BIO FINAL

Know the key characteristics of hagfish, lamprey, cartilaginous fish, ray-finned fish, as well as organisms found in each. (cont.)

Cartilaginous fish- Includes sharks, skates, and chimeras (rattail fishes). • have jaws • cartilaginous • no swim bladder (oil in their liver gives them buoyancy) • sandpaper skin made of tooth-like dermal denticles • ventral mouth with teeth • consecutive rows replaced like conveyor belt • streamlined body shape • 5-7 pairs of gill slits with no covering (operculum) • extremely well-developed senses Ray-finned fish- • jaws present • mostly bony skeleton • fins usually paired with rays of cartilage or bone • respiration with gills covered by an operculum • swim bladder often present • most are oviparous (lay eggs) • most do external fertilization Using different adaptions to maintain position in the water. They use a gas-filled swim bladder to compensate for their heavier bony skeleton. (EX. flatfish, rockfish)

Be able to explain osmoregulation, the circulatory system, and countercurrent gas exchange in fishes. (cont.)

Circulatory System- In fishes, the heart has two chambers: one atrium and one ventricle. Blood flows through one circuit. It picks up oxygen in the capillary beds of the gills, and delivers it to capillary beds in all body tissues. Oxygen poor-blood then returns to the heart. Countercurrent gas exchange- Gills are very efficient at taking out what little oxygen is present in the water. Counter current involves blood in the capillaries flowing in the opposite direction to the flow of water flowing over them.

Understand the following senses in fishes: Ampullae of Lorenzini, lateral line, hearing, eyesight, and smelling.

Apullae of Lorenzi- It is an extra sense organ. Detects electrical impulses in prey muscles. Lateral line- Lines of holes that sense the movement of water. Hearing- Fish can sense sound through their lateral lines or their otoliths (ears). Some fishes, such as some species of carp and herring, hear through their swim bladders, which function rather like a hearing aid.

Understand the following senses in fishes: Ampullae of Lorenzini, lateral line, hearing, eyesight, and smelling. (cont.)

Eyesight- Among jawless fishes, the lamprey has well-developed eyes, while the hagfish has only primitive eyespots. Fish who live at the bottom of the ocean have eyes adjusted to the dark. Smelling- Fish use their noses for smelling rather than breathing. With its nostrils, usually two openings on either side of the snout, a fish can smell food from great distances.

Know the differences between hatchery and farm (aquaculture) processes, their problems, and outcomes.

Fish farming or pisciculture involves raising fish commercially in tanks or enclosures such as fish ponds, usually for food. It is the principal form of aquaculture. Fish hatcheries are facilities where Tribes, local, state, and the federal governments breed, grow, study, and protect fish. Hatcheries contribute to sustainable fisheries, improve fish health, provide insight into fish and their ecosystems, and give sustenance of the people and animals that depend on them.

Be able to explain the anatomical and habitat differences between lamprey and hagfish.

Hagfish live near the sea floor while Lamprey live in the open ocean and migrate to fresh water to spawn.

Know the key characteristics of hagfish, lamprey, cartilaginous fish, ray-finned fish, as well as organisms found in each.

Hagfish- Marine species that consume dead organisms such as whales. Commonly referred to as slime eels because they produce copious amounts of slime as a defense to ward off predators. Can tie themselves into knots to help them rip off larger chunks of food. (Pacific Hagfish, Atlantic Hagfish.) Lamprey- The Pacific sea lamprey is anadromous meaning they hatch in streams and migrate to the Pacific after 4-6 years. Then every 1-3 years they migrate back to fresh water to mate and die. Other lamprey spend their whole lives in freshwater and never migrate to the Pacific ocean. In the rivers and creeks they primarily eat decaying leaves. (Pacific Sea Lamprey, Western Brook Lamprey)

Know the four key characteristics of Chordates.

Hollow dorsal nerve cord, notochord, pharyngeal gill slits, post anal tail.

Know the anatomy of lancelets and sea squirts, as well as which of the four key features occur at larval versus adult stages. (cont.)

LANCELETS Adults and larvae have all four key chordate characteristics.

Understand how sea squirts and lancelets feed and their habitats.

Lancelets filter feed using mouth & gill slits. Water is taken in through the mouth and expelled through an opening called the atriopore. The sea squirt feeds by drawing water into the body through one of its siphons. Eat the plankton and detritis they filter from water. There are 32 species of lancelets world wide, they are benthic (ocean floor). Sea squirts are sessile and they can be found from intertidal zones to greatest depths.

Be able to explain osmoregulation, the circulatory system, and countercurrent gas exchange in fishes.

Osmoregulation- (salt balance) Osmosis- Water moves from a low solute (salt) concentration to a high solute concentration (water is drawn toward the higher level of salt).

Understand the difference between oviparous, ovoviviparous, and viviparous, and be able to provide examples of each type of reproduction.

Oviparous- egg-laying (ex: horn shark). Ovoviviparous- internal but consume a yolk sac. (ex: thresher shark). Viviparous- internal plancental-like connection (ex. Hammerhead shark)

Be able to explain what has impacted lamprey and salmon populations as well as potential solutions.

Poor stream habitat and dams affect lamprey and salmon populations. Rivers were channeled, riparian vegetation removed, water temperatures increased, and non-native warm-water fish were introduced. Fish ladders aren't that successful and not all dams have fish ladders. Predators have learned that salmon get stuck in the dam and wait for them to come and feast. Solutions are habitat restoration, dam removal, predator removal

Know the differences between hatchery and farm (aquaculture) processes, their problems, and outcomes. (cont.)

Problems with hatcheries: hatchery fish compete with the wild born salmon, they are larger that born salmose because they are fed constantly with high fat fish food, hatchery fish can breen with wild born salmon and affect the genetics of wild salmon. Problems with fish farms- seals and sea lions are killed by staff to prevent them from breaking open the nets, salmon must be fed food coloring so they match the wild salmon's flesh color.

Know the anatomy of lancelets and sea squirts, as well as which of the four key features occur at larval versus adult stages.

TUNICATES (SEA SQUIRTS) Adult tunicates have pharynx with numerous slits. Larvae tunicates have all 4 key characteristics.

Understand the anadromous life cycle and which groups of fish are anadromous in Oregon.

The Green Sturgeon and White Sturgeon are two species from Oregon. -Don't die after reproducing in rivers and creeks. Green Sturgeon -In Oregon, adults spawn in the Rogue River and Klamath River Basic -Adults can live to be over 70 years old -Threatened Species White Sturgeon -In Oregon, can be found in the Columbia and Willamette Rivers. -Adults can live to be over 100 years old.

Know the animals that belong in each subphyla: Urochordata, cephalochordata, and vertebrata.

Urochordata- the tunicates, or sea squirts Cephalochordata- the lancelets Vertebrata- fishes

Know how and why fish are raised in hatcheries.

We have hatcheries for commercial and recreational fishing. Fish remain at the hatchery until they are large enough to be transferred to a fish or shellfish farm or released into the wild as part of a stock enhancement program.