Marine organisms Flashcards
Learn some of the main groups of plankton, nekton, and benthos
What is the general name for those organisms that live free in the water but can’t successfully swim against the ocean currents (are ultimately at their mercy)?
Plankton
The drifters
- In terms of large scale movement, just go with the flow
- The key is their ability to move relative to the currents: it’s not that they can’t swim at all (although indeed many can’t), but rather that what swimming they can achieve isn’t enough to overcome an overall drifting with the currents
- Even those that can swim quite well for their size simply can’t cover the distance necessary to escape the currents
What is the general name for the photosynthetic plankton?
Phytoplankton
- Comprised of cyanobacteria (a type of photosynthetic bacteria) and various protists
What is the general name for the nonphotosynthetic (heterotrophic) eukaryotic plankton?
Zooplankton
- Comprised of various animals and protists
What is the general name for the prokaryotic plankton?
Bacterioplankton
- As a practical matter, this is typically meant to refer just to the nonphotosynthetic prokaryotic plankton (since the photosynthetic ones are functionally phytoplankton)
What is the general name for the viral (as in literally viruses) plankton?
Virioplankton
What is the general name for organisms that spend every stage of their life (their entire life cycle) as plankton?
Holopolankton
What is the general name for those organisms that only live a portion of their life (certain stages of their life cycle) as plankton?
Meroplankton
What is the general name for organisms that live free in the water and can successfully swim against the ocean currents (are not simply at their mercy–can go against the flow)?
Nekton
The swimmers
- Can cover enough distance to escape the currents and achieve movement independent of the water motion
What is the general name for those organisms that live in or on the seafloor?
Benthos
The bottom dwellers
What is the name for those organisms that swim independently of the currents, but are also strongly associated with the sea floor?
Demersal organisms
Nektonic, but also benthic
Generally speaking, what are plankton?
Drifters: organisms that live free in the water but can’t successfully swim against the ocean currents (are ultimately at their mercy)
- In terms of large scale movement, just go with the flow
- The key is their ability to move relative to the currents: it’s not that they can’t swim at all (although indeed many can’t), but rather that what swimming they can achieve isn’t enough to overcome an overall drifting with the currents
- Even those that can swim quite well for their size simply can’t cover the distance necessary to escape the currents
Generally speaking, what are phytoplankton?
Photosynthetic plankton
Generally speaking, what are zooplankton?
Nonphotosynthetic eukaryotic plankton
Generally speaking, what are bacterioplankton?
Prokaryotic plankton,
especially the nonphotosynthetic ones
Generally speaking, what are virioplankton?
Viral (as in literally viruses) plankton
Generally speaking, what are holoplankton?
Those organisms that spend every stage of their life (their entire life cycle) as plankton
Generally speaking, what are meroplankton?
Those organisms that spend only a part of their life as plankton
Generally speaking, what are nekton?
Swimmers: organisms that live free in the water and can swim against the ocean currents (are not ultimately at their mercy)
- Can cover enough distance to escape and achieve movement independent of the water motion
Generally speaking, what are benthos?
Bottom dwellers: organisms that live in or on the seafloor
Generally speaking, what are demersal organisms?
Organisms that swim like nekton, but are also strongly associated with the sea floor like benthos
What is the term for the main (most common) photosynthetic bacteria?
Cyanobacteria
- Mainly planktonic (= phytoplankton)
- Technically bacterioplankton as well, but nobody thinks of them that way (their importance is as contributors to photosynthesis)

What are the large unicellular photosynthetic eukaryotes with cell walls of silica (glass) called?
Diatoms
- Mainly planktonic (= phytoplankton), but some benthic

What is the name for the large phytoplankton that have two flagella in grooves, one longitudinal (down the length) and one transverse (encircling the waist)?
- This causes them to spin while swimming
Dinoflagellates
- Mainly planktonic and photosynthetic (= phytoplankton), but some are heterotrophic and/or endosymbiotic
- Their main, important role as a group is photosynthesis
- dino = “whirling” in this case

What is the name for the medium sized phytoplankton that are armored in a coating of overlapping calcium carbonate plates?
Coccolithophores

Which group are the single-celled nonphotosynthetic eukaryotes that extend threadlike pseudopodia through pores in their shell made of calcium carbonate or, less commonly, scavenged mineral particles?
Foraminiferans
- Mainly benthic, but some planktonic
(foraminifera, forams)

What is the name of the single-celled zooplankton that have skeletons of silica (glass) and pseudopodia that radiate out from their central mass?
Radiolarians
(radiolaria)

Which zooplankton are single-celled, ciliated, and shaped like a vase?
Tintinnids

What is the name for the group of large carnivorous zooplankton that are ovoid, globular, and transparent, usually with two sticky contractile tentacles and eight comb bands formed of fused cilia running down their bodies?
Kingdom: Animalia
Phylum: Ctenophora
Ctenophores
(comb jellies)

What is the name for the group of etremely large, carnivorous zooplankton characterized by a “medusa” stage consisting of a bell or umbrella morphology with trailing tentacles full of stinging cells?
Kingdom: Animalia
Phylum: Cnidaria
Jellies
- Also have a polyp stage that is frequently benthic
(jellyfish)

What is the name for the group of teardrop- or torpedo-shaped herbivorous zooplankton that are typically about 1-2mm long with two pronounced antennae?
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Copepods
- There are also some benthic and parasitic species

What is the name for the large (> 1 cm) zooplankton that look like glassy anorexic shrimp?
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Euphausiids
- Typically herbivorous
(krill)

What are the names for the large zooplankton with stalked eyes and sometimes a calcareous shell, with a flattened foot that acts as a fin for swimming?
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
with shell: Pteropods (sea butterflies)
and
without shell: Heteropods (sea elephants)

What is the name for the long, arrow-shaped carnivorous zooplankton with a head, trunk, and tail, often with one or two pairs of lateral fins?
Kingdom: Animalia
Phylum: Chaetognatha
Chaetognaths
(arrow worms)

What is the name for the very large barrel-shaped transparent zooplankton that propel themselves forward by squirting water out of their bodies?
Kingdom: Animalia
Phylum: Chordata
Salps
- Sometimes divide asexually via budding to form long chains (colonies)

What is the name for the group of multicellular algae that are typically yellowish-brownish to greenish in color, and includes the giant kelps?
Kingdom: Chromista
Division (Phylum): Ochrophyta
Class: Phaeophyceae
Brown algae
(phaeophytes)

What is the name for the group of multicellular algae that are typically reddish in color?
Kingdom: Archaeplastida (Plantae)
Division (Phylum): Rhodophyta
Red algae
(rhodophytes)

What is the name for the group of multicellular algae that are typically bright green in color?
Kingdom: Archaeplastida (Plantae)
Division (Phylum): Chlorophyta
Green algae
(chlorophytes)

What are these?

Cyanobacteria

Photosynthetic bacteria, important as phytoplankton
What are these?

Diatoms
Large unicellular phytoplankton with cell walls of silica (glass)
- Mainly planktonic, but some benthic

What are these?

Coccolithophores

Medium sized phytoplankton armored in a coating of overlapping calcium carbonate plates
What are these?

Dinoflagellates
Large phytoplankton having two flagella in grooves, one longitudinal (down its length) and one transverse (encircling its waist)
- This causes them to spin while swimming (dino = “whirling” in this case)
What are these?

Foraminiferans
Single-celled heterotrophic eukaryotes that extend threadlike pseudopodia through pores in their shells made of calcium carbonate or, less commonly, scavenged mineral particles
- Mainly benthic, some planktonic
(foraminifera, forams)

What are these?

Radiolarians
(radiolaria)

Single-celled zooplankton with skeletons of silica (glass) and pseudopodia that radiate out from their central mass
What are these?

Tintinnids

Single-celled, ciliated zooplankton that are shaped like a vase
What are these?
- Common name for the group
- Kingdom
- Division (phylum)
- Class

Brown algae

Kingdom: Chromista
Division (Phylum): Ochrophyta
Class: Phaeophyceae
What are these?
- Common name for the group
- Kingdom
- Division (phylum)

Red algae

Kingdom: Archaeplastida (Plantae)
Division (Phylum): Rhodophyta
What are these?
- Common name for the group
- Kingdom
- Division (phylum)

Green algae

Kingdom: Archaeplastida (Plantae)
Division (Phylum): Chlorophyta
What are these?
- General common name
- Kingdom
- Phylum

Sponges
Kingdom: Animalia
Phylum: Porifera

What kind of organism is this?
- General common name
- Main characteristics
- Kingdom
- Phylum

Ctenophore
(comb jelly)

Very large, globular, usually ovoid, transparent, carnivorous zooplankter usually with eight comb bands formed of fused cilia running down its body and two sticky contractile tentacles
Kingdom: Animalia
Phylum: Ctenophora
What are these?
- General common name
- Main characteristics
- Kingdom
- Phylum

Jellies
Extremely large, carnivorous zooplankton characterized by “medusa” stage consisting of a bell or umbrella morphology with trailing tentacles full of stinging cells
- Have a polyp stage, frequently benthic, in their life cycle as well
Kingdom: Animalia
Phylum: Cnidaria
(jellyfish)

What is this?
- General common name
- Kingdom
- Phylum
- Class

Sea anemone
Kingdom: Animalia
Phylum: Cnidaria
Class: Anthozoa

What are these?
- General common name
- Kingdom
- Phylum
- Class

Soft (Alcyonacid) corals
Sea fans (Gorgonians), sea fingers, sea whips, sea pens, etc.
Kingdom: Animalia
Phylum: Cnidaria
Class: Anthozoa

What are these?
- General common name
- Kingdom
- Phylum
- Class

Stony (Scleractinid) corals
Elkhorn, staghorn, shelf or table, brain, mushroom, fire, encrusting, etc.
Kingdom: Animalia
Phylum: Cnidaria
Class: Anthozoa
- May be individual, colonial, or reef-building colonial (hermatypic)

What are these?
- General common name
- Kingdom
- Phylum
- Class

Sea stars
Kingdom: Animalia
Phylum: Echinodermata
Class: Asteroidea
(starfish)

What are these?
- General common name
- Kingdom
- Phylum
- Class

Brittle stars
Kingdom: Animalia
Phylum: Echinodermata
Class: Ophiuroidea

What are these?
- General common name
- Kingdom
- Phylum
- Class

Sea urchins
sand dollars are a flattened, burrowing type of sea urchin
Kingdom: Animalia
Phylum: Echinodermata
Class: Echinoidea

What are these?
- General common name
- Kingdom
- Phylum
- Class

Sea cucumbers
Kingdom: Animalia
Phylum: Echinodermata
Class: Holothuroidea

What are these?
- General common name
- Kingdom
- Phylum

Moss animals
bryozoans
Kingdom: Animalia
Phylum: Bryozoa / Ectoprocta

What is this?
- General common name
- Main characteristics
- Kingdom
- Phylum

Chaetognath
(arrow worm)

Long, arrow-shaped carnivorous zooplankter with a head, trunk, and tail, often with one or two pairs of lateral fins
Kingdom: Animalia
Phylum: Chaetognatha
What is this?
- Common name
- Kingdom
- Phylum
- Subphylum

Horseshoe crab
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata

What are these?
- General common name
- Kingdom
- Phylum
- Class

Bristle worms
Kingdom: Animalia
Phylum: Annelida
Class: Polychaeta
(polychaetes)

What are these?
- General common name
- Kingdom
- Phylum
- Class

Clams
Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia

What are these?
- General common name
- Kingdom
- Phylum
- Class

Mussels
Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia

What are these?
- General common names
- Main characteristics
- Kingdom
- Phylum
- Class

Pteropods (sea butterflies; have shell)
Heteropods (sea elephants; no shell)
Large zooplankton with stalked eyes and a flattened foot that acts as a fin for swimming, sometimes with a calcareous shell
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda

What are these?
- General common name
- Kingdom
- Phylum
- Class

Sea slugs
Sea hares, nudibranchs, ets.
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda

What are these?
- General common name
- Kingdom
- Phylum
- Class

Nudibranchs
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
All nudibranchs are sea slugs, but not all sea slugs are nudibranchs. Nudibranchs (“naked gills”) are distinguished from other sea slugs by the tuft of fluffy gills protruding from their rears.

What are these?
- General common name
- Kingdom
- Phylum

Flatworms
Kingdom: Animalia
Phylum: Platyhelminthes
Flatworms are generally much thinner than sea slugs, with less developed tentacle structures on their heads and no external gill tufts as seen in nudibranchs.

What are these?
- General common name
- Kingdom
- Phylum
- Class

Limpets
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda

What are these?
- General common name
- Kingdom
- Phylum
- Class

Chitons
Kingdom: Animalia
Phylum: Mollusca
Class: Polyplacophora

What is this?
- General common name
- Main characteristics
- Kingdom
- Phylum
- Subphylum

Copepod
Small (typically 1-2 mm long) teardrop- or torpedo-shaped herbivorous zooplankton with two pronounced antennae
- There are also some benthic and parasitic species
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea

What are these?
- General common name
- Main characteristics
- Kingdom
- Phylum
- Subphylum

Euphausiids
Large (> 1 cm) zooplankton that look like glassy anorexic shrimp
- Mostly herbivorous
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
(krill)

What are these?
- General common name
- Kingdom
- Phylum
- Subphylum

Crabs
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea

What are these?
- General common name
- Kingdom
- Phylum
- Subphylum

Shrimp
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea

What are these?
- General common name
- Kingdom
- Phylum
- Subphylum

Lobsters
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea

What is this?
- General common name
- Kingdom
- Phylum
- Subphylum

Amphipod
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
(beach flea, beach hopper)

What are these?
- General common name
- Kingdom
- Phylum
- Subphylum

Isopods
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea

What are these?
- General common name
- Kingdom: Animalia
- Phylum
- Subphylum

Acorn barnacles
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea

What are these?
- General common name
- Kingdom
- Phylum
- Subphylum

Gooseneck barnacles
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea

What is this?
- General common name
- Kingdom
- Phylum
- Class

Octopus
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda

What are these?
- General common name
- Kingdom
- Phylum
- Class

Squid
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda

What is this?
- General common name
- Kingdom
- Phylum
- Class

Cuttlefish
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
- There can be a lot of gray area between squid, cuttlefish, and to a lesser extent octopuses, and individual common names often reflect this ambiguity
- Example: bobtail squids are really more like cuttlefish

What is this?
- General common name
- Kingdom
- Phylum
- Class

Chambered nautilus
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda

What are these?
- General common name
- Main characteristics
- Kingdom
- Phylum

Salps
Large barrel-shaped transparent zooplankton that propel themselves forward by squirting water out their body
- Sometimes divide asexually via budding to form long chains (colonies)
Kingdom: Animalia
Phylum: Chordata

What are these?
- General group name
- Kingdom
- Phylum
- Class

Ray-finned bony (Osteichthyid) fishes
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
The overwhelming majority of fish in the world are both bony and ray-finned.
- The other main branch of bony fishes are the lobe-finned fishes, which we aren’t concerned with since there are so few of them

What are these?
- General group name
- Kingdom
- Phylum
- Class

Cartilaginous (Chondrichthyid) elasmobranch fishes
Kingdom: Animalia
Phylum: Chordata
Class: Elasmobranchii
- For our purposes, effectively cartilaginous = elasmobranch
- Technically not all cartilaginous fishes belong to the elasmobranchs, since there is one other tiny main branch we will not encounter
(sharks, rays, skates, and sawfish)

What is this?
- General common name
- Kingdom
- Phylum
- Class

Sea turtle
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia

What are these?
- General common name for the group
- Kingdom
- Phylum
- Class

Baleen whales (mysticetid cetaceans)
gray, humpback, blue, etc. whales
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia

What are these?
- General common name for the group
- Kingdom
- Phylum
- Class

Toothed whales (odontocetid cetaceans)
dolphins, orcas, sperm whale, etc.
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia

What are these?
- General common name for the group
- Kingdom
- Phylum
- Class

True seals (phocid pinnipeds)
harbor seals, elephant seals, leopard seals, etc.
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia

What is this?
- General common name for the group
- Kingdom
- Phylum
- Class

Sea lions (otariid pinnipeds)
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia

What animal is this?
- General common name
- Kingdom
- Phylum
- Class

Walrus (odobenidid pinniped)
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
There is only one species of walrus!

What are these?
- General common name for the group
- Kingdom
- Phylum
- Class

Sea cows
manatees and dugongs
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia

What is this?
- General common name for the group
- Kingdom
- Phylum
- Class

Sea otter
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia

What are these?
- General common name for the group
- Kingdom
- Phylum
- Class

Penguins
Kingdom: Animalia
Phylum: Chordata
Class: Aves
