Basics - Lexicon / Physiology Flashcards
Getting a firm grasp of the structures and vocabulary used in freshwater mussel Identification.
What structures are identified in the picture?
Umbo(s) or beak structures
Does a mussel have a left and right side?
Sure does
Does a mussel have a front (anterior) and back (posterior) part?
Sure does
How to identify the anterior part of a mussel?
Identify dorsal side (where the two halves attach)
-locate the umbos
The umbos are on the anterior part of the midline
So the part with the umbos is the anterior part.
How to Identify the left half of the mussel?
1-Locate the _____ side, where the two halves attach.
put this side UP
2-Locate the _____ . They are on the anterior part of the dorsal side
3-Put the _______ side containing the umbos forward.
4-The left side will be on the _______
1-Locate the “DORSAL” side, where the two halves attach.
put this side UP
2-Locate the “UMBOS”. They are on the anterior part of the dorsal side
3-Put the “ANTERIOR” side containing the umbos forward.
4-The left side will be on the “LEFT”
How is the larval stage of mussels called?
One _____
A bunch of _____
One glochidium
A bunch of glochidia
Do mussels have teeth?
If yes, where?
if not, why?
trick question!
They do have teeth, but only visible on dead specimen because they are on the inside of the shell’s halves (and they are not used to bite things, but to help close tightly)
name the two types of teeth we can possibly encounter on a mussel (knowing that not every mussel have the two kind of teeth)
1-pseudocardinal teeth
2-hinge teeth (also called lateral teeth)
What is the nacre
iridescent inside of the shell. Often white, sometime from pink to purple.
The Nacre from Quebec’s and Ontario’s mussel were used in button making until the 1940s where the use of plastic became more popular.
Which end is the posterior and which is the anterior?
A: 1=anterior, 2=posterior
B: 1=posterior, 2=Anterior
B
Why? because the beak structure is at the bottom in that photo, so the mussel is “upside down”
Identify the pseudocardinal and the lateral teeth
What is the most common Mussel species around Kitigan Zibi?
Elliptio complanata (Eastern Elliptio)
It can have varied body shape, size and color but always have a diagonal ridge and a trapezoidal(ish) body.
What tooth is the arrow pointing at?
A-Pseudocardinal tooth
B-Hinge tooth
A- Pseudo cardinal tooth.
(Not always easy to spot, sometime big, small or absent. The shape is widely varied so the tell-tell is the position, right under the beak)
What tooth is the arrow pointing at?
A-Pseudocardinal tooth
B-Hinge tooth
B- Hinge tooth or lateral tooth
can be on either side of the pseudocardinal teeth
Is there a difference between the hinge and the hinge teeth?
If so, what is it?
Yes,
the hinge is on the outside of the shell. It is the area where the two half of the shells are linked by an elastic ligament
The hinge teeth are a tooth like structure along the dorsal margin INSIDE the shell
what are “rays’’ on the shell?
Colored lines, usually green that radiate from or near the beak towards the ventral margin of the shell. here is a very distinct example:
What tooth is the arrow pointing at?
A-Pseudocardinal teeth
B-Hinge teeth
A - Pseudocardinal teeth
Are “rays” parallel or perpendicular to growth rings?
“Rays” lines, usually green going from the beaks to the outside, perpendicular to the growth rings.
where are “Ridges” situated?
A- Inside the shell, usually underneath the hinge teeth
B- between the umbos
C- on the outside surface of the shell
C - The ridges are big grooves on the outside of the shell.
They can be faint like on Eastern Elliptio, or very pronounced like the Washboard mussel, which we wont encounter but has very obvious ridges
What structure is identified in the picture
Hinge teeth
What structure is identified in the picture
Beak or umbo
What structure is identified in the picture
Ridge
What structure is identified in this picture
Pseudocardinal teeth (in this case, has a rough surface)
Which is the anterior section (front) of the mussel? A or B
B - Anterior part of the shell is the one with the beak or Umbo
Visually Identify those 4 structures on this half shell
-pseudocardinal teeth
-hinge teeth
-umbo
-posterior end
This half shell is the left half or right half?
Left
Find which part of the shell has the beak (anterior)
place the anterior part looking forward, the left half will be on the left, the right half will be on the right
What is the general shape of this Mussel?
A-Trapezoidal
B-Elliptical
C-Elongate
D-Quadrate
E-Circular
F-Oval
G-Triangular
A - Trapezoidal
What is the general shape of this Mussel?
A-Trapezoidal
B-Elliptical
C-Elongate
D-Quadrate
E-Circular
F-Oval
G-Triangular
B - Elliptical (about twice as long as it is large)
(Tip: ellipse or oval?
Ellipse: both ends more or less same size, like a watermelon or a football (American)
Oval: one end distinctly smaller than the other, like an egg or an avocado)
What is the general shape of this Mussel?
A-Trapezoidal
B-Elliptical
C-Elongate
D-Quadrate
E-Circular
F-Oval
G-Triangular
C - Elongate (kind of stretched)
What is the general shape of this Mussel?
A-Trapezoidal
B-Elliptical
C-Elongate
D-Quadrate
E-Circular
F-Oval
G-Triangular
G - triangular
What is the general shape of this Mussel?
A-Trapezoidal
B-Elliptical
C-Elongate
D-Quadrate
E-Circular
F-Oval
G-Triangular
F - Oval
Tip: ellipse or oval?
Ellipse, both ends more or less same size, like a watermelon or a football (American)
Oval, one end distinctly smaller than the other, like an egg or an avocado
What is the general shape of this Mussel?
A-Trapezoidal
B-Elliptical
C-Elongate
D-Quadrate
E-Circular
F-Oval
G-Triangular
D - Quadrate
What is the general shape of this Mussel?
A-Trapezoidal
B-Elliptical
C-Elongate
D-Quadrate
E-Circular
F-Oval
G-Triangular
E - Circular
