scholarly journals Voyage of the argonauts in the pelagic realm: physiological and behavioural ecology of the rare paper nautilus, Argonauta nouryi

2010 ◽  
Vol 67 (7) ◽  
pp. 1494-1500 ◽  
Author(s):  
Rui Rosa ◽  
Brad A. Seibel
Keyword(s):  
Citrate Synthase ◽  
Behavioural Ecology ◽  
Metabolic Potential ◽  
Trade Off ◽  
Critical Oxygen ◽  
A Chain ◽  
The Vertical Distribution ◽  
Aerobic And Anaerobic ◽  
Octopine Dehydrogenase ◽  
Oxygen Minimum

Abstract Rosa, R., and Seibel, B. A. 2010. Voyage of the argonauts in the pelagic realm: physiological and behavioural ecology of the rare paper nautilus, Argonauta nouryi. – ICES Journal of Marine Science, 67: 1494–1500. The metabolic demands of a rare paper nautilus, Argonauta nouryi, in the eastern tropical Pacific (ETP) are evaluated. After adjusting for temperature and size, the rates of oxygen consumption and of aerobic and anaerobic metabolic potential (as evidenced by citrate synthase and octopine dehydrogenase activities, respectively) of A. nouryi were much higher than those in holopelagic octopods that exhibit float-and-wait predation strategies. In fact, the rates were similar to those found in small epipelagic squids and benthic octopods. The critical oxygen partial pressure was 4.9 kPa at 20°C, suggesting that the strong oxygen minimum layer found at intermediate depths in the ETP may constrain the vertical distribution of A. nouryi to the upper few metres of the water column. We also report the occurrence of a chain of shelled females at the surface, in which each animal was attached, as if on the benthos, to the next individual in the chain. Although it may constitute an effective strategy to increase the rates of mate encounter in the vast open ocean, there may be an important ecological trade-off for such behaviour, namely the increase in visibility at the surface with concomitant attraction of predators.

scholarly journals Flight of the vampire: ontogenetic gait-transition in vampyroteuthis infernalis (Cephalopoda: vampyromorpha)

1998 ◽  
Vol 201 (16) ◽  
pp. 2413-2424 ◽  
Author(s):  
BA Seibel ◽  
EV Thuesen ◽  
JJ Childress
Keyword(s):  
Body Size ◽  
Citrate Synthase ◽  
Gait Transition ◽  
Positive Allometry ◽  
Factors Affecting ◽  
Jet Propulsion ◽  
Primary Means ◽  
Vampyroteuthis Infernalis ◽  
Aerobic And Anaerobic ◽  
Oxygen Minimum

Vampyroteuthis infernalis is a cosmopolitan cephalopod that lives in the oxygen minimum layer between 600 and 800 m depth. Morphometric and physiological studies have indicated that V. infernalis has little capacity for jet propulsion and has the lowest metabolic rate ever measured for a cephalopod. Because fin swimming is inherently more efficient than jet propulsion, some of the reduction in energy usage relative to other cephalopods may result from the use of fins as the primary means of propulsion. V. infernalis undergoes a rapid metamorphosis which consists of changes in the position, size and shape of the fins. This suggests that there are changes in the selective factors affecting locomotion through ontogeny. The present study describes these changes in relation to models for underwater 'flight'. Citrate synthase (CS) and octopine dehydrogenase (ODH) activities, indicative of aerobic and anaerobic metabolism, respectively, were measured in fin, mantle and arm tissue across a range of body size of four orders of magnitude. The low enzymatic activities in both posterior and anterior fin tissue and the relatively high activity in mantle muscle prior to metamorphosis indicate that jet propulsion using mantle contraction is the primary means of propulsion in juvenile V. infernalis. The increase in CS activity with size after metamorphosis suggests an increased use of the fins for lift-based propulsion. Fin swimming appears to be the primary means of propulsion at all adult sizes. The negative allometry of CS activity in mantle and arm muscle is consistent with the scaling of oxygen consumption previously measured for V. infernalis and with the scaling of aerobic metabolism observed in most animals. The unusual positive allometry of fin muscle CS activity suggests that the use of fins is either relatively more important or more costly in larger animals. Positive scaling of ODH activity in all tissues suggests that fin propulsion, jet propulsion and medusoid 'bell-swimming' are all important for burst escape responses. Enzyme activities in Cirrothauma murrayi are consistent with fin-swimming observed from submersibles, while those in Opisthoteuthis californiana suggest a strong reliance on medusoid swimming using the arms. The transition from jet propulsion to paired-fin 'flight' with increasing body size in Vampyroteuthis infernalis appears functionally to be an ontogenetic 'gait-transition'.

The impact of aerobic pretreatment of agro and industrial wastes on their biomethanation potential in Nisargruna technology

2021 ◽  
Vol 11 (5) ◽  
pp. 548-556
Author(s):  
Shubhada Nayak ◽  
Madhuri Sahasrabuddhe ◽  
Sharad Kale
Keyword(s):  
Rice Straw ◽  
Phase 1 ◽  
Industrial Wastes ◽  
Methane Formation ◽  
Municipal Solid Wastes ◽  
Metabolic Potential ◽  
Downward Displacement ◽  
Complex Polymers ◽  
The Impact ◽  
Aerobic And Anaerobic

Anaerobic digestion is among the essential biological techniques used for stabilization of organic sludge from sewage and highly concentrated efflu-ents from food processing industries. It also recycles the municipal solid wastes into compost with simultaneous production of methane. The current study was performed to estimate the biomethanation potential of various agro- and industrial wastes like Jatropha de-oil cake, prawn shells, chicken feathers, bagasse, rice straw and wheat husk by mimicking the conditions in the biphasic Nisargruna biogas plant. A small volume of samples was chemi-cally characterized and allowed to decompose under aerobic and anaerobic conditions to determine the effect of aerobic predigestion (i.e. phase 1 of Nisargruna plant) on final methane production. The biogas produced was quantified by downward displacement of water. The observations indicated that approximately 60-80% methane was produced when Jatropha de-oil cake, prawn shells and rice straw was used. Conversely, the wheat straw and sugarcane wastes showed less methane formation, which may be due to the presence of complex polymers like lignocellulose and silica that considerably reduces the metabolic potential of microorganisms.

scholarly journals Increased wave action promotes muscle performance but increasing temperatures cause a tenacity–endurance trade-off in intertidal snails (Nerita atramentosa)

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Samuel Clayman ◽  
Frank Seebacher
Keyword(s):  
Maximum Stress ◽  
Citrate Synthase ◽  
Wave Action ◽  
Sea Surface ◽  
Muscle Performance ◽  
Trade Off ◽  
Physiological Capacity ◽  
Winter Temperatures ◽  
Summer Temperatures ◽  
Physical Impact

Abstract Concurrent increases in wave action and sea surface temperatures increase the physical impact on intertidal organisms and affect their physiological capacity to respond to that impact. Our aim was to determine whether wave exposure altered muscle function in intertidal snails (Nerita atramentosa) and whether responses to wave action and temperature are plastic, leading to compensation for altered environmental conditions. We show that field snails from exposed shores had greater endurance and vertical tenacity than snails from matched protected shores (n = 5 pairs of shores). There were no differences in muscle metabolic capacities (strombine/lactate dehydrogenase, citrate synthase and cytochrome c oxidase activities) between shore types. Maximum stress (force/foot area) produced by isolated foot muscle did not differ between shore types, but foot muscle from snails on exposed shores had greater endurance. A laboratory experiment showed that vertical tenacity was greater in animals acclimated for 3 weeks to cool winter temperatures (15 C) compared to summer temperatures (25 C), but endurance was greater in snails acclimated to 25°C. Acclimation to water flow that mimicked wave action in the field increased vertical tenacity but decreased endurance. Our data show that increased wave action elicits a training effect on muscle, but that increasing sea surface temperature can cause a trade-off between tenacity and endurance. Ocean warming would negate the beneficial increase in tenacity that could render snails more resistant to acute impacts of wave action, while promoting longer term resistance to dislodgment by waves.

Aerobic and anaerobic enzymatic activities ofCalyptogena gallardoi(Vesicomyidae): a clam associated with methane cold seeps off Chile

2008 ◽  
Vol 88 (5) ◽  
pp. 983-986 ◽  
Author(s):  
R.R. González ◽  
R.A. Quiñones ◽  
E. Quiroga ◽  
J. Sellanes
Keyword(s):  
Anaerobic Metabolism ◽  
Citrate Synthase ◽  
Enzymatic Activities ◽  
Cold Seeps ◽  
Anaerobic Conditions ◽  
Muscle Tissues ◽  
Central South ◽  
Aerobic And Anaerobic ◽  
Vesicomyid Clam ◽  
Low Activity

Calyptogena gallardoiis a recently described species of vesicomyid clam associated to the extensive gas-hydrate field reported for the Chilean margin along 35°S to 45°S. Enzymatic analysis in foot, gill and abductor muscle tissues ofC. gallardoicollected in central-south Chile (~36°21′S 73°44′W), show high activities for malate dehydrogenase (MDH), strombine dehydrogenase (STRDH) and alanopine dehydrogenase (ALPDH) and a low activity of citrate synthase (CS) and ETS (electron transport system). Positive significant correlations (log–log scale) were found between enzymatic activities involved in anaerobic metabolism (MDH versus LDH and ALPDH versus STRDH), as well as between CS and opines dehydrogenases. The ratio MDH/LDH or any other opine dehydrogenase assayed was >> 1 in all tissues analysed. These results indicate thatC. gallardoiis highly adapted to the harsh anaerobic conditions of marine chemosynthesis-based communities inhabiting a reduced environment.

Acoustic detection of mesopelagic fishes in scattering layers of the Balearic Sea (western Mediterranean)

2014 ◽  
Vol 71 (8) ◽  
pp. 1186-1197 ◽  
Author(s):  
Marian Peña ◽  
M. Pilar Olivar ◽  
Rosa Balbín ◽  
Jose Luis López-Jurado ◽  
Magdalena Iglesias ◽  
...  
Keyword(s):  
Western Mediterranean ◽  
Thermocline Depth ◽  
Late Autumn ◽  
Balearic Sea ◽  
Acoustic Methods ◽  
Minimum Zone ◽  
And Migration ◽  
Gas Bearing ◽  
The Vertical Distribution ◽  
Oxygen Minimum

The distributions of micronekton layers in the Balearic Sea (western Mediterranean) were investigated by acoustic methods. Two multidisciplinary surveys were carried out in late autumn 2009 and summer 2010, recording acoustic, biological, and hydrographic data. We described acoustic layers, migratory behavior, sampled species, and water masses processes. Acoustic modeling of gas-bearing organisms was employed to explain differences between acoustic estimates and sampled abundances. The influence of environmental variables on the vertical distribution and migration pattern of these organisms was analyzed. The thermocline depth was related to the preferred depth for migrating myctophids, while nonmigrant species dwelled in the oxygen minimum zone of the water column both in late autumn and summer periods.

Enzyme activities in the Atlantic hagfish, Myxine glutinosa: changes with captivity and food deprivation

1986 ◽  
Vol 64 (5) ◽  
pp. 1080-1085 ◽  
Author(s):  
Glen D. Foster ◽  
T. W. Moon
Keyword(s):  
Food Deprivation ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Citrate Synthase ◽  
Krebs Cycle ◽  
Metabolic Potential ◽  
Metabolizing Enzymes ◽  
Myxine Glutinosa ◽  
Hydroxyacyl Coa Dehydrogenase ◽  
Krebs Cycle Enzymes ◽  
Glucose 6 Phosphate Dehydrogenase

Selected Krebs cycle enzymes and carbohydrate, amino acid, and lipid metabolizing enzymes were assayed in the muscle and liver of newly captured (April, 4 °C; August, 15 °C), fed (for 7 months), and food-deprived (for 7 and 11 months) hagfish, Myxine glutinosa. Seasonal differences were found in the glycogen content of the muscle and liver of newly captured hagfish (lower in the cold temperature), while consistently high levels were maintained in the fed group. Food deprivation decreased the content. All enzymes measured were found in both tissues, except glucose-6-phosphate dehydrogenase (liver only) and glycerol kinase (absent in both tissues). Activities of the enzymes were lower than teleost values, except for pyruvate kinase, citrate synthase, and 3-hydroxyacyl-CoA dehydrogenase, for which activities resembled teleost levels. Enzyme values from the fed fish (7 months) were generally the same as the newly captured group, and food deprivation increased phosphoenolpyruvate carboxykinase activities without altering other enzyme levels. These results support the view that hagfish are anoxia tolerant with low metabolic potential and demonstrate that the muscle and liver rely on carbohydrate and lipid reserves during fasting.

Volunteering in Religious Events

2019 ◽  
pp. 310-337
Author(s):  
Martina González Gallarza ◽  
Teresa Fayos-Gardo ◽  
Francico J. Arteaga-Moreno
Keyword(s):  
Social Behavior ◽  
Social Value ◽  
Trade Off ◽  
Mega Events ◽  
Event Marketing ◽  
Consumer Value ◽  
Religious Tourism ◽  
The Common ◽  
A Chain ◽  
The One

Religious event volunteering is a contemporary form of religious tourism that has interest for both scholars and practitioners: for the former, it is a social behavior that can be analyzed through many disciplines, consumer behavior being the one chosen here; for the latter, religious events do contribute to destinations development, although their impact is difficult to measure. This chapter explores (conceptually) the common origins of religion and volunteering and reviews briefly the event marketing to better understand the second part, which (empirically) reflects the results of two surveys undertaken with volunteers in two Catholic mega-events held in Spain. Findings show appropriateness of the consumer value-based approach as a trade-off between benefits (efficiency, social value, entertainment, and spirituality) and effort (time and effort spent) outcomes of volunteering. These value dimensions are also embedded in a chain of effects value-satisfaction-loyalty (as likelihood of repeating or/and recommending). Guidelines for organizations dealing with religious events as a form of religious tourism are offered.

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