Marine Biology Notes
Stanford University ~ 1975

Personal Reference
California Kelp Forest Disaster
ere are my Marine Biology Notes, enhanced and brought up-to-date, from my days at Stanford University. I'm happy to share my personal resource.
Domain: Eukaryota
Eukaryota - Organisms with a Nucleus in their Cells surrounded by a Membrane (from the Greek, eu, 'true' and karyon, 'kernel'). These Kingdoms & Phylums are relevant to Marine Biology.
Protists - Dinoflagellates, Diatoms, Radiolarians et. al. Protista is a grouping of Microscopic Plankton that are NOT Animal, Plant, or Fungus. They are uni-cellular or colonial uni-cellular organisms. There are Millions of species found in all the world's oceans. Protists are the Ancestors of ALL Plants & Animals on earth and they have been here for OVER ONE BILLION YEARS! In One Teaspoon of sea water there can be more than a million creatures! The food web of Protists and other Plankton is so complex, that scientists cannot say with certainty who eats whom.
🎦 The Protists "Cells in the Sea" (3 min) (The Plankton Chronicles), Music by Romain Strugala

🎦 The Secret life of Plankton (6 min) (TED Ed)

Plankton - (from the Greek planktos, 'drifter') is a term applied to any micrscopic organism that drifts along at the whim of the ocean currents. The term was coined by the German zoologist, Victor Hensen, in 1887. Each night Zooplankton and many other creatures swim hundreds of meters vertically from the deeper Mesopelagic Zone to feast on the Phytoplankton that live in the Epipelagic Zone near the surface. It is the largest daily migration of Biomass on earth and is known as the Diel Vertical Migration (DVM) (from the Greek diel, 'day'). During the day the Zooplankton return to the relative safety of the Mesopelagic Zone, but they are still susceptible to being eaten by other carnivores & filter feeders.
Phytoplankton are microscopic creatures that get their energy from sunlight, usually by Photosynthesis. Phytoplankton are the basis for the entire global food chain.

Zooplankton are small animals, many of which are much larger creatures going through an early stage of their life cycle. These Zooplankton prey upon and eat the Phytoplankton and also other Zooplankton.

Dinoflagellata - Dinoflagellates (from the Latin, dinos, 'whirling' and flagellum, 'tiny whips'). They all have ('dino') Flagellum that are used for locomotion and prey capture. Their roughly 2,000 Marine Species are a large component of the Plankton and they are found worldwide as the ocean currents dictate. Many Dinoflagellates are Bioluminescent and in great concentrations their luminescence can be quite spectacular. Some prey upon other species of Plankton.

Their Frustules, which are two-part spiky shells, together with Planktonic Diatoms form a large component of all ocean sediments and create Diatomaceous Earth, which is used for fine polishing and liquid filtration. The complex structure of their microscopic shells is also a source of study in Nanotechnology.

A Red Tide is caused by a large bloom of Algae and species of Dinoflagellata, most notably Gonyaulax (Lingulodinium polyedra). In summer months (months without an r, May - August) they are consumed by Plankton-Feeders in large quantities and their minute amount of internal toxins can accumulate in shellfish, sardines, and anchovies in sufficient amounts that a buildup of the toxin Domoic Acid occurs. This can cause ASP (Amnesic Shellfish Poisoning). Exposure to Domoic Acid affects the brain, causing seizures, and occassionally death, especially in Sea Birds that feed on contaminated animals.

Ceratium ranipes

The species Ceratium ranipes has a unique ability. At dawn they grow 'fingers' on their 'arms' that enable them to float to the surface and gather more light. At night these 'fingers' shrink down to nothing and essentially disappear allowing them to more easily sink into the depths for protection. The fingers are packed with Green Chloroplast Cells which enable Photosynthesis. Chloroplasts (from the Greek, chloros, 'green' and plastes, 'one who forms') possess their own DNA, seperate from their host. Chloroplasts cannot be made by the host and must be inherited by each daughter cell during cell division. Chloroplast origins are thought to be traced back to ONE event when a Cyanobacterium (Blue-Green Algae) was engulfed by a Eukaryote.

🎦 Ceratium ranipes Grow fingers to catch more light (The Plankton Chronicles)

🎦 Ceratium ranipes ~ 3D Videos in Red/Blue Anaglyph & Side x Side

The Fascinating Chloroplast Cell (lots of infomation)
Diatoms - Diatoms (from the Greek, dia-tom-os, 'cut in half'), are a major group of unicellular microscopic Phytoplankton. The prolific numbers of Diatoms found in the oceans produce 20 percent of all the oxygen on earth. The Frustules (Silica shells) of dead Diatoms drift down through the sea as part of the Marine Snow and settle out on the ocean floor, accumulating up to a half mile deep in places. Exposed ocean sediments of Diatoms are mined and known as Diatomaceous Earth which is useful as a fine abrasive and liquid filtering enhancer. Under ideal conditions Diatom populations can double every 24 hours although their life spans are typically less than a week. They are a major source of nutrients and form the basis of the entire food chain on earth.
Radiolaria - Radiolarians are microscopic Zooplankton with elaborate mineral exoskeletons usually made of Silica (SiO2) but sometimes made of Calcium Carbonate (CaCO3). Much like the Diatoms, their skeletal remains make up a large part of the sediment that falls to the ocean floor as Marine Snow. Radiolarians have many needle-like spikes, which can aid in their buoyancy.

The Class Acantharea are Radiolarians whose skeletons are composed of Strontium Sulfate Crystals (SrSO4). Members of his group have either ten or twenty radial spines. The arrangement of the spines is very precise, and is used for classification. Their placement is described by what is known as the Müllerian Law. This Law determines Spine placement in terms of lines of Latitude & Longitude.

Rhodophyta (Red Algae) and Phaeophyta (Brown Algae) are defined as Algae. The Chlorophyta (Green Algae) are grouped under Plantae (Plants). All utilize Photosynthesis and many exist as Phytoplankton. Marine Algae have no roots, leaves, or vascular systems to transfer nutrients like land plants. Instead they absorb all their nutrients directly from the sea water in which they are bathed, and their energy solely from sunlight.

Unlike Marine Animal species, the Taxonomy of Marine Algae is in a state of constant flux with widespread disagreement among the scientific community. Basically, it's a mess. Current molecular studies are proving to be the most reliable tool to sort things out. Until the dust settles, I have decided to accept the following Algae Taxonomy…

Rhodymenia californica
Rhodophyta - Red Algae contain the pigment Phycoerythrin which reflects red light and absorbs blue light. Since blues penetrate sea water to a greater depth than other wavelengths this gives Red algae more opportunity to Photosynthesize.
Macrocystis pyrifera
Phaeophyta - Brown Algae. Typically Algaes in this Phylum build Holdfasts which anchor their Stipes to a substrate.

The world's largest and fastest growing Marine Algae is in this group. The Giant Bladder Kelp (Macrocystis pyrifera) can grow at the rate of 0.5 meter/day (18"/day) and can reach lengths exceeding 50 meters (150 ft). The deepest growing of the Phaeophyta is the Elk Kelp (Pelagophycus porra) which only grows in water cooler than 16°C (60°F) and prefers depths from 20m (66 ft) down to 90m (300 ft).

Algin (C6H8O6)n is a compound found in the cell walls of all Phaeophyta. The compound is harvested in great quantities worldwide to produce Sodium Alginate (C6H7NaO6)n which is an important emulsifier used in products ranging from lipstick to ice cream.

Plantae Kingdom
Phyllospadix scouleri
Chlorophyta - Green Algae contain the pigment Chlorophyll which allows them to Photosynthesize. These are only found in shallow intertidal waters with access to abundant sunlight. Eel Grass (Phyllospadix scouleri) and Sea Lettuce (Ulva expansa) are two local species in this classification. The Sea Lettuce Taxonomy :
Domain: Eukaryota
Kingdom: Plantae
Subkingdom: Viridiplantae
Infrakingdom: Chlorophyta infrakingdom
Phylum: Chlorophyta
Subphylum: Chlorophytina
Class: Ulvophyceae
Order: Ulvales
Family: Ulvaceae
Genus: Ulva
Species: exspansa
Animalia Kingdom
Membranipora membranices
Bryozoa - Colonial Animals that build simple calcareous shapes with Operculums. They filter the seawater by extending a retractable Lophophore, an appendage with a crown of tentacles lined with Cilia. Individuals in Bryozoan colonies are known as Zooids and are tiny, on the order of 0.2 x 0.5 mm (.008 x .020 inches).

The Nudibranch Corambe steinbergae feeds upon Bryozoan colonies, especially Membranipora membranices. The tiny Nudibranch is only 7mm (¼ inch) long and is almost transparent.

🎦 Nudibranch feeding on Bryozoan Lophopores
Porifera - Sponges. There are about 9,000 species in all with most belonging to the Class Demospongiea. They are all Sessile and filter the seawater that flushes through their many body pores for nutrients. They expel waste through a usually larger central orifice known as an Osculum. They do not have nervous, digestive, or circulatory systems.

As they grow and their cells divide the cells leave behind Spicules which are hard shapes made of Silica. These Spicules are much like a pile of interlocking 'Jacks' that create and reinforce their body structure. The Class Demospongiea, have special cells known as Spongocytes that produce very flexible Spongin fibers, that are a type of collagen protein. Some Porifera have external skeletons made of Aragonite (Calcium Carbonate, CaCO3).

The interior regions of Sponges are lined with Choanocyte cells. These cells have Flagellum that beat regularly thus generating a flow of water through their pores and out through the Osculum. This pulls in oxygen and nutrients from the seawater and expels carbon dioxide and waste products. Choanocytes can also turn into Spermatocytes providing Sperm for sexual reproduction. Sponges are Hermaphodites. Sperm and ovum are both produced by these special cells. Sperm are released into the seawater through the Osculum which must then be captured by other Porifera of the same species.

Porifera > Class Hexactinellida - (Glass Sponges ~ 400 species)
Porifera > Class Calcarea - (Calcite Sponges ~ 500 species)
Porifera > Class Demospongiea - (Silica & Spongin Fiber Sponges ~ 8,100 species)
Porifera > Class Archeocyatha - (Fossil Sponges from the Cambrian period)
Basic Ctenophore Anatomy
Ctenophora - Comb Jellies. There are only about 150 species, all marine. Ctenophores are small walnut-sized animals with Transparent Gelatinus Bodies with eight rows of Ctena (combs) of fused Cilia arranged along their sides. The fused Cilia beat synchronously, often producing dazzling displays of Iridescent Rainbow Colors, and propel the Ctenophores through the water. Many Ctenophores are also Bioluminescent.

They are found world-wide but much work remains to classify and properly describe them. Some Ctenophores have two long external Flagellum. Ctenophores are voracious predators, using their sticky Colloblast Cells which line their tentacles to capture prey. They lack the stinging Nematocyst Cells of the Cnidaria.

🎦 Iridescent Ctenophores (The Plankton Chronicles)
Chrysaora fuscescens
Cnidaria - Jellyfishes, Anemones, and Corals are in this Phylum. There are over 10,000 species, all of which are aquatic and almost all are marine. The Cnidaria (previously Coelenterata) have been on earth for 600 million years, which is 180 million years before any land animals. They have a basic body structure consisting of a central body cavity used for digestion and respiration. Surrounding this are tentacles with food gathering and reproductive functions. There are two basic body shapes; the Polyp which is cylindrical and sessile, and the Medusa which is umbrella-like and free swimming. Some Medusae begin life as a Polyp.

Corynactis californicus
All Cnidaria have billions of stinging Nematocyst Cells used for capturing and digesting food. Inside each Nematocyst Cell is a coiled, barbed harpoon covered with toxins. Outside of each cell is a trigger mechanism next to an Operculum (trap door). When activated they explode into the victum, anchoring themselves on the victum's epidermis and turning themselves inside-out. The toxin covered harpoon injects itself deep inside the victum at the nearly instantaneous speed of 100,000 m/s (223,000 mph) [290x sound]. Nematocyst Cells have the fastest response time in the entire animal Kingdom.

They are opportunistic feeders usually eating what ever happens to brush by their stinging tentacles. However, the Pacific Sea Nettle (Enchelycore schismatorhynchus) is a Medusivore, preferring to eat other Medusae Jellyfish. The Phylum is divided into four Classes

Anthozoa - Anemones and Corals
Scyphozoa - True Jellyfishes
Cubozoa - Box Jellies e.g Sea Wasp Box Jelly, Chironex fleckeri (world's deadliest Jellyfish)
Hydrozoa - Small Colonial Hydras & Colonial Jellies (e.g. Portuguese Man o' War, Physalia physalis)
Anthopleura sola
In the year 2000, the Sunburst Anemone, Anthopleura sola, was determined to be a seperate species. Previously it was considered to be a non-clonal variation of the Aggregating Anemone, Anthopleura elegantissima. I never quite belived it though because they are so dissimilar in size and preferred habitat to the Aggregating Anemone. I am glad it is now official. Welcome Home!

🎦 Animation of Nematocyst Cells Firing
The Cnidaria species Turritopsis dohrnii is Biologically Immortal. After reaching its mature Medusa stage, if the tiny Jellyfish becomes stressed or threatened it can asexually transform back into its Polyp stage and essentially 'start over' again.
🎦 The Immortal Jellyfish By Shin Kubota (3 min Video)
🎦 The Strange But Incredible Immortal Jellyfish (3 min Video)
Turritopsis dohrnii (Wikipedia)
Haliotis sorenseni
White Abalone
Mollusca - These are the Abalones, Snails, Clams, Octopii, Squids, Cuttlefish, and Nudibranchs. It is the largest marine Phylum, comprising 1/4 of all marine organisms. All Molluscs have a Mantle which is a thin skin-like organ that covers and protects the visceral organs and in most can excrete minerals to build and/or clean its protective shell. Almost all have a Radula which is a rasp-like tongue which is used for grazing on algae. The Radula is pushed onto the algae by means of a cartilaginous structure known as an Odontophore. Most Gastropods have gill structures and a heart which floods the muscles with a clear 'blood' that has no coagulation chemicals. Because of this, if the animal experiences a slicing wound it cannot prevent loss of its 'blood' and soon dies. Gastropods comprise 80% of all Molluscs. Most Gastropods graze upon Macroalgaes but some are filter feeders. It is believed the Phylum goes back approximately 500 million years.
Mollusca > Gastropoda > Nudibranchia

Nudibranchia is a fascinating clade (organisms having a single common ancestor) within the Class Gastropoda. Commonly known as Sea Slugs, they are without shells and have exposed gills and are usually brightly colored. There are over 3,000 species. All Nudibranchs are Hermaphrodites. They are voracious Carnivores to the extent of being Cannibalistic.

Flabellinopsis iodinea

Nudibranchia use their normally bright coloration as a warning sign to potential predators. Nudibranchs have the amazing ability to produce distasteful chemicals and store them inside their bodies and even add toxins they ingest from their prey (e.g. Sponges, other Nudibranchs). Some Nudibranchs however go the other way and invest in Camouflage. One in particular, Corambe steinbergae, specializes in feeding on Bryozoans, especially Membranipora membranices. When grazing it is practically invisible as it has matched its translucent body's dermal pattern to that of the Bryozoan.

Oral Tentacles
Propodial Tentacles ↑
Dorsal Cerata
Phidiana hiltoni, Showing Typical Nudibranchia Parts
Nudibranchia can also feed on stinging Nematocyst Cells that are ingested from Cnidaria and store them in the tips of their Dorsal Cerata in sacs known as Cnidosacs. The stolen Nematocysts are known as Kleptocnidae. These wander through the Nudibranch's alimentary tract without harming the Nudibranch itself. Rhinophores are a pair of ear-like Anterior Dorsal Tentacles on Nudibranchs that are used for smell. Two longer Anterior Tentacles known as Oral Tentacles are used for both touch and to sense chemicals. Two stubby Tentacles known as Propodial Tentacles are used to assist in locomotion.
Stronglyocentrotus purpuratus
Echinodermata - These comprise the Sea Urchins, Starfish, Sand Dollars, and Sea Cucumbers. There are about 7,000 species, all of which are marine. They all display a Five-sided radial symmetry. Most have spines and some have a hard shell known as a Test. They use Tubefeet for locomotion. The center ventral Five-sided mouth apparatus of the Sea Urchin is known as Aristotle's Lantern. Echinoderms use tufts of thin membranes that act as simple Gills and also use their tube feet to take in oxygen and pass out carbon dioxide.
Spirobranchus giganteus
Annelida - Segmented Worms. Each segment has the same basic set of organs which may sometimes also possess a pair of Parapodia used for locomotion. Feeding structures near the mouth can vary radically. Most are filter feeders.

In the Class Polychaeta, Family Serpulidae are the Tube Worms, the most colorful of which is the local species know as the Christmas Tree Worm (Spirobranchus giganteus). Although the name suggests great size, their Tubes are only about 5-10mm wide (¼ - ½ inch). They have two spiral-shaped feather-like tentacles known as Radioles, covered with Cilia for filter feeding and which are shaped like tiny Christmas trees. When they sense shadows, or water currents from other marine life, an entire grouping can instantly withdraw into their tubes for protection and seal their Tubes with a custom shaped Operculum. Great care and patience is required to photograph them.

Panulirus interruptus
Arthropoda - Crabs, Lobsters, and Shrimps comprise this very diverse Phylum. There are about 15,000 species of marine Arthropoda, almost all of which are in the Subphylum Crustacea > Order Decapoda. They are all characterized by their hard Exoskeletons which must be shed during a molt in order for them to grow. They possess many complex feeding appendages and sensory antennae.
Pugettia producta
Their eyes range from compound eyes to Pigment-pit Ocelli. Included in this Phylum is the amazing Peacock Mantis Shrimp (Odontodactylus scyllarus) with the most sophisticated eyes in the entire animal Kingdom, able to see 12 separate color bands (to our 3) and even see and produce polarized light (both linear and circular).
🎦 Amazing Peacock Mantis Shrimp Video
Chordata - All animals with spinal chords & back bones, which in the ocean includes all the Fishes, Marine Mammals, Sharks, Rays, Tunicates, and the Salps.

Chondrichthyes (cartilaginous fish)
Rhinobatos productus
Osteichthyes (bony fish)
Sebastes rastrelliger
Chordata > Tunicata - Tunicates, Sea Salps
Chordata > Gnathostomata (with jaws) > Osteichthyes (bony fish) - Fishes
Chordata > Gnathostomata (with jaws) > Chondrichthyes (cartilaginous fish) - Sharks, Rays
Chordata > Mammalia > Carnivora > Pinnipedia - Seals, Sea Lions
Chordata > Mammalia > Cetacea > Balaenopteridae - Baleen Whales
Chordata > Mammalia > Cetacea > Physeterida - Toothed Whales
Chordata > Mammalia > Cetacea > Delphinidae - Dolphins

Styela montereyensis
Tunicata - This Sub-Phylum (formerly Urochordata), contains the Tunicates, because they have a vestigial internal skeleton known as a Notochord, during their immature growth phase, but it dissapears by the time they reach maturity. Tunicate physiology is fascinating. They have a highly developed heart and circulatory system as well as a cerebral ganglion. A common local species is the Stalked Tunicate Styela montereyensis.

Tunicata - Sea Salps which are barrel-shaped Planktonic Tunicates with transparent gelatinous bodies are also included in this Sub-Phylum. Sea Salps can live as individuals but usually combine to form chains (colonies) several meters long, of individual Blastozooids. Sea Salps drift at the mercy of the currents even though they pump water through their bodies with one of the most efficient examples of jet propulsion in the animal kingdom. Salps strain the pumped water through internal feeding filters, consuming Phytoplankton.

Cyclosalpa affinis
Sea Salps are the fastest growing multicelluar animal. Studies show they can grow up to 20% of their body length per hour under ideal conditions, i.e. double their length every 4 hours! They asexually reproduce and when food is available their populations can explode. In April, 2012 The Diablo Canyon Nuclear power plant in California was taken offline when a massive aggregation of Sea Salps clogged their seawater intakes. A not uncommon local species is Cyclosalpa affinis which I have personally observed at over 10 meters in length.
🎦 Salps, Exploding Populations (The Plankton Chronicles)
Fish Fin Terminology

Dorsal Fin (Spiny)
Dorsal Fin (Soft)
Nares (Nostrils)
Lateral Lines (Sensors)
Operculum (Gill Plate)
Scales (Main Body)
Pectoral Fins
Caudal Fin (Tail Fin)
Anal Fin Pelvic (Ventral) Fins
Adult Garibaldi, Hypsypops rubicundus
Marine Biology & Oceanography Terms
Marine Biology Terms      
Aboral - the side opposite the mouth or Oral side
Abyss - Greek word meaning "no bottom"
Anterior - relating to the front of an animal
ASP - Amnesic Shellfish Poisoning caused by ingestion of Domoic Acid from shellfish and anchovies feeding on Algae blooms
Berm - built up sand & rocks on a beach due to wave and tidal action
Bioluminescence - chemical production of light in organisms
Biomass - total mass of organisms in a given volume
Bivalve - Mollusc with two opposing shells that can close
Blade - wide appendage of a macroalgae similar to a leaf in appearance
Blastozooid - an individual in a colony of budded, connected individuals (e.g. Salps)
Calcareous - made of Calcium Carbonate
Calcium Carbonate - CaCO3
Cartilaginous - having a skeleton of cartilage
Caudal - relating to a tail
Cephalic - relating to the head
Cerata - the dorsal tentacles on Nudibranchs
Chaete - bristles in Annelida (segmented worms)
Chlorophyll - a green pigment that can Photosynthesize sunlight
Chloroplast - a specialized cell containing Chlorophyll that enables Photosynthesis
Chlorophyta - green algaes
Choanocyte - a specialized cell in Sponges with Flagellum that provide a constant flow of seawater through their bodies
Chromatophore - light and color reflecting/producing cells common in Squids and Octopi
Cilia - small hairlike device to move water/food, plural of cilium
Clade - a group of organisms that are all descendants of a common ancestor, one branch of a 'Family Tree', the Cladistic approach is revolutionizing the biological classification of organisms
Clone - genetically identical organisms produced asexually from one ancester
Cnidosac - sacs of Kleptocnidae in the tips of Nudibranch Cerata
Ctena - Greek for comb
Colloblast Cell - cell with a coiled spiral filament that is embedded in the epidermis of Ctenophora and with an axial filament with a granular dome. The surface of these cells consist of toxic granules that act as an adhesive for capturing prey
Cyanobacteria - aka 'blue-green algae', a Phylum in the Domain: Bacteria (Not an Algae)
Dermal - relating to the skin
Diatomaceous Earth - a sediment composed of Diatom Frustules
Diel Vertical Migration (DVM) - aka Diurnal Vertical Migration, the daily migration of zooplankton and other organisms from the deeper Mesopelagic Zone to the upper Epipelagic Zone at night and reversed during the daytime
Dinoflagellates - planktonic organisms that are not Animal, Plant, or Fungus living within two part silica or carbonate casings, called Frustules, and possessing Flagellum
Diurnal - twice daily
DNA - DeoxyriboNucleic Acid, a molecule containing an organism's complete genetic code
Dorsal - topside of an organism
Estuary - coastal area of sea water mixed with fresh water
Eukaryota - a major classification of life, all members of which contain cells with a nucleus
Eutrophic - water bodies having high concentrations of nutrient
Exoskeleton - rigid external covering for the body
Flagellum - a whiplike appendage enabling locomotion
Frustule - silica cell wall of a diatom, consisting of two overlapping halves
Gill - respiratory organ which extracts oxygen from water
Heme - an iron rich compound found in Hemoglobin which enables the transport of Oxygen in the blood
Hermaphroditic - possessing both male and female reproductive organs
Holdfast - the anchoring structure of sessile seaweeds
Invertebrates - lacking any bony vertebrata or backbones
Kingdom - major classification of natural objects just below Domains. (e.g. Animalia, Plantea)
Kleptocnidae - stolen Nematocyst Cells ingested by Nudibranchs
Lateral - relating to the side of an organism
Lateral Line - a line of pressure sensitive organs (Neuromasts) along the sides of fishes
Littoral - area immediately adjacent to the shoreline
Littoral Drift - transport of sand along a coastline due to oblique wave action
Lophophore - small feeding crown of tentacles lined with cilia
Mantle - the soft fleshy membrane in Molluscs that protects its organs and is capable of building/cleaning its shell
Marine - relating to salt water oceans
Marine Snow - biological debris from the top layers of the ocean that constantly drifts to the seafloor, providing the primary source of energy for deep-sea organisms
Medusa - an umbrella like and usually free swimming body shape of Cnidaria (pl. Medusae)
Myoglobin - a red protein containing Heme that can carry and store Oxygen in the muscle tissue of Marine Mammals for use during deep dives
Mytosis - method of asexual reproduction via cell division
Nektonic - able to swim or move against currents (opposite of Planktonic)
Notochord - a vestigial vertebra in immature Tunicates
Nematocysts - explosive stinging Cnidoblast cells of Cnidaria that consist of a colied barbed harpoon lined with powerful toxins
Neuromast - a Mechanoreceptive organ in fishes located along their Lateral Lines that can sense minute changes in water pressure or motion
Odontophore - a cartilaginous structure used to press a Radula against its macroalgae food source
Oligotrophic - water bodies having low concentrations of nutrients
Operculum - a door like structure
Osculum - the large opening on a sea sponge through which seawater is expelled
Papulae - a small raised swelling of the skin
Parapodia - paired bristle-like appendages in segmented worms used for locomotion
Pedicellaria - minute pincer organs usually used for defense on Echinoderms
Pelagic - inhabiting the open ocean
Phaeophyta - brown algaes
Photosynthesis - the use of sunlight energy to synthesize Glucose (C6H12O6) from Carbon Dioxide (CO2) and Water (H2O), yielding Oxygen (O2) as a by-product
Phototrophic - organisms that carry out photon capture to acquire energy
Phycoerthrin - a red protein-pigment capable of blue light Photosynthesis
Phylum - major classifications of Animals
Phytoplankton - microscopic marine algae that utilize Photosynthesis
Pincer - a small device for grasping, a minute claw
Planktonic - unable to swim or move against currents (opposite of Nektonic)
Pneumatocyst - air bladder on macro phaeophyta keeping the algae closer to the sunlight
Polychaete - common Class of segmented worms with many Chaete (bristles)
Polyp - a cylindrical and usually fixed body shape of Cnidaria
Posterior - relating to the rear of an animal
Protists - microscopic plankton, the ancestors of all living things on earth, not Animal, Plant, or Fungus
Radiole - spiral, feather like, Cilia lined, feeding tentacles found in Serpulidae Tube Worms
Radula - a long tongue of rasp like teeth, found in gastropods and chitons
Roe - a mass of eggs in a female organism
Rhinophore - the ear-like tentacles on Nudibranchs which sense smell
Rhodophyta - red algaes
Sea Salt - various salts dissolved in sea water: 98+% NaCl, & traces of KCl, MgCl, NaI, & KI
Sea Slug - common name for a Nudibranch
Sessile - immobile, permanently attached or fixed in place
Silica - Silicon Dioxide, SiO2
Spicule - small Spogin or Silica fibers found in Sea Sponges
Stipe - stalk or stem of marine algae
Strontium Sulfate - SrSO4
Substrate - surface on which an organism is attached
Symbiotic - mutually beneficial relationship
Taxonomy - the scientific classification of organisms
Test - shell of a sea urchin
Thermocline - boundary in a fluid with a significant thermal gradient
Tube Feet - hollow appendages operated by hydraulic pressure in a water-vascular system
Upwelling - an upward current usually nutrient rich
Ventral - underside of an organism
Zooid - an individual animal in a colony
Zooplankton - microscopic marine animals
Oceananic Zones      
Intertidal Zone - coastal area subjected to rise & fall of tides
Littoral Zone - part of the ocean close to shore affected by wave action
Subtidal Zone - below the range of tides and their influence
Epipelagic Zone - aka Sunlight Zone, surface to -200 meters
Mesopelagic Zone - aka Twilight Zone, -200 meters to -1,000 meters
Bathypelagic Zone - aka Midnight Zone, -1,000 meters to -4,000 meters
Abyssopelagic Zone - aka the Abyss, -4,000 meters to -6,000 meters
Hadalpelagic Zone - from -6,000 meters to the deepest trenches
Technical Notes      
Ocean Exploration - Only 0.0001% of the deep ocean has ever been explored. Only four people have ever visited the Challenger Deep at nearly -11,000 meters; Jacques Piccard & Don Walsh (in 1960) and James Cameron (in 2012). The latest explorer was Victor Vescovo whose dive was the deepest ever at -10,927 meters (in May, 2019). More people have walked on the surface of the Moon than have explored the ocean's deepest point.
Ocean Dimensions - Oceans cover 70.9% of the earth's surface. The deepest point is the Challenger Deep in the Mariana Trench at -10,927 meters (-35,849 feet).

The World's Oceans
OceanArea (km2)
% of Total
Volume (km3)
% of Total
Avg Depth
meters (ft)
Pacific Ocean168,723,000
3,970 m (13,025 ft)
Atlantic Ocean85,133,000
3,646 m (11,960 ft)
Indian Ocean70,560,000
3,741 m (12,274 ft)
Antarctic Ocean21,960,000
3,270 m (10,728 ft)
Artic Ocean15,558,000
1,205 m (3,953 ft)
Mediterranean Sea2,500,000
1,500 m (4,920 ft)
TOTAL364,434,0001,338,590,9003,690 m (12,100 ft)

Archimedes' Principle - An object immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced.
Bar - Measure of Barometric Pressure, 1 Bar = 1,000 millibar = 1,000 hPa (hectoPascal) Pressure at Sea Level = 1013 millibar (1 Atmosphere).
Bernoulli's Principle - An increase in the speed of a fluid results in a decrease of the fluid's pressure.
Boyle's Law - The volume of gas in a compressible container is inversely porportional to the pressure.
Color Loss - Sea water absorbs all color frequencies. Gone are the reds at -4m, oranges at -10m, yellows at -20m, greens at -40m, and blues at -60m. Below 60m there is a gradual fade to black.
Coriolis Effect - The deflection of fluids, relative to the solid earth beneath, as a result of the earth's spherical shape and its eastward rotation. Clockwise in the northern hemisphere, Counter-Clockwise in the southern hemisphere.
Density - Sea water is 827 times denser than air.
Freediving - Underwater diving without the use of any breathing apparatus.
Hard Hat - A heavy diving helmet made of brass and copper with small circular windows and open on the bottom. Surface air (or HeliOx) is supplied through a tube to pressurize the helmet. Because of their buoyancy the diver typically wears heavy lead weight shoes to maintain a vertical posture. They are still used for deep diving below 60 meters.
Hookah - A surface supplied air source for diving that can be dynamic (via active compressor) or static (via air tank). Air is supplied through a tube to a standard regulator. The diver usually wears a standard mask or a full face mask.
Nitrogen Narcosis - (aka rapture of the deep) A reversible intoxication caused by breathing Nitrogen at high pressure, usually at a partial pressure of over 400%.
Oxygen Toxicity - (aka Hyperoxia) an excess of oxygen in body tissues which can be fatal at diving depths exceeding 56 meters (184 feet) where the partial pressure of Oxygen (from compressed air) exceeds 120%. MOD (Maximum Operating Depth) Diving Tables
pH - potential of Hyrogen is defined as the negative of the base 10 logarithm of the activity of hydrogen ions. It ranges from pH 0 (very acidic) through pH 7 (neutral) to pH 14 (very alkaline). Water is neutral but seawater has a pH of 8 (slightly alkaline).
Pressure - Sea water pressure increases 0.44 psi per foot OR roughly 1 atmosphere of pressure per every 10 meters (32.8 feet). The pressure on a diver is equal to the water pressure PLUS the atmospheric pressure (e.g. 2 atmoshperes at 10 meters, 3 atmospheres at 20 meters, etc.)
Reynolds Number - A very important dimensionless value in fluid mechanics that measures the ratio of Inertial Forces to Viscous Forces and determines if the fluid has Laminar or Turbulent flow. Re < 1,000Laminar flow. Re > 2,000Turbulent flow. Between Re = 1,000 and Re = 2,000Flow Transistion Zone.
Salinity - Sea water contains 35 PPT (Parts Per Thousand) of Sodium Chloride (NaCl), the equivalent of 35 grams of salt per liter.
SCUBA - Self Contained Underwater Breathing Apparatus
Shallow Water Blackout - A loss of consciousness (usually fatal) caused by cerebral Hypoxia when a Freediver acends and the partial pressure of Oxygen in the lungs drops suddenly to near zero.
The Bends - aka Decompresion Sickness. The painful result of Nitrogen-saturated blood undergoing decreasing pressure as when rising from a deep dive OR flying within 12 hours after a moderate dive. This causes small Nitirogen bubbles to come out of solution and form in the blood stream where they accumulate in the tiny capillaries of the joints and the brain. The only course of action to alleviate the condition is to place the victim in a Recompression Chamber (aka Hyperbaric Chamber), increasing the pressure in order to shrink the bubbles, and then slowly (over 12+ hours) lowering the pressure to 1 atmosphere.

The Deepest Diving Marine Mammals
NameLatinMax Dive (feet)Max Dive (meters)
Southern Elephant SealMirounga leonina7,000 feet2,130 meters
Sperm WhalePhyseter macrocephalus7,400 feet2,250 meters
Cuvier's Beaked WhaleZiphius cavirostris9,800 feet3,000 meters
Taxonomy Basics & Resource Links

NOTE 1 → There can be Super, Sub, Infra, and Clade groupings at each classification level above Species

NOTE 2 → At the Species level there can be Subspecies which are usually geographically non-interactive. These are given trinomen latin names. e.g Camellia sinensis assamica (Assam Tea)

Lingcod, Ophiodon elongatus (Lengthy Snaketooth)

Domain Eukaryota
Kingdom Animalia
Phylum Chordata
Superclass Osteichthyes
Class Actinopterygii
Subclass Neopterygii
Order Scorpaeniformes
Family Hexagrammidae
Genus Ophiodon
Species elongatus
Resource Links
S Stanford University SEANET