Marine Bio Exam 4 STUDY GUIDE QUESTIONS

FISH STUDY QUESTIONS

Contrast the anatomy and physiology of bony and cartilaginous fishes

• Bony fishes have skeletons made of bone, swim bladders for buoyancy, and gills covered by an operculum

• Cartilaginous fishes like sharks and rays have skeletons made of cartilage, no swim bladder, and exposed gill slits

What are the differences between bony and cartilaginous fish anatomy (TAIL)

• Bony fish: tail homoceral (upper lobe about equal length to lower lobe

• Cartilaginous: heteroceral (upper lobe longer than lower lobe)

Identify and describe the function of the various fins found in fishes

• Caudal fin propulsion and speed

• Dorsal fin stability, steering

• Anal fin stability, steering, reduce drag

• Pectoral fins steering and lift

• Pelvic fins balance and maneuvering

Describe examples of how the body form of a fish supports particular lifestyles

1. Fusiform: torpedo-shaped → fast swimmers (tuna)

2. Depressiform: flatenned top to bottom → live seafloor (sea moth)

3. Compressiform: flattened side to side → quick manuvering & fit in narrow spaces (flatfish)

4. Anguliform: long cylindrical serpentine → slithering crevices (freshwater eel)

5. Teeniform: ribbon like more vertically compressed (gunnel)

6. Filiform: thread like /long thin (snipe eel)

7. irregular: complex specialized → camouflage

8. ostraciiform: box like/triangular → rigid armour like scales

9. Globiform: sub spherical defensive shape→ inflate to deter predators

Describe how fish swim and what impact the shape of the caudal fin has on speed and maneuverability

• throwing their bodies into undulatory waves that pass from head to tail

• streamlining rigid bodies packed full of swimming muscles with high metabolic rates and regional endothermy :contribute to high speed

• Forked/lunate tails fast sustained swimming (concentrated movement at rear)

• Rounded tails slow but high maneuverability

Describe gas exchange in fish and how the respiratory system is specialized

• Water moves into mouth and flows over gills in one direction

• can be enhanced by ram ventillation

• gill arches support rows of gill filaments that bear lamellae(thin membranes increase surface area)

• arrangement of capillaries allows Blood flow opposite direction → countercurrent exchange

• Maximizes oxygen absorption efficiency

What is the function of the lateral line system? What is the function of the ampullae of Lorenzini?

• Lateral line detects vibrations and movement in water

• Ampullae of Lorenzini detect electrical fields in prey

What are some potential benefits of schooling and what sensory structures are used for schooling?

• Benefits: protection, confusion of predators, drag reduction, reproduction, feeding/hunting

• Uses vision and lateral line

Describe reproduction in fishes.

• internal fertilization common in cartilaginous fishes (male use claspers to inseminate female/ but also in some bony fishes)

• External fertilization common, many groups of bony

• development: ovoviviparous(EGG, most common) viviparous(LIVE BIRTH, least common)

Define sequential hermaphroditism, protandry and protogyny

• Sequential hermaphroditism changing sex during life

• Protandry male to female

• Protogyny female to male

Give an example of protandry and protogyny and explain why it is favorable

• clownfish protandry: if female is removed, adult male will change into female, next individual matures into adult male

• wrasses protogyny: if male is removed, largest female changes to male within 2 weeks

• Advantage maximizes reproductive success based on size or social structure

• Size advantage model: reproductive success at a given size of one gender becomes higher than if the individual remained the other gender

Define fish stocks

• Fish stock: population that has nearly complete reproductive separation from other populations of the same species

define maximum sustainable yield

highest catch that can be continued year after year without threatening the stock (allow stock to maintain constant population size)

What is the relationship between stock growth and maximum sustainable yield

• Bell shaped curve, they are directly related. MSY occurs at moderate levels of effort (underutilization and overfishing both decrease)

How does fishing effort relate to catch size, stock health, and MSY

• Increased effort increases catch until Maximum sustainable yeild and then causes decline

• Overfishing reduces stock health

what is an example organism of overfishing and stock

atlantic cod

what are some of the collateral damage effects of fishing

1. destroy reefs

2. destroy seamounts

3. destroy deep coral reef communities and even soft bottoms

4. bycatch: organisms unintentionally caught and killed

Describe different fishing techniques and their impacts

• Trawling: damages seafloor

• Longlining: bycatch issues

• Gillnets: entangle non-target species

• purse seine: targets large schools of fish → overfishing

What is meant by “fishing down the food web?”

• large top level carnivores get overexploited → move down to next level of the food chain and begin to exploit those species

• cascading effects

How did removal of large sharks impact scallop fisheries?

• Loss of sharks increased ray populations

• Rays overconsumed scallops causing fishery collapse

Why is fisheries management challenging and strategies for sustainability

• hard to estimate maximum sustainable yield

• real fisheries are more complex than the simple models such as the catch effort curve

• Strategies: set catches somewhat lower than estimated limits just to be on the safe side (but difficult for fisherman who rely on fishing for income)

how can you manage fisheries after catch level is set

1. limit by closing season when target is reached

2. limit the length of the season

3. limit number of boats or fishers

4. limit areas open to fishing

5. limit size and power of boats

6. limit, ban, strictly regulate certain fishing techniques

How can you make sustainable seafood choices?

• Follow guides like Monterey Bay Aquarium Seafood Watch

• Choose certified sustainable seafood (different fish = different levels of sustainability)

🐢 SEA TURTLE STUDY QUESTIONS

Describe general anatomy and physiology

• Two part bony shell to protect(Plastron: ventral underside / Carapace: top shell dorsal)

• The Rhampotheca: different types of hard, keratinous, toothless beak for feeding

• shell structure: either hard and bony or thick oily leathery (leatherback turtle)

GENERAL seaturtle adaptations

• Feeding: Rhampotheca (keratinous beak)

• respiration: rapid gas exchange in single breath/ hold breath

• Osmoregulation: salt glands

Distinguish between different species

• Green sea turtle herbivorous

• Loggerhead sea turtle strong jaws

• Leatherback sea turtle largest and no hard shell

identification key

What adaptations are seen in leatherbacks

• Thick fat and oil layers retain heat

• feed on jellyfish

• greatest range of any sea turtle

• long-distance migration/ survival in colder temps: very long flippers, shell ridges, large mass, countercurrent heat exchange, subcutaneous fat

different types of sea turtles

1. leatherbacks

2. green turtle, chelonia midas: herbivourus adults, one widely exploited

3. loggerhead, caretta caretta: adult head larger than other species, strong thick jaw

4. Hawksbill, eretmochelys imbricata: narrow hawk like beak, feed on invertebrates

5. flatback, natator depressus: flattened carapace

6. kemps ridley, lepidochellys kempii: smallest & most endangered, one major nesting together

7. olive ridley, lepidochellys olivacae: likely most abundant species, nest in arribadas

What is an arribada and benefits

• Mass nesting event

• Benefits predator saturation and increased survival

Briefly describe life history

• Hatch on beaches → ocean juvenile stage → adult migration → return to nest

Mating process

1. copulation in water (insertion)

2. female may mate with several male

3. sperm stored for duration of nesting season

4. female return to natal beach to lay eggs

5. may lay several clutches of eggs during season but wont reproduce every season

Nesting process

1. female emerge from water

2. search for nest site above high tide

3. dig

4. eggs deposited

5. fling sand , disguise nest

6. return to sea and may nest several more times during season

hatchlings process

1. average incubation: 50-75 days

2. 24 hour frenzy state making way to water , enter sea, swim offshore to safer deeper waters

what cues do sea turtles use to orient during different phases of their life cycle

• Visual Cues: Upon emerging, hatchlings use the bright, low horizon over the ocean to move away from dark, elevated silhouettes (dunes/vegetation).

• Wave Direction: They swim into waves to move away from the shore.

• Magnetic Compass: Earth's magnetic field as a compass to maintain an eastward (or appropriate direction) heading.

How does temperature affect development and sex

• Warmer temperatures produce females

• Cooler produce males

What environmental cues do sea turtles use

• Visual cues toward ocean

• Wave direction offshore

• Magnetic fields for migration

Describe experimental design for magnetoreception

• Hatchlings exposed to magnetic fields in lab

• Orientation changes based on field direction

What are some threats to sea turtles

• destruction and alteration of nesting and foraging habitats

• vessel strikes

• incidental capture/ entanglement in debris

• pollution

• poaching of eggs or adult turtles

• disease

• climate change/ sea level rise

🐦 SEABIRDS STUDY QUESTIONS

How are seabirds adapted to life near ocean

• water proof feathers

• many have salt glands / salt secretion

• long wings for gliding

• webbed feet for swimming and diving are common

• breed in colonies

• many migrate considerable distances

seabirds life history timelines compared to songbirds

• Reach sexual maturity later: 2-9 years vs. 1-2

years

• Have smaller clutch sizes: 1-5 eggs vs 4-8 eggs

• Longer incubation periods: 20-69 days vs 12-18

days

• Longer time to fledging: 30-280 days vs. 20-35

days

• Longer maximum lifespan: 12-60+ years vs. 5-15

years

What types of seabirds are in each order

Sphenisciformes: penguins

Procellariformes: albratrosses, petrels, shearwaters, fulmars

Charadriiformes: puffins, skimmers, gulls, terns, sandpipers, plovers

Pelecaniformes: pelicans

Suliformes: boobies, gannets, cormorants, frigate birds

Sphenisciformes key features

• southern hemisphere (many antarctic, subantarctic)

• blubber , thick layer of feathers

• countercurrent heat exchange / huddle

• flightless/ swim using wings

• solid bones = less bouyant

procellariformes key features

• most of their lives at sea

• large external nostrils/ sensitive to krill and phytoplankton odors

• albatrosses (long wing span/ travel great distances)

charadriiformes key features

• most diverse group

• gulls: predators and scavengers , successful in company of humans

• puffins: cold water diving, heavy specialized beaks hold fish

• terns: smaller more marine than gulls , arctic= migrate 10,000 miles

threats to seabirds

• bycatch

• contaminants/ pollutants , oil spills, chemicals

• plastic pollution

• coastal development = loss of nesting and feeding habitat

• toxic algal blooms

• climate change

Beak shape and feeding style

A: short, hooked beak for holding and tearing prey that is too big to be swallowed whole. good for shallow feeding

B: Heavy, but streamlined beak. works well for birds that dive deeper to feed on crustaceans and other prey

C: straight, and narrow beak is well suited for plunge divers who swallow prey whole

D: Longer lower beak allows for feeding while flying above the water

E: (curlews) Exceptionally long sensitive downturned beak to probe deep into mud to capture prey

Feeding strategies of specific seabirds

• Shorebirds foraging: Birds walk along shorelines probing or picking prey from sand/mud

• plunge diving: Birds dive from the air straight into water to catch prey

• pursuit diving with feet: Birds use their feet to propel themselves underwater while chasing prey

• pursuit diving with wings: Birds use their wings like flippers to “fly” underwater

• surface plunging: Birds dip or grab prey from the water surface without fully diving

• aerial pursuit: Birds catch prey in midair while flying

• skimming: Birds fly low over water with lower bill slicing the surface to catch prey

🐳 MARINE MAMMALS STUDY QUESTIONS

Main marine mammal orders and example animals

• carnivora : suborder pinnipedia = true seals, sea lions, fur seals, walruses / polar bears and sea otters

• sirenia: manatees , dugongs

• cetacea: suborder mysticeti = baleen whales / suborder odontoceti = toothed whales

General adaptations for marine life

• thermoregulation: endothermic and homeothermic/ blubber in most/ countercurrent heat exchange/ thick fur in some

• reproduction: viviparous = embryo recieve nutrients through placenta , newborns fed milk from mammary gland, low numbers of offspring with lots of parental care

• swimming: streamlined, hydrodynamic bodies, spindle shaped, smooth skin, blubber, reduced hair in many, internal genitals, appendages for swimming

Adaptations of mammalian dive reflex / why each beneficial for diving

• respiratory adaptations : apneustic breathing , exchange much higher proportion of air in lungs with each breath, collapsable lungs and ribcages

• increased storage of oxygen: larger blood volume , large spleen can store and release additional red blood cells during dives, high levels of myoglobin

• reduced utilization of oxygen: reduction in metabolic rate, peripheral vasoconstriction= shunting blood flow to brain and heart, bradycardia

Describe anatomy of pinnipeds, polar bears, sea otters, manatees, dugongs

• Pinnipeds: Streamlined body, Blubber insulation, Flippers (modified limbs), Walrus tusks (some species)

• Polar bears: Thick fur + fat layer, Black skin, Large paws (partially webbed)

• Sea otters: Dense fur (no blubber), Webbed hind feet

• Manatees: Large, rounded body, Paddle tail, Flippers

• Dugongs: Streamlined body, Fluked tail, Flippers

Distinguish between true seals and sea lions

• true seals no ear flap , sea lions ear flap

• true seals propel with tail/ short flippers , sea lions propel with long strong flippers

• true seals flop on belly on land , sea lions can walk with flippers

• true seals fatter , sea lions more streamlined

what do crabeater seals eat

antarctic krill

what adaptations facilitate crabeater seals feeding behavior

specialized lobed (lobodontine) teeth that interlock to form a sieve-like filter. They fill their mouths with water and krill, then push the water out, trapping the krill inside

where are weddell seals found

coast of antarctic

what role do leopard seals play in foodweb

apex predators :bridging the gap between top-level carnivores and lower-trophic levels

feeding behavior of walruses

benthic feeders, using whiskers and tusks to dig up and locate prey in shallow, dark seafloor sediment

reproductive behavior of elephant seals

• intense male competition: one alpha male mate with all the females and challenge many males daily. if beaten by new male that male becomes alpha

• fighting: males will ram heads/ teeth into eachother until one gives up

compare and contrast mysticetes and odontocetes/ distinguishing features

• mysticetes: baleen filter feeders, two nostril holes in blowhole

• odontocetes: toothed predators echolocate

how are cetaceans adapted for marine life

• tail: fluked = up and down propel

• streamline body

• flippers for steering / some have dorsal fin for stability

• reproduction: slow growing, long baby developing in uterus period, typically born tail first to help maintain oxygen connection, members of group help push whale to surface

feeding behaviors of rorquals, right whales/bowhead whales, gray whales

• rorquals: engulfment (big throat furrows, swim forward open mouth gulp water and then raise tongue push water out through baleen and then swallow food left) 

• right whales/ bowhead whales: skimming (swim forward with mouth open shut mouths push tongue up push out water and swallow trapped food in baleen)

• bubble nest feeding

• gray whales: eats invertebrates at the bottom (still baleen but swim to bottom move head on sediment to stir up and then strain that material out)

what has lead to low population size of north atlantic right whales / how did it get its name

• “right” whale to hunt: slow-moving, lived near the coast, floated after death, and yielded high volumes of valuable oil.

• lead to brink of extinction

• long time to reproduce: Sexual maturity ~10 year, females produce 1 calf, Current interval between calves is 7-10 years (3 years would be healthy/ expected

• ship collisions

• entanglement in fishing gear

what lead to decline of vaquitas

• Critically endangered due to overfishing getting caught in nets 

• Only about 10 left 

• Entanglement in gill nets for endangered totoaba is the major cause of decline

what are callosities observed on right whales

thickened, rough patches of skin on right whales’ heads, appearing white or yellowish due to colonies of whale lice

why are whales widely hunted

• Oil, blubber, baleen products, tissues, meat food : all used for different household products

function of echolocation / which whales echolocate

• Clicks are produced by pushing air from sacs in the nasal
  passages through the phonic lips

• evaluate environment and catch prey

• sound waves bounce of things and tell them how far away/ what around them 

• toothed whales odontoceti echolocate: killer whales beluga whales, narwhales, dolphins, porpoises , sperm whale 

what is the melon

• Fatty organ on head focuses sound in echolocation to regulate and focus signal

• The melon acts as an acoustic lens to focus sound into a beam

what is the narwhal tusk and its functions

• one long tooth

• believed to stun prey to eat

• possible mating display

distinguish between dolphins and porpoises

• Dolphins curved dorsal fins longer snouts

• Porpoises smaller blunt faces

what is amergris? what are possible functions of spermaceti organ in sperm whales

• Ambergris waxy substance in sperm whales

• Spermaceti organ aids buoyancy and sound

why do some whales migrate

take long distance migrations from summer (peak productivity) in polar regions and then move into more equatorial areas and thats where they give birth

what regulations help protect marine mammals

• The United States passed the Marine Mammal Protection Act in 1972

• Protects all marine mammals (not only whales)

• Prohibits (with certain exceptions) the "take" of marine mammals in U.S. waters and by U.S. citizens on the high seas, and the importation of marine mammals and marine mammal products into the U.S.

• “Take” = touching, killing, injuring, collection or harassment of marine mammals