Echinococcus granulosus (Continued)
OVA
SIZE: 30 to 40 mcm.
SHAPE: Ovoid to round.
COLOR: Brown.
OPERCULUM: Absent.
CONTENTS: Hexacanth oncosphere.
MISCELLANEOUS: Embryophore with double layer and a striated outer layer;
indistinguishable from taenioid ova.
ADULT
SIZE: 3 to 6 mm.
COLOR: Grayish white.
SCOLEX
SIZE: 0.3 mm.
SHAPE: Pyriform.
ROSTELLUM: Armed with 28 to 50 hooklets.
PROGLOTTID
USUALLY THREE: Immature, mature, and gravid.
SIZE: 1.3 to 2.5 mm by 0.5 mm.
SHAPE: Longer than broad.
GENITAL PORE: Lateral, single, equatorial.
UTERUS: Irregular longitudinal sac.
OVARIES: Two, oval.
TESTES: Minute, spherical (45 to 60).
Figure 3-53. Stages of Echinococcus granulosus. (continued)
MD0842
3-61