scholarly journals Environmental cycles and individual variation in the vertical movements of a benthic elasmobranch

2021 ◽  
Vol 168 (11) ◽  
Author(s):  
Edward Lavender ◽  
Dmitry Aleynik ◽  
Jane Dodd ◽  
Janine Illian ◽  
Mark James ◽  
...  
Keyword(s):  
Individual Variation ◽  
Functional Data ◽  
Habitat Preferences ◽  
Individual Characteristics ◽  
Seasonal Cycles ◽  
Benthic Species ◽  
Vertical Movements ◽  
Depth Data ◽  
Regression Framework ◽  
Autumn And Winter

AbstractTrends in depth and vertical activity reflect the behaviour, habitat use and habitat preferences of marine organisms. However, among elasmobranchs, research has focused heavily on pelagic sharks, while the vertical movements of benthic elasmobranchs, such as skate (Rajidae), remain understudied. In this study, the vertical movements of the Critically Endangered flapper skate (Dipturus intermedius) were investigated using archival depth data collected at 2 min intervals from 21 individuals off the west coast of Scotland (56.5°N, −5.5°W) in 2016–17. Depth records comprised nearly four million observations and included eight time series longer than 1 year, forming one of the most comprehensive datasets collected on the movement of any skate to date. Additive modelling and functional data analysis were used to investigate vertical movements in relation to environmental cycles and individual characteristics. Vertical movements were dominated by individual variation but included prolonged periods of limited activity and more extensive movements that were associated with tidal, diel, lunar and seasonal cycles. Diel patterns were strongest, with irregular but frequent movements into shallower water at night, especially in autumn and winter. This research strengthens the evidence for vertical movements in relation to environmental cycles in benthic species and demonstrates a widely applicable flexible regression framework for movement research that recognises the importance of both individual-specific and group-level variation.

scholarly journals Analysis of spatio-temporal structure of EEG-activity to form an objective assessment of the individual characteristics of the sleep-wake behavior

2010 ◽  
Vol 9 (2) ◽  
pp. 145-152
Author(s):  
A. A. Putilov ◽  
O. G. Donskaya ◽  
Ye. G. Veryovkin ◽  
D. A. Putilov
Keyword(s):  
Sleep Deprivation ◽  
Individual Variation ◽  
Temporal Structure ◽  
Objective Assessment ◽  
Quantitative Relationship ◽  
Individual Characteristics ◽  
Eeg Activity ◽  
Individual Vulnerability ◽  
Spatio Temporal ◽  
The Individual

The structure of individual variation in waking EEG was elaborated in 130 sleep deprived subjects. Its quantitative relationship with chronotype (morning and evening lateness), somnotype (daytime and anytime sleepability) and trototype (daytime and anytime wakeability) was described. The findings indicate that individual vulnerability of wakeability to sleep loss can serve as a quantitative predictor using the structures of waking EEG at daytime and during sleep deprivation.

scholarly journals Horizontal and Vertical Movement Patterns and Habitat Use of Juvenile Porbeagles (Lamna nasus) in the Western North Atlantic

2021 ◽  
Vol 8 ◽  
Author(s):  
Gregory Skomal ◽  
Heather Marshall ◽  
Benjamin Galuardi ◽  
Lisa Natanson ◽  
Camrin D. Braun ◽  
...  
Keyword(s):  
Continental Shelf ◽  
North Atlantic ◽  
Gulf Stream ◽  
Gulf Of Maine ◽  
Habitat Preferences ◽  
Fork Length ◽  
Vertical Movement ◽  
Vertical Movements ◽  
The North ◽  
History Of

The porbeagle (Lamna nasus) is a large, highly migratory endothermic shark broadly distributed in the higher latitudes of the Atlantic, South Pacific, and Indian Oceans. In the North Atlantic, the porbeagle has a long history of fisheries exploitation and current assessments indicate that this stock is severely overfished. Although much is known of the life history of this species, there is little fisheries-independent information about habitat preferences and ecology. To examine migratory routes, vertical behavior, and environmental associations in the western North Atlantic, we deployed pop-up satellite archival transmitting tags on 20 porbeagles in late November, 2006. The sharks, ten males and ten females ranging from 128 to 154 cm fork length, were tagged and released from a commercial longline fishing vessel on the northwestern edge of Georges Bank, about 150 km east of Cape Cod, MA. The tags were programmed to release in March (n = 7), July (n = 7), and November (n = 6) of 2007, and 17 (85%) successfully reported. Based on known and derived geopositions, the porbeagles exhibited broad seasonally-dependent horizontal and vertical movements ranging from minimum linear distances of 937 to 3,310 km and from the surface to 1,300 m, respectively. All of the sharks remained in the western North Atlantic from the Gulf of Maine, the Scotian Shelf, on George's Bank, and in the deep, oceanic waters off the continental shelf along the edge of, and within, the Gulf Stream. In general, the population appears to be shelf-oriented during the summer and early fall with more expansive offshore radiation in the winter and spring. Although sharks moved through temperatures ranging from 2 to 26°C, the bulk of their time (97%) was spent in 6-20°C. In the summer months, most of the sharks were associated with the continental shelf moving between the surface and the bottom and remaining < 200 m deep. In the late fall and winter months, the porbeagles moved into pelagic habitat and exhibited two behavioral patterns linked with the thermal features of the Gulf Stream: “non-divers” (n = 7) largely remained at epipelagic depths and “divers” (n = 10) made frequent dives into and remained at mesopelagic depths (200–1000 m). These data demonstrate that juvenile porbeagles are physiologically capable of exploiting the cool temperate waters of the western North Atlantic as well as the mesopelagic depths of the Gulf Stream, possibly allowing exploitation of prey not available to other predators.

scholarly journals The repeatability of variability: exploring intra- and inter-individual variation in seasonality

2016 ◽  
Author(s):  
Kevin D Matson ◽  
Maaike A Versteegh ◽  
B Irene Tieleman
Keyword(s):  
Individual Differences ◽  
Natural Selection ◽  
Immune Function ◽  
Individual Variation ◽  
Preliminary Analysis ◽  
Animal Experimentation ◽  
The Body ◽  
Statistical Techniques ◽  
Seasonal Cycles ◽  
Behavioral Traits

Animals exhibit seasonal cycles in a variety of physiological and behavioral traits. Studies of these cycles can potentially offer new insights into the evolution of individual differences. For natural selection to act, a trait must be both distinctive within individuals and variable among individuals. The extent to which the amplitude and phase of seasonal cycles fulfill these requirements is not well documented. As a preliminary analysis, we investigated seasonal cycles in the body mass of pigeons, which we weighed quarterly over a period of six years. [Our work with these animals complied with all applicable institutional regulations (University of Groningen Animal Experimentation Committee, license no. 5095) and Dutch and European laws.] We employed several of statistical techniques aimed at 1) quantifying the repeatability of seasonality and 2) comparing within- and among-individual variation in seasonality. Our goal is to take what we have learned from our analyses of mass and apply it to other seasonally variable physiological traits, including variables related to immune function.

scholarly journals Effect of Housing Conditions on Cortisol and Body Fat Levels in Female Rhesus Macaques

Biology ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 744
Author(s):  
Dian G. M. Zijlmans ◽  
Lisette Meijer ◽  
Marit K. Vernes ◽  
Jacqueline A. M. Wubben ◽  
Linda Hofman ◽  
...  
Keyword(s):  
Body Fat ◽  
Individual Variation ◽  
Rhesus Macaques ◽  
Dominance Rank ◽  
Individual Characteristics ◽  
Study Results ◽  
Female Rhesus ◽  
Cortisol Levels ◽  
Female Rhesus Macaques

Macaques are among the most commonly used non-human primates in biomedical research. They are highly social animals, yet biomedical studies often require group-living animals to be pair-housed in a controlled environment. A change in environment causes only short-term stress in adapting individuals, while non-adapting animals may experience long-term stress that can adversely affect study results. Individuals likely differ in their ability to adapt depending on individual characteristics. Changes in cortisol and body fat levels may reflect these different individual responses. Here, we investigate the long-term effect of a change from group- to pair-housing on cortisol and body fat levels in 32 female rhesus macaques, exploring whether age, dominance rank, original cortisol, and body fat levels are related to long-term stress in pair-housing. Hair samples were analyzed for cortisol levels, while anthropometric measurements and computed tomography were performed to quantify body fat. Monkeys served as their own control with a 7.5-month period between the measurements. Cortisol levels increased, while average body fat levels did not differ when individuals were moved from group- to pair-housing. Cortisol and body fat levels were not significantly correlated. Changes in cortisol were independent of age and dominance rank, whereas individual variation in body fat alterations was related to the group-housed body fat level and dominance rank. Although this study did not identify individual characteristics related to long-term stress in pair-housing, the individual variation confirms that some individuals are more resilient to change than others and provides possibilities for future refinement studies.

scholarly journals Costs of reproduction and ageing in the human female

2020 ◽  
Vol 375 (1811) ◽  
pp. 20190615 ◽  
Author(s):  
Grazyna Jasienska
Keyword(s):  
Individual Variation ◽  
Individual Characteristics ◽  
Costs Of Reproduction ◽  
Negative Effects ◽  
Cross Sectional ◽  
Trade Offs ◽  
High Reproductive Effort ◽  
Reproductive Events ◽  
Developmental Conditions ◽  
Reproductive Processes

Evolutionary theories of ageing point to reproduction as a significant factor to consider when asking why ageing occurs and why there is inter-individual variation in its progression. Reproduction in human females is costly, in terms of energy, nutrients and metabolic adjustments. Thus, it is expected that women who experienced high reproductive effort resulting from multiple reproductive events will age faster. However, the evidence for long-term negative effects of reproduction is not conclusive. The lack of understanding of whether there are trade-offs between reproduction and ageing in women is partly due to methodological challenges. The costs of reproduction are often calculated based only on parity, while other elements contributing to these costs (e.g. breastfeeding, timing of reproduction) are neglected, which may significantly underestimate the total costs and obscure the all-important inter-individual variation in such costs. Costs must be evaluated in relation to individual characteristics, including developmental conditions, nutritional status and social support that a mother receives during reproduction. Furthermore, ageing and health must be assessed based on comprehensive markers rather than arbitrarily assembled variables. Finally, longitudinal rather than cross-sectional studies and new statistical approaches are needed to reveal how much of a decline in health and progressing ageing can actually be attributed to past reproductive processes. This article is part of the theme issue ‘Evolution of the primate ageing process'.

Long-term changes in some benthic species in the Firth of Clyde, with particular reference to Tellina tenuis da Costa

1986 ◽  
Vol 90 ◽  
pp. 287-302 ◽  
Author(s):  
P. R. O. Barnett ◽  
J. Watson
Keyword(s):  
Seawater Temperature ◽  
Present Knowledge ◽  
Seasonal Cycles ◽  
Benthic Species ◽  
Temperature Changes ◽  
Annual Variations ◽  
Long Term Changes ◽  
Natural Temperature ◽  
A Site

SynopisPresent knowledge of long-term changes in benthic species in the Firth of Clyde is reviewed.Recent work on the annual variations in seasonal cycles of the sand-dwelling bivalve Tellina tenuis da Costa shows some correlations with natural and man-made variations in seawater temperature. Between 1973 and 1984 inclusive good settlements of young occurred on the two beaches examined in the autumns of years when higher mean seawater temperatures occurred in June and July. The implications are discussed in relation to cycles of climatic change. In general, settlements at Hunterston, a thermally enriched area, were considerably greater than at Kames Bay, a site affected only by natural temperature changes. However, T. tenuis at Kames Bay grew to much larger maximum sizes than at Hunterston, except in 1979, when Hunterston animals were larger. The possible interactions of food availability and the modifying effects of heated discharges are discussed.Earlier results by Dr A. C. Stephen between 1926 and 1951 are reassessed in the light of present knowledge.

scholarly journals Snow-load excitation of the Earth's annual wobble

1988 ◽  
Vol 128 ◽  
pp. 373-380 ◽  
Author(s):  
B. Fong Chao ◽  
William P. O'Connor ◽  
Alfred T. C. Chang
Keyword(s):  
Rotation Axis ◽  
Microwave Remote Sensing ◽  
Seasonal Cycles ◽  
Data Set ◽  
Snow Load ◽  
Depth Data ◽  
Motion Measurements ◽  
Remote Sensing Techniques ◽  
Annual Wobble ◽  
Future Plans

A global, monthly snow depth data set has been generated from weather satellite (Nimbus 7) observations using passive microwave remote-sensing techniques. In this paper we analyzed five years of data, 1980–1984, to compute the snow-load excitation of the annual wobble of the Earth's rotation axis. A uniform sea-level decrease has been assumed in order to conserve water mass. The result shows dominant seasonal cycles. The prograde component of the annual excitation is Ψ+ = (5.0 milliarcsec, −110*) and the retrograde component Ψ− = (5.0 milliarcsec, −31*). These computed values are compared with previous groundwater estimates, as well as the inferred values from ILS and LAGEOS polar motion measurements. The importance of accurate data is stressed and future plans proposed.

First record of vertical movements of the totoaba (Totoaba macdonaldi) as evidenced by pop-up satellite tags in the Upper Gulf of California

2020 ◽  
Vol 100 (1) ◽  
pp. 143-151
Author(s):  
Cristina Hernández-Tlapale ◽  
Juan Antonio De-Anda-Montañez ◽  
Armando Trasviña-Castro ◽  
Fausto Valenzuela-Quiñonez ◽  
James T. Ketchum ◽  
...  
Keyword(s):  
Gulf Of California ◽  
Habitat Preferences ◽  
Linear Displacement ◽  
Early Summer ◽  
Past Century ◽  
Depth Range ◽  
Vertical Movements ◽  
Preferred Temperature ◽  
Fishery Resource ◽  
Totoaba Macdonaldi

AbstractThe description of the movements and habitat preference of marine fishes is essential to understand their biology and in the evaluation of commercially exploited species and the conservation of endangered ones. In this regard, little is known about the movements of the totoaba (Totoaba macdonaldi), despite its being listed as critically endangered and having been a relevant fishery resource in the past century in Mexico. Totoaba is a fish species endemic to the Gulf of California characterized by late maturation, prolonged life and annual reproduction. Totoaba has maintained its known historical distribution range, although its movements and habitat occupancy in the water column have remained poorly understood. The present study describes, for the first time and at a daily fine scale, the vertical movements and habitat preferences of the totoaba in the Upper Gulf of California. Pop-up satellite archival tags (PSATs) were used to record depth and temperature at 4-minute intervals. Ten individuals were caught and tagged in May 2016 in the Upper Gulf of California and Colorado River Delta Biosphere Reserve. All PSATs were either prematurely released or lost. Data derived from two recovered tags that saved data for 43 and 75 tracking days, respectively, were analysed. The results showed that tagged fishes moved southward to the vicinity of Angel de la Guarda Island; these are consistent with spatial displacement patterns reported in the literature, with a linear displacement of 223 km from deployment to pop-up sites. Fish spent 47% of the time within a depth range of 25–35 m. Depth increased to 70 m for one fish in early summer (late June). The preferred temperature of fishes ranged between 21–23°C. A generalized linear model revealed that vertical movement was influenced by temperature. The vertical displacement of the totoaba shows a diurnal variation that may be associated with the distribution of its prey. Further work is needed to test this hypothesis with a larger number of organisms.

Seasonal variation in the strength of byssal attachment of the common mussel Mytilus edulis L.

1980 ◽  
Vol 60 (4) ◽  
pp. 1035-1037 ◽  
Author(s):  
Hilary Ann Price
Keyword(s):  
Mytilus Edulis ◽  
Field Studies ◽  
Gonadal Development ◽  
Seasonal Cycles ◽  
Winter Storms ◽  
South Wales ◽  
Attachment Strength ◽  
The Common ◽  
Autumn And Winter ◽  
Stored Reserves

A seasonal cycle in byssal attachment strength of Mytilus edulis is described in a population of mussels on the South Wales coast. Attachment strength reaches a maximum in September with a minimum in May.INTRODUCTIONMany seasonal cycles of a physiological nature have been described in the common mussel Mytilus edulis L. (reviewed by Gabbott, 1976; also Pieters et al. 1978; Zurburg et al. 1978), some of which, for example the annual accumulation and subsequent utilization of energy substrates, appear to be linked to gametogenesis. Following spawning in the spring the gonads of Mytilus enter a resting phase; metabolic demands are low. Glycogen and protein are accumulated in the tissues at this time as phytoplankton is abundant. Gonadal development commences in autumn when phytoplankton density has declined and energy is supplied by the utilization of stored reserves. Pieters et al. (1978) have suggested that the resulting decline in reserves is accentuated by the need for greater byssus production at this time to secure the mussels against the rigours of autumn and winter storms. No accounts exist of field studies which might support this hypothesis.

Short-term movement and behaviour of black marlin Makaira indica in the Coral Sea as determined through a pop-up satellite archival tagging experiment

2003 ◽  
Vol 54 (4) ◽  
pp. 515 ◽  
Author(s):  
John S. Gunn ◽  
Toby A. Patterson ◽  
Julian G. Pepperell
Keyword(s):  
Habitat Preferences ◽  
Diving Behaviour ◽  
Archival Data ◽  
Data Sets ◽  
Data Set ◽  
Daily Movement ◽  
Depth Data ◽  
The North ◽  
Coral Sea ◽  
North Western

Pop-up satellite tags were deployed on seven black marlin, Makaira indica,in the north-western Coral Sea, to examine movement, post-capture mortality and habitat preferences. Five of these tags popped up and transmitted positions, and detailed data on diving behaviour, ambient water temperature and daily movement were received via ARGOS transmission from two tags. One tag was later found on a beach, allowing a complete archival data set to be downloaded and geolocation estimates provided by software on-board the pop-up tags and those based on the complete archival tag data sets to be compared. The tags indicated rapid movement away from release sites; three south-easterly displacements (222 km (120 nm), 222 km (120 nm), and 1185.3 km (640 nm) net) appeared to be associated with the East Australian Current, one moved 555.6 km (300 nm) directly east, and the last tag moved offshore and then back towards the coast over a 2-month period for a net displacement of 384 km (207 nm). Based on displacement speeds and diving behaviour, it was concluded that five of the seven fish survived capture and handling for periods ranging from 3 to 64 days. The fate of the other two is unknown. Estimates of longitude made on board the pop-up tag were very similar to the best estimates that could be made using the complete archival data set; however, pop-up tag latitude estimates were significantly more variable than those using the archival data. In the two cases in which pop-up tags were scheduled to stay on the marlin for more than 3 months, the tags detached prematurely, after 39 and 64 days. Temperature and depth data indicated a preference for waters of the mixed layer (20–120 m) and temperatures warmer than 24°C.

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