CVA - INTEGUMENTARY SYSTEM

fish skin

serves as a multifunctional organ that protects against external threats, assists in movement, and plays a role in sensory perception.

fish skin

It is constantly exposed to environmental factors such as water currents, predators, parasites, and microorganisms; a highly specialized and adaptable structure that ensures survival in various environments.

protection

Acts as a physical barrier against infections and injuries.

sensory perception

Contains nerve endings that detect changes in the environment.

osmoregulation

Helps regulate water and ion balance, crucial for survival in freshwater and marine environments.

pigmentation and camouflouge

Allows fish to blend into their surroundings or display warning signals.

streamlining

Reduces water resistance to improve swimming efficiency.

epidermis

protection, mucous secretion

dermis

strength, flexibility, houses scales

scales

protection, reduces drag

pigmentation

camouflage, communication

mucous

immune defense, osmoregulation

hagfish and lampreys

example of jawless fish

jawless fish

skin is smooth, scaleless, and covered with a thick mucous layer.

jawless fish

Epidermis: Contains numerous mucous cells that secrete copious amounts of slime, helping in defense against predators and pathogens.

jawless fish

Dermis: Lacks rigid support structures like scales but contains collagen fibers for flexibility.

hagfish

produce large amounts of slime for defense.

lampreys

have keratinized teeth-like structures in their mouth, but no true scales.

Cartilaginous Fish

Tough and covered with placoid scales (dermal denticles), giving them a rough texture.

Cartilaginous Fish

Epidermis: Contains mucous and sensory cells that help in detecting environmental changes.

Cartilaginous Fish

Dermis: Contains connective tissues and blood vessels, along with structures that support the placoid scales.

placoid scales

reduce water resistance, aiding in efficient swimming.

dermis

houses chromatophores, enabling coloration and camouflage.

bony fish

Covered with overlapping scales (cycloid, ctenoid, or ganoid) embedded in the dermis.

bony fish

Epidermis: Contains mucous cells that help in reducing friction and protecting against infections.

bony fish

Dermis: Composed of connective tissues, chromatophores, and scale-producing cells.

scales

provide protection and flexibility while allowing for growth.

chromatophores

enable color changes for camouflage or communication.

integumentary

The of fish varies significantly depending on their evolutionary adaptations.

jawless fish

rely on mucous for protection

Cartilaginous Fish

have tough placoid scales for durability

bony fish

possess various scale types that balance protection and flexibility

epidermis

is a thin, non-keratinized layer, unlike the epidermis in terrestrial vertebrates and produces mucous (reduces friction, prevents infections).

epidermis

Contains club cells and granule cells, which help in immune defense and Has alarm substance cells in some species that release chemicals to warn others of predators.

superficial layer

outer layer is also called

outer layer

Composed of flattened epithelial cells that form the first barrier.

outer layer

Contains mucous cells (goblet cells) that secrete mucus, which protects against infections and reduces friction and Some species have club cells, which release chemicals when injured (alarm substances).

intermediate layer

middle layer is also called

middle layer

Contains stratified epithelial cells arranged in multiple layers and Cells migrate outward as they mature.

middle layer

Some fish have granule cells, which may play a role in immune defense and key feature: Supports epithelial regeneration.

basal germinative layer

inner layer is also called

inner layer

Located just above the basal lamina and contains basal cells, which continuously divide and replace old epithelial cells.

inner layer

The basal cells are undifferentiated, meaning they can develop into different types of epidermal cells; Key Feature: Responsible for cell renewal and epidermal growth.

basal lamina

thin, specialized structure that separates the epidermis from the dermis.; made up of collagen fibers and serves as an anchor for the basal germinative layer.

basal lamina

Provides structural support to the epidermis and helps in cell attachment and migration; Acts as a selective barrier, controlling molecular exchange between the epidermis and dermis.

dermis

thicker than the epidermis and contains collagen fibers, blood vessels, and pigment cells and the structural foundation of the skin; Supports the epidermis by supplying blood, oxygen, and nutrients.

dermis

Houses chromatophores, determining skin coloration for camouflage, signaling, or warning.; Provides flexibility and strength due to collagen fibers.

dermis

Anchors scales in bony fish (e.g., cycloid, ctenoid, ganoid scales).; Contains sensory structures like the lateral line system, allowing fish to detect movements and water currents.

stratum spongiosum

outer dermis

stratum spongiosum

Located just below the epidermis; Contains blood vessels, nerves, and chromatophores (pigment cells responsible for coloration).

stratum spongiosum

Houses mucous glands and sensory structures like the lateral line system, which detects vibrations in water; Plays a key role in wound healing and immunity.

stratum compactum

inner dermis

stratum compactum

Deeper, denser layer composed of collagen fibers.; Provides strength, elasticity, and structural support to the skin.

stratum compactum

Connects with muscles, helping in locomotion and body flexibility; Helps anchor scales in bony fish.

scales

embedded within the dermis, giving fish protection while maintaining flexibility.

scales

serve as protection and hydrodynamic support. Their structure and composition vary across classes.

jawless fish

No true scales, but may have bony plates or tough skin

Cartilaginous Fish

Tooth-like placoid scales, reducing drag in water

bony fish

Overlapping cycloid, ctenoid, or ganoid scales that grow with the fish.

cycloid scales

smooth, thin, round, and overlapping

ctenoid scales

similar to cycloid but with tiny spines on the edges

ganoid scales

thick, diamond-shapeds, and bony, covered with ganoine

lung fish

considered living fossils because they have remained relatively unchanged for millions of years. They are part of Sarcopterygii (lobe-finned fish) and are closely related to tetrapods (amphibians, reptiles, birds, and mammals).

cosmoid scales

common in Sarcopterygians, early but they are not present in most modern bony fish

chromatophores

pigment-containing cells responsible for coloration in fish. They help in camouflage, communication, and thermoregulation

camouflage

helps fish blend into their environment

communication

some fish change color for mating or dominance displays

thermoregulation

darker colors absorb more heat

melanophores

black or brown pigments

xanthophores

yellow pigments

erythrophores

red pigments

irodophores

reflect light, producing a shiny or iridescent effect

class agnatha

Limited chromatophores, mostly dull-colored.

class agnatha

No iridophores, resulting in minimal iridescence.

class chondrichthyes

Mostly melanophores; colors are usually black, grey, or brown for camouflage.

class chondrichthyes

Some deep-sea species have bioluminescent photophores for light production.

class osteichthyes

Wide variety of chromatophores, allowing bright colors and patterns.

class osteichthyes

Some species have highly developed iridophores for vibrant coloration.