4333 test 2 rev.docx

Ampullae of Lorenzini

Receptors in sharks detecting changes in the Earth's magnetic field for navigation, located on the snout, jaw, and around the eyes.

Razor sharp teeth

Teeth in sharks used for catching prey, with the ability to have hundreds at a time and constantly replace lost teeth.

Shark's need to keep swimming

Sharks must swim to avoid sinking, aided by large pectoral fins, a large oily liver for buoyancy, and to provide oxygenated water over their gills.

Shark's reproduction

Sharks reproduce internally, with male sharks having claspers between pelvic fins, embryos developing internally in some species like the Dogfish shark, and externally in a leathery pouch (mermaid's purse) in others like the Leopard shark.

Ovaparity/Ovaparious

External development where eggs hatch outside the mother, with examples of external fertilization in some cartilaginous fish like bamboo sharks and cat sharks.

Ovoviviparity/Ovoviviparous

Internal development where embryos develop within the uterus, as seen in species like mako sharks and sand tiger sharks.

Viviparity/Viviparous

Internal development where embryos develop within the uterus, receiving direct nourishment from the mother through a yolk sac placenta, as seen in species like Caribbean reef sharks and hammerheads.

Monomorphic

Fish with no visible external differences between sexes.

Dimorphic

Fish with visible external differences, where males are typically more colorful and ornate, which may be permanent or only during spawning, seen in species like wrasses and parrotfish.

Lateral line system

A sensory organ along the side of a fish's body that detects vibrations and movements, sensitive to differences in water pressure, consisting of neuromasts that send nerve impulses.

External tagging

Attaching visible markers like plastic discs or injected elastomer to fish for identification purposes.

Internal tagging

Inserting tags like radio or sonar tags inside fish for tracking and monitoring.

Markers technique

Using methods like fluorescent dye, tetracycline, or radioisotopes for marking and studying fish.

Advantages of fish migration

Benefits such as adaptation, access to food and growth, and improved reproductive success.

Disadvantages of fish migration

Drawbacks like the risk of getting lost or being preyed upon by predators.