Marine Biology: Species, Adaptations, and Ecosystems

Census of Marine Life

Census of Marine Life

Study revealing most marine species are unknown

Prokaryotic

Organisms like Archaea and Bacteria lacking nucleus and cell walls

Eukaryotic

Organisms like Eukaryotes with nuclei and organelles bounded by a cell wall

Common Names Issue

Different names for the same animal; what could be a panther to one person may be a jaguar to another

Scientific Names

Names italicized, like Homo sapiens

Linnaeus

Developed binomial system for naming organisms

Size and Numbers Relationship

Inversely related, many small vs. fewer large organisms

Blue Whale

Largest animal ever, Balaenoptera musculus

Microbes vs. Stars

More microbes in the ocean than stars in the universe

Darwin's Speciation Concept

Defines species based on viable fertile offspring

Anagenesis

Evolution into something new

Cladogenesis

Splitting into different species, classic speciation

Reticulate Evolution

Lineage origination through merging of ancestor lineages

Microevolution

Intraspecies or interspecies change

Macroevolution

Speciation and higher-level change

Hybridization

Occurs during speciation before genetic distance is achieved

Barcodes

Unique genetic sequences for species identification

Dr. Mahmood Shivji's Project

Analysis revealing mislabeled fish at a restaurant

Organisms Size Variation

Range from smallest bacteria to largest cetaceans

Organisms Quantity Variation

Differences in populations among bacteria, phytoplankton, and fish

Camouflage

Blending in through coloration, texture, body shape, and other traits that match the environment

Mimicry

Blending in by resembling an inedible or unthreatening species (e.g., coral sea grass)

Countershading

Blending in by being darker on the side of the body that receives the strongest illumination

Cephalopods

Animals that change color using chromatophores in their skin to blend in with their environment

False eyespots

Eye-like markings on the body that can distract predators or make the animal look bigger

Ink

Used by cephalopods to startle and confuse predators

Light producing bacteria

Found in female deep-sea anglerfishes to attract prey with a glowing lure

Aposematic Coloration

Coloration that advertises to predators an animal's defenses like toxicity, venom, or sharp spines

Batesian mimicry

When creatures lacking poison mimic the coloration of poisonous species to avoid predation

Eyes in deep-sea animals

Develop very large eyes to cope with low light conditions in the deep sea

Hammerhead sharks' head

Their oddly shaped head gives them binocular vision to track fast-moving prey effectively

Male Elephant Seals

Use noses to resonate sound during the winter breeding season

Albatross

Capable of picking up the scent of food from miles away

Goblin Shark

Under debate for its nose's role in detecting electromagnetic signals of prey

Mantis shrimp

Has the best vision with 16 types of photoreceptors detecting different light wavelengths

Scallops

Have up to 200 individual eyes in their mantle

Ampullae of Lorenzini

Electroreceptors in cartilaginous fishes detecting electric fields

Black drum

Produces drumming sounds to threaten prey like the mud crab

Salmon

Memorize the smell of their birthplace to return to spawn in the same river

Sophisticated whiskers in marine mammals

Used to detect water flow changes in their environment

Animal Magnetism

Ability of many animals to detect and navigate using the Earth's magnetic field

Loggerhead turtles

Use magnetic signature to navigate back to natal habitat for spawning

Scalloped hammerheads

Navigate using geomagnetic anomalies to reach seamounts

Chemical cues

What some marine animals rely on to smell since they don’t have noses

Dolphins

Cognitive abilities close to humans, recognize selves in mirror

Oceanic migrators travel __________ distances than their counterparts on land

far greater

Arctic terns (bird)

conduct the longest annual migration known for any animal, traveling 44,000 miles from the Arctic to the Antarctic and back every year

satellite tag technology

allows researchers to track marine animal movement patterns

To achieve efficient movement underwater, marine organisms must find a balance between forces of…

drag and thrust

Drag is caused by

friction against the body and pressure… skin drag and pressure drag

Animals have evolved to achieve the most thrust with the least drag using a thin, tapering caudal fin shaped like a crescent moon called

lunate tail

Predators that are honed for acceleration

Sit-and-wait predators

What do sit-and-wait predators do

sit on the bottom or amble around the reef relatively slowly until they get prey in sight, at which point they take off with incredible acceleration

Flying fish

an extreme example of a prey species with exceptional accelerative abilities, able to launch themselves out of the water and “fly” using their wing-like pectoral fins for up to 40 seconds, allowing them to escape any attacking predators

fish that prioritize maneuverability they primarily use…

fins besides their caudal fin for swimming, including their dorsal, anal, pectoral, and pelvic fins

Vertical Migration

At dusk, every day around the world’s oceans, trillions of tiny copepods, shrimps, jellies, squid and fish move from the deep to shallower waters to feed on phytoplankton; avoids/limits predation for the vertical migrators

Mobile organisms

may disperse as larvae

Sessile organisms

MUST disperse as larvae

Why does larvae size matter?

The bigger they are, the more space they can occupy… competition for space AND increased reproductive potential AND escape from predation

indeterminate growth

when an organism keeps growing throughout its entire life

what is the limiting factor of indeterminate growth

metabolic rate as increased size creates increased metabolic demands

Pro of asexual reproductio

if you are successful, then your offspring will successful since they are exactly like you (cloning)

pro of sexual reproduction

genetic diversity

If organisms live for a long time and don’t reproduce quickly, then there will be depopulation due to

overfishing

What factors limit sustainable fishing?

By catch, slow growth, age of first reproduction

marine larval ecology

the study of the factors influencing the dispersing larval stage exhibited by many marine invertebrates and fishes

Lecithotrophic

Organism that gets all its nutrients from the yolk

Planktonic

On the water column

Benthic

Bottom of ocean

Pelagic

Open ocean/water

Demersal

Fish that lives close to the ocean floor

Mixed

Organisms that spend one part of their life on the water column and another part on the bottom (benthic)

Ovoviviparous

Producing young by means of eggs which are hatched within the body of the parent, as in some snakes

Oviparous

Producing young by means of eggs that are hatched after they have been laid by the parent

Viviparous

Producing live young that have developed inside the body of the parent

Competency

The stage at which a larva first becomes responsive to localized settlement cues

Embryonic and larval development stages of Acropora millepora

Fertilization (0 hrs) - Cleavage (2 hrs) - Morula (6 hrs) - Bowl (12 hrs) - Round (20 hrs) - Ciliation (36 hrs) - Competency (96 hrs)

Hydrothermal vents

Life has adapted to 350°C

Global Warming

On average +1.0°C since the industrial revolution, leading to sea level rise, coral bleaching, and fisheries impacts

Why is the sea level rising

as the temperature of the ocean water increases, its volume expands

Chemosynthesis

Organisms create organic matter (food) using energy derived from chemical reactions involving inorganic compounds, rather than sunlight as in photosynthesis

The deep sea never freezes

true

Marine mammal insulation for whales and seals is

blubber (non compressible)

Marine mammal insulation for sea otters is

air (compressible, limiting how deep otters can dive)

Antifreeze Glycoproteins

Substances that prevent tissues from freezing in polar seas

Mutualism

A symbiotic relationship where both organisms benefit

Commensalism

A symbiotic relationship where one organism benefits and the other has no effect

Parasitism

A symbiotic relationship where one organism benefits and the other is harmed

Photosynthesis

One of the strategies marine organisms use to acquire nutrition

Scavenging

One of the strategies marine organisms use to acquire nutrition by feeding on dead organisms

Detritivore

Organism that feeds on detritus

Herbivore

Organism that feeds on plants

Carnivore

Organism that feeds on other animals

Omnivore

Organism that feeds on both plants and animals

hypoxic

low oxygen levels

anoxic

no oxygen

While snorkeling, you clearly hear the sound of a motor. When you surface to see where it is, you don’t see or hear anything. What is the most likely reason?

  Sound travels 4x faster in water than air.

Male elephant seals possess impressively big noses. What is this “strange feature” used for?

 Producing vocal threats to scare off other males during breeding season.

Some organisms stand out by using dramatic, bright colors and startling shapes. Which one of the following is NOT a reason for this coloration?

 Bright colors reflect more light and allow the organism to stay cooler in hot water.

Animals that successfully use countershading are …

 Dark on dorsal (back) surfaces and light on ventral (underside) surfaces.