Animal Reproduction, Growth, and Activity: Key Factors

Reproduction and Growth

The hypothalamus is responsible for synthesizing sex steroids. The whole process is triggered by environmental sexual stimuli. Hormones are similar. There are invertebrate males and females.

Growth in vertebrates is dependent on growth hormone released by the adenohypophysis.

The exoskeleton of crustaceans limits their growth. In this case, the juvenile hormone (JH) is synthesized at a low rate to allow the organ to synthesize molting hormone (ecdysone) at higher concentrations for the molt to take place. This happens when they reach sexual maturity and to allow copulation, once the old exoskeleton is clear (allows gonadal development). Once removed, large amounts of JH are re-synthesized to build a new exoskeleton. Regeneration is a mechanism of asexual reproduction that is given in some invertebrate organisms.

Animal Activity

Anaerobic Catabolism

It consumes more O₂, making breathing difficult and hindering ATP formation. This type of catabolism consumes glucose to form lactic acid that goes to the liver, recovering glycogen by ATP. This only happens in extreme cases, and abuse of this catabolism could cause death.

Activity Level

• Supramaximal exercise: Increased energy expenditure is consumed.
• Submaximal exercise: Self into anaerobic capacity.

Part of the energy is used to keep the body alive and another in musculature (part dissipates heat and part is used in mechanics).

Lending Rate

The rate of the breathing apparatus corresponds to the aerobic capacity. Above that is the supramaximal work rate.

Standard Rate

Minimum energy requirements. Limit of anaerobic capacity.

Irruption Speed

It can be maintained for a limited time before entering the stage of fatigue and possibly anaerobic.

Normal Load

Small, negligible anaerobiosis.

The extent of aerobic activity is the difference between the lending rate and the standard rate (grade increases O₂ consumption from rest).

Temperature influences, especially when the body is at rest. At very high temperatures, metabolism decreases, and it costs more to recover at high temperatures. With stress, much energy is lost.

Energetic Cost of Migration

The cost of transportation is the spending needed to travel a unit distance. Migrating animals take to store lipids and have energy when needed, since the respiratory quotient is thanks to what we have used. Swimming and flying organisms take advantage of currents to have a lower energy expenditure, like dolphins with boats.