Class Arachnida Flashcards
Class Arachnida includes the ff:
king crab
spiders
scorpions
ticks and mites
General Characteristics of Class Arachnida
Wingless. Head, thorax, and abdomen are not defined. They feed on tissue fluids by means of sucking pharynx.
4 main body parts of Class Arachnids
- Gnasthosoma
- Propodosoma
- Metapodosoma
- Opisthosoma
bears the mouthparts and the plate that bears it, the capitulum or gnathobases
Gnasthosoma
Gnasthosoma bears the mouthparts and the plate that bears it is called
capitulum or gnathobases
bears the first and second pairs of legs
Propodosoma
Bears the third and fourth parts of legs.
Metapodosoma
posterior part behind the fourth pair of legs, the abdomen
Opisthosoma
Two main body parts of Class Arachnids
- Prosoma
a. Gnathosoma (mouthparts)
b. Podosoma (bears the legs) - Opisthosoma (abdomen part)
a. Prosoma and opisthosoma = idiosoma
Two types of Prosoma
Gnathosoma (mouthparts)
Podosoma (bears the legs)
mouthparts
Gnathosoma
bears the legs
Podosoma
abdomen part
Opisthosoma
idiosoma
prosoma and opisthosoma
The mouthparts of arachnids are composed of the following:
Chelicerae
Hypostome
Pedipalps or palpi
a pair of cutting structures
Chelicerae
median structure with recurved teeth for anchorage
Hypostome
segmented appendages lateral to the chelicerae
Pedipalps or palpi
Stages of development of Class Arachnida:
- Egg – oval or spherical
- Larva - with 3 pairs of legs
-
Nymph – with 4 pairs of legs without sexual organs. May have 2-3 nymphal instars before developing into an adult.
a) Protonymph –first instar
b) Deutonymph – second instar
c) Tritonymp – third instar - Adult – with 4 pairs of legs and well developed sexual organs
Three orders of veterinary importance of Class Arachnids
- Acarina – ticks and mites
- Araneida – spiders
- Scorpionidea – scorpions
ticks and mites
Acarina –
spiders
Araneida
scorpions
Scorpionidea
Four Sub-orders of Veterinary Importance under Order Acarina:
- Ixodoidea – ticks
- Mesostigmata – mites
- Trombidiformes – mites
- Sarcoptiformes – mites
2 groups of sub-order Ixodidea
Family Argasidae (Soft ticks)
Family Ixodidae (Hard Ticks)
Soft ticks
Family Argasidae
Hard Ticks
Family Ixodidae
without scrutum
Family Argasidae (Soft ticks)
with scrutum
Family Ixodidae (Hard Ticks)
Family Argasidae (Soft ticks) genera
- Argas, Otobius, Ornithodoros* (AOO)
Family Ixodidae (Hard Ticks) Genera:
Boophilus, Rhipicephalus, Amblyomma, Ixodes, Dermacentor, Hyalomma (BRAIDH)
Important differences between Argasidae and Ixodidae: SCRUTUM
A: absent
I: present
Important differences between Argasidae and Ixodidae: SEXUAL DIMORPHISM
A: not marked
I: marked
Important differences between Argasidae and Ixodidae: MOUTHPARTS AND CAPITULUM
A: ventral
I: anterior
Important differences between Argasidae and Ixodidae: PALPI
A: leg-like
I: rigid
Important differences between Argasidae and Ixodidae: FESTOONS
A: absent
I: generally present
Important differences between Argasidae and Ixodidae: COXAE
A: unarmed
I: armed
Important differences between Argasidae and Ixodidae: EGG LAYING HABIT
A: laid in small batches
I: laid in one large batch
Important differences between Argasidae and Ixodidae: FEEDING HABIT
A: feed moderately and frequently
I: take one large meal and increase in size dramatically
Important differences between Argasidae and Ixodidae: LIFE SPAN
A: live for several years, 5 years or more
I: live for less than one year, rarely 2 years
Important differences between Argasidae and Ixodidae: ADAPTATION TO ENVIRONMENT
A: drought resistant
I: cannot live w/out adequate humidity
Genus Argas species:
- *Argas persicus *(fowl tick)
- Argas reflexus (pigeon tick)
- Argas persicus* common name
fowl tick
- Argas reflexus* common name
pigeon tick
Argas persicus (fowl tick) are common in
chickens, turkeys, pigeons, ducks, ostriches, canaries
Argas reflexus (pigeon tick) are common in
pigeon, doves
Genus Otobius species
- Otobius megnini (spinose ear tick)
It occurs in America and Africa. Larvae and nymphs occur in the ear of dogs, cattle, horses, and all other mammals. Adults are non-parasitic
Otobius megnini (spinose ear tick)
Otobius megnini (spinose ear tick) lays _________ eggs, which may last for 6 months then dies.
500-600 eggs
Pathogenicity of Genus Otobius or Otobius megnini (spinose ear tick)
• Irritation, scratching, and shaking of ears.
• Inflammation, suppurative lesions (bacterial infestation)
Genus Ornithodoros species:
1. O. moubata
2. O. savignyi
3. O. turicata
Larvae do not hatch but molt into nymph inside the egg. Adult and nymphs attack animals.
Genus Ornithodoros
Transmits: Borrelia recurrentis, the cause of relapsing fever in man
Genus Ornithodoros
Genus Ornithodoros transmits this disease
Borrelia recurrentis, the cause of relapsing fever in man
the cause of relapsing fever in man
Borrelia recurrentis
attacks wild and domestic mammals
Ornithodoros moubata
occurs on the livestock in Africa and India
Ornithodoros savignyi
occurs in the U.S.
Ornithodoros turicata
Female lay 2,000 – 20,000 eggs
Ixodine ticks
active, climb up the pinnacle or tip of grasses and attach themselves to passing animals and suck blood
Seed ticks
Unfed ticks live longer than well-nourished ticks
True
Ixodid ticks are classified according to the number of host
- One-host tick
- Two-host tick
- Three-host tick
Larva attaches to a host, molt into nymph and finally adult stage on the same animal, e.g. Boophilus microplus, Boophilus annulatus
One-host tick
Example of one-host tick
1. Boophilus microplus,
2. Boophilus annulatus
larva attaches to a host molts into nymph on the host body, nymph drops to the ground after having engorged, molts into the ground to adult (imago) which seeks a new host (one molting on the ground, one molting on the host) e.g. Rhipicephalus evertsi, R. bursa
Two-host tick
Example of two-host tick
1. Rhipicephalus evertsi,
2. R. bursa
They drop off each time after having engorged and molt on the ground (all moltings occurs on the ground or off the host), (different host or the same host is required every instar), e.g. Ixodes ricinus, Rhipicephalus appendiculatus, R. sanguineus
Three-host ticks
Three-host ticks
1. Ixodes ricinus
2. Rhipicephalus appendiculatus
3. R. sanguineus
Genus Ixodes
1. Ixodes ricinus “castor bean tick”
2. I. holocylus “paralysis tick”
3. I. rubicundus “paralysis tick”
4. I. scapularis “black legged tick”
Ixodes ricinus transmits these diseases
- Tick paralysis (three-host tick)
- Red water diseases or babesiosis
- Anaplasmosis
- Tick borne fever
“tick paralysis” in cattle is caused by why type of Ixodid ticks?
Three-host tick
Causative agents of “red water diseases” or babesiosis of cattle
- Babesia bovis,
B. divergens*
Causative agent of Anaplasmosis
Anaplasma marginale
Causative agent of “tick borne fever” of sheep.
viruses of louping ill and rickettsiae
Ixodes holocylus common name
“paralysis tick”
Common name of Ixodes rubicundus
“paralysis tick”
Common name of Ixodes scapularis
“black legged tick”
Species under Genus Boophilus
- Boophilus annulatus – “North America cattle tick” or texas fever cattle tick
- Boophilus decoloratus – “blue tick”
- Boophilus microplus (B. australis) – “tropical cattle tick”
one host tick; important transmitter of Babesia bigemina and Babesia argentina (B. bovis)
Boophilus annulatus (North America cattle tick) or (texas fever cattle tick)
Boophilus annulatus (North America cattle tick) or (texas fever cattle tick) transmits these
Babesia bigemina and Babesia argentina (B. bovis)
one-host tick, transmits Babesia bigemina, Anaplasma marginale, Borrelia theileri (spirochaetosis of ruminants)
Boophilus decoloratus (blue tick)
transmited by Boophilus decoloratus or “blue tick”
Babesia bigemina, Anaplasma marginale, Borrelia theileri (spirochaetosis of ruminants)
One-host tick. Most common cattle tick in the Philippines. Attacks cattle, carabaos, buffaloes, sheep, goats including horse and deer
Boophilus microplus (B. australis) or “tropical cattle tick”
transmits Anaplasma marginale, Babesia bigemina, B. argentina (B. bovis)
Boophilus microplus (B. australis) or “tropical cattle tick”
Example of one-host ticks
Genus Boophilus
1. B. annulatus
2. B. decoloratus
3. B. microplus (B. australis)
the genus Boophilus is closest to what Genus?
Genus Rhipicephalus
Common name of Boophilus annulatus
“North America cattle tick” or “Texas fever cattle tick”
Common name of Boophilus decoloratus
“blue tick”
Common name of Boophilus microplus (B. australis)
“tropical cattle tick”
Species under Genus Rhipicephalus
- Rhipicephalus appendiculatus – “brown ear tick”
- R. evertsi – “red-legged tick”
- *R. bursa
- Rhipicephalus sanguineus – “brown dog tick”, “kernel tick”
Rhipicephalus appendiculatus or “brown ear tick” transmits the ff:
1. Theileria parva
2. T. mutans, Hepatozoon canis
3. Babesia bigemina
4. Rickettsia conorii
Causative Agents of theileriosis or east coast fever
Theileria parva
Disease transmitted by Theileria parva
theileriosis or east coast fever
Causative agent of hepatozoonosis
T. mutans, Hepatozoon canis
Disease transmitted by T. mutans, Hepatozoon canis
hepatozoonosis
Causative agent of Piroplasmosis
Babesia bigemina
Disease transmitted by Babesia bigemina
Piroplasmosis
Causative agent of tick-bite fever
Rickettsia conorii
Disease transmitted by Rickettsia conorii
tick-bite fever
Rhipicephalus evertsi – “red-legged tick” transmits the ff:
Theileria mutans, T. parva, Babesia bigemina, B. equi
Rhipicephalus bursa transmits the ff:
Babesia ovis
B. equi
B. caballi
Theileria ovis
Anaplasma marginale
Coxiella burnetii
Rhipicephalus sanguineus – “brown dog tick”, “kernel tick” transmits the ff:
Babesia canis
B. equi
B. caballi
Hepatozoon canis
Rickettsia canis
R. conori
R. rickettsii
Ehrlichia canis
Causative agent of Rocky Mountain Spotted Fever (RMSF)
Rickettsia rickettsii
Common name of Rhipicephalus appendiculatus
brown ear tick
Common name of Rhipicephalus evertsi
“red-legged tick”
Common name of Rhipicephalus sanguineus
“brown dog tick” or “kernel tick”
Species under Genus Dermacentor
1. Dermacentor andersoni (D. venustus) or “Rocky mountain wood tick”.
2. Dermacentor variabilis (American dog tick)
3. Dermacentor reticulatus (Ornate cow thick)
4. Dermacentor nitens (Tropical horse tick)
Example of three-host ticks
1. Dermacentor andersoni (D. venustus)
2. Dermacentor variabilis
3. Dermacentor reticulatus
One-host tick in Genus Dermacentor
Dermacentor nitens
Dermacentor andersoni (D. venustus) or “Rocky mountain wood tick (RMWT)” transmits the ff:
1. Leptospira Pomona
2. Rickettsia rickettsii
3. Anaplasma marginale
4. Babesia canis
5. Coxiella burnetii
Disease transmitted by Leptospira pomona
Leptospirosis
Causative agent of Leptospirosis
Leptospira Pomona
Causative agent of Rocky Mountain Fever
“Rickettsia rickettsii*
Disease transmitted by Rickettsia rickettsii
Rocky mountain fever
Causative agent of Anaplasmosis
Anaplasma marginale
Disease transmitted by Anaplasma marginale
Anaplasmosis
Causative agent of canine babesiosis
Babesia canis
Disease transmitted by Babesia canis
Canine babesiosis
Causative agent of Q fever
Coxiella burnetii
Disease transmitted by Coxiella burnetii
Q fever
It is the cause of American tick paralysis.
Dermacentor andersoni (D. venustus) or “Rocky mountain wood tick”
Common name of Dermacentor andersoni (D. venustus)
“Rocky mountain wood tick”
Common name of Dermacentor variabilis
American dog tick
Common name of Dermacentor reticulatus
Ornate cow tick
Common name of Dermacentor nitens
Tropical horse tick
vector of equine piroplasmosis
Dermacentor nitens or Tropical horse tick
Specie under Genus Hyalomma
Hyalomma truncatum
causes “sweating sickness” in cattle
Hyalomma truncatum
Disease caused by Hyalomma truncatum
sweating sickness
Genus of Three-host ticks
Genus Haemaphysalis
Genus Amblyomma
CN of Haemaphysalis leachi leachi
– “yellow dog tick”
Haemaphysalis leachi leachi or yellow dog tick transmits the following:
1. B. canis
2. Rickettsia conorii
3. Coxiella burnetii
Haemaphysalis cinnabarina punctata transmits the following on livestock
1. Babesia bigemina
2. B. motasi
3. A. marginale
Causative agent of paralysis in cattle and sheep (Haemaphysalis cinnabarina punctata)
1. Babesia bigemina
2. B. motasi
3. A. marginale
Haemaphysalis leporispalustris transmits the following on rabbits
- Coxiella burnetii
- Rocky Mountain Spotted Fever (RMSF)
- tularensis
Species under Genus Amblyomma
- Amblyomma americanum or “lone star tick”
- A. variegatum or “tropical bont tick”
- A. cajennense or “cayenne tick”
Common name of Amblyomma americanum
“lone star tick”
Common name of Amblyomma variegatum
tropical bont tick
Common name of Amblyomma cajennense
cayenne tick
Characterized by the presence of white spots on the scutum of the female
Amblyomma americanum (lone star tick)
Amblyomma americanum transmits this that causes heart water disease
Rickettsia ruminantium
Disease caused by Rickettsia ruminantium
heart water disease
Causative agent of heart water disease
Rickettsia ruminantium
Diseases transmitted by Amblyomma americanum (lone star tick)
• heart water disease
• Nairobi sheep disease
• Q fever
Amblyomma cajennense (cayenne tick) transmits these disease
spotted fever and leptospirosis
members are exclusively of reptiles (phytons, snakes, lizard, etc)
Genus Aponomma
occur on a wide variety of mammals
Genus Rhipicentor
• Rhipicentor nuttalli
• Rhipicentor bicornis
Species under Genus Margaropus
- Margaropus winthemi (argentine tick)
- Margaropus reidi (Sudanese tick) (beady-legged tick)
Ticks in general transmit these causative agent
louping ill virus, rickettsia, protozoa
CN of Margaropus winthemi
“argentine tick”
SN of argentine tick
Margaropus winthemi
Hosts are horses and cattle. One-host tick
Margaropus winthemi – “argentine tick”
CN of Margaropus reidi
Sudanese tick, beady-legged tick
SN of Sudanese tick, beady-legged tick
Margaropus reidi
host – giraffe. One-host tick
Margaropus reidi (Sudanese tick, beady-legged tick)
Pathogenicity of Ticks in general:
• Irritation leads to licking and scratching, thus predisposing animals to myiasis and pyemia.
• Ticks suck blood leading to anemia, loss of weight, loss of milk.
• Transmits louping ill virus, rickettsia, and protozoa.
• Secrete toxins causing “tick paralysis”
• Cause “tick worry” and “sweating sickness”
Ticks in general transmit the ff. disease and causative agents
- Transmits louping ill virus
- ** (Leptospira Pomona)
- Rickettsia (R. prowazekii, Anaplasma, R. rickettsii, R. conorii, R. ruminantium)
- Protozoa (Babesia spp., Theileria)
begins with the limbs then spread to the medulla oblongata resulting in respiratory failure and death
tick paralysis
Secrete toxins causing “tick paralysis” and causes “tick worry”
Ticks
as a result of irritation, anemia and other secondary skin infections combine
tick worry
Crossing these to produce sterile male offspring as prevention of ticks.
B. microplus and B. annulatus