Related Experiment Video
Updated: Dec 29, 2025
05:31
Gonadectomy and Blood Sampling Procedures in the Small Size Teleost Model Japanese Medaka Oryzias latipes
Published on: December 11, 2020
4.9K
Hormones as adaptive control systems in juvenile fish
Jacqueline Weidner1, Camilla Håkonsrud Jensen2, Jarl Giske2
1University of Bergen, Department of Biological Sciences, Postboks 7803, N-5020 Bergen, Norway Jacqueline.Weidner@hvl.no.
Biology Open
|January 31, 2020
Summary
This study models fish growth, integrating hormone levels with food and predation risks. Optimal hormone strategies balance growth and survival, adapting to environmental conditions for evolutionary fitness.
Area of Science:
- Evolutionary biology
- Physiology
- Ecology
Background:
- Growth is central to biology, influenced by hormones and environmental factors.
- Few studies integrate hormonal control with environmental influences on growth.
- Understanding these combined effects is crucial for ecological and physiological insights.
Purpose of the Study:
- To develop an evolutionary optimization model of fish growth.
- To investigate the interplay of hormone levels, food availability, and predation risk on growth and survival.
- To determine dynamic hormone profiles that optimize fitness.
Main Methods:
- Developed an evolutionary optimization model for fish growth.
- Simplified hormonal regulation to three key functions: growth hormone, thyroid hormone, and orexin.
- Simulated varying environmental conditions (food availability, predation risk).
Main Results:
- Identified evolutionarily optimal hormone profiles that balance growth and survival up to 30 cm.
- Demonstrated that higher food availability leads to higher optimal hormone levels, increasing metabolism and growth.
- Showed strategic use of thyroid hormone to enhance predator escape in risky environments.
Conclusions:
- Environmental factors significantly shape optimal hormonal strategies for growth and survival.
- Hormonal regulation is a key component of evolutionary adaptation to ecological pressures.
- Model results align with empirical observations of pace-of-life and resource strategies.
Related Concept Videos
02:32Osmoregulation in Fishes
52.6K
When cells are placed in a hypotonic (low-salt) fluid, they can swell and burst. Meanwhile, cells in a hypertonic solution—with a higher salt concentration—can shrivel and die. How do fish cells avoid these gruesome fates in hypotonic freshwater or hypertonic seawater environments?
52.6K
01:19Regulation of Hormone Secretion
5.9K
Regulation of hormone secretion is a finely tuned orchestration driven by various types of stimuli, encompassing neural, humoral, and hormonal signals. Environmental cues instigate neural stimuli, where action potentials traverse nerve fibers to reach their designated targets. An illustrative scenario is the body's response to stress, wherein the sympathetic nervous system releases epinephrine from the adrenal glands, inducing the well-known 'fight or flight' reaction.
Humoral...
Humoral...
5.9K
01:33Hormonal Regulation
35.5K
The renin-aldosterone system is an endocrine system which guides the renal absorption of water and electrolytes, thus managing blood pressure and osmoregulation. Activation of the system begins in the kidneys with a small cluster of cells adjacent to the afferent and efferent blood vessels of the renal corpuscle. As the nephrons are filtering blood, juxtaglomerular cells monitor blood pressure. If they detect a decrease in pressure, they release the hormone renin into the bloodstream.
35.5K
01:40Hormonal Regulation
47.5K
Hormones regulate a significant portion of digestion through activation of the neuroendocrine system. The neuroendocrine system of digestion contains many different hormones all with multiple functions that are both, directly and indirectly, involved in digestion.
47.5K
01:01Feedback Loops
63.4K
In most cases, excessive hormone production is prevented by negative feedback—a loop that starts with a stimulus inducing the release of a particular substance, like a hormone, to maintain a certain level before triggering a signal that results in a decrease in further release of the hormone.
63.4K
01:27Hormones of the Pituitary Gland
9.0K
The small, pea-sized pituitary gland is located at the base of the brain. It is crucial in regulating various bodily functions, from growth to reproduction. The gland is divided into the anterior lobe and the posterior lobe. The secretory cell clusters in the pars distalis of the anterior pituitary lobe are controlled by hypothalamic regulators and synthesize six primary hormones.
The most abundantly secreted hormone from the anterior lobe is the growth hormone, which controls overall growth by...
The most abundantly secreted hormone from the anterior lobe is the growth hormone, which controls overall growth by...
9.0K