Marine Biology: Elasmobranchs and Fish Behavior

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Questions and Answers

How do great white sharks improve their prey detection while hunting?

By remaining in shadow while facing the sun. (correct)

By using echolocation to find prey.

By rapidly swimming to create a wave effect.

By making loud sounds to attract prey.

What unique method do manta rays use to concentrate plankton while feeding?

They move cephalic lobes to concentrate prey. (correct)

They swim in tight circles around their prey.

They use their tails to stir up the water.

They release bubbles to trap plankton.

How does the saw of a sawfish assist in locating prey?

It produces sound waves that attract prey.

It acts like an antenna to detect vibrations in the water. (correct)

It serves primarily as a weapon, not for locating prey.

It uses biofluorescence to lure in other fish.

Which of these species primarily uses filter feeding as their feeding strategy?

Basking shark. Signup and view all the answers

What is the function of dermal denticles in elasmobranchs?

They protect the skin and enhance hydrodynamics. Signup and view all the answers

Which sensory capability is NOT mentioned as part of the sensory systems in elasmobranchs?

Thermoreception. Signup and view all the answers

What does neuroecology study?

The interaction between nervous systems and ecological environments. Signup and view all the answers

What process is involved in the neural basis of behavior regarding signals?

Sampling the received signals. Signup and view all the answers

What role do cryptochromes play in navigation for certain species?

They sense light wavelengths and magnetic fields. Signup and view all the answers

Which of the following statements about metabolic scope in teleost fish is true?

Metabolic scope represents the range of metabolic rates from basal to maximum levels. Signup and view all the answers

Which of the following best describes sedentary species of fish?

They remain within a limited home range. Signup and view all the answers

What distinguishes the moray eel from the gulper eel?

Moray eels are muscular and flexible while gulper eels have a collapsible stomach. Signup and view all the answers

How do migratory species of fish differ from sedentary species?

Migratory species exhibit seasonal patterns of movement. Signup and view all the answers

Which method do sharks use to navigate that does NOT involve magnetic fields?

Electric currents induced by their movement. Signup and view all the answers

What characteristic of deep-sea animals like gulper eels influences their muscular structure?

Low food availability reducing the necessity for muscle. Signup and view all the answers

Why is it important to understand fish biology in relation to conservation management?

To manage fish populations and biodiversity effectively. Signup and view all the answers

What is the primary source of steroid hormones?

Cholesterol Signup and view all the answers

Which type of hormone typically elicits fast but transient effects?

Protein hormones Signup and view all the answers

How do steroid hormones exert their effects on target cells?

By migrating into the nucleus and binding DNA Signup and view all the answers

What role do adrenal glucocorticoids play in the body?

Managing stress responses Signup and view all the answers

What is one challenge in using stress as a measure of animal health?

Separating normal actions from stress-induced reactions is complex Signup and view all the answers

What can endocrine biomarkers indicate about animal populations?

Reproductive health and stress responses Signup and view all the answers

Which of the following hormones is considered a progestogen?

Progesterone Signup and view all the answers

What significant impact has hunting had on North Atlantic right whales?

Decreased population numbers Signup and view all the answers

Which of the following mechanisms helps marine iguanas cope with high salt intake from sea grass?

They possess cranial glands that excrete salt. Signup and view all the answers

What type of salt glands do crocodiles and alligators possess?

Lingual salt glands located in the mouth. Signup and view all the answers

How do sea snakes reduce water intake when consuming prey?

They have a pterygoid walk mechanism. Signup and view all the answers

What initiates a response in target cells after hormone binding?

The receptors undergo a structural change. Signup and view all the answers

Which of the following best describes the endocrine system?

A collection of glands secreting hormones directly into the bloodstream. Signup and view all the answers

In the context of animal communication, what does the signaller do?

Generates and elicits a signal. Signup and view all the answers

Which characteristic distinguishes the endocrine system from the nervous system?

Endocrine systems rely on chemical messengers in the bloodstream. Signup and view all the answers

What is the primary function of receptors in endocrine cells?

To bind with hormones and trigger cellular responses. Signup and view all the answers

What alternative method is used to sample hormones from whales instead of blood collection?

Collecting whale poo Signup and view all the answers

What can be determined from whale poo regarding the population?

The ratio of males to females Signup and view all the answers

Why are steroid hormones easier to monitor compared to protein hormones?

Steroid hormones remain stable for longer periods Signup and view all the answers

What was the initial species for which dogs were trained to find poo?

Right whales Signup and view all the answers

Which method provides the broadest measure of hormone fluctuations in whales?

Urine analysis Signup and view all the answers

What is a disadvantage of using hair samples for hormone monitoring?

They provide a long-term timeframe but can be harder to interpret Signup and view all the answers

What happens to steroid hormones that are not picked up by target organs?

They are excreted in bile after processing by the liver Signup and view all the answers

What is a key advantage of non-invasive hormone monitoring compared to blood sampling?

It allows monitoring without impacting the animal Signup and view all the answers

What hormone is released by the anterior pituitary gland in response to corticotrophin releasing hormone (CRH)?

Adrenocorticotropic hormone (ACTH) Signup and view all the answers

Which of the following describes a role of glucocorticoids (GCs)?

Suppressing immune responses Signup and view all the answers

How do glucocorticoids affect gene expression?

They bind to receptors and influence gene expression Signup and view all the answers

During which phase do glucocorticoid levels typically show an increase?

At the beginning of the active phase Signup and view all the answers

Which of the following factors can influence glucocorticoid levels?

Seasonal changes Signup and view all the answers

What percentage of the genome can glucocorticoids regulate?

20% Signup and view all the answers

What type of genes can be impacted by glucocorticoids (GCs)?

Clock genes Signup and view all the answers

Which of the following is NOT a role of glucocorticoids?

Stimulating muscle growth Signup and view all the answers

Study Notes

Lecture 1 - General Overview of Animal Camouflage and Transparency

Terrestrial and aquatic animals use various strategies to blend with their surroundings, either to avoid predators or for hunting. These include hiding, mimicking, and using substrate.
Animals can camouflage themselves in three ways:
- Color matching the substrate, like the anemone shrimp
- Mimicking the substrate's structure, breaking up the body outline, like the stonefish
- Combining color and structure for camouflage, like the flounder or cigar wrasse.
Crypsis is the goal, camouflaging to blend in with surroundings, accomplished using different mechanisms to reduce conspicuousness.
Transparency is a way animals can reduce visibility, achieved by minimizing light scattering and reflection so photons pass through the organism. This can be partial (a portion of the organism is transparent) or total (the whole organism is transparent).
Transparency is more common in aquatic environments, specifically deep-sea oceanic environments, due to factors limiting its evolution and more commonality in the ocean.
Transparency depends on the difference between an organism and its environment's refractive index.

Lecture 2 - Bioluminescence

Bioluminescence is the production and emission of cold light (not heat) by living organisms, functioning for survival. It's an extremely efficient chemical reaction.
Bioluminescence is widespread in invertebrates, and some in vertebrates.
Organisms may obtain their luciferin (the light-producing chemical) from their diet, or synthesize it.
Luciferase is an enzyme that catalyzes the reaction creating light.
Bioluminescence may serve various functions, including attracting prey, mate attraction, communication, predator deterrence, and counter-illumination.
Bioluminescence is most common in marine environments due to the lack of sunlight. Factors that limit the evolution and use of transparency in the earth's environment include the following:
1. Gravity
2. UV radiation
3. Refractive index.

Lecture 3 - Deep-sea Organisms

High pressure, lack of light, cold temperatures, and limited food availability pose special challenges for deep-sea species.
Organisms living in deep water have evolved adaptations to cope with high pressure, including altered protein structures (in cell membranes, for example) to withstand compression.
Deep-sea animals have low metabolic rates to conserve energy and accommodate the food scarcity that these habitats present.
Some deep-sea species have adapted their mouth size to consume food opportunistically.
Many deep-sea species have reduced musculature and increased fat reserves to cope with energy conservation.
Glycosylation enzymes are an indicator of metabolic rates and decrease with depth. Cellular respiration activity declines with increased depth.

Lecture 1 - Fish Diversity and Feeding

Cartilaginous fishes (sharks, skates, rays, elephant sharks) have existed for over 400 million years.
Bony fish has approximately 20,000 species.
Fish feeding varies greatly, with strategies including sit-and-wait (ambush), active pursuit, and filter feeding, in a diversity of habitats.

Lecture 2 - Sensory and Communication Systems in Fishes

Chemoreception (sense of smell and taste) is important in fishes, often for locating food and mates.
Fishes have various olfactory systems, with some variations related to their diet and environment. Internal and external tastebuds are also employed.
Fishes use specialized cells to detect chemicals in water, and receptors are found in specific locations in the mouth, throat, skin, nasal openings, and gill arches.
Light detection is important.
Acoustic signaling for communication, feeding, and avoiding predators is also crucial. Many differences in hearing adaptations are related to the environment.

Lecture 3 - Physiology of the Catch Mechanism in Bivalves

Bivalves, like scallops, can exhibit a "catch" mechanism where muscles contract without constant ATP use. This is a specialized type of muscle contraction that can be used for a long period of time.
The pathways involved in causing contraction can be related to serotonin levels.

Lecture 3 - Osmoregulation in Marine Organisms

Aquatic animals can be either osmoregulators or osmoconformers.
Osmoregulation in marine creatures: The process of regulating internal water balance in response to external water conditions.
Euryhaline animals can tolerate a wide range of salinity.
Stenohaline animals can only tolerate a narrow range of salinity.
Freshwater fish tend to lose salts and gain water in the surrounding environment. Saltwater fish tend to gain salts but lose water.
Adaptations include specialized glands and/or kidneys to excrete salts or water and concentrate or conserve water based on their specific environment.

Lecture 1 – Behavioural Endocrinology

Hormones are chemical messengers that travel through the bloodstream to target cells or organs.
The endocrine system, with its various glands and organs, controls critical body functions and responses throughout an animal's life cycle.

Lecture 1 – Hormonal Influences (Endocrine System) in Different Environments

Endocrine biomarkers in the study of animal behavior: Understanding how hormones are related to behavior through time, especially regarding reproduction, stress, and immune response.
Factors such as temperature, food availability, social cues, and photoperiods influence reproductive functions and hormonal balance in animals.

Additional Notes - Aquatic Ecosystems

Environmental changes (like pollution and rising sea temperatures) can affect the function of the endocrine systems that are used to regulate behavior.
Various species of marine animals exhibit specialized physiology and behavioral responses to cope with different characteristics of their environment.
Fishes can either be migratory or sedentary, which affects their adaptation to changing environments.

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Description

Test your knowledge on the fascinating world of marine biology, focusing on elasmobranchs like sharks and rays, as well as teleost fish behaviors. Discover how these creatures detect prey, use unique feeding strategies, and navigate their environments. This quiz covers sensory systems, feeding methods, and neural behavior in marine animals.