Marine Biophysics:
Taxa Project
By Nicholas Marra
Kingdom: Chlorophyta
(Green Algae)

Habitat and Distribution:




Found in both marine and freshwater habitats (of the roughly 7000-8000
species, about 800 are marine and the latter are often found in tropical seas)
Some are terrestrial and live in soil or on rocks or trees, others form
symbiotic relationships with fungi in the form of lichens.
Most species are adapted to shallow freshwater and marine environments.
Characteristics





Photosynthetic pigments include Chlorophyll a and b as well as accessory
pigments such as carotenoids and xanthophylls (same pigments as plants).
They have cell walls (sometimes have varying degrees of cellulose and some
may even incorporate Calcium Carbonate and membrane-bound
chloroplasts where photosynthesis occurs.
Some types of green algae are unicellular while others are multicellular,
coenocytic, or colonial.
They are autotrophic and store the food produced from photosynthesis in
the form of starch, oils, or fats (similar to plants in this characteristic).
Some species have flagella that allow mobility, others are immobile but have
mobile gametes.

Sexual Characteristics:


Various forms of asexual reproduction have been observed
including fission, fragmentation, and production of spores.
Sexual reproduction also occurs in many species. In sexual
reproduction the gametes may be isogamous (identical size and
motility), anisogamous (different sizes, same motility), or
oogamous (male gamete motile, female non-motile)
(http://www.seaweed.ie/algae/chlorophyta.lasso)


Some species exhibit an alternation of generations (a common plant
characteristic) where there is a haploid gametangia and diploid phase.
There are also species with other life histories that may range from a
haploid life stage formed by meiosis in the zygote to the alternation of
generations described above.
http://www.botany.hawaii.edu/BOT201/Algae/Chlorophyta%20lecture%20notes.htm

Significance: They are primary producers and the
group is paraphyletic and excludes Plantae even
though many of their characteristics are shared.
Pictured to the right is an
example of the marine group of
Chlorophyta known as sea lettuce
(Uva) which grow in tide pools
and is exposed in this picture.
Below is a picture of various
growth forms of Chlorophyta spp.
http://www.ucmp.berkeley.edu/greena
lgae/greenalgae.html
http://www.botany.hawaii.edu/BOT201/Algae/Bot
%20201%20Chlorophytes%20page.gif


Common names not often found but Uva spp. are known
as sea lettuce and overall the group is often called green
algae or some will call the algae seaweed.
Marine (Caribbean) Representatives:











Valonia utricularis: Creeping Bubble Alga
Caulerpa racemosa: Green Grape Alga
Halimeda incrassata: Three Finger Leaf Alga
Halimeda copiosa: Large-leaf Hanging Vine
Avrainvillea asarifolia: Saucer Blade Alga
Microdictyon marinum: Network Alga
Ventricaria ventricosa: Sea Pearl
Dictyosphaeria cavernosa: Green Bubble Weed
Neomeris annulata: Fuzzy Tip Alga
Udotea flabellum: Stalked Lettuce Leaf Alga
Species in the Hope College Collection:



Ulva sp.: Sea Lettuce
Spongomorpha sp.
Desmarestia herbacea

Phylum Chordata, Subphylum:
Urochordata
Distribution: About 2000 Species




Class Ascidiacea: (Sea Squirts and Tunicates) found as
generally benthic organisms in tide pools and shallower
waters around the world (although some have been found
fairly deep at up to a few hundred feet).
Class Thaliacea: (Salps) found as slow swimmers in warm
seas around the world. (about 70 species)
Class Larvacea: (Larvaceans): Planktonic organisms globally
found near the surface of warm seas. (about 70 species)
Characteristics


As Chordates, they have a notochord, post anal tail, and
hollow nerve cord (though some of these characteristics can
be absent in adult forms). They also have a nervous system
and lack excretory organs.
The body is covered in some type of a shell or coating
composed of secreted proteins and compounds that are
similar to cellulose in some species.




The layer is not composed of cells but is secreted by the
epidermis beneath it.
Solitary individuals range from 1 mm to 20 cm in Ascidiacea.
Some Thaliacea colonies can reach 2 m in length (individual
salps can be on the order of a few cm.
Larvaceans are about 1 inch in diameter.
http://www.earthlife.net/inverts/ascidiacea.html

Food and general habits:

Most are filter feeders although each class does so differently:






Sea Squirts and Tunicates are usually sessile and filter water that enters
their body through their incurrent siphons, gleaning food particles from
the water by trapping it in mucus at the pharyngeal slits.
The Thaliacea use circular and longitudinal muscles (Ascidians possess
these muscles as well and use them to shoot water out of their excurrent
siphon, possibly as a defense mechanism) draw water in (which is
filtered for food particles) the incurrent siphon and push it out of the
excurrent siphon, which propels the organism through the water.
Larvaceans secrete a gelatin ‘house’ around them that traps extremely
small members of the plankton such as coccolithophorids that are
filtered out at the pharyngeal slits.
Some Urochordates live as single individuals that can be either
unicellular or multicellular while others are known as zooids as
part of colonies that can propagate asexually or sexually.
All Urochordates have a larval life stage, which in the case of
tunicates and sea squirts is used primarily for dispersal.
Urochordates are important filter feeders that form an
important section of the lower heterotrophic organisms that are
preyed upon by larger organisms (some by nudibranchs and
other organisms) in reef and open water communities.

Sexual Habits:
Both asexual and sexual modes of reproduction are
seen in the Urochordates.
 Most Urochordates are hermaphroditic.

Self-fertilization is avoided in Tunicates through chemical
self-incompatibility or temporal separation in the release of
gametes.
 Some species exhibit an alternation of generations with
asexual and sexual forms (especially in the Thaliacea) with
the dominant stage varying between species and groups.

Ascidea sydneiensis:
Picture of a Salp
Yellow-Green Sea
http://www.wetwebme Squirt found worldwide
dia.com/ascidians.htm http://www.wetwebme http://www.earthlife.net/inverts/larvacea.html
dia.com/ascidians.htm

Caribbean Species:


Ascidea sydneiensis: Yellow-Green Sea Squirt
Trididemum solidum: the Overgrowing Mat
Tunicate

Trematooecia aviculifera: Bleeding Teeth
Bryozoan



Distaplia corolla: Button Tunicate
Clavelina cyclus: Pale Club Sea Squirt
Clavelina picta, the Painted Tunicate
http://ww
w.wetwebm
edia.com/as
cidpt2.html
http://www.wet Clavelina picta, the Painted Tunicate
webmedia.com/ Symplegma viride: Encrusting Social Tunicate
ascidpt2.html Eudistoma obscuratum: Black Condominium
Tunicate
Botrylloides nigrum: Flat Tunicate

Species in the Hope College Collection:
Molgula sp.: Sea Grapes
Corella sp.: Glassy Tunicate
Amoransium
Stellatum

Class Bivalvia (part of Mollusca),
Distribution:

About 1500 species of Bivalves exist and they occur worldwide (and at
various latitudes) in both marine and freshwater habitats.




These environments range from the deep areas of the ocean to the shallow water
of streambeds.
Usually these species are benthic organisms that attach themselves to the
substrate or bury themselves in it using their muscular foot (sometimes they
form byssal threads and use these structures to attach themselves to the
substrate. Occasionally, some, like Scallops will use the opening and
closing of their shell to propel them through the water
Bivalves are characterized by their two shells which are produced
as secretions from the mantle of the organism. The oldest area of
the shell is a hump near the anterior called the umbo and the two
shells are joined together at the ligament and two adductor
muscles (one anterior and one posterior) are used to close the
shell.
When buried, most bivalves extend an incurrent siphon above the
substrate to take in water and an excurrent siphon to expel water
and waste.

Feeding and other habits:



Most bivalves are filter feeders, straining plankton and other food particles
out of the water column using the siphons that form as an extension of the
mantle.
Often external structures called labial palps are adapted to be
photoreceptors or other sensory structures.
Bivalves use their large gills to trap food particles that enter through their
incurrent siphon and these gills are adapted in different ways to form four
different types of feeding.

An exception is in the first group, the protobranchs only use their gills for
respiration (the labial palps trap food)
Both the filibranchs and lamellibranchs take the food stopped at the ctenida and
use mucous to trap the food before cilia are used to move the food to the labial
palps.
Septibranchs pump food in using a septum across its mantle

(http://animaldiversity.ummz.umich.edu/site/accounts/information/Bivalvia.html)



Reproductive Characteristics



Bivalves can be either hermaphroditic or have separate sexes.
Usually fertilization is external with sperms and eggs being released into the
water column and leading to trochophore and veliger larvae.
In some species sperm are released while the organism retains its eggs and
takes in sperm via its incurrent siphon. After fertilization these species may
release their new embryos into the water column.

Significance and examples:
Several species of bivalves are used as important food
sources throughout the world and pearl oysters form a
significant economic resource.
 Other species have larval can cause significant
damage to wharfs, ships, etc.

http://animaldiversity.ummz.umich.edu/sit
e/resources/biodidac/biva002b.gif/view.ht
ml
http://www.ucmp.berkeley
.edu/taxa/inverts/mollusc
a/bivalvia.php

Examples of Caribbean Bivalves:











Lima Scabra: Rough Fileclam
Spondylus americanus: Atlantic Thorny-oyster
Pteria colymbus: Atlantic Wing-oyster
Lima lima: Spiny Fileclam
Chlamys imbricata: Knobby Scallop
Dendostrea frons: Frond Oyster
Isognomon radiatus: Lister Purse-oyster
Isognomon alatus: Flat Tree-oyster
Pinna carnea: Amber Penshell
Tellina radiata: Sunrise Tellin
Bivalves in the Hope College Collection:





Dinocardium robustum: Giant Heart Cockle
Chione Cancellata
Trachycardium egmontianum: Prickly Cockle
Crassostrea Virginica: Eastern Oyster
Lucina floridina
Order: Salmoniformes, Common Name:
Salmons


This taxonomic group consists of one direct family of fish, the
salmonidae and several suborders of fish. Common species of
this order include various salmon, trout, char, and whitefish.
Members of this group have been found in marine, brackish and
freshwater environments and some live in marine and freshwater
environments at stages of their lives.





For example Coho Salmon, Oncorhynchus kisutch, are born in freshwater
streams and travel out to the coastal waters of the ocean where they mature
and feed. Once they reach maturity they return to the freshwater streams
where they were born.
The salmonidae contain 66 species of salmon, trout, and whitefish.
Most species prefer areas where the water is relatively cool, clear, and rich in
dissolved oxygen. Thus there are many species found in the temperate
regions of the northern hemisphere and few tropical salmonid species.
Most species are anadromous.
The members of this order have soft-rayed fins (no spines in the fins).

Food and Reproductive Habits:





In many species the juveniles will feed on insect larvae, crustaceans,
mollusks, etc. in shallow freshwater streams where they were born.
As they mature, most salmonid fishes swim downstream to the sea and
spend the next several years feeding on small fish, squid, and shrimp in the
ocean waters.
After they have reached adulthood and reached the time to breed these fish
use chemical and visual cues (vision is used more for feeding) to navigate
back to the streams where they were born.
These adults then travel upstream to the areas where they were born and
clear areas of gravel for nests where the females lay hundreds to a few
thousand eggs.
In some species the tremendous stress of traveling upstream to their
spawning sites results in the death of adult salmon after they reproduce.
http://animaldiversity.ummz.umich.edu/site/accounts/pictures/Salmoniformes.html (all pictures
are from this site, from left to right they are gila trout, cutthroat trout, and coho salmon)

Significance:


Salmon and other members of the salmoniformes are
important members of both marine and freshwater food chains.
They also form an important source of nutrients through the
decomposition of their bodies after their strenuous trip to
breed as adults.
Through aquaculture and both sport and commercial fisheries,
salmonid fishes have an important economic impact.

The popularity of some species as sport fish has led to the introduction
of these species to areas around the world.
http://alaskanabroad.typepad.com/an_alaskan_ab
road/070429salmon%20cooked%201.jpg
Salmon Farm in Lucas Bay, Alaska
http://images.google.com/imgres?imgurl=http://www.akaroasalmon.co.nz/images/salmon%2520farm
.jpg&imgrefurl=http://www.akaroasalmon.co.nz/history.html&h=448&w=300&sz=28&hl=en&start=
6&um=1&tbnid=Wgd35rmCxVBQMM:&tbnh=127&tbnw=85&prev=/images%3Fq%3DSalmon%2B

Caribbean Species (I couldn’t find any tropical species so
I’ve listed five other species below in addition to the ones
found in Hope’s Collection):

Esox niger: Chain Pickerel (part of the Escoidei suborder but
found in Florida)





Oncorhynchus nerka: Sockeye Salmon
Salmo salar: Atlantic Salmon
Salvelinus alpinus: Arctic Char
Coregonus pidschian: Humpback Whitefish
Species in the Hope College Collection:




Salmo gairdneri (old name now known as Oncorhynchus
mykiss): Rainbow trout
Salmo trutta: Brown Trout
Salvelinus fontinalis: Brook Trout
Oncorhynchus kisutch: Coho Salmon
Class Mammalia: Mammals


This class is part of the subphylum Vertebrata in the phylum
Chordata.
As Homo sapiens we are members of this class which has about
26 orders with about 5000 extant species.


Of these, marine examples are found in three orders, Carnivora (pinnepids),
Sirenia (manatees and dugongs), and Cetacea (whales and dolphins)
As a class, most mammals share the characteristics of middle ear
bones, hair, and mammary glands that separate them from other
groups of animals. Additionally, most mammals are endothermic
and give birth to live young (except for monotremes)

Marine mammals have special adaptations to deal with the stresses of life in
the oceans.


These adaptations include a thick layer of blubber and counter-current flow to
help regulate temperature since heat loss is quicker in water than on land, slower
heart rate and divergence of oxygen away from unimportant organs to allow
deep diving, a well-developed sense of vision for the water and communication
adaptations such as echolocation in cetaceans.
Most marine mammals also have adaptations for swimming such as a tail
modified to be a fin or paddle like appendages.

Food Habits and Reproductive habits






The pinnipeds feed using sharp teeth to grasp fish and may use
tools such as stones to crack open the shells of various bivalves
that they also feed on.
Similarly toothed whales use their sharp teeth to capture fish,
squid, and fellow marine mammals for food.
Other Cetaceans are filter feeders and use plates of baleen
(made of keratin) that extend from the upper jaw and trap
plankton and other food particles from the water column. The
tongue then licks the baleen clean of food.
Manatees and dugongs are completely herbivorous, feeding on
various sea grasses, mangrove leaves, etc.
Most Marine mammals make long migrations in order to follow
food species or to give birth in warmer waters of the tropics
before going to feed in the cooler waters of the poles.
They are also viviparous and have relatively long gestation
periods, leading to low brood sizes of one or maybe two pups
per female for pinnipeds and usually only one offspring is born
per female in most whale species (the cost of lactating and
providing the food necessary for a young whale to put on
enough blubber for arctic seas can be extraordinary.

Significance:
 Several marine mammals are endangered or threatened due to
over (and often illegal) hunting and accidents such as collisions
with boats and entanglement in fishing nets. They are an
important part of the food chain with some acting as top level
predators (such as Orcinus orca: Killer Whale)
 Below are some pictures of various marine mammals
A manatee cow and calf (courtesy of NOAA).
Pacific White-Sided Dolphins
(Lagenorhynchus obliquidens).
http://www.onr.navy.mil/focus/ocean/life/mammals1.htm
http://www.onr.navy.mil/focus/ocean/life/mammals7.htm
A group of walrus
sun themselves on a
beach (courtesy of
NOAA).
http://www.onr.navy.mil/fo
cus/ocean/life/mammals1.h
tm

10 Caribbean Species of Marine Mammals, no
species found in Hope College Collection:
Trichechus manatus manatus: West Indian Manatee
 Balaenoptera acutorostrata: Minke Whale
 Kogia breviceps: Pygmy Sperm Whale
 Grampus griseus: Risso's Dolphin
 Orcinus orca: Killer Whale
 Mesoplodon europaeus: Gervais' Beaked Whale
 Delphinus delphis: Atlantic Dolphin, Pacific Dolphin,

etc.
Peponocephala electra: Melon-headed Whale
 Stenella attenuata: Pantropical Spotted Dolphin
 Tursiops truncatus: Bottle-nosed Dolphin
