Past SAQs

List 4 features of mako sharks which allow them to swim faster and maintain high cruising speeds

Endothermic - maintain a high metabolism

Streamlined

Denticles with microprojections that disturb laminar flow

Lunate/heterocercal tail

Compare characteristics of red muscle and white muscle tissue. How do these characteristics allow the muscle types to perform different roles in fishes?

Red muscle - high in myoglobin, longitudinal fibres, good for prolonged swimming

White muscle - no myoglobin, oblique fibres, good for short bursts of fast swimming

Name the two sub-families of sea snakes, and describe how their reproductive strategies differ.

Hydrophiinae - viviparous (live birth)
Laticaudinae - oviparous (egg laying)

Monitoring sea turtle populations from the number of nesting females poses several problems. Outline the problems you think about most important.

No all females nest each year

Habitat loss of nesting beaches

Briefly describe four foraging techniques used by seabirds. Give an example species for each.

Plunging - Terns

Diving - Emperor penguins

Scavenging - Giant petrels

Predation - Sub-antarctic Skua

The migrations of humpback whales are among the longest known of all animals. Describe the migratory behaviour of humpback whales and the characteristics of the destinations that drive these journeys.

Annual migrations from high latitude productive feeding grounds in summer to low latitude breeding grounds in winter. Tropics provide shelter and stability for raising young.

What features characterise the dive reflex in marine mammals?

Reduced heart rate

Peripheral vasoconstriction

Reduced aerobic metabolism

Explain briefly why pinnipeds sometimes have to undergo prolonged periods of fasting.

Under fasting during limited feeding periods like nursing, breeding, and moulting.

Give two reasons why Maui dolphin is threatened with extinction.

Restricted habitat that coincides with fishing effort

Small population size

What are the functions of sigittal otoliths in fish? Why are otoliths so useful for fisheries scientists?

Otoliths are used to age fish, they provide fisheries with population dynamics and growth/reproduction dynamics

Explain the difference between promiscuous and monogamous mating systems. State which of these strategies is more common in teleost fish, and give an example of a species that uses it.

Promiscuous - both sexes mate with multiple partners

Monogamous - mated pair spend prolonged time together

Promiscuous mating is most commonly seen in teleost fishes e.g. guppies

What are the different orientation cues hypothesised to guide sea turtle hatchlings from teh beach to the open ocean?

Light intensity and also light wavelength (specifically low frequency colour)

Briefly explain why El Nino conditions in the Eastern Tropical Pacific Ocean can result in a shortage of food for marine iguanas.

El Nino conditions cause lowered productivity in tropical surface waters, causing a shift in algae dominance from red/green to brown

Why do penguins sometimes have to go through prolonged periods of fasting?

Breeding

Moulting

Name the two endemic species of marine mammals in NZ. For each species, briefly describe a significant anthropogenic threat to their populations.

New Zealand Sea Lion - bycatch

Hector’s Dolphin - bycatchand habitat degradation

How do pelagic sharks avoid sinking, despite lacking a swim bladder?

Squalene and hydrocarbon filled liver that causes neutral buoyancy & pectoral fins provide lift

List 4 life-history characteristics that are typical of seabirds

Old age at first breeding
Long incubation period

Long nesting/fledging period

Long lived

Describe two feeding strategies used by baleen whales, and give an example species for each

Lunge feeding - Rorqual whales

Skim feeding - Right whales

Explain how the inter-pulse interval within the echolocation click of a sperm whale can be used to estimate the length of the whale

The interpulse interval measures the time between clicks (P0-P1) and is correlated with the time it takes for a click to travel the span of a sperm whales head twice

List four adaptations of albatrosses to maximise energy efficiency during flight.

Wing locks by bone at elbow

Wing locks by tendon at shoulder

Slender winds for gliding

Short feathers to prevent fluttering

Briefly explain the mechanics of lunge feeding by baleen whales, and give an example of a species that uses this foraging method.

Whale accelerates to patch of food, opens mouth (stops) and sucks in water by expanding the buccal cavity and inverting its tongue. Expel water through baleen preventing prey from escaping.

Rorqual whales

Briefly explain the morphological differences among the three extant families of pinnipeds.

Phocids - No pinnae, no fur, forelimbs short with claws, hindlimbs used for propulsion, cannot rotate

Odobenids - No pinnae, no fur, forelimbs intermediate, rudementary claws, himblimbs can rotate

Otariids - Pinnae, fur, forelimbs long (flipper like), no claws, himblimbs can rotate

Describe two solutions for mitigating the bycatch of marine mammals in commercial fisheries.

FRML - Fishing related mortality limit

SLEDs - sea lion exclusionary devices