Marine Biophysics: Taxa Project

1. Marine Biophysics: Taxa Project By Nicholas Marra

2. 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.

3. 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

4. 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. • Significance: They are primary producers and the group is paraphyletic and excludes Plantae even though many of their characteristics are shared. http://www.ucmp.berkeley.edu/greenalgae/greenalgae.html http://www.botany.hawaii.edu/BOT201/Algae/Bot%20201%20Chlorophytes%20page.gif

5. 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

6. 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

7. 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.

8. 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: Yellow-Green Sea Squirt found worldwide http://www.wetwebmedia.com/ascidians.htm Picture of a Salp http://www.wetwebmedia.com/ascidians.htm http://www.earthlife.net/inverts/larvacea.html

9. http://www.wetwebmedia.com/ascidpt2.html • 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 • Clavelina picta, the Painted Tunicate • Symplegma viride: Encrusting Social Tunicate • Eudistoma obscuratum: Black Condominium Tunicate • Botrylloides nigrum: Flat Tunicate http://www.wetwebmedia.com/ascidpt2.html • Species in the Hope College Collection: • Molgula sp.: Sea Grapes • Corella sp.: Glassy Tunicate • Amoransium Stellatum

10. 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.

11. 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.

12. 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://www.ucmp.berkeley.edu/taxa/inverts/mollusca/bivalvia.php http://animaldiversity.ummz.umich.edu/site/resources/biodidac/biva002b.gif/view.html

13. 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

14. 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).

15. 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)

16. 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. 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%2BFarm%26um%3D1%26hl%3Den http://alaskanabroad.typepad.com/an_alaskan_abroad/070429salmon%20cooked%201.jpg

17. 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) • Oncorhynchusnerka: 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

18. 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.

19. 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.

20. 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 group of walrus sun themselves on a beach (courtesy of NOAA). A manatee cow and calf (courtesy of NOAA).  Pacific White-Sided Dolphins (Lagenorhynchus obliquidens). http://www.onr.navy.mil/focus/ocean/life/mammals7.htm http://www.onr.navy.mil/focus/ocean/life/mammals1.htm http://www.onr.navy.mil/focus/ocean/life/mammals1.htm

21. 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