Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 2021
Climate changes affecting aquatic environments are increasing, and the resultant environmental ch... more Climate changes affecting aquatic environments are increasing, and the resultant environmental challenges require animals to adopt alternative compensatory behavioral and physiological strategies. In particular, low levels of dissolved O2 are a regular problem for estuarine animals, leading to activation of a series of behavioral and physiological responses. This study on the semi-terrestrial crab Neohelice granulata examined patterns of emersion behavior under different levels of dissolved O2 availability and the role of lactate in this behavior. Emersion behavior was recorded for 4.5 h for crabs in water at four different levels of dissolved O2 (6, 3, 2, and 1 mg O2/L) and with free access to air. Oxygen consumption and hemolymphatic lactate levels were measured using the same experimental design. Emersion behavior was also recorded for 70 min in normoxic water after lactate or saline injections. Crabs increased their emersion behavior only in severe hypoxia (1 mg O2/L), and O2 consumption decreased under more severe hypoxic conditions. Despite the increase in emersion behavior, which leads to higher O2 availability, an increase in hemolymphatic lactate levels indicates that the animals still need to resort to anaerobic pathways to fulfill their metabolic demand. Furthermore, animals injected with lactate showed higher emersion behaviors than animals injected with a saline solution even in normoxia. These results suggest that the increase in hemolymphatic lactate can act directly or indirectly as a trigger for the increase in emersion behavior in the semi-terrestrial crab N. granulata.
Anais da Academia Brasileira de Ciencias, Jan 25, 2018
The aim of this study was to evaluate the efficacy and safety of several anesthetics in the brach... more The aim of this study was to evaluate the efficacy and safety of several anesthetics in the brachyuran crab Neohelice granulata, an emergent experimental model. The essential oils (EOs) of Lippia alba, Aloysia tryphilla, and Melaleuca alternifolia (tea tree oil; TTO), the isolated compounds eugenol, menthol, terpinen-4-ol, and the nanoencapsulated form of TTO, were administered in one or more of the following ways: added to the water (immersion), through an arthrodial membrane (injected), or by oral gavage. Unexpectedly, most EOs did not produce an anesthetic effect after immersion. Only TTO and eugenol induced anesthesia by immersion, with very long induction and recovery times compared to anesthesia of other crustaceans. However, a good anesthetic effect was observed with the injection of terpinen-4-ol and nanoencapsulated TTO in N. granulata; both demonstrated ideal induction and recovery times. These substances appear to be promising anesthetic alternatives for crustaceans.
The air exposure behavior of the semi-terrestrial crab Neohelice granulata during severe hypoxia ... more The air exposure behavior of the semi-terrestrial crab Neohelice granulata during severe hypoxia was studied. This study also verified whether this behavior mitigates possible oxidative damage, namely lipoperoxidation, caused by hypoxia and reoxygenation cycles. The lethal time for 50% of the crabs subjected to severe hypoxia (0.5 mgO2.L(-1)) with free access to air was compared to that of crabs subjected to severe hypoxia without access to air. Crabs were placed in aquaria divided into three zones: water (when the animal was fully submersed), land (when the animal was completely emerged) and intermediate (when the animal was in contact with both environments) zones. Then the crabs were held in this condition for 270 minutes, and the time spent in each zone was recorded. Lipid peroxidation (LPO) damage to the walking leg muscles was determined for the following four experimental conditions: a-normoxic water with free access to air; b- hypoxic water without access to air; c- hypoxic ...
ABSTRACT In this study, a simple, rapid and sensitive analytical method for the detection of TCS ... more ABSTRACT In this study, a simple, rapid and sensitive analytical method for the detection of TCS from Poecilia vivipara tissues (muscle, gills, brain, liver, gonads and whole fish) was developed. A matrix solid phase dispersion (MSPD) extraction method followed by analysis with a liquid chromatography tandem mass spectrometry (LC-MS/MS) system was developed and the application of the multivariate statistical approach (experimental design) was used to optimize the extraction conditions. The results showed that the method is accurate as robust and highly reproducible, since high recoveries were achieved. The analytical method showed high extraction yields for the determination of this compound in a complex matrix such as tissue. Moreover, the extraction procedure is very fast and it is possible to perform on a small sample aliquot. Besides, the extraction and clean up are performed in a single step. The LOQ value in fish tissue was 0.083 μg g-1 and LOD was 0.016 μg g-1 . The RSDs for repeatability and intermediate precision studies were in the range of 1.1 to 8.9% and from 0.2% to 8.9%, respectively. Adequate linearity with correlation coefficients (r) higher than 0.99 was obtained for the range of 0.005 to 0.25 µg g-1. Quantitative recoveries (≥80%) and satisfactory precision (average 9%) were obtained. The application of the vortex-assisted MSPD method to the analysis of real samples shows TCS in some liver and gills fish samples at trace levels.
Effects of the crustacean hyperglycemic hormone on total lipids in the hemolymph of Chasmagnathus... more Effects of the crustacean hyperglycemic hormone on total lipids in the hemolymph of Chasmagnathus granulata and on free fatty acids, phospholipids, and triglycerides in the hemolymph of Carcinus maenas, as well as on their release by Orconectes limosus hepatopancreas in vitro, were investigated. Eyestalk ablation led to a significant decrease of total lipids in the hemolymph of C. granulata and of free fatty acid levels in C. maenas. Crustacean hyperglycemic hormone injections completely reversed the effects of eyestalk extirpation in short-term experiments. Crustacean hyperglycemic hormone also caused significant elevations of hemolymph phospholipids and triglycerides in eyestalkless C. maenas. The release of free fatty acids and phospholipids from O. limosus hepatopancreas in vitro was significantly increased in the presence of crustacean hyperglycemic hormone. These results suggest a physiological role for crustacean hyperglycemic hormone in the control of lipid metabolism in crustaceans. This role may be similar to that of the adipokinetic hormone of insects.
Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 2021
Climate changes affecting aquatic environments are increasing, and the resultant environmental ch... more Climate changes affecting aquatic environments are increasing, and the resultant environmental challenges require animals to adopt alternative compensatory behavioral and physiological strategies. In particular, low levels of dissolved O2 are a regular problem for estuarine animals, leading to activation of a series of behavioral and physiological responses. This study on the semi-terrestrial crab Neohelice granulata examined patterns of emersion behavior under different levels of dissolved O2 availability and the role of lactate in this behavior. Emersion behavior was recorded for 4.5 h for crabs in water at four different levels of dissolved O2 (6, 3, 2, and 1 mg O2/L) and with free access to air. Oxygen consumption and hemolymphatic lactate levels were measured using the same experimental design. Emersion behavior was also recorded for 70 min in normoxic water after lactate or saline injections. Crabs increased their emersion behavior only in severe hypoxia (1 mg O2/L), and O2 consumption decreased under more severe hypoxic conditions. Despite the increase in emersion behavior, which leads to higher O2 availability, an increase in hemolymphatic lactate levels indicates that the animals still need to resort to anaerobic pathways to fulfill their metabolic demand. Furthermore, animals injected with lactate showed higher emersion behaviors than animals injected with a saline solution even in normoxia. These results suggest that the increase in hemolymphatic lactate can act directly or indirectly as a trigger for the increase in emersion behavior in the semi-terrestrial crab N. granulata.
Anais da Academia Brasileira de Ciencias, Jan 25, 2018
The aim of this study was to evaluate the efficacy and safety of several anesthetics in the brach... more The aim of this study was to evaluate the efficacy and safety of several anesthetics in the brachyuran crab Neohelice granulata, an emergent experimental model. The essential oils (EOs) of Lippia alba, Aloysia tryphilla, and Melaleuca alternifolia (tea tree oil; TTO), the isolated compounds eugenol, menthol, terpinen-4-ol, and the nanoencapsulated form of TTO, were administered in one or more of the following ways: added to the water (immersion), through an arthrodial membrane (injected), or by oral gavage. Unexpectedly, most EOs did not produce an anesthetic effect after immersion. Only TTO and eugenol induced anesthesia by immersion, with very long induction and recovery times compared to anesthesia of other crustaceans. However, a good anesthetic effect was observed with the injection of terpinen-4-ol and nanoencapsulated TTO in N. granulata; both demonstrated ideal induction and recovery times. These substances appear to be promising anesthetic alternatives for crustaceans.
The air exposure behavior of the semi-terrestrial crab Neohelice granulata during severe hypoxia ... more The air exposure behavior of the semi-terrestrial crab Neohelice granulata during severe hypoxia was studied. This study also verified whether this behavior mitigates possible oxidative damage, namely lipoperoxidation, caused by hypoxia and reoxygenation cycles. The lethal time for 50% of the crabs subjected to severe hypoxia (0.5 mgO2.L(-1)) with free access to air was compared to that of crabs subjected to severe hypoxia without access to air. Crabs were placed in aquaria divided into three zones: water (when the animal was fully submersed), land (when the animal was completely emerged) and intermediate (when the animal was in contact with both environments) zones. Then the crabs were held in this condition for 270 minutes, and the time spent in each zone was recorded. Lipid peroxidation (LPO) damage to the walking leg muscles was determined for the following four experimental conditions: a-normoxic water with free access to air; b- hypoxic water without access to air; c- hypoxic ...
ABSTRACT In this study, a simple, rapid and sensitive analytical method for the detection of TCS ... more ABSTRACT In this study, a simple, rapid and sensitive analytical method for the detection of TCS from Poecilia vivipara tissues (muscle, gills, brain, liver, gonads and whole fish) was developed. A matrix solid phase dispersion (MSPD) extraction method followed by analysis with a liquid chromatography tandem mass spectrometry (LC-MS/MS) system was developed and the application of the multivariate statistical approach (experimental design) was used to optimize the extraction conditions. The results showed that the method is accurate as robust and highly reproducible, since high recoveries were achieved. The analytical method showed high extraction yields for the determination of this compound in a complex matrix such as tissue. Moreover, the extraction procedure is very fast and it is possible to perform on a small sample aliquot. Besides, the extraction and clean up are performed in a single step. The LOQ value in fish tissue was 0.083 μg g-1 and LOD was 0.016 μg g-1 . The RSDs for repeatability and intermediate precision studies were in the range of 1.1 to 8.9% and from 0.2% to 8.9%, respectively. Adequate linearity with correlation coefficients (r) higher than 0.99 was obtained for the range of 0.005 to 0.25 µg g-1. Quantitative recoveries (≥80%) and satisfactory precision (average 9%) were obtained. The application of the vortex-assisted MSPD method to the analysis of real samples shows TCS in some liver and gills fish samples at trace levels.
Effects of the crustacean hyperglycemic hormone on total lipids in the hemolymph of Chasmagnathus... more Effects of the crustacean hyperglycemic hormone on total lipids in the hemolymph of Chasmagnathus granulata and on free fatty acids, phospholipids, and triglycerides in the hemolymph of Carcinus maenas, as well as on their release by Orconectes limosus hepatopancreas in vitro, were investigated. Eyestalk ablation led to a significant decrease of total lipids in the hemolymph of C. granulata and of free fatty acid levels in C. maenas. Crustacean hyperglycemic hormone injections completely reversed the effects of eyestalk extirpation in short-term experiments. Crustacean hyperglycemic hormone also caused significant elevations of hemolymph phospholipids and triglycerides in eyestalkless C. maenas. The release of free fatty acids and phospholipids from O. limosus hepatopancreas in vitro was significantly increased in the presence of crustacean hyperglycemic hormone. These results suggest a physiological role for crustacean hyperglycemic hormone in the control of lipid metabolism in crustaceans. This role may be similar to that of the adipokinetic hormone of insects.
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