mussel collection & dissection
TRANSCRIPT
Mussel Collection & Mussel Collection & DissectionDissection
http://hmsc.oregonstate.edu/projects/rocky/blue_mussels.jpg
MytilusMytilus ecology ecology
M. trossulus
Native to the North Pacific (originally)
Considered tolerant of: Lower salinity Large tidal fluctuation Colder waters
M. galloprovinicialis
Native to the Mediterranean Sea
Considered tolerant of: Higher salinity Small tidal fluctuation Warmer waters
Reference: Braby & Somero, 2005, Marine BiologyReference: Braby & Somero, 2005, Marine Biology
External morphological External morphological differencesdifferences
Photo from McDaniel UniversityPhoto from McDaniel UniversityPhoto by Dr. YM YakovlevPhoto by Dr. YM Yakovlev
M. californianusM. californianusM. trossulusM. trossulus
Photo from Ulster Museum
M. galloprovincialis
Bay mussel Hatchet shape Smooth texture Periostracum* intact
*Thin chitinous covering that protects the shell
California mussel Elongate shape Ribbed texture Periostracum eroded
Random samplingRandom sampling
Mussels are collected at intervals along a transect line
The intervals are drawn from a list of random numbers
0 cm 500 cm
100 cm 170 cm 380 cm
Mussel collectionMussel collection
500 cm
0 cm
Quick QuizQuick Quiz
Why do we use random sampling?
a. So our data will accurately represent the actual populationb. Because it’s a convenient way to collect specimensc. So we can be consistent with previous researchersd. All of the above
Quick QuizQuick Quiz
Why do we use random sampling?
a. So our data will accurately represent the actual populationb. Because it’s a convenient way to collect specimensc. So we can be consistent with previous researchersd. All of the above
Quick QuizQuick Quiz
What is the proper way to transport marine mussels?
a. In ethanol so they will be preserved quickly
b. In freshwater to facilitate cleaning
c. In seawater so they will stay alive
d. In a plastic bag on ice
Quick QuizQuick Quiz
What is the proper way to transport marine mussels?
a. In ethanol so they will be preserved quickly
b. In freshwater to facilitate cleaning
c. In seawater so they will stay alive
d. In a plastic bag on ice
Quick QuizQuick Quiz
If the mussels will be sacrificed, why must they be kept alive after collection?
a. It is the humane thing to do
b. To keep DNA intact
c. To allow cells to finish dividing
d. To make dissection easier
Quick QuizQuick Quiz
If the mussels will be sacrificed, why must they be kept alive after collection?
a. It is the humane thing to do
b. To keep DNA intact
c. To allow cells to finish dividing
d. To make dissection easier
Mussel Dissection
HingeHinge
AnteriorAnteriorPosteriorPosterior
DorsalDorsal
VentralVentral
ByssusByssus
ExcurrentExcurrentSiphonSiphon
IncurrentIncurrentSiphonSiphon
Posterior adductor muscle (shell closers)Posterior adductor muscle (shell closers)
Mussel DissectionMussel Dissection
HingeHinge
Mantle edge (secretes shell Mantle edge (secretes shell and is sensory)and is sensory)
Mantle surface (containing Mantle surface (containing outgrowth of gonad)outgrowth of gonad)
Incurrent Incurrent and and excurrent excurrent siphonssiphons
Mussel DissectionMussel Dissection
Mantle has now been lifted, but nothing is cut awayMantle has now been lifted, but nothing is cut away
Mantle edgeMantle edge
Gill surfaceGill surface
Gonad (proliferates Gonad (proliferates into mantle which into mantle which is otherwise thin is otherwise thin and translucent)and translucent)
Cut adductor muscleCut adductor muscle
Oral palp Oral palp (one of two pairs)(one of two pairs)
Mussel DissectionMussel Dissection
ByssusByssus FootFoot PalpPalp
Visceral Visceral massmass
Right gill (filaments separated)Right gill (filaments separated)
Left Left
gillgill
Mussel DissectionMussel Dissection
HingeHinge
Posterior adductor Posterior adductor muscle (shell closer)muscle (shell closer)
Foot retractorsFoot retractors
Mantle attachment scarMantle attachment scarTiny anterior adductor Tiny anterior adductor muscle (shell closer)muscle (shell closer)
Mussel DissectionMussel Dissection
Posterior adductor & retractor Posterior adductor & retractor muscles elongate, thin (California)muscles elongate, thin (California)
Anterior adductor Anterior adductor muscle on ventral muscle on ventral edgeedge (Bay)(Bay)
Mussel DissectionMussel Dissection
Anterior adductor Anterior adductor muscle centered muscle centered (California)(California)
Posterior adductor & retractor muscles Posterior adductor & retractor muscles shortened, wideshortened, wide (Bay)(Bay)
Muscle scars on shell distinguish Bay from Muscle scars on shell distinguish Bay from California musselsCalifornia mussels
Tissue for extractionTissue for extraction
Cell density is highCell density is highConnective tissue Connective tissue
content is lowcontent is lowMucus content is lowMucus content is low
Therefore tissue Therefore tissue breaks down easily breaks down easily and contains lots of and contains lots of DNADNA
We use gill tissue for DNA extractions because…We use gill tissue for DNA extractions because…
Gills are used for respiration and sieving of food particles (e.g. phytoplankton)
Gill PhysiologyGill Physiology
Siphons move water in and out
Small particles are passed by the gills to the mouth region
Palps transfer food from gill into the mouth
Food
H2O In
H2O Out
Quick QuizQuick Quiz
Mussel gill tissue is optimal for DNA extraction for all of the following reasons EXCEPT:
a. low mucus contentb. high cell densityc. proximity to digestive tissued. low connective tissue content
Quick QuizQuick Quiz
Mussel gill tissue is optimal for DNA extraction for all of the following reasons EXCEPT:
a. low mucus contentb. high cell densityc. proximity to digestive tissued. low connective tissue content
Quick QuizQuick Quiz
Why do we measure the size of the mussels?
a. It’s a good thing to do
b. To see if different sexes are different sizes
c. To see if animals on docks are bigger
d. To see if there are correlations with species
Quick QuizQuick Quiz
Why do we measure the size of the mussels?
a. It’s a good thing to do
b. To see if different sexes are different sizes
c. To see if animals on docks are bigger
d. To see if there are correlations with species
Continue dissection and identification of internal body parts
Mussel dissectionMussel dissection
Identify gender of mussel
Place gill tissue in tube and begin DNA extraction
Locate gill and cut off one rice grain worth of tissue
Cut posterior adductor muscle and open valves of mussel
Use muscle scar to confirm not M. californianus
END
ResourcesResources Mussel Collection Handout
Mussel Dissection Handout
Ecological gradients and mussels paper
Diversity of The Invertebrates: A Laboratory Manual Pacific Coast Version. by James W. Nybakken. William C. Brown Publications. 1995.
Light’s Manual: Intertidal Invertebrates of the Central California Coast. Smith & Carlton, eds. University of California Press. 1975.
Living Invertebrates. by Pearse, Pearse, Buchsbaum, & Buchsbaum. Boxwood Press. 1987.
California State Chemistry StandardsCalifornia State Chemistry Standards
Grade 8
6c. Living organisms have many different kinds of molecules
California State Biology StandardsCalifornia State Biology Standards
Grade 7
5a. Plants and animals have levels of organization for structure and function5b. Organ systems function because of the contribution of individual organs, tissues, and cells
Grades 9-12
9. As a result of the coordinated structures and functions of organ systems, the internal environment of the [human] body remains relatively stable (homeostatic) despite changes in the outside environment
California State California State Investigation and ExperimentationInvestigation and Experimentation
StandardsStandards
Grades 7, 9-12
a/b. Select and use appropriate tools and technology to perform tests, collect data, analyze relationships, and display data
Grade 8
a. Plan and conduct a scientific investigation to test a hypothesis
National Standards National Standards
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Content Standard A: Science as Inquiry
Content Standard C: Life Science
Content Standard E: Science and Technology