Polyarthra vulgaris: the "Formenkreis" P. dolichoptera and P. vulgaris have a pair of ventral appendages which discriminate these two from the other Polyarthra-groups. P. vulgaris has broader fins than P. dolichoptera; the specimen here has stretched one pair of fins forwardly. Because of the anisotropy the muscles appear dark or whitish (see image below) depending on the orientation of the polarizers of the DIC. (1)
Polyarthra vulgaris; specimen with male eggs (males hatch out of these eggs only ) which are clearly smaller than the amictic female eggs. (1)
Polyarthra vulgaris: specimen with parthenogenetic diploid amictic egg. (1)
Polyarthra vulgaris: specimen from (2) covered with zooflagellates
Polyarthra vulgaris; zooflagellates, detailed view. The lateral antenna (LA) is visible together with the sensory cell (SZ) and the nerve fiber (triangles). Also recognizalble are the striated muscles which move the paddles. (2)
Polyarthra vulgaris; optical transect at the level of the insertion points of the 4x3 paddles. DLA: dorsal lateral appendages; VLA: ventral lateral appendages; VA ventral appendages (ventral finlets); DA: dorsal antenna. (5)
Polyarthra vulgaris; insertion points of some of the 4x3 paddles. Focus point on the some of the transversely striated muscles; left: muscles for the movenment of the paddles; center: mastax muscles.
Polyarthra vulgaris; specimen macerated with sodium dodecylsulfate (SDS). This image shows the dorsal (the inner two) and ventral (the outer two) joints of all 12 paddles.
Polyarthra vulgaris; covered with euglenid flagellates Colacium sp.
Polyarthra vulgaris; the male has no eyespot and is very small. The arrowheads point to some of the sperm cells. Pe: penis; Ft: foot the conspicuous orange spot is a lipid droplet (DIC). (3)
Polyarthra vulgaris; male (transmitted light) . The arrowheads point to some of the sperm cells. The triangles point to the rods, which are produced from atypical sperm cells. Ci: locomotive cilia; Pe: penis; PG: prostate glands; Li: lipid droplet. (3)
Polyarthra vulgaris; two images of a specimen hatching from an amictic egg. (6)