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101 Cards in this Set
- Front
- Back
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What does the consistency of the fish capture suggest? |
Declining fish populations with an increasing demand. Supplies are working harder to maintain the same capture. |
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Which economic status consumes the most fish? The least? |
Most=Industrialized Least=Low income, food deficient countries |
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What factors are leading to an increase in seafood consumption? |
increasing population, economic development, urbanization, health concerns. |
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What does "farming" in the definition of aquaculture refer to? |
intervention in the rearing process to enhance production |
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Aquaculture is ___% inland and ___% mariculture. |
Aquaculture is 63.8% inland and 36% mariculture
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Why does the U.S. have such a large seafood trade deficit? |
-Policy against aquaculture in many areas -lack of manual labor force -funding -bias against aquaculture. |
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As reliance increases, environmental control _____ and stocking density _____. |
As reliance increases, environmental control decreases and stocking density decreases. |
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Annual production ______ with intensity |
Annual production increases with intensity |
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What 4 aspects must aquaculture provide? |
1. Maintain environmental parameters. 2. Provide or augment food. 3. Oxygen. 4. Waste Removal. |
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What does a closed production system involve? |
Little to no contact with the ambient environment. Isolated. |
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What are the pros and cons of a closed production system? |
Pros: May be more environmentally sound. More control. More production. Cons: Higher investment. More risk. More labor. |
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What does a semi-closed production system involve? |
The aquaculture is removed but not isolated from the natural environment. Water moves between both. |
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What are the pros and cons of a semi-closed production system? |
Pros: Lower cost. Less labor. Cons: Little improvement in control. |
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What does an open production system involve? |
A culture taking place in the natural environment. |
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What are the pros and cons of an open production system? |
Pros: Very low cost. Minimal maintenance. Cons: Little to no control. Exposure to predators, poachers, natural disasters, etc. |
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The phylum Mollusca is the ___ most diverse |
The phylum Mollusca is the second most diverse |
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Bivalves are 85% ____ and 15% ____ |
Bivalves are 85% marine and 15% freshwater |
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Bivalve ancestors are adapted for ___ |
Bivalve ancestors are adapted for infaunal lifestyles |
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What defines the Bivalvia subclass, Heterodonta? (3 things) |
1. Infaunal 2. Wedge-shaped foot 3. Ventrally fused mantle w/posterior siphon. |
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Where do most Pteriomorpha live? |
Most epibenthic and attached, some are motile |
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What is the foot in Pteriomorpha like? |
Reduced or absent. |
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What is the mantle margin in Pteriomorpha like? |
Not fused and lacks siphon. |
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How do Pteriomorphas attach to substrates? |
Cement or byssal threads. |
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What do teeth do for a bivalves shell? |
Prevent slippage. |
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Teeth are more present in _____ bivalves than _____ bivalves. |
Teeth are more present in infaunal bivalves than benthic bivalves.
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What is the pallial line? |
It marks where the mantle muscles were attached. |
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How is the height of a bivalve measured? |
Hinge to ventral margin. |
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How is the length of a bivalve measured? |
Anterior to posterior side. |
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How is the width of a bivalve measured? |
From anterior to posterior valve. |
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Why are the scallops in Massachusetts flatter and more colorful? |
The water is murkier, so a brighter shell isn't detrimental. Their main predator is the sea star, so the scallop swims away in defense. Having a flatter shell allows it to swim away faster. |
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Why are the scallops in North Carolina wider with deep ridges on their shells and grey in color? |
Clearer waters with grey sandy bottoms means that grey coloration acts as camouflage. The main predator of scallops in north Carolina is crabs. The deeper ridges helps prevent being crushed by their claws. |
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What is the outermost layer of the shell? |
Periostracum |
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What is the middle layer of the shell? |
Prismatic layer |
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What is the innermost layer of the shell? |
Nacreous layer |
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What is periostracum made of? |
Mainly protein. |
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What is the prismatic and nacreous layers made of? |
calcium carbonate crystals in an organic layer. |
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What is the organic layer in the middle and inner layer of shell made of? |
calcite or aragonite. |
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What is the tradeoff of using aragonite over calcite? |
Aragonite is harder, stronger, less resistant to dissolution, but more costly to deposit. |
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How is shell formed? |
The outer fold of mantle. -Inner surface of the tissue secretes proteins that harden into the periostracum -The outer surface secretes prismatic layer and nacreous layer |
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What two muscle types exist within a bivalve? |
Slow twitch (white) and fast twitch (translucent) |
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What is the most common gill type? |
Lamellibranch |
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Describe lamellibranch gill structure |
Elongated, v-shaped filament |
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What is the difference between filibranch and eulamellibranch? |
Filibranch gills have no tissue connections between filaments Eulamellibranch gills have tissue connections between gills. |
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What fluid is circulated throughout the circulatory system? |
Hemolymph. |
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What kind of circulatory system do bivalves have? |
Open circulatory system of sinuses |
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How does suspension feeding work in bivalves? |
1. Gills used to capture particles 2. Cilia flick particles into mucus, which moves through dorsal groove and is digested. 3. Unwanted particles moved to ventral groove and excreted. |
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What are pseudo-feces? |
Unwanted food particles that are sorted out and never digested. |
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What does the pericardial sac usually contain? |
The heart and the kidneys.
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Bivalves are mostly ____ spawners, but sometimes employ ____ spawning |
Bivalves are mostly broadcast spawners, but sometimes employ brood spawning |
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Veliger life stage is ______ phototactic while pediveliger is ______ phototactic |
Veliger life stage is positively phototactic while pediveliger is negatively phototactic |
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Why are pediveligers positively geotactic? |
To search for a suitable substrate |
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48 hours after settling, an oyster loses its _____, _____, and _____ |
48 hours after settling, a pediveliger loses its eyespot, foot, and velum. |
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What are the three phases of shellfish aquaculture? |
1. Stock acquisition 2. Nursery culture 3. Grow out. |
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What are the up and downsides of sourcing well water? |
Positive: More constant temperature and salinity, organisms naturally filtered out. Negative: Expensive to access and exploit, difficult to truly know best spot without test drills. |
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What is the downside of nearshore sourced water? |
Highly variable temperature and salinity, sediments, and fouling organisms. |
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Three sources of freshwater are _____, _____, and _____. |
Three sources of freshwater are ground, surface, and municipal. |
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Temperature directly influences _____, _____, _____, and _____. |
Temperature directly influences growth, reproduction, development, and survival. |
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The salinity in open ocean is _____ ppt. |
The salinity in open ocean is 35 ppt. |
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How do gravitational filters work? |
They rely on sedimentation in low or no flow bodies of water. |
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How do particle filters work? |
Water is run through a bed of unconsolidated sand and or gravel and particles are retained in the pore space between the grains. This can be done by gravity or force fed. |
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What are four types of splash aerators? |
splashboards, nozzles, spray aerators, and floating paddle wheels. |
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How does a Venturi aerator work? |
Water flows through a constricted pipe with a small opening. The resulting pressure vacuum pulls air in through the opening. |
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What is a positive and a negative aspect of a Venturi aerator? |
Positive: doesn't require compressed air or O2. Negative: can cause nitrogen over saturation. |
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How is water hardness measured? |
Cation content (Mg, Ca, etc.) |
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What is alkalinity? |
Water's ability to neutralize acids. |
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What effect can "soft water" have on bivalves? |
Restricts calcification, fertilization, and osmoregulation. |
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What does disinfection do? |
Reduce, not remove, microscopic organisms to prevent diseases, predators, and competition. |
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How does UV light disinfect? |
It disrupts genetic material. |
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What three ways do modern systems utilize UV light to disinfect water? |
1. A thin layer of water is circulated around a bulb protected by a quartz sleeve. 2. Water is circulated through a quartz sleeve surrounded by bulbs. 3. A thin layer of water is circulated under an array of UV bulbs. |
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What kinds of bulbs produce UV light? |
Fluorescent and mercury. |
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The _____, _____ and _____ of the bulb, and _____ of the water impact the effectiveness of a UV filter. |
The flow rate, depth, and age of the bulb, and turbidity of the water impact the effectiveness of a UV filter |
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How does ozone disinfect water? |
Free radicals disrupt cell membrane and structural elements of organisms. |
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Ozone improves water quality by the _____ of fine particles and dissolved materials and the _____ of long-chain molecules and nitrates. |
Ozone improves water quality by the flocculation of fine particles and dissolved materials and the oxidation of long-chain molecules and nitrates. |
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Ozone can be produced on-site from _____ or _____ or produced with a generator by _____ or _____. |
Ozone can be produced on site from dry air or pure O2, or produced with a generator by UV irradiation or corona discharge. |
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What four methods can be used to deal with residual ozone? |
1. degassing 2. activated carbon filters. 3. chemicals (sodium thiophosphate) 4. UV |
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Which cleaning system is used for facility/equipment clean up and exotics quarantining? |
Chlorination |
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How does chlorination work as a disinfectant? |
It is a strong oxidizer that disrupts enzyme systems. |
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What three factors influence choice in microalgal food species? |
1. Size of micro algae in comparison to gill structure
2. nutritional value 3. ease of culture. |
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What four components do algae cultures need? |
1. "high quality" water 2. nutrients 3. light 4. aeration. |
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What macronutrients do algae cultures need? |
nitrate, phosphate. silicate for diatoms. |
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What trace metals do algae cultures need? |
Fe, Cu, Zn, Mg |
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What vitamins do algae cultures need? |
B, B12, Biotin |
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What 3 factors can artificial light be optimized for? |
1. Intensity 2. Wavelength 3. Photoperiod |
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What does axenic mean? |
Free of foreign organisms |
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In batch cultures, in what state is the stock culture maintained? |
Slow growing and axenic |
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What are the benefits to batch cultures? |
Each stock is kept for a shorter duration, so less possibility for error or infection. Flexibility within regimen. |
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What are the negative aspects of batch culture? |
Labor intensive, complicated schedule, replicates needed for insurance (space, time, money) |
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During what phase are algae inoculated in batch cultures? |
Exponential phase |
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What two strategies are used to regulate continuous cultures? |
1. Chemostats
2. Turbidostats |
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How do chemostats regulate continuous cultures? |
By prescribing addition of limiting nutrients on a fixed schedule. |
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How do turbidostats regulate continuous cultures? |
Via the addition of fresh media as needed to maintain a desired culture density. |
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What are some problems with continuous cultures? (5) |
1. Not all spp do well in continuous cultures. 2. Risk of invasive spp/competition 3. Photoinhibition due do algal buildup on glass with infrequent cleaning opportunities 4. More expensive 5. Advanced technology means expensive maintenance |
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What are the benefits of using semi-continuous algae cultures? |
1. More algae production than with batch 2. Lower risk of competition/predator/contaminant introduction. |
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What two methods are used to make algal paste? |
1. Centrifuge 2. Flocculation |
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How is an algal paste produced using flocculation? |
Chemicals like aluminum sulfate and ferric chloride are added, cells clump and sink, then media is siphoned off. |
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How is a hemocytometer used to quantify density? What are the pros/cons? |
Cell are hand counted on a microscopic grid then averaged. Reasonably accurate, but time consuming. |
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How is a fluorometer used to quantify density? What are the pros/cons? |
Measures light emission from algal chlorophyll. Much faster than a hemocytometer, but less accurate. |
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How is a coulter counter, or multi sizer, used to quantify density? What are the pros/cons? |
An electrode with an aperture between it relies on electron disruption from algal particles passing through aperture. -Can tell algal species proportions (which can tell researches what species their bivalves are eating when measured in outflow water.) |
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What type of setup does a photobioreceptor have? |
axenic cultures in closed tubes or plates with high SA:V. |
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What are the three benefits of using a photobioreceptor system? |
1. high production with low risk of contamination 2. Better parameter control (no water or co2 loss) 3. reduced light expense (can be directed more precisely |
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What are the four problems with using a photobioreceptor system? |
1. Excess O2 inhibition 2. Overheating 3. Turbulent flow that can damage fragile species 4. Cannot sanitize without taking down whole system. |
