Marine Enviro Quiz 2

Marine mammals that vocalise underwater tend to recycle air, whereby they keep air moving between the lungs and other air sacs in their body. Which of the statements below is not a reason to recycle air?

Recycling air means that they can dive deeper

What is true about pregnancy in seahorses?

Seahorse dads remove the embryo's waste like carbon dioxide and nitrogen. Seahorse dads produce antibacterial and antifungal molecules to protect their developing embryos from infection.

Seals hear underwater in a similar fashion to land mammals. Yet land mammals cannot hear very well underwater because sound has difficulty travelling from a watery medium to the air-filled chamber in our ear. How do seals overcome this problem?

Seals overcome the problem by engorging tissue with blood to fill air-spaces in the ear canal and middle ear so that sound travels to the inner ear.

Relative to their body size, how big are the lungs of deep-diving whales compared to those of humans?

Smaller

Land mammals can identify the direction a sound comes from by the difference in the time that the sound arrives at their left and right ear. This is because...?

Sound in air bends around the animal's head because flesh and air have vastly different sound conducting properties.

The ear canals of whales and dolphins are no longer functional, so how does sound from the water travel to the middle and inner ear?

Sound travels through "acoustic fat" in the lower jaw to the middle ear.

Cetaceans, whales, dolphins and porpoises hear well underwater. Which of the statements is/are true?

The auditory bullae of cetaceans are extremely thick, dense and highly mineralized, so they are very heavy.

Which of the following statements is false about the dolphin's fluke?

The dolphin's fluke is supported predominantly by bones equivalent to our ankle and toe bones

What is hyperphalangy?

Their flippers have a higher than average number of finger bones

What is true of the Phronima?

They are tiny voracious predators. They carve out the insides of a salp to make a home and a nursery for their young.

Which of the following statements is true of the early baleen whales?

They arose 37 million years ago. They didn't have baleen, but had lobed teeth that they used to filter feed. Llanocetus was one of the earliest baleen whales.

The beaked whale is the deepest diving mammal that we know of. How deep can they dive and for how long can they stay underwater?

They dive to depths of nearly 3,000 m and stay underwater for well over 2 hours

How does the Christmas tree worm - a tube-building polychaete worm - feed?

They filter-feed using their brightly coloured radioles to filter microorganisms from the water.

True or False: large land carnivores feed on large prey that is at least 45% of their body size, whereas large marine carnivores feed on small prey. Large baleen whales feed on prey that is approximately 0.01% of their body size.

True

True or False: parthenogenesis is a form of asexual reproduction where the embryo develops from an unfertilized egg cell

True

True or False: the gulper eel has an enormous mouth because there is little prey at great depths, so having a large mouth allows it to take any sized prey that comes its way

True

True or False: the hooded seal has the shortest lactation period (the time they produce milk to nurse their pups) of any mammal, at only 4 days

True

True or False: the largest size that a carnivorous mammal can reach on land is 1 tonne, whereas those that live in the water can get up to 180 tonnes

True

True or False: there is less variation in the body size of aquatic mammals compared to land mammals. The African elephant is only 25 times smaller than the largest marine mammal, the blue whale

True

True or False: whale sharks can filter 14.5 million litres of water every day

True

True or False: whales, such as the humpback whale, use baleen to strain krill from the water

True

Why are the leopard seals nasal bonds, called turbinates, greatly modified?

Turbinates are enlarged to save water when they exhale as it ensures a greater surface area for seals to capture water vapour from their exhaled breath

Food webs in the ocean typically have ____ food chains with many ____ trophic levels.

long, trophic

When were whales first living completely aquatic lifestyles and what was the name of that whale?

37 million years ago, Dorudon

Based on the lecture you know that herbivory is rare among marine mammals. How many marine mammal species are herbivores?

4

How many times faster does sound travel through water than air?

4 times

What is the name of the most ancestral whale and when did they live?

48-50 million years ago, Pakicetus

Dugongs consume how much seagrass per day?

9% of their body weight

Which of the following statements are true about the birth of smalltooth sawfish?

A thick protective sheath of tissue covers the teeth along the newborn pup's rostrum. The newborn pup's snout (its rostrum) is studded on either side with razor-sharp teeth.

Although marine mammals belong to unrelated groups, each group independently evolved to be a similar average body mass. How big is that?

~500 kg

Describe the role of the male jawfish in fathering his children.

After courtship, the male fertilises the eggs and then collects them in his mouth, keeping them until they hatch to protect them from predators. He aerates the egg brood by opening its mouth wide and rotating the egg mass. During the incubation period, he cannot feed, which means he is underweight by the time their eggs hatch.

Describe Antarctic krill

Antarctic krill are herbivorous and migrate to the surface waters at night to feed on phytoplankton. They live at depth because the darkness helps them to avoid predators

Why do marine mammals use sound to communicate underwater?

Because vision is limited

How does being large help baleen whales?

Being large helps baleen whales feed on often patchy and unpredictable distributions of krill as they can go for long periods and travel over great distances between feeding events

What statement best describes the cultivation grazing of dugongs?

Dugongs selectively feed on the seagrass species that grow rapidly, removing them roots and all, leaving bare feeding trails through the sand. Dugongs move from area to area so that the seagrass regrows in the feeding trails.

How are excessive nitrogen and phosphorous levels toxic to seagrass?

Extra nutrients stimulate the growth of epiphytic algae that grow on the seagrass as well as the growth of free-floating algae, which reduces the amount of sunlight available to the seagrass. This reduces its ability to photosynthesise, so it starves.

True or False: a baleen whale's nose opens as a single opening, called the blowhole, which is held closed while underwater

False

True or False: a trophic level describes a group of animals that inhabit the same area

False (a trophic level describes a group of animals that fulfill a similar role within a food web)

True or False: comb jellies capture their prey by poisoning them with toxins

False (comb jellies capture their prey by trapping them in adhesive cells on their tentacles)

True or False: coral can reproduce by spawning, which involves releasing eggs and sperm into the water column simultaneously, timing the spawning with ocean currents

False (coral can reproduce by spawning, which involves releasing eggs and sperm into the water column simultaneously at the right time by timing the spawning with the lunar cycle)

True or False: small males of the giant Australia cuttlefish make themselves look larger in order to intimidate territorial males by varying the speed and intensity of colour changes across their body

False (small males of the giant Australia cuttlefish mimic the colouration and behavior of females to sneak close to the females being guarded by territorial males in order to mate with the females)

Flatworms mate by traumatic insemination. Describe this.

Flatworms are hermaphroditic- each individual has both egg-producing ovaries and sperm- producing testes. While mating, both individuals can transfer sperm to the other, and both are capable of being fertilised.

How do herbivores influence reefs?

Herbivores maintain the balance between corals and macroalgae. The loss of herbivores mean that macroalgae can over-grow coral reefs. Coral reefs have large herbivorous communities. The loss of an important herbivore on Caribbean coral reefs caused the loss of coral , but also the loss of many other species such as worms, snails, and fish.

Some land mammals, like howler monkeys and humans, cheat as they produce vocalisations that make themselves sound bigger than they actually are. Which of the following statements is false?

Howler monkeys produce very low-pitched sounds by opening their mouths very wide.

Large numbers of herbivorous fish aggregate because...

Large quantities of phytoplankton become trapped between the boundaries where water bodies meet. They can evade predators by schooling in large groups.

Do male elephant seals have elaborate courtship displays directed at females?

No, instead, male elephant seals have an aggressive display directed at males, and this is part of establishing dominance. The dominant male elephant seals use their display to establish and hold those regions favoured by the females to father more pups

Which of the following statements about the PON1 gene are true?

PON1 gene is found in all mammals but is not functional in marine mammals, so they cannot produce enzyme that detoxifies organophosphates.

What are phytoplankton?

Phytoplankton are tiny, floating microscopic organisms that make their own food via photosynthesis. They are restricted to living in the upper well-lit layers of the ocean. They are so numerous that they make up 50% of the photosynthesis on Earth and are an extremely diverse group which includes single-celled microbes like bacteria and archaea.

What is false about fur seals?

Fur seals and sea lions use their hind-flippers to move through the water in a similar way as penguins and sea turtles do.

Describe the pelvis of cetaceans (whales and dolphins).

Most cetaceans have a tiny pelvis, but the right whale has a well-developed pelvis as this is where the muscles that control their extremely long and agile penis attach.

What is right whale mating like?

The males take turns to mate with a female in oestrus. When the female is ready (in oestrus), she will mate with up to ten males. Males have enormous testicales (1 tonne) that are about 3 to 4% of their body mass.

True or False: chromatophores are pigmented cells which allow cephalopods to change color

True

What are microscopic drifting herbivorous animals called?

Zooplankton

The smallest land mammal, the Etruscan shrew, is how many times smaller than the smallest marine mammal, the sea otter?

~1,000 times

The Etruscan shrew is the smallest mammal. How big are they?

~1.8 g

The closest living relatives of whales and dolphins are...

Even-toed ungulates like the hippopotamus

True or False: seagrass and algae are both flowering plants

False (seagrass is a flowering plant and algae is not)

True or False: tardigrade mating lasts only a few seconds

False (tardigrades have marathon mating sessions, where foreplay includes mutual stimulation that lasts for over an hour, before ejaculation)

True or False: comb jellies are carnivores

True

From the lecture you know that seagrass requires shallow water habitats to grow. However, most of the oceans are deep, with an average of average depth of 3,500 m, and there are few habitats suitable for seagrasses to grow. What is the maximum depth below which seagrass can no longer grow?

200 m

Which of the marine mammal groups have damaged, non-functional PON1 genes and so cannot detoxify toxic organophosphates?

All marine mammal groups

Along with watching the lecture, in the lab observe the differences between the dentition of the leopard seal and other seals. Which of the following statements below is incorrect?

Between their teeth they grow baleen that assists in sieving.

Based on the lecture, which of the following statements below is true about blue whales?

Blue whales accelerate to 37 km per hour into prey swarms and slow to 1.8 km per hour when they open their mouths to feed.

What is true for the Nazca booby?

Booby mothers secrete extra testosterone into their first-laid egg, which makes the first chick larger, stronger, and more aggressive, regardless of whether it's male or female. Once the second chick hatches, its older sibling kills the newly hatched chick within days of hatching.

What types of reproduction do jellyfish use?

Both asexual and sexual reproduction

What type of algae is kelp classified as?

Brown algae

What is the difference between fragmentation and budding?

Budding is when an outgrowth of an existing polyp creates a new individual (such as an anemone). Fragmentation is when a piece of an individual's body breaks off and regrows to become a complete adult.

Along with watching the lecture, in the lab, compare the dugong's skull to those of other mammals. Notice that compared to other mammals, the snout of the dugong is deflected relative to the palate at the top of the mouth. This down-turned rostrum places their mouth nearly parallel to the ocean floor, an advantage for these benthic foragers. By how much is their snout deflected?

By ∼70°

The closest living relatives of seals and sea lions are...

Carnivores like weasels and raccoons

Baleen whales, which were once the size of dolphins, became giants about 4.5 million years ago. Which of the factors below was not involved in driving this dramatic change in body size?

Deep diving allowed baleen whales to feed on more prey living at great depths.

From the lecture. Which of the following statements is true about dugongs?

Dugongs eat predominantly seagrass and prefer to feed in regions where the seagrass is sparse.

The closest living relatives of the dugong and manatees are...

Elephants

True or False: comb jellies are jellyfish

False

True or False: some species of cephalopod (octopus and squid) guard their eggs during incubation, and a deep-sea octopus has the longest known incubation guarding period of 40 years.

False (some species of cephalopod (octopus and squid) guard their eggs during incubation and a deep-sea octopus has the longest known incubation guarding period of 4.5 years)

True or False: the eggs of the clownfish need to be cleaned by removing algae that can grow over them, and fanned with fins to circulate oxygen-carrying water over the eggs. Both the male and female clownfish tend to the eggs.

False (the male clownfish tends to the eggs while the female watches, and if he does not do a good job aerating their eggs, the larger aggressive female will chase him away and find a new mate.

True or False: the mating system of the humpback whale involves the males attracting a group of females with their underwater display

False (the mating system of the humpback whale involves the males competing via aggressive behavior to gain access to females in oestrus)

True or False: pompeii worms survive living at great depths in the hot waters around hydrothermal vents by burying themselves in the sand

False (they live in a symbiotic relationship with bacteria that provide them with food and protect them from high temperatures)

Land mammals do not hear well underwater. Why can they not identify where sounds come from?

Flesh and water have similar sound conduction properties, so sound vibrates the entire skull. As land mammals have ears attached to their skull, the left and right ears detect sound vibrations at the same time.

The ancestral whales looked nothing like whales today, but more like wolves, but what characteristic whale-like trait did they have?

Heavy dense boned auditory bulla

Where do herbivorous zooplankton live?

Herbivorous zooplankton live at depth during the daylight hours and migrate to the surface waters at night to feed on phytoplankton. Herbivorous zooplankton live at depth because it is dark so they can avoid predators.

Mammals that live on land and at sea signal differently. Which of the following is false?

Land mammals sometimes cheat by producing higher-pitched sounds for their body size.

Can nudibranchs fertilize themselves?

Nudibranchs are hermaphroditic, which means they have both male and female reproductive organs. However, they cannot fertilize themselves and need to mate with another individual by laying their eggs in a gelatinous spiral.

How do marine mammals come into contact with organophosphates?

Organophosphates have been heavily used as pesticides in agriculture. They was into river systems and travel out to sea. They are eaten by small organisms and move up through the food chain, accumulating in high toxic doses in top predators, like marine mammals.

What is true about pregnancy?

Pregnancy for female animals occurs inside the reproductive tract, but not in the male seahorse. Many of the same processes, and even many of the same genes, control both male and female pregnancy.

The pinna and ear canal make up the outer ear. They are least modified in which group of marine mammals?

Sea lions

The cochlea of the toothed whales is adapted to detect high-pitched, low-intensity sounds for echolocation. To do this their cochlea is:

Stiffer and proportionately thicker compared to the cochlea of land mammals.

Pick up the skull of the dugong and that of the horse. Which of the following statements is true?

The dugong skull is heavier than that of the horse, and the teeth don't have a ridged grinding surface like the horse.

Based on the lecture, which of the following statements is true about baleen whale and teeth?

The earliest baleen whales did not have baleen, only teeth.

Why does this angler fish have a second angler fish attached to it?

The larger angler fish is a female; she has a smaller parasitic male permanently fused to her body who will fertilise her eggs.

What is the courtship display of the male hooded seal?

The male hooded seal blows a pink balloon out its nose to attract females and to show dominance over other males

What is the courtship display of the male Japanese pufferfish?

The males use their artwork to attract and win a mate. The males decorate the sandcastles with intricate designs, comprising repeating patterns of ridges and grooves. The males carve the perfect circular sandcastles, which are up to 2 meters wide, using their fins.

What is the mating display of the giant Australian cuttlefish?

The males vary the speed and intensity of the colour changes along the edges of banner-like webs along their body and arms. The males are bigger than the females and displaying males make themselves look bigger by extending banner-like webs along their body and arms. The males have iridescent colours that pulse along the edges of banner-like webs along their body and arms.

What is true of maternal care in crocodiles?

The mother carries her hatchlings in her mouth to the water. She remains and protects her young for several months after hatching.

Mammals that live in the water are big. What limits how small or how large they can be?

The need to stay warm sets a lower limit of how small a marine mammal can be, but how much they can eat sets an upper limit on how big they can get

What is true about the pelvis of the dolphin?

The pelvis is a vestigial structure; even though it remains, it no longer serves a function or purpose

Which of the following statements is false about vocal sounds?

The pitch of the sounds produced by mammals is related to the size of their body.

What is algae?

The term algae is an informal term to group together a diverse group of photosynthetic organisms that are not necessarily closely related. Algae are grouped according to the coloured photosynthetic pigments that they carry, either brown, red, or green.

Along with watching the lecture, in the lab observe the differences between the dentition of the cetacean skulls compared with other mammal skulls. Which of the following statements is false?

Toothed whales and dolphins have teeth that are similar to those of other land mammals.

The first group of mammals to return to live in the sea were:

Whales

Which of the following adaptations is not involved in allowing marine mammals to hold their breath for longer periods than other mammals?

Whales have larger lungs to store more oxygen

When comparing deep-diving whales and humans, which of the following is true?

Whales have small lungs, collapse their lungs when they dive, and inflate them at the surface, so they are more efficient at moving air in and out

How do flying seabirds benefit from the feeding of marine mammals?

When fish are in a large three-dimensional space and at depth, flying seabirds cannot capture them. Thus, flying seabirds benefit from the feeding of marine mammals as they work together to drive a shoal of fish to the water's surface within the range of diving seabirds.

Describe seahorse birth.

With about a week to go before birth, seahorse dads produce hormones to prepare their embryos. Hatching hormone signals cause the embryos to hatch out of thin-walled membranes, and once free they swim and move freely inside the dad's brood pouch.

What are the advantages of asexual reproduction?

You can make many copies of yourself quickly and so exploit a new resource quickly, outcompeting other species.

What are the advantages of sexual reproduction?

Your offspring has greater genetic variation, and there is a greater chance that they will have features that will help them survive in a changing environment.

Sea lettuce is an example of ___ algae. Sea lettuce is ____ by a range of different species, including ____.

green, eaten, humans