhance in vitro chondrogenic differentiation and functional development [4]. A key requirement however, is that the hydrogel must allow for remodeling of the engineered hypertrophic cartilage into bone and also facilitate vascularization of the graft. The first objective of this study was to compare the capacity of different naturally derived hydrogels (alginate, chitosan, and fibrin) to generate in vivo endochondral bone. The secondary objective was to investigate the possibility of engineering a ‘scaled-up’ anatomically accurate distal phalange as a paradigm for whole bone tissue engineering.



Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 225
Author(s):  
Lei Xuan ◽  
Jianfeng Hua ◽  
Fan Zhang ◽  
Zhiquan Wang ◽  
Xiaoxiao Pei ◽  
...  

The Taxodium hybrid ‘Zhongshanshan 406’ (T. hybrid ‘Zhongshanshan 406’) [Taxodium mucronatum Tenore × Taxodium distichum (L.). Rich] has an outstanding advantage in flooding tolerance and thus has been widely used in wetland afforestation in China. Alcohol dehydrogenase genes (ADHs) played key roles in ethanol metabolism to maintain energy supply for plants in low-oxygen conditions. Two ADH genes were isolated and characterized—ThADH1 and ThADH4 (GenBank ID: AWL83216 and AWL83217—basing on the transcriptome data of T. hybrid ‘Zhongshanshan 406’ grown under waterlogging stress. Then the functions of these two genes were investigated through transient expression and overexpression. The results showed that the ThADH1 and ThADH4 proteins both fall under ADH III subfamily. ThADH1 was localized in the cytoplasm and nucleus, whereas ThADH4 was only localized in the cytoplasm. The expression of the two genes was stimulated by waterlogging and the expression level in roots was significantly higher than those in stems and leaves. The respective overexpression of ThADH1 and ThADH4 in Populus caused the opposite phenotype, while waterlogging tolerance of the two transgenic Populus significantly improved. Collectively, these results indicated that genes ThADH1 and ThADH4 were involved in the tolerance and adaptation to anaerobic conditions in T. hybrid ‘Zhongshanshan 406’.



2015 ◽  
Vol 173 ◽  
pp. 827-837 ◽  
Author(s):  
Domien De Paepe ◽  
Katleen Coudijzer ◽  
Bart Noten ◽  
Dirk Valkenborg ◽  
Kelly Servaes ◽  
...  


BMC Cancer ◽  
2014 ◽  
Vol 14 (1) ◽  
Author(s):  
An Wouters ◽  
Bea Pauwels ◽  
Natalie Burrows ◽  
Marc Baay ◽  
Vanessa Deschoolmeester ◽  
...  




2017 ◽  
Vol 23 (6) ◽  
pp. 2321-2330 ◽  
Author(s):  
Marcelo E. Lagos ◽  
Diego R. Barneche ◽  
Craig R. White ◽  
Dustin J. Marshall


1990 ◽  
Vol 255 (3) ◽  
pp. 286-295 ◽  
Author(s):  
J. R. Fleming ◽  
T. Crockford ◽  
J. D. Altringham ◽  
I. A. Johnston


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