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REMAINING (number with state)
A. nasatum vs. A. vulgare - A comparison of distinctive head shapes
A. nasatum - See the picture of the head below (1)
A. vulgare - See the picture below (1)
Ability to roll into a ball
Unable to roll up - all specimens included here, in case rolling up has not been observed (14)
Able to roll up (3)
Head, antennae, number of flagella
Two (7)
Three (5)
One, may appear to be more under high magnification (3)
Head, eyes, number of ocelli per side of the head
Numerous (12)
One (2)
Three (1)
Head, forehead, scutellum, shape
Distinct snout-like projection between the antennae, extends well above the head (1)
Small, shallow bump which does not rise above the top of the head (1)
Head, lateral lobes, shape
The central lobe about the same length and shape as those of the sides (5)
Center lobe clearly shorter than those on the sides (3)
Center lobe similiar length to those on the side, but pointed (1)
Live bugs, rolling up, placement of antennae
Unknown - not observed live (14)
Antennae left outside of the dorsal surface while rolled up (1)
Antennae pulled inside ball when rolled up (1)
Pereon - pleon junction
Smooth, continuous line (9)
A step between them, not aligned (6)
Pereon and pleon, color
Unknown - faded (13)
Obvious dark central stripe (4)
Mostly uniformly colored (3)
Pereon, texture of dorsal surface
Smooth (12)
Rows of small bumps or spines, transverse or latitudinal across pereonites (4)
Longitudinal ridges on pereonites (2)
Pleon, outer pair of uropods, shape
Long, tapering to a point (12)
Flat, similar length and width (2)
Pleon, telson, shape
Triangle, narrowly concave sides (5)
With broadly concave sides, the tip narrowing to a long penninsula similar in shape to the outer uropod, the end of which is narrowly rounded over (4)
Flat on left and right narrowing to a very broad, slightly convex tip (3)
Pleon, ventral view, number of lungs
Zero - or unknown due to their loss when in alcohol - note that sometimes it is still possible to detect the lungs in alcohol specimens (14)
Two pairs (5)
Five pairs (2)
T. rathkii vs P. laevis and P. scaber
P. laevis and P. scaber - In fresh specimens has 2 pairs of lungs present - Male leg character not as above (2)
T. rathkii - In fresh specimens 5 pairs of lungs present - Seventh leg of the male has a prominent keel-like expansion on the dorsal border of the third segment from the distal end (1)