Marine Marine Biophysics: Taxa Biophysics: Taxa

ProjectProjectBy Nicholas MarraBy Nicholas Marra

Kingdom: Chlorophyta Kingdom: Chlorophyta (Green Algae)(Green Algae)

Habitat and Distribution:Habitat and Distribution: Found in both marine and freshwater habitats (of the roughly Found in both marine and freshwater habitats (of the roughly

7000-8000 species, about 800 are marine and the latter are 7000-8000 species, about 800 are marine and the latter are often found in tropical seas)often found in tropical seas)

Some are terrestrial and live in soil or on rocks or trees, others Some are terrestrial and live in soil or on rocks or trees, others form symbiotic relationships with fungi in the form of lichens.form symbiotic relationships with fungi in the form of lichens.

Most species are adapted to shallow freshwater and marine Most species are adapted to shallow freshwater and marine environments.environments.

CharacteristicsCharacteristics Photosynthetic pigments include Chlorophyll a and b as well as Photosynthetic pigments include Chlorophyll a and b as well as

accessory pigments such as carotenoids and xanthophylls (same accessory pigments such as carotenoids and xanthophylls (same pigments as plants).pigments as plants).

They have cell walls (sometimes have varying degrees of They have cell walls (sometimes have varying degrees of cellulose and some may even incorporate Calcium Carbonate cellulose and some may even incorporate Calcium Carbonate and membrane-bound chloroplasts where photosynthesis and membrane-bound chloroplasts where photosynthesis occurs.occurs.

Some types of green algae are unicellular while others are Some types of green algae are unicellular while others are multicellular, coenocytic, or colonial.multicellular, coenocytic, or colonial.

They are autotrophic and store the food produced from They are autotrophic and store the food produced from photosynthesis in the form of starch, oils, or fats (similar to photosynthesis in the form of starch, oils, or fats (similar to plants in this characteristic).plants in this characteristic).

Some species have flagella that allow mobility, others are Some species have flagella that allow mobility, others are immobile but have mobile gametes.immobile but have mobile gametes.

Sexual Characteristics:Sexual Characteristics: Various forms of asexual reproduction have been Various forms of asexual reproduction have been

observed including fission, fragmentation, and observed including fission, fragmentation, and production of spores.production of spores.

Sexual reproduction also occurs in many species. In Sexual reproduction also occurs in many species. In sexual reproduction the gametes may be isogamous sexual reproduction the gametes may be isogamous (identical size and motility), anisogamous (different (identical size and motility), anisogamous (different sizes, same motility), or oogamous (male gamete sizes, same motility), or oogamous (male gamete motile, female non-motile) motile, female non-motile) ((http://www.seaweed.ie/algae/chlorophyta.lassohttp://www.seaweed.ie/algae/chlorophyta.lasso))

Some species exhibit an alternation of generations (a common Some species exhibit an alternation of generations (a common plant characteristic) where there is a haploid gametangia and plant characteristic) where there is a haploid gametangia and diploid phase.diploid phase.

There are also species with other life histories that may range There are also species with other life histories that may range from a haploid life stage formed by meiosis in the zygote to from a haploid life stage formed by meiosis in the zygote to the alternation of generations described above.the alternation of generations described above.

http://www.botany.hawaii.edu/BOT201/Algae/Chlorophyta%20lecture%20notes.htm

Significance: They are primary producers and Significance: They are primary producers and the group is paraphyletic and excludes the group is paraphyletic and excludes Plantae even though many of their Plantae even though many of their characteristics are shared. characteristics are shared.

http://www.ucmp.berkeley.edu/

greenalgae/greenalgae.html

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.botany.hawaii.edu/BOT201/Algae/Bot%20201%20Chlorophytes%20page.gif

Common names not often found but Common names not often found but Uva Uva spp. spp. are known as sea lettuce and overall are known as sea lettuce and overall the group is often called green algae or the group is often called green algae or some will call the algae seaweed.some will call the algae seaweed.

Marine (Caribbean) Representatives: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, Phylum Chordata, Subphylum: UrochordataSubphylum: Urochordata

Distribution: About 2000 SpeciesDistribution: About 2000 Species Class Ascidiacea: (Sea Squirts and Tunicates) Class Ascidiacea: (Sea Squirts and Tunicates)

found as generally benthic organisms in tide pools found as generally benthic organisms in tide pools and shallower waters around the world (although and shallower waters around the world (although some have been found fairly deep at up to a few some have been found fairly deep at up to a few hundred feet). hundred feet).

Class Thaliacea: (Salps) found as slow swimmers Class Thaliacea: (Salps) found as slow swimmers in warm seas around the world. (about 70 species)in warm seas around the world. (about 70 species)

Class Larvacea: (Larvaceans): Planktonic Class Larvacea: (Larvaceans): Planktonic organisms globally found near the surface of organisms globally found near the surface of warm seas. (about 70 species)warm seas. (about 70 species)

CharacteristicsCharacteristics As Chordates, they have a notochord, post anal As Chordates, they have a notochord, post anal

tail, and hollow nerve cord (though some of these tail, and hollow nerve cord (though some of these characteristics can be absent in adult forms). characteristics can be absent in adult forms). They also have a nervous system and lack They also have a nervous system and lack excretory organs.excretory organs.

The body is covered in some type of a shell or The body is covered in some type of a shell or coating composed of secreted proteins and coating composed of secreted proteins and compounds that are similar to cellulose in some compounds that are similar to cellulose in some species. species.

The layer is not composed of cells but is secreted by The layer is not composed of cells but is secreted by the epidermis beneath it.the epidermis beneath it.

Solitary individuals range from 1 mm to 20 cm in Solitary individuals range from 1 mm to 20 cm in Ascidiacea.Ascidiacea.

Some Thaliacea colonies can reach 2 m in length Some Thaliacea colonies can reach 2 m in length (individual salps can be on the order of a few cm.(individual salps can be on the order of a few cm.

Larvaceans are about 1 inch in diameter.Larvaceans are about 1 inch in diameter.http://www.earthlife.net/inverts/ascidiacea.html

Food and general habits:Food and general habits: Most are filter feeders although each class does so Most are filter feeders although each class does so

differently:differently: Sea Squirts and Tunicates are usually sessile and filter water Sea Squirts and Tunicates are usually sessile and filter water

that enters their body through their incurrent siphons, gleaning that enters their body through their incurrent siphons, gleaning food particles from the water by trapping it in mucus at the food particles from the water by trapping it in mucus at the pharyngeal slits.pharyngeal slits.

The Thaliacea use circular and longitudinal muscles (Ascidians The Thaliacea use circular and longitudinal muscles (Ascidians possess these muscles as well and use them to shoot water out possess these muscles as well and use them to shoot water out of their excurrent siphon, possibly as a defense mechanism) of their excurrent siphon, possibly as a defense mechanism) draw water in (which is filtered for food particles) the incurrent draw water in (which is filtered for food particles) the incurrent siphon and push it out of the excurrent siphon, which propels siphon and push it out of the excurrent siphon, which propels the organism through the water.the organism through the water.

Larvaceans secrete a gelatin ‘house’ around them that traps Larvaceans secrete a gelatin ‘house’ around them that traps extremely small members of the plankton such as extremely small members of the plankton such as coccolithophorids that are filtered out at the pharyngeal slits.coccolithophorids that are filtered out at the pharyngeal slits.

Some Urochordates live as single individuals that can Some Urochordates live as single individuals that can be either unicellular or multicellular while others are be either unicellular or multicellular while others are known as zooids as part of colonies that can propagate known as zooids as part of colonies that can propagate asexually or sexually.asexually or sexually.

All Urochordates have a larval life stage, which in the All Urochordates have a larval life stage, which in the case of tunicates and sea squirts is used primarily for case of tunicates and sea squirts is used primarily for dispersal.dispersal.

Urochordates are important filter feeders that form an Urochordates are important filter feeders that form an important section of the lower heterotrophic organisms important section of the lower heterotrophic organisms that are preyed upon by larger organisms (some by that are preyed upon by larger organisms (some by nudibranchs and other organisms) in reef and open nudibranchs and other organisms) in reef and open water communities.water communities.

Sexual Habits: Sexual Habits: Both asexual and sexual modes of Both asexual and sexual modes of

reproduction are seen in the Urochordates. reproduction are seen in the Urochordates.

Most Urochordates are hermaphroditic.Most Urochordates are hermaphroditic. Self-fertilization is avoided in Tunicates Self-fertilization is avoided in Tunicates

through chemical self-incompatibility or through chemical self-incompatibility or temporal separation in the release of gametes.temporal separation in the release of gametes.

Some species exhibit an alternation of Some species exhibit an alternation of generations with asexual and sexual forms generations with asexual and sexual forms (especially in the Thaliacea) with the dominant (especially in the Thaliacea) with the dominant stage varying between species and groups.stage varying between species and groups.

Picture of a Salphttp://www.wetwebmedia.com/ascidians.htm

Ascidea sydneiensis: Yellow-Green Sea Squirt found worldwidehttp://www.wetwebmedia.com/ascidians.htm

http://www.earthlife.net/inverts/larvacea.html

Caribbean Species:Caribbean Species: Ascidea sydneiensis: Yellow-Green

Sea Squirt Trididemum solidum: the

Overgrowing Mat Tunicate Trematooecia aviculiferaTrematooecia aviculifera: :

Bleeding Teeth BryozoanBleeding Teeth Bryozoan Distaplia corolla: Button Tunicate Clavelina cyclusClavelina cyclus: Pale Club Sea : Pale Club Sea

Squirt Squirt Clavelina pictaClavelina picta, the Painted , the Painted

Tunicate Tunicate

http://www.wetwebmedia.com/ascidpt2.html

http://www.wetwebmedia.com/ascidpt2.html

Clavelina pictaClavelina picta, the Painted , the Painted TunicateTunicateSymplegma virideSymplegma viride: Encrusting : Encrusting Social TunicateSocial TunicateEudistoma obscuratumEudistoma obscuratum: Black : Black Condominium TunicateCondominium TunicateBotrylloides nigrumBotrylloides nigrum: Flat Tunicate: Flat Tunicate Species in the Hope College Collection:

Molgula sp.: Sea GrapesCorella sp.: Glassy TunicateAmoransium Stellatum

Class Bivalvia (part of Class Bivalvia (part of Mollusca), Mollusca), Distribution:Distribution:

About 1500 species of Bivalves exist and they occur About 1500 species of Bivalves exist and they occur worldwide (and at various latitudes) in both marine and worldwide (and at various latitudes) in both marine and freshwater habitats. freshwater habitats.

These environments range from the deep areas of the ocean to These environments range from the deep areas of the ocean to the shallow water of streambeds.the shallow water of streambeds.

Usually these species are benthic organisms that attach Usually these species are benthic organisms that attach themselves to the substrate or bury themselves in it using themselves to the substrate or bury themselves in it using their muscular foot (sometimes they form byssal threads and their muscular foot (sometimes they form byssal threads and use these structures to attach themselves to the substrate. use these structures to attach themselves to the substrate. Occasionally, some, like Scallops will use the opening and Occasionally, some, like Scallops will use the opening and closing of their shell to propel them through the waterclosing of their shell to propel them through the water

Bivalves are characterized by their two shells which Bivalves are characterized by their two shells which are produced as secretions from the mantle of the are produced as secretions from the mantle of the organism. The oldest area of the shell is a hump organism. The oldest area of the shell is a hump near the anterior called the umbo and the two shells near the anterior called the umbo and the two shells are joined together at the ligament and two adductor are joined together at the ligament and two adductor muscles (one anterior and one posterior) are used to muscles (one anterior and one posterior) are used to close the shell.close the shell.

When buried, most bivalves extend an incurrent When buried, most bivalves extend an incurrent siphon above the substrate to take in water and an siphon above the substrate to take in water and an excurrent siphon to expel water and waste.excurrent siphon to expel water and waste.

Feeding and other habits:Feeding and other habits: Most bivalves are filter feeders, straining plankton and Most bivalves are filter feeders, straining plankton and

other food particles out of the water column using the other food particles out of the water column using the siphons that form as an extension of the mantle. siphons that form as an extension of the mantle.

Often external structures called labial palps are adapted Often external structures called labial palps are adapted to be photoreceptors or other sensory structures.to be photoreceptors or other sensory structures.

Bivalves use their large gills to trap food particles that Bivalves use their large gills to trap food particles that enter through their incurrent siphon and these gills are enter through their incurrent siphon and these gills are adapted in different ways to form four different types of adapted in different ways to form four different types of feeding.feeding.

An exception is in the first group, the protobranchs only use An exception is in the first group, the protobranchs only use their gills for respiration (the labial palps trap food)their gills for respiration (the labial palps trap food)

Both the filibranchs and lamellibranchs take the food stopped Both the filibranchs and lamellibranchs take the food stopped at the ctenida and use mucous to trap the food before cilia are at the ctenida and use mucous to trap the food before cilia are used to move the food to the labial palps.used to move the food to the labial palps.

Septibranchs pump food in using a septum across its mantle Septibranchs pump food in using a septum across its mantle (http://animaldiversity.ummz.umich.edu/site/accounts/information/Bivalvia.html)(http://animaldiversity.ummz.umich.edu/site/accounts/information/Bivalvia.html)

Reproductive CharacteristicsReproductive Characteristics Bivalves can be either hermaphroditic or have separate Bivalves can be either hermaphroditic or have separate

sexes.sexes. Usually fertilization is external with sperms and eggs Usually fertilization is external with sperms and eggs

being released into the water column and leading to being released into the water column and leading to trochophore and veliger larvae.trochophore and veliger larvae.

In some species sperm are released while the organism In some species sperm are released while the organism retains its eggs and takes in sperm via its incurrent retains its eggs and takes in sperm via its incurrent siphon. After fertilization these species may release their siphon. After fertilization these species may release their new embryos into the water column.new embryos into the water column.

Significance and examples: Significance and examples: Several species of bivalves are used as Several species of bivalves are used as

important food sources throughout the world important food sources throughout the world and pearl oysters form a significant economic and pearl oysters form a significant economic resource. resource.

Other species have larval can cause Other species have larval can cause significant damage to wharfs, ships, etc.significant damage to wharfs, ships, etc.

http://animaldiversity.ummz.umich.edu/site/resources/biodidac/biva002b.gif/view.html

http://www.ucmp.berkeley.edu/taxa/inverts/mollusca/bivalvia.php

Examples of Caribbean Bivalves:Examples of Caribbean Bivalves: Lima ScabraLima Scabra: Rough Fileclam: Rough Fileclam Spondylus americanusSpondylus americanus: Atlantic Thorny-oyster: Atlantic Thorny-oyster Pteria colymbusPteria colymbus: Atlantic Wing-oyster: Atlantic Wing-oyster Lima limaLima lima: Spiny Fileclam: Spiny Fileclam Chlamys imbricataChlamys imbricata: Knobby Scallop: Knobby Scallop Dendostrea fronsDendostrea frons: Frond Oyster: Frond Oyster Isognomon radiatusIsognomon radiatus: Lister Purse-oyster: Lister Purse-oyster Isognomon alatus: Isognomon alatus: Flat Tree-oysterFlat Tree-oyster Pinna carneaPinna carnea: Amber Penshell: Amber Penshell Tellina radiataTellina radiata: Sunrise Tellin: Sunrise Tellin

Bivalves in the Hope College Collection:Bivalves in the Hope College Collection: Dinocardium robustumDinocardium robustum: Giant Heart Cockle: Giant Heart Cockle Chione CancellataChione Cancellata Trachycardium egmontianumTrachycardium egmontianum: Prickly Cockle: Prickly Cockle Crassostrea VirginicaCrassostrea Virginica: Eastern Oyster: Eastern Oyster Lucina floridinaLucina floridina

Order: Salmoniformes, Order: Salmoniformes, Common Name: SalmonsCommon Name: Salmons

This taxonomic group consists of one direct family of fish, This taxonomic group consists of one direct family of fish, the salmonidae and several suborders of fish. Common the salmonidae and several suborders of fish. Common species of this order include various salmon, trout, char, species of this order include various salmon, trout, char, and whitefish. and whitefish.

Members of this group have been found in marine, Members of this group have been found in marine, brackish and freshwater environments and some live in brackish and freshwater environments and some live in marine and freshwater environments at stages of their marine and freshwater environments at stages of their lives.lives. For example Coho Salmon, For example Coho Salmon, Oncorhynchus kisutchOncorhynchus kisutch, are born in , are born in

freshwater streams and travel out to the coastal waters of the freshwater streams and travel out to the coastal waters of the ocean where they mature and feed. Once they reach maturity they ocean where they mature and feed. Once they reach maturity they return to the freshwater streams where they were born. return to the freshwater streams where they were born.

The salmonidae contain 66 species of salmon, trout, and whitefish.The salmonidae contain 66 species of salmon, trout, and whitefish. Most species prefer areas where the water is relatively cool, clear, Most species prefer areas where the water is relatively cool, clear,

and rich in dissolved oxygen. Thus there are many species found and rich in dissolved oxygen. Thus there are many species found in the temperate regions of the northern hemisphere and few in the temperate regions of the northern hemisphere and few tropical salmonid species.tropical salmonid species.

Most species are anadromous.Most species are anadromous. The members of this order have soft-rayed fins (no spines in the The members of this order have soft-rayed fins (no spines in the

fins).fins).

Food and Reproductive Habits:Food and Reproductive Habits: In many species the juveniles will feed on insect larvae, In many species the juveniles will feed on insect larvae,

crustaceans, mollusks, etc. in shallow freshwater streams crustaceans, mollusks, etc. in shallow freshwater streams where they were born.where they were born.

As they mature, most salmonid fishes swim downstream to the As they mature, most salmonid fishes swim downstream to the sea and spend the next several years feeding on small fish, sea and spend the next several years feeding on small fish, squid, and shrimp in the ocean waters. squid, and shrimp in the ocean waters.

After they have reached adulthood and reached the time to After they have reached adulthood and reached the time to breed these fish use chemical and visual cues (vision is used breed these fish use chemical and visual cues (vision is used more for feeding) to navigate back to the streams where they more for feeding) to navigate back to the streams where they were born. were born.

These adults then travel upstream to the areas where they These adults then travel upstream to the areas where they were born and clear areas of gravel for nests where the females were born and clear areas of gravel for nests where the females lay hundreds to a few thousand eggs.lay hundreds to a few thousand eggs.

In some species the tremendous stress of traveling upstream In some species the tremendous stress of traveling upstream to their spawning sites results in the death of adult salmon to their spawning sites results in the death of adult salmon after they reproduce.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:Significance: Salmon and other members of the salmoniformes Salmon and other members of the salmoniformes

are important members of both marine and are important members of both marine and freshwater food chains. They also form an freshwater food chains. They also form an important source of nutrients through the important source of nutrients through the decomposition of their bodies after their strenuous decomposition of their bodies after their strenuous trip to breed as adults.trip to breed as adults.

Through aquaculture and both sport and Through aquaculture and both sport and commercial fisheries, salmonid fishes have an commercial fisheries, salmonid fishes have an important economic impact. important economic impact.

The popularity of some species as sport fish has led to the The popularity of some species as sport fish has led to the introduction of these species to areas around the world.introduction of these species to areas around the world.

http://alaskanabroad.typepad.com/an_alaskan_abroad/070429salmon%20cooked%201.jpg

Salmon Farm in Lucas Bay, Alaskahttp://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%2BFarm%26um%3D1%26hl%3Den

Caribbean Species (I couldn’t find any Caribbean Species (I couldn’t find any tropical species so I’ve listed five other tropical species so I’ve listed five other species below in addition to the ones species below in addition to the ones found in Hope’s Collection):found in Hope’s Collection): Esox niger: Chain Pickerel (part of the : Chain Pickerel (part of the

Escoidei suborder but found in Florida)Escoidei suborder but found in Florida) OncorhynchusOncorhynchus nerkanerka: Sockeye Salmon: Sockeye Salmon Salmo salarSalmo salar: Atlantic Salmon: Atlantic Salmon Salvelinus alpinusSalvelinus alpinus: Arctic Char: Arctic Char Coregonus pidschianCoregonus pidschian: Humpback Whitefish: Humpback Whitefish

Species in the Hope College Collection:Species in the Hope College Collection: Salmo gairdneri (old name now known as Salmo gairdneri (old name now known as

Oncorhynchus mykissOncorhynchus mykiss)): : Rainbow troutRainbow trout Salmo truttaSalmo trutta: Brown Trout: Brown Trout Salvelinus fontinalisSalvelinus fontinalis: Brook Trout: Brook Trout Oncorhynchus kisutchOncorhynchus kisutch: Coho Salmon: Coho Salmon

Class Mammalia: Class Mammalia: MammalsMammals This class is part of the subphylum Vertebrata in the This class is part of the subphylum Vertebrata in the

phylum Chordata.phylum Chordata. As As Homo sapiensHomo sapiens we are members of this class which we are members of this class which

has about 26 orders with about 5000 extant species.has about 26 orders with about 5000 extant species. Of these, marine examples are found in three orders, Of these, marine examples are found in three orders,

Carnivora (pinnepids), Sirenia (manatees and dugongs), and Carnivora (pinnepids), Sirenia (manatees and dugongs), and Cetacea (whales and dolphins)Cetacea (whales and dolphins)

As a class, most mammals share the characteristics As a class, most mammals share the characteristics of middle ear bones, hair, and mammary glands that of middle ear bones, hair, and mammary glands that separate them from other groups of animals. separate them from other groups of animals. Additionally, most mammals are endothermic and Additionally, most mammals are endothermic and give birth to live young (except for monotremes)give birth to live young (except for monotremes) Marine mammals have special adaptations to deal with the Marine mammals have special adaptations to deal with the

stresses of life in the oceans. stresses of life in the oceans. These adaptations include a thick layer of blubber and counter-These adaptations include a thick layer of blubber and counter-

current flow to help regulate temperature since heat loss is current flow to help regulate temperature since heat loss is quicker in water than on land, slower heart rate and divergence quicker in water than on land, slower heart rate and divergence of oxygen away from unimportant organs to allow deep diving, a of oxygen away from unimportant organs to allow deep diving, a well-developed sense of vision for the water and communication well-developed sense of vision for the water and communication adaptations such as echolocation in cetaceans.adaptations such as echolocation in cetaceans.

Most marine mammals also have adaptations for swimming Most marine mammals also have adaptations for swimming such as a tail modified to be a fin or paddle like appendages.such as a tail modified to be a fin or paddle like appendages.

Food Habits and Reproductive habitsFood Habits and Reproductive habits The pinnipeds feed using sharp teeth to grasp fish and The pinnipeds feed using sharp teeth to grasp fish and

may use tools such as stones to crack open the shells may use tools such as stones to crack open the shells of various bivalves that they also feed on.of various bivalves that they also feed on.

Similarly toothed whales use their sharp teeth to Similarly toothed whales use their sharp teeth to capture fish, squid, and fellow marine mammals for capture fish, squid, and fellow marine mammals for food.food.

Other Cetaceans are filter feeders and use plates of Other Cetaceans are filter feeders and use plates of baleen (made of keratin) that extend from the upper baleen (made of keratin) that extend from the upper jaw and trap plankton and other food particles from jaw and trap plankton and other food particles from the water column. The tongue then licks the baleen the water column. The tongue then licks the baleen clean of food. clean of food.

Manatees and dugongs are completely herbivorous, Manatees and dugongs are completely herbivorous, feeding on various sea grasses, mangrove leaves, etc.feeding on various sea grasses, mangrove leaves, etc.

Most Marine mammals make long migrations in order Most Marine mammals make long migrations in order to follow food species or to give birth in warmer to follow food species or to give birth in warmer waters of the tropics before going to feed in the cooler waters of the tropics before going to feed in the cooler waters of the poles.waters of the poles.

They are also viviparous and have relatively long They are also viviparous and have relatively long gestation periods, leading to low brood sizes of one or gestation periods, leading to low brood sizes of one or maybe two pups per female for pinnipeds and usually maybe two pups per female for pinnipeds and usually only one offspring is born per female in most whale only one offspring is born per female in most whale species (the cost of lactating and providing the food species (the cost of lactating and providing the food necessary for a young whale to put on enough blubber necessary for a young whale to put on enough blubber for arctic seas can be extraordinary.for arctic seas can be extraordinary.

Significance: Significance: Several marine mammals are endangered or threatened due Several marine mammals are endangered or threatened due

to over (and often illegal) hunting and accidents such as to over (and often illegal) hunting and accidents such as collisions with boats and entanglement in fishing nets. They collisions with boats and entanglement in fishing nets. They are an important part of the food chain with some acting as are an important part of the food chain with some acting as top level predators (such as top level predators (such as Orcinus orcaOrcinus orca: : Killer Whale)Killer Whale)

Below are some pictures of various marine mammals Below are some pictures of various marine mammals

 Pacific White-Sided Dolphins (Lagenorhynchus obliquidens). http://www.onr.navy.mil/focus/ocean/life/mammals7.htm

                                                                                   

A manatee cow and calf (courtesy of NOAA).http://www.onr.navy.mil/focus/ocean/life/mammals1.htm

                                   

               

A group of walrus sun themselves on a beach (courtesy of NOAA).

http://www.onr.navy.mil/focus/ocean/life/mammals1.htm

10 Caribbean Species of Marine Mammals, 10 Caribbean Species of Marine Mammals, no species found in Hope College no species found in Hope College Collection:Collection: Trichechus manatus manatusTrichechus manatus manatus: : West Indian West Indian

ManateeManatee Balaenoptera acutorostrataBalaenoptera acutorostrata: : Minke WhaleMinke Whale Kogia brevicepsKogia breviceps: : Pygmy Sperm WhalePygmy Sperm Whale Grampus griseusGrampus griseus: Risso's Dolphin: Risso's Dolphin Orcinus orcaOrcinus orca: : Killer WhaleKiller Whale Mesoplodon europaeusMesoplodon europaeus: Gervais' Beaked Whale: Gervais' Beaked Whale Delphinus delphisDelphinus delphis: : Atlantic Dolphin, Pacific Atlantic Dolphin, Pacific

Dolphin, etc.Dolphin, etc. Peponocephala electraPeponocephala electra: : Melon-headed WhaleMelon-headed Whale Stenella attenuataStenella attenuata: : Pantropical Spotted Pantropical Spotted

DolphinDolphin Tursiops truncatusTursiops truncatus: Bottle-nosed Dolphin : Bottle-nosed Dolphin