Trematodes Adult

Question 1

elongated, cylindrical in shape, measuring 12 - 20 mm by 0.5 - 0. 55 mm in greatest diameter
integument is nontuberculate;

gynecophoric canal is present oral and ventral suckers lie close together at the anterior end with the ventral sucker as a shallow cup suspended from a short base

Answer 1

S japonicum male

Question 2

alimentary system consists of the mouth surrounded by the oral sucker, the esophagus, then the intestine which bifurcates in front of the ventral sucker and joins again in the last fourth of the body

has 7 (6-8) medium, ovoid, slightly lobate testes in single column near the anterior end of the worm, each provided with a short vas deferens emerging into the seminal vesicle before opening into the exterior through the genital pore

Answer 2

S japonicum male

Question 3

elongate, cylindrical in shape measuring 6 - 14 mm by 1.1 mm

integument is grossly tuberculate

intestinal ceca unite early, in the anterior half of the body, united intestine is long

testes are small, 8 - 9 and are zigzag row.

Answer 3

S mansoni male

Question 4

measures 14 mm by 0.25 mm

ovary is located in the anterior half of the body

uterus is short with usually 1 - 3 eggs

Answer 4

S mansoni female

Question 5

elongate cylindrical in shape, measuring 19 - 15 mm by 0.8 - 1 mm

integument is covered with minute integumentary tuberculations (fine tuberculate)

intestinal ceca is long, reunite at the middle of the body

testes are in groups, 4-5 in number, found just behind the ventral sucker

Answer 5

S haematobium male

Question 6

long and slender, measures 20 mm by 0.25 mm

suckers are small, subequal and not conspicuously muscular

ovary is in the posterior half of the body

uterus has 20 - 30 eggs at a time
other structures are similar to S. japonicum

Answer 6

S haematobium female

Question 7

large, flat, brownish, leaf-shaped

Answer 7

Fasciola spp

Question 8

the anterior end has a conical projection called the cephalic cone, giving the worm a shouldered appearance (_______has a shorter cephalic cone)

integument is covered with scales, but posterior surface may be smooth

Answer 8

Fasciola spp

F. gigantica

Question 9

alimentary system has an inverted Y appearance, the branched intestinal ceca

bear a number of lateral compound branches

genital system is similar to the other trematodes

Answer 9

Fasciola spp

Question 10

narrow, oblong, flat, tapering anteriorly and rounded posteriorly

measures 10 - 25 mm by 2– 3 mm
oral sucker is larger than the ventral sucker

ventral sucker is situated at the junction of the anterior and middle third of the body

simple blind intestinal ceca and extend to the caudal region

large testes which are deeply lobed, and found in the posterior third of the body, one behind the other

Answer 10

Chlonorchis sinensis

Question 11

flat, elongated, aspinous, tapering anteriorly and rounded posteriorly

measures 5 - 10 by 1 - mm

oral and ventral suckers are about the same size

testes are lobate situated in the posterior fourth of the body

Answer 11

Opisthorchis viverrini

Question 12

large, broadly ovate or oval, anterior end is narrower than the posterior end

measures 2 - 7.5 cm by 0.8 - 2 cm

ventral sucker is larger than oral sucker

resembles F. hepatica but does not possess any cephalic cone

alimentary tract is simple, but ceca do not bear any lateral branches

Answer 12

Fasciolopsis buski

Question 13

small, elongate, oval, reddish gray fluke
measures 0.25 - 0.65 cm in length by 0.1 - 0.13 cm in width

anterior end has a circumoral disc surrounded with a crown of 49-51 spines, attenuated posteriorly

integument is covered with plaque-like scales

oral sucker is smaller than the ventral sucker

simple intestine of unequal length which extend to the subcaudal region

2 deeply lobed testes which lie one behind the other in the middle of the posterior body behind the globular ovary

vitellaria are medium-sized follicles in the lateral fields through the posterior ¾ of the body

Answer 13

Echinostoma ilocanum

Question 14

elongate, pyriform, grayish fluke*

small size, measures 1 - 1.7 by 0.3 - 0.4 mm

cuticle is covered with fine scale-like spines

oral sucker is minute, ventral sucker is thick-walled, muscular and lies in the anterior part of the middle third of the body

the genital sucker is situated on the left posterior border of the ventral sucker

two ovoid testes side by side in the posterior fifth of the body

**subglubose ovary¥¥ anterior to the testes

vitellaria with large polygonal follicles in the lateral posterior third of the body

Answer 14

Heterophyes heterophyes

Question 15

small, pyriform in shape with rounded posterior and tapering anterior end

measures 1 - 2.5 by 0.4 - 0.75 mm

the ventral sucker is deflected to the right of the midline

the 2 oval testes are located at the posterior third of the body

globose ovary is found at the junction of the middle and lower third of the body

coarse vitellaria in a fan-shaped distribution in the posterior lateral fields

Answer 15

Metagonimus yokogawai

Question 16

thick, fleshy, egg-shaped

measures 01.8 - 1.2 cm by 0.4 - 6 cm
oral and ventral suckers are of the same size, the ventral sucker is situated near the middle of the body

integument has minute spines

testes are irregularly lobed, placed oblique to each other in the posterior third of the body

ovary is lobed located anterior to the testes

vitellaria in the extreme lateral fields along the entire length of the body

blind intestinal ceca have no lateral branches and extend to the caudal region

excretory vesicle is large ard extends from the posterior extremity to the anterior region dividing of the body into two equal parts

Answer 16

Paragonimus westermani