scholarly journals Hawksbill sea turtle life stage durations, somatic growth patterns, and age at maturation

2021 ◽  
Author(s):  
L Avens ◽  
MD Ramirez ◽  
LR Goshe ◽  
JM Clark ◽  
AB Meylan ◽  
...  
Keyword(s):  
Life Stage ◽  
Somatic Growth ◽  
Sea Turtle ◽  
Growth Patterns ◽  
Age At Maturation

scholarly journals Vitamin D deficiency serves as a precursor to stunted growth and central adiposity in zebrafish

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Megan M. Knuth ◽  
Debabrata Mahapatra ◽  
Dereje Jima ◽  
Debin Wan ◽  
Bruce D. Hammock ◽  
...  
Keyword(s):  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Early Life ◽  
Life Stage ◽  
Somatic Growth ◽  
Early Life Stage ◽  
Cytokine Signaling ◽  
Central Adiposity ◽  
Stage Development ◽  
Life Stage Development

Abstract Emerging evidence demonstrates the importance of sufficient vitamin D (1α, 25-dihydroxyvitamin D3) levels during early life stage development with deficiencies associated with long-term effects into adulthood. While vitamin D has traditionally been associated with mineral ion homeostasis, accumulating evidence suggests non-calcemic roles for vitamin D including metabolic homeostasis. In this study, we examined the hypothesis that vitamin D deficiency (VDD) during early life stage development precedes metabolic disruption. Three dietary cohorts of zebrafish were placed on engineered diets including a standard laboratory control diet, a vitamin D null diet, and a vitamin D enriched diet. Zebrafish grown on a vitamin D null diet between 2–12 months post fertilization (mpf) exhibited diminished somatic growth and enhanced central adiposity associated with accumulation and enlargement of visceral and subcutaneous adipose depots indicative of both adipocyte hypertrophy and hyperplasia. VDD zebrafish exhibited elevated hepatic triglycerides, attenuated plasma free fatty acids and attenuated lipoprotein lipase activity consistent with hallmarks of dyslipidemia. VDD induced dysregulation of gene networks associated with growth hormone and insulin signaling, including induction of suppressor of cytokine signaling. These findings indicate that early developmental VDD impacts metabolic health by disrupting the balance between somatic growth and adipose accumulation.

scholarly journals Heat, health and hatchlings: associations of in situ nest temperatures with morphological and physiological characteristics of loggerhead sea turtle hatchlings from Florida

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Kelsey A Fleming ◽  
Justin R Perrault ◽  
Nicole I Stacy ◽  
Christina M Coppenrath ◽  
Alison M Gainsbury
Keyword(s):  
Life Stage ◽  
Sea Turtle ◽  
Additional Stress ◽  
Loggerhead Sea Turtle ◽  
Righting Response ◽  
In Situ Incubation ◽  
Risk Of Predation ◽  
Increased Risk ◽  
Incubation Temperatures

Abstract Incubation temperatures, in addition to an embryo’s genetic makeup, are critical in many aspects of adequate sea turtle embryonic development. The effects of high and low incubation temperatures on hatchling quality have been previously examined; however, many of these studies were conducted on relocated or laboratory-reared nests, which do not accurately reflect natural nest temperature fluctuations. To observe the impacts of varying in situ incubation temperatures on loggerhead sea turtle (Caretta caretta) hatchling morphology, various health variables and locomotor performance, temperature data loggers were deployed in 15 loggerhead nests on Juno Beach, Florida, between May and July 2018. Over the course of the study period, 10 morphological traits were measured, blood analytes and heart rate were assessed for the establishment of reference intervals and the self-righting response in seawater was evaluated. Warmer months were associated with smaller body size and higher body condition index, larger umbilical scar size, slower righting time, lower heart rates and higher packed cell volume, hemoglobin, total solids, total white blood cell count, absolute heterophils and absolute basophils. These findings provide evidence that higher in situ incubation temperatures have the potential to adversely affect hatchlings from warmer nests due to increased risk of predation from smaller body sizes, decreased physical responses and overall fitness, altered hemodynamic balance (e.g. dehydration) and potential inflammation and/or stress. With rising temperatures, we predict sea turtle hatchlings may have increasing risks of developing suboptimal physiological features affecting overall fitness and ultimately survival. These results demonstrate that rising environmental temperatures can negatively impact sea turtle hatchlings, thus representing additional stress on sea turtle populations and contributing to our understanding of potential pathophysiological effects of climate change on the delicate life-stage class of the sea turtle hatchling. This information will be useful for formulating effective future sea turtle management plans.

In situ growth rate estimates of Southern Ocean krill, Thysanoessa macrura

2019 ◽  
Vol 31 (3) ◽  
pp. 116-122 ◽  
Author(s):  
Jake R. Wallis ◽  
Jessica E. Melvin ◽  
Robert King ◽  
So Kawaguchi
Keyword(s):  
Growth Rate ◽  
Southern Ocean ◽  
Growth Rates ◽  
Somatic Growth ◽  
Growth Patterns ◽  
Daily Growth ◽  
Thysanoessa Macrura ◽  
Growth Method ◽  
Repeated Sampling ◽  
The Antarctic

AbstractGrowth, which is intrinsically linked to environmental conditions including temperature and food availability are highly variable both temporally and spatially. Estimates of growth rates of the Southern Ocean euphausiid Thysanoessa macrura are currently restricted to limited studies which rely upon repeated sampling and length-frequency analysis to quantify growth rates. The instantaneous growth method (IGR) was used to measure the growth rate of T. macrura successfully in the southern Kerulen Plateau region during summer, providing the first IGR parameters for the Southern Ocean euphausiid species. Results of the four-day IGR incubation indicate a period of low somatic growth for adult T. macrura. Males had a longer intermoult period (IMP) (62 days) than females (42 days), but the sexes exhibited similar daily growth rates of 0.011 mm day−1 and 0.012 mm day−1 respectively. Juveniles exhibited the fastest growth, with an IMP of 13 days and daily growth rate of 0.055 mm day−1 indicating a prolonged growth season, similar to the Antarctic krill E. superba. Consequently, we highlight the usability of the IGR method and strongly encourage its use in developing a comprehensive understanding of spatial and seasonal growth patterns of T. macrura.

scholarly journals A Comparative Study of Growth Patterns in Crested Langurs and Vervet Monkeys

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Debra R. Bolter
Keyword(s):  
Somatic Growth ◽  
Growth Patterns ◽  
The Body ◽  
Physical Growth ◽  
Long Bone ◽  
Growth Stages ◽  
Vervet Monkeys ◽  
Foot Length ◽  
Epiphyseal Fusion ◽  
Trachypithecus Cristatus

The physical growth patterns of crested langurs and vervet monkeys are investigated for several unilinear dimensions. Long bone lengths, trunk height, foot length, epiphyseal fusion of the long bones and the pelvis, and cranial capacity are compared through six dental growth stages in male Trachypithecus cristatus (crested langurs) and Cercopithecus aethiops (vervet monkeys). Results show that the body elements of crested langurs mature differently than those of vervets. In some dimensions, langurs and vervets grow comparably, in others vervets attain adult values in advance of crested langurs, and in one feature the langurs are accelerated. Several factors may explain this difference, including phylogeny, diet, ecology, and locomotion. This study proposes that locomotor requirements affect differences in somatic growth between the species.

scholarly journals Incorporating habitat suitability and demographic data for developing a reintroduction plan for the critically endangered yellow spotted mountain newt, Neurergus derjugini

2019 ◽  
pp. 282-294
Author(s):  
Somaye Vaissi
Keyword(s):  
Age Structure ◽  
Captive Breeding ◽  
Demographic Data ◽  
Life Stage ◽  
Survival Rates ◽  
Age Groups ◽  
Old Adults ◽  
Before And After ◽  
Maximum Entropy Modelling ◽  
Age At Maturation

In reintroduction programmes for amphibians, data on age structure in hosting populations and choices of life stage or age groups in releasing captive bred individuals are often missing. Similarly, employing site selection procedures for selecting appropriate reintroduction locations are often neglected. Here, we obtained data on longevity, age at maturation, and age structure from skeletochronological data in a free living population of the yellow spotted mountain newt, Neurergus derjugini. A maximum longevity of 13 years for males and 12 years for females showed that N. derjugini is a long living newt with a stable age structure. We also employed maximum entropy modelling, geographic information system, and multicriteria decision analysis to obtain ranked suitability scores for reintroduction sites. Finally, we determined post-release survival rates for different life stage and age groups of N. derjugini including 30 eggs and 60 individuals of six-months old larvae, one and three-year old juveniles, and six-year old adults (15 each) born and raised in a captive-breeding facility and released into mesh enclosures in a selected stream. Over 10 visits to the site before and after overwintering, the survival rates for eggs, larvae, one and three-year juveniles and six-year old adults were 25, 80, 86.66, 93.33 and 53.33 % respectively. Applying survival rates obtained from current experimental reintroductions through a static life table suggest that an optimal release strategy to arrive at a numerical target of 100 adults aged three can be achieved by reintroduction of 650 fertilised eggs and fostering them in meshed enclosures in the selected stream.

Regional environmental drivers of Kemp’s ridley sea turtle somatic growth variation

2020 ◽  
Vol 167 (10) ◽  
Author(s):  
Matthew D. Ramirez ◽  
Larisa Avens ◽  
Lisa R. Goshe ◽  
Melissa L. Snover ◽  
Melissa Cook ◽  
...  
Keyword(s):  
Somatic Growth ◽  
Sea Turtle ◽  
Environmental Drivers ◽  
Growth Variation ◽  
Kemp's Ridley

scholarly journals First satellite tracks of neonate sea turtles redefine the ‘lost years’ oceanic niche

2014 ◽  
Vol 281 (1781) ◽  
pp. 20133039 ◽  
Author(s):  
Katherine L. Mansfield ◽  
Jeanette Wyneken ◽  
Warren P. Porter ◽  
Jiangang Luo
Keyword(s):  
North Atlantic ◽  
Sea Turtles ◽  
Life Stage ◽  
Sea Turtle ◽  
Sea Surface ◽  
The North ◽  
Satellite Transmitters ◽  
The North Atlantic ◽  
Solar Powered

Few at-sea behavioural data exist for oceanic-stage neonate sea turtles, a life-stage commonly referred to as the sea turtle ‘lost years’. Historically, the long-term tracking of small, fast-growing organisms in the open ocean was logistically or technologically impossible. Here, we provide the first long-term satellite tracks of neonate sea turtles. Loggerheads ( Caretta caretta ) were remotely tracked in the Atlantic Ocean using small solar-powered satellite transmitters. We show that oceanic-stage turtles (i) rarely travel in Continental Shelf waters, (ii) frequently depart the currents associated with the North Atlantic Subtropical Gyre, (iii) travel quickly when in Gyre currents, and (iv) select sea surface habitats that are likely to provide a thermal benefit or refuge to young sea turtles, supporting growth, foraging and survival. Our satellite tracks help define Atlantic loggerhead nursery grounds and early loggerhead habitat use, allowing us to re-examine sea turtle ‘lost years’ paradigms.

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