Muscle Types in Fish and Deep Sea Ecosystems

Organisms that obtain energy by oxidizing inorganic compounds and use this energy to fix carbon dioxide into organic compounds.

A diverse ecosystem found at hydrothermal vents on the ocean floor, characterized by unique organisms adapted to extreme conditions.

A dominant species in deep sea vent communities, characterized by a tube-like body and a symbiotic relationship with chemoautotrophic bacteria.

A specialized organ in tube worms that houses chemoautotrophic bacteria, providing them with food and a place to live.

A species that has a disproportionately large impact on the structure and function of an ecosystem.

They have evolved insensitive forms of haemoglobin and proteins that bind to hydrogen sulfide, removing it from the body.

Movement of an organism in response to chemical gradients.

Fishes with skeletons made primarily of cartilage, such as sharks, rays, and skates.

Type 1 muscle, slow muscle, high oxygen demand, oxidative fibers, lots of capillaries, myoglobin for oxygen transport, more mitochondria for ATP production

Type 2 muscle, fast muscle, high glycolytic capacity, lots of stored glucose, works well without oxygen, inefficient ATP production, good for quick contractions

Predominantly red muscle, needs to swim at least 1 body length per second to avoid suffocation, swims even while sleeping

Almost entirely white muscle, ambush predator, uses quick bursts of speed to capture prey

High percentage of white muscle with red muscle on the sides, active swimmer, migrates long distances, can grow to 5 kg

Deep-sea creatures are opportunistic feeders and don't need to move frequently, so they have reduced muscle mass.

Red muscle is responsible for sustained swimming and steering. It's used for cruising and maintaining position.

White muscle is used for bursts of speed and power. It's activated when the fish needs to accelerate or exert maximum force.

Movement of the hair cell towards the kinocilium is excitatory, meaning it sends a signal to the brain. Movement away from the kinocilium is inhibitory, meaning it doesn't send a signal. This is how fish sense movement and pressure changes in the water.

Sound travels through water as compressional, longitudinal waves. This means that the water molecules are compressed and expanded as the sound wave passes through, much like a slinky.

Factors like absorption, reflection, refraction, and ambient noise can affect how sound travels in aquatic environments. Absorption turns sound energy into heat, reflection makes sound bounce off objects, refraction bends sound waves as they pass through different densities of water, and ambient noise makes it harder to hear other sounds.

Natural sounds are produced by animals or non-living things like earthquakes. Non-natural sounds are man-made, like those from ships, sonar systems, and airguns.

Fish use their ears and otolith organs to detect sound. The ears are paired structures in the cranium, and the otolith organs are located in the inner ear. Some fish also use their swim bladder to enhance sound detection.

A cod's ear has 3 semicircular canals, 3 macula areas, and 7 end organs: the semicircular canals, otolith organs, and the macula neglecta.

The saccular otolith is the largest of the otolith structures in the inner ear of bony fish. It's a white, bony structure that forms growth rings, which can be used to age the fish. The chemical composition of these rings can also provide insights into the different environments the fish has lived in.

Otolith organs contain a bundle of hair cells that sit within a structure called a cupula. These hair cells are responsible for detecting the movement of the otoliths, which in turn helps the fish sense sound and maintain balance.

Migratory fish have a higher proportion of red muscles (10-30%) compared to non-migratory fish. This allows them to sustain long-distance swimming for feeding or reproduction.

Fish are ectothermic, meaning their body temperature is influenced by the surrounding environment. Increasing water temperature affects fish growth, oxygen availability, and metabolism.

Warmer water holds less dissolved oxygen than colder water. This impacts fish because their metabolism increases in warmer temperatures, demanding more oxygen.

Higher water temperatures increase acidity (lower pH), which reduces the oxygen carrying capacity and hinders the gills' ability to absorb oxygen. This further stresses fish metabolism.

Fish body mass plateaus with age due to the influence of temperature on their growth. This means there's a limit to how large fish can grow in specific temperature conditions.

Pejus is when fish can survive but are stressed, while Pssimum is when conditions are unsustainable. Fish have an optimal temperature for growth, outside of which growth decreases.

Rising temperatures lead to a shrinking range of suitable temperatures for fish, potentially leading to fewer and smaller fish populations in the future.

Fish have limited ability to regulate their body temperature, especially when facing sudden temperature spikes. This makes them vulnerable to stress and reduced growth.

A complex system involving the hypothalamus, pituitary gland, and adrenal glands, responsible for regulating stress responses, metabolism, and other bodily functions.

A hormone released by the hypothalamus that stimulates the pituitary gland to release ACTH.

A hormone released by the pituitary gland that stimulates the adrenal glands to produce cortisol.

A hormone produced by the adrenal glands that plays a crucial role in stress response, glucose regulation, and circadian rhythm.

The natural, cyclical pattern of bodily processes that occur over a 24-hour period, influenced by cortisol.

Proteins that bind to cortisol and regulate gene expression in various cells.

Cortisol binds to glucocorticoid receptors, causing them to migrate to the nucleus, where they bind to DNA, influencing gene expression.

Cortisol can upregulate or downregulate gene expression, depending on the specific gene and type of receptor involved.

Boat activity produces low-frequency sounds that interfere with whale communication, affect their perception of the environment, and cause stress.

After 9/11, the closure of harbors led to reduced boat activity and a quieter ocean. This resulted in significantly lower stress levels in North Atlantic right whales.

Chemicals, natural or synthetic, that mimic or interfere with the body's hormones. Examples include plastics, flame retardants, pesticides, cosmetics, and drugs.

Endocrine disruptors that bind to a hormone receptor and cause a similar response to the natural hormone.

Powerful endocrine disruptors that bind to a receptor and cause an exaggerated response compared to the natural hormone.

Endocrine disruptors that bind to a hormone receptor but block the natural hormone from binding and having an effect.

Chemicals that mimic the effects of estrogen in the body.

Male sand gobies exposed to estrogenic compounds showed reduced testes development, altered reproductive behavior, and even started producing yolk, a female characteristic.