Phasmidea Flashcards
smallest nematodes measuring 2.2 x 0.04 mm
Strongyloides
colorless, semi-transparent, with a finely striated cuticle
Parasitic or Filariform Female
Strongyloides
• it has a slender tapering anterior end and a short conical pointed tail
“ the short buccal cavity has 4 indistinct lips
the long slender esophagus extends to the anterior fourth of the body, and the intestine is continuous to the subterminal anus
the vulva is located 1/3 the length of the body from the posterior end
• the uteri contain a single file of eicht to twelve thin-shelled, transparent, segmented ova
Strongyloides stercoralis (Threadworm)
Parasitic or Filariform Female
measures 1 mm by 0.06 mm and is smaller than the parasitic fernale
” it has a muscular double-bulbed esophagus and the intestine is a straight cylindrical tube
Free living
Strongyloides
” measures 0.7 mm by 0.04 mm and is smaller than the female
• it has a ventrally curved tail, two copulatory spicules, a gubernaculum but no caudal alae
Free-living Male
Strongyloides
rarely seen in the stool specimen
” it has a clear, thin shell and are similar to those of hookworms except that they measure about 50-58 micra by 30 to 34 micra
Eggs
Strongyloides
•they have cuticular alar expansions at the anterior end and a prominent posterior esophageal bulb
Adult Worm Enterobius vermicularis (Pinworm)
Male Worm
spindle-shaped
• measures 2 to 5 mm by 0.1 to 0.2 mm in greatest diameter
” oral end is provided with 3 lips and a pair of laterally placed cephalic “alae” or wings
- bursa is greatly reduced and designated as “caudal alae” which is supported by 6 pairs of caudal papillae
” it has a characteristic curved tail with a single spicule
• posterior end is strongly curved ventrad
• relatively smaller than the female worm they are rarely seen because they die after copulation
Enterobius vermicularis
Female Worm
measures 8 to 13 mm in length by 0.3 -0.5 mm in greatest diameter
• it has a long pointed tail hence the common name pinworm
• vulva opens in front of the middle third of the body
” vagina is long, extending posteriorly some distance from the vulva before
it joins the paired genital organs
the uteri of the gravid female are distended with eggs
they are capable of laying as much as 4, 672 to 16, 888 eggs/day
Enterobius vermicularis
• are asymmetrical, with one side flattened and the other side convex
• measures 50 to 60 micra by 20 to 30 micra averaging 55 by 36 micra
“ fully convexed
• the translucent shell consists of an outer, triple albuminous covering for mechanical protection and an inner lipoidal membrane for chemical protection
” outside the host, eggs become infective in four to six hours
Ova
Enterobius vermicularis
Ascaris lumbricoides (common name)
Giant Intestinal Roundworm
” also known as the pink worm
• they have the so-called “polymyarian type” of somatic muscle arrangement in which cells are numerous and project well into the body cavity
• they have anterior 3 lips
relatively large worms
Adult Worm
Ascaris lumbricoides
measures 10 to 31 cm by 2-4mm in diameter with smooth striated cuticles
they have a terminal mouth with three lips and a sensory papillae
they have a ventrally curved posterior end with two spicules
a single, long, tortuous tubule is found in the posterior 2/3 of the body
posterior end is curved ventrad
Male Worm
Ascaris lumbricoides
.
measures 22 to 35 cm with smooth striated cuticles
they have a terminal mouth with three lips and a sensory papillae
they have paired reproductive organs in the posterior 2/3
posterior end is conical and straight
productive capacity of 26 million eggs or 200, 000 eggs per day
Female Worm ascaris lumbricoides
• measures 88 to 94 micra by 39 to 44 micra, longer and narrower than fertilized eggs
• it is thin-shelled with an irregular mammillated coating filled with refractile granules
” vitelline membrane is absent
” has thinner shell composed of inner chorionic and outer irregular coating
of albumin
” they are difficult to identify and are found only in the absence of males
Unfertilized Egg
Ascaris lumbricoides
measures 45 to 70 micra by 35 to 50 micra, shorter than the infertile eggs
.
golden brown in color
there is an outer coarselv mammillated albuminous covering which may be absent or lost in “decorticated eggs”
the egg has a thick, transparent, hyaline shell with a thick, outer layer as a supporting structure and a delicate vitelline, lipoidal, inner membrane
at oviposition, these eggs have an ovoid mass of protoplasm which will develop into larvae in about 14 days
Fertilized Egg
Ascaris lumbricoides
both fertilized and unfertilized eggs at times may lack the outer albuminoid coat
Decorticated Egg
Ascaris lumbricoides
(New World Hookworm)
Necator americanus
Adult Worm
“ adult worms are small, cylindrical, fusiform, grayish-white nematodes
Necator americanus
Male Worm
• measures 5 to 9 mm by 0.30 mm and are shorter than the female worm
“ the posterior end has a broad, membranous caudal bursa with rib-like rays, which are used for copulation
“ the buccal capsule has a ventral pair of semi-lunar cutting plates
• the head is curved opposite to the curvature of the body which is like a hook at the anterior end
Necator americanus
Female Worm measures 9 to 11 mm by 0.35 mm and are larger than the male worm
“ they have a blunt posterior end
the buccal capsule has a ventral pair of semi-lunar cutting plates
Necator americanus
Filariform Larva
. buccal spears are conspicuous and parallel throughout their lengths there are conspicuous transverse striations present on the sheath of the tail region
tail is pointed covered with sheath
Necator americanus
• adult worms are slightly larger than N. americanus . they have a single-paired reproductive organ
• the shape is such that the head continues in the same direction as the curvature of the body
“the buccal capsule has two pairs of curved veritral teeth
Ancylostoma duodenale
A. Adult Worm
Ancylostoma duodenale (common name)
Old World Hookworm
Male Worm
“ measures nearly 1 cm (10 mm)by 0.5 mm
“ the mouth is well-developed with a pair of teeth on either side of the median line
“ they have a prominent fan-like copulatory bursa called bursa copulatrix found in the posterior portion of the worm
Ancylostoma duodenale
Female Worm
“ longer than the male worm measuring about 12-15 mm by 0.7 mm
median line
“ they have a blunt posterior end
Ancylostoma duodenale
Filariform Larva
inconspicuous buccal spears and transverse striations on the sheath in the tail region
• tail is pointed covered with sheath
Ancylostoma duodenale
• it resembles that of Strongyloides stercoralis, but are somewhat larger
“ it is more attenuated posteriorly
“ it has a longer buccal capsule
*• genital primordium is incospicuous
Hookworm Rhabditiform Larva
measures about 64 to 76 micra by 36 to 40 micra eggs are regularly oval
colorless and usually seen in 2-8 cell stages
Hookworm Egg
buccal capsule is provided with a pair of big teeth posterior end of the male worm is provided with bursa copulatrix
• parasite of the dogs
Ancylostoma braziliense
. buccal capsule is provided with three pairs of ventral teeth, the innermost is the smallest
posterior end of the male worm is provided with bursa copulatrix that is flaring
with long, slender rays
• parasite of the dogs cutaneous larva migrans in man
Ancylostoma caninum
pairs of teeth but the outer pair is bigger than the inner pair
posterior end of the male worm is provided with bursa copulatrix
Ancylostoma ceylanicum
“ buccal capsule is provided with two
