Waliullah MASROOR - Academia.edu (original) (raw)

Papers by Waliullah MASROOR

Diversity

Pheasants play a distinctive and significant role in high altitudinal ecosystems. These are good ... more Pheasants play a distinctive and significant role in high altitudinal ecosystems. These are good indicators of environmental changes, and their presence determines the health and balance of the bio-network. Recent human pressure continues to degrade their populations, and some pheasant species are already extinct. Therefore, the current study focuses on pheasant abundance and emerging conservation issues. The pheasant population was assessed using “Call count methods” and analyzed by DISTANCE software. The results revealed that the valleys where human interference is minimum had significantly higher encounter rates and densities of pheasants. At the same time, the pheasant population was severely affected, whether found at lower or higher altitudes, showing seasonal migration toward human settlements. The habitat suitability modeling was performed using the MaxEnt model and showed that human activities overlap with the suitable natural habitats of pheasants. The threats were identif...

Journal of Thermal Biology, 2019

The responses of European sea bass to temperature increase and salinity decrease were investigate... more The responses of European sea bass to temperature increase and salinity decrease were investigated measuring mRNA expression levels of main genes involved in ion transport. Juvenile fish were preacclimated to seawater (SW) at 18 °C (temperate) or 24 °C (warm) for two weeks and then transferred for two weeks to either fresh water (FW) or SW at the respective temperature. Unlike temperate conditions, there is no change in Na+/K+-ATPase α1a (nka α1a) and Na+/H+ exchanger 3 (nhe3) mRNA expression following FW transfer in warm conditions. This is linked to the high expression of these genes in warm SW compared to temperate SW. Na+/Cl−-cotransporter (ncc2a) expression however is increased following FW transfer in temperate and warm conditions. Main transporters involved in ion excretion (Na+/K+/2Cl-1 cotransporter, nkcc1 and cystic fibrosis transmembrane conductance regulator, cftr) as well as nitrogen excretion (Rh-glycoproteins, rhcg1 and rhbg) and acid-base regulation (V-H+-ATPase, vha-a and b) are highly expressed in SW warm conditions vs FW warm. Overall, our results suggest a higher activation of ion transport processes in warm conditions and more strikingly in SW. This is linked to a strong interplay between diverse ion transporters in order to coordinate physiological responses at the gill level. Highlights ► The expression of various branchial ion transporters is increased at 24 °C. ► The induction of ion transport processes is less striking in fresh water. ► In warm seawater, CFTR seems to be a key player in the regulation of Cl − balance. ► Transporters regulating H + and nitrogen excretion are highly expressed at 24 °C.

The European sea bass Dicentrarchus labrax undertakes seasonal migrations to estuaries and lagoon... more The European sea bass Dicentrarchus labrax undertakes seasonal migrations to estuaries and lagoons that are characterized by fluctuations in environmental conditions. It is unclear to what extent salinity acclimation mechanisms are affected at temperatures higher than in the sea, as usually encountered in transitional waters in spring and summer. In this study, juvenile sea bass were pre-acclimated to seawater (SW) at 18 °C (temperate) or 24 °C (warm) for two weeks and then transferred to either fresh water (FW) or SW at the considered temperatures. We have shown that sea bass are able to efficiently maintain blood osmolality at 24 °C at both salinities. However, temperature increase induced significant changes regarding several physiological traits related to osmoregulation, acid-base regulation, ammonia excretion and mucus production. This study showed that thermal acclimation at 24 °C affects gill morphology through gill remodeling and whole-organism ion balance. Plasma Na+ level...

Le loup ou bar europeen effectue une partie de son cycle de vie dans les lagunes et estuaires, de... more Le loup ou bar europeen effectue une partie de son cycle de vie dans les lagunes et estuaires, des eaux de transitions caracterisees par des fluctuations environnementales plus marquees qu’en milieu marin. Les mecanismes d’acclimatation a la salinite a des temperatures plus elevees qu’en milieu marin sont encore relativement inexplores. Dans cette etude, des juveniles de loup ont ete preacclimates pendant deux semaines a l’eau de mer (EM) a 18 °C (eau temperee) ou a 24 °C (eau chaude) puis transferes soit dans l’eau douce (ED) soit dans l’EM aux deux temperatures testees. A 24 °C, les loups parviennent a maintenir leur pression osmotique sanguine relativement constante, quelle que soit la salinite testee. En revanche, la hausse de temperature affecte significativement differents traits physiologiques lies a l’osmoregulation, la regulation acido- basique, l’excretion azotee et la production de mucus. Cette etude a notamment montre qu’une acclimatation thermique a 24 °C modifie la str...

Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology

Diversity

Pheasants play a distinctive and significant role in high altitudinal ecosystems. These are good ... more Pheasants play a distinctive and significant role in high altitudinal ecosystems. These are good indicators of environmental changes, and their presence determines the health and balance of the bio-network. Recent human pressure continues to degrade their populations, and some pheasant species are already extinct. Therefore, the current study focuses on pheasant abundance and emerging conservation issues. The pheasant population was assessed using “Call count methods” and analyzed by DISTANCE software. The results revealed that the valleys where human interference is minimum had significantly higher encounter rates and densities of pheasants. At the same time, the pheasant population was severely affected, whether found at lower or higher altitudes, showing seasonal migration toward human settlements. The habitat suitability modeling was performed using the MaxEnt model and showed that human activities overlap with the suitable natural habitats of pheasants. The threats were identif...

Journal of Thermal Biology, 2019

The responses of European sea bass to temperature increase and salinity decrease were investigate... more The responses of European sea bass to temperature increase and salinity decrease were investigated measuring mRNA expression levels of main genes involved in ion transport. Juvenile fish were preacclimated to seawater (SW) at 18 °C (temperate) or 24 °C (warm) for two weeks and then transferred for two weeks to either fresh water (FW) or SW at the respective temperature. Unlike temperate conditions, there is no change in Na+/K+-ATPase α1a (nka α1a) and Na+/H+ exchanger 3 (nhe3) mRNA expression following FW transfer in warm conditions. This is linked to the high expression of these genes in warm SW compared to temperate SW. Na+/Cl−-cotransporter (ncc2a) expression however is increased following FW transfer in temperate and warm conditions. Main transporters involved in ion excretion (Na+/K+/2Cl-1 cotransporter, nkcc1 and cystic fibrosis transmembrane conductance regulator, cftr) as well as nitrogen excretion (Rh-glycoproteins, rhcg1 and rhbg) and acid-base regulation (V-H+-ATPase, vha-a and b) are highly expressed in SW warm conditions vs FW warm. Overall, our results suggest a higher activation of ion transport processes in warm conditions and more strikingly in SW. This is linked to a strong interplay between diverse ion transporters in order to coordinate physiological responses at the gill level. Highlights ► The expression of various branchial ion transporters is increased at 24 °C. ► The induction of ion transport processes is less striking in fresh water. ► In warm seawater, CFTR seems to be a key player in the regulation of Cl − balance. ► Transporters regulating H + and nitrogen excretion are highly expressed at 24 °C.

The European sea bass Dicentrarchus labrax undertakes seasonal migrations to estuaries and lagoon... more The European sea bass Dicentrarchus labrax undertakes seasonal migrations to estuaries and lagoons that are characterized by fluctuations in environmental conditions. It is unclear to what extent salinity acclimation mechanisms are affected at temperatures higher than in the sea, as usually encountered in transitional waters in spring and summer. In this study, juvenile sea bass were pre-acclimated to seawater (SW) at 18 °C (temperate) or 24 °C (warm) for two weeks and then transferred to either fresh water (FW) or SW at the considered temperatures. We have shown that sea bass are able to efficiently maintain blood osmolality at 24 °C at both salinities. However, temperature increase induced significant changes regarding several physiological traits related to osmoregulation, acid-base regulation, ammonia excretion and mucus production. This study showed that thermal acclimation at 24 °C affects gill morphology through gill remodeling and whole-organism ion balance. Plasma Na+ level...

Le loup ou bar europeen effectue une partie de son cycle de vie dans les lagunes et estuaires, de... more Le loup ou bar europeen effectue une partie de son cycle de vie dans les lagunes et estuaires, des eaux de transitions caracterisees par des fluctuations environnementales plus marquees qu’en milieu marin. Les mecanismes d’acclimatation a la salinite a des temperatures plus elevees qu’en milieu marin sont encore relativement inexplores. Dans cette etude, des juveniles de loup ont ete preacclimates pendant deux semaines a l’eau de mer (EM) a 18 °C (eau temperee) ou a 24 °C (eau chaude) puis transferes soit dans l’eau douce (ED) soit dans l’EM aux deux temperatures testees. A 24 °C, les loups parviennent a maintenir leur pression osmotique sanguine relativement constante, quelle que soit la salinite testee. En revanche, la hausse de temperature affecte significativement differents traits physiologiques lies a l’osmoregulation, la regulation acido- basique, l’excretion azotee et la production de mucus. Cette etude a notamment montre qu’une acclimatation thermique a 24 °C modifie la str...

Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology