Study Guide for Test 2 - Marine Biology | BIOL 477, Study notes of Marine Science and Biology

Download Study Guide for Test 2 - Marine Biology | BIOL 477 and more Study notes Marine Science and Biology in PDF only on Docsity! Study Guide for Test 2, Marine Biology, Dr. Meier, Spring 2005 Highlights from lectures and accompanying assigned readings Note: this is an outline, not an exhaustive list of facts to know for the test. Most of this information is already included in the powerpoint slides. Guest Lecture, Dr. Huskey: Vertebrate Functional Morphology Defined as any design characteristic that performs a specific utility; one must also consider the physiology that drives the action and the behaviors that shape it. To quantify functionality, a morphological feature (from cells to systems) that performs a dynamic event must be used as a model. Form and Function: • The basis for functional anatomy • Pits the design of a system, or multiple systems that have been integrated, against the utility of that system(s) • Finding the link between form and function helps clarify the selective pressures that have shaped organisms • Spawns the ‘chicken before the egg’ or ‘the egg before the chicken’ debate Morphology: Gross Anatomy – Useful to describe anatomical features of an animal. Comparative Anatomy – Useful to establish relationships between animals. Functional Anatomy – Useful to establish the link between design and function relative to the evolutionary pressures that have shaped it. Approaches: Regional Approach: Compare body parts Taxonomic Approach: Compare groups Systems Approach: Structure/function link Evolution: Has neither direction nor purpose – organisms are not designed in advance; It is entirely contingent; It is continuous and continuing – all biologists are studying moving targets changing with time; Extant organisms are evolutionary experiments with functional properties that have resulted from past conditions. Ecomorphology: A specific case of functional morphology where the design of the animal is linked to ecological characters that either shaped the morphology OR the morphology can be used to make predictions about the niche an animal fills. Again, some dynamic function must be performed in order to quantify the link between ecology and morphology. Fish Ecomorphology: Fishes present the best examples. Why? • >27,000 species – more than all other vertebrate classes combined • Inhabit every aquatic environment • Fill every ecological niche in the aquatic environment • Richest phylogenetic history • Used in feeding and locomotion comparisons Feeding Styles: • 27,000 species of fish and each uses only one of three feeding modes (or a combination thereof). • Ram-feeders over take their prey with tremendous forward velocity and large mouths • Suction-feeders create negative pressure in their mouths to draw in a volume of water and the prey housed within it. • Biters use strong jaws and teeth to scour surfaces with attached prey items. Examples: Ram feeders – barracuda, whale shark, gar, moray eel, lizard fish, bass, scorpion fish Suction feeders – butterfly fish, pipefish, seahorse; tend to get eaten by ram feeders but have very maneuverable bodies Biters – porcupine fish, parrotfish, triggerfish, black drum, sheepshead, redear sunfish; use strong jaws to scour: oral jaws (triggerfish, sheepshead) or pharyngeal jaws (black drum) Force Generating Capability = 2 [(V/w)σ sin 2α] [closing lever ratio]] [closing lever ratio] Where:V = muscle volume w = mean muscle width σ = force production per unit cross sectional area α] [closing lever ratio] = muscle angle of pinnation CLR = CIL/Outlever Lecture 4: Representative Marine Invertebrates Be able to recognize and describe or assign organisms to these major marine invertebrate groups, and know some basics about their defining characteristics, their functional role in ecosystems, and their trophic level(s). Phylum Porifera – sponges. Distinguished by characteristic spicules. Class Demospongiae (marine sponges) Phylum Cnidaria – distinguished Class Hydrozoa- hydroids, fire corals, jellyfish-like siphonophores Class Scyphozoa – true jellyfish Class Anthozoa – anemones, corals, gorgonians (soft corals) Phylum Bryozoa – a lophophorate group; encrusting, erect, or gelatinous forms. Phylum Mollusca Class Amphineura – chitons Class Gastropoda – snails, whelks, limpets, sea hares, nudibranchs Class Bivalvia – clams, mussels, oysters Class Cephalopoda – squid, octopi Characteristics of mammals: • Viviparous • Body hair • Milk-secreting mammary glands • Specialized teeth • Separate reproductive / digestive tract openings [other vertebrate groups oviparous or ovoviparous, and have a cloaca] Featured links: • Basic background on marine mammals • Pinniped photo gallery • Cetacean photo gallery • National Marine Mammal Lab, Cetacean Assessment Program • Sea Otter Evolution and Adaptations Lecture 6: Rocky Intertidal Ecosystems Physical parameters confer the first layer of ordering on ecosystems (handout); physiological tolerances determine which organisms can survive under a given set of physical conditions; biotic events and interactions are the next layer determining community structure; and finally, the organisms present in a community modify their environment. Physical Structuring: • Tides – Highs and lows, periodicity – Spring and neap tides • Wave Action – Force – Submergence • Substrate – Stability – Slope • Temperature - fluctuation • Desiccation Biological Structuring: Physiology (interaction with physical environment) • Resistance to desiccation • Ability to tolerate forces • Ability to tolerate fluctuations • Ability to maintain position Biotic Interactions (interactions with other organisms) • Settlement • Competition • Predation Keystone Predators (Robert Paine) - read the details of this study in the reading assignment. Lecture 7: Coastal Ecosystems: Salt Marshes and Mangroves Factors Driving Coastal Ecosystems: Latitude – temperature – light, seasonality Tidal cycles – amplitude – frequency Wave energy Degree of riverine input – freshwater input – alluvial sediments and deposition – turbidity Geological characteristics – rock – sand – sediment Hydrological characteristics – nearshore currents – transport Continental proximity – nutrient input – anthropogenic impacts Recap: Rocky Intertidal  Our example (Pacific Northwest): high latitude, so  Cold Pacific waters, strong seasonality  Tidal cycle: high amplitude, semi-diurnal  Wave energy high  Freshwater input – riverine characteristics modified by bay / estuary  Geology: rocky cliffs, interspersed w/sandy beach  Hydrology: strong nearshore currents & transport  Continental edge, input via interaction with terrestrial systems Salt Marsh Ecosystems  Our example (southeastern U.S.: Gulf and Atlantic coasts): moderate latitude, so  “Warm” Atlantic and warmer Gulf and Gulf stream waters, moderated seasonality  Tidal cycle: low amplitude  Wave energy low  Freshwater input often critical – deltaic riverine input can result in extensive marsh systems, abundant alluvial sediment input. Salt accumulation a challenge.  Geology: long-term alluvial sediment accumulation  Hydrology: nearshore currents & transport important  Continental edge, nutrient input via runoff, rivers Plants of the Salt Marsh Community:  Spartina alterniflora – marsh cordgrass o height depends on riverine or tidal flushing o export of dried mats during winter storms o exclude salt from roots  Salicornia – a succulent o Salt pans  Fresher water and soils / higher ground: other grasses (Spartina patens), rushes (Juncus romerianus), sedges  Zonation based on topography, inundation of freshwater, fresh/salt fluctuation, tidal flushing, relative stresses, anoxia of soils, latitudinal gradient (e.g., east coast U.S.). Animals of the Salt Marsh Community:  Geukensia demissa – dominant mussel o lives in sediment o physiological variation with tidal cycles  Crassostrea virginica – oyster o dense beds in well-flushed tidal channels  Littorina irrorata – salt marsh snails; pulmonates  Thais haemostoma – oyster drill  Uca pugnax, other Uca spp. – fiddler crabs  Sesarma cinereum - marsh crabs  (These examples are particularly for south Louisiana and coastal Georgia; other species will occur elsewhere, filling slightly modified niches depending upon range, region, and local conditions.) Summary of salt marsh community characteristics:  Highly productive  Very stressful  Trap sediment  Stabilize and extend coastlines, especially those with fluvial input  Food webs detritus-based; herbivory may be more important than previously thought; “trophic relays” convey biomass to adjacent ecosystems  Low diversity, high productivity Wetlands Loss: Salt Marshes  Coastal erosion and wetland loss due to channelization and levees along the Mississippi, dams on its tributaries, land settling from groundwater pumping and use, and channels cut through the marsh for offshore drilling platforms.  Estimates of Louisiana coastal wetland loss for 1978-90 indicate a loss of about 35 square miles a year of freshwater and non-freshwater marshes and forested and scrub-shrub wetlands. From 1978-90, that equalled a 12-year loss of about 420 square miles, an area twice the size of the populated greater New Orleans area.