Hatchery

SKELETAL MUSCLES

Straited muscles hold the skeleton in place • Propulsion and stabilizers • Myomeres divided by fibrous myocommata • Myomeres in zig-zag formation • Used to contract and bend the body

The appendicular skeleton

Supports the fins

Changes seen in fish

cartilage to bone • Reduction in scale thickness • Reduction in skull thickness

Sacciform cells

secretion that may be antiparasitic

Zygapophyses

strengthen spinal column

SKIN

- Boundary between fish and environment • Functional roles Defense, communication, camouflage, immunity against disease, regulate gas exchange, • Mucigenic not keratinzed • Fluctuates • Secretions, season, temperature

Epidermis

- Outer layer, lies over scales • Mostly consists of Malpighian cells

MALPIGHIAN CELLS

- Produces a mucous • Has been linked to antibacterial roles and antimicrobial activity

skull

- Protects the brain and jaws • Becomes ossified in bony fish

Pharyngeal jaw

- Secondary set of jaws used to hold prey

Neurocranium

- cartilaginous portion around the brain • Partially supports the eyes and internal ears

Endoskeleton

- linked by ligaments, tendons, and muscles • Secures the skeleton and allow mobility • Joints exist where skeleton components combine

Dermotrichia

- long fin rays projecting into water

Endoskeleton

All extant fish, cartilage or bone - some have specialized structures like bowfin and gular plate

Vertebrae

Allow flexibility and protect dorsal nerve cord • Not support, supported by water buoyancy - Runs from brain to tail -Varies from 25-50 vertebrae

SKIN VARIABILITY

Can vary greatly through life • Associated with migration, season, reproduction

DERMIS

Connective tissue with collagen fibers • Scales (if present) • "strong flexible jacket with scales and collagen fibers providing constraint" • Two major layers: stratum spongiosum/stratum compactum

Exoskeleton

Evolved in early jawless fish • Evolved as a predatory response • Currently- scales, scutes and bony plates • Maintain shape, protection, streamlining

GOBLET CELLS

Goblet shaped mucous cells • Been shown to contain antibacterial peptide

Ionocytes

Ionic regulation, aid with gill chloride cells

HYPODERMIS

Loose connective tissue • Adipose tissue (potential reserve) • Energy reserve that varies

STRATUM SPONGIOSUM

Scale bases and chromatophores

FISH SCALES

Show annual rings, like tree rings

White muscle

anaerobic, used for speed

Chondrocranium

cartilage bones and exocranium

Median fins

dermotrichia can be hard or soft

Centrum

encloses the notochord concave shape, replaces notochord

Mandible

lower jaw

Ostariophysi

modified for hearing

Red muscle

myoglobin and rich blood supply

• Club cells

release a pheromone when injured

Cycloid

round and smooth

Ctenoid

round and spiny/toothed

Ganoid

thick scales with basal bone layer

Maxilla

upper jaw

jaw

• Derived from branchial skeleton • First arch- upper and lower jaw • Second arch- may contribute to jaw suspension • Rest supports the gills

STRATUM COMPACTUM

• Inner most layer of the dermis • Contains collagen strands • Organized in opposing spirals • Allows for support and strength • Around myotomal musculature

LOCOMOTION

• Red and white muscle fish • Two types: undulations of body and tail and fin movement • Fin muscles for steering

SKELETONS

• Support movement/muscles • Protect soft organs • Hard skeletons and hydrostatic skeleton • Hydrostatic- mostly invertebrates (think earthworms) • Exoskeleton and endoskeleton