Cockroach(1) Flashcards
give the taxonomy of a cockroach
Phylum- Arthropoda (jointed appendages and and chitinous skeleton)
Class - Insecta (3 pairs of jointed legs)
Order- Dictyoptera
Genus- Periplaneta
Species- americana
explain some features about cockroach
Cockroach is omnivorous, cursorial (fast runner) and
nocturnal animal. It also exhibits Cannabalism.
Parental Care does not found in Cockroach.
Cockroach chromosome no. = 34.
how are the three segments of coackroach divided
Body of cockroach is divided in to 3 parts called →Tegmata. They are-
HEAD, THORAX AND ABDOMEN.
In Embryo stage head (6) + thorax (3) + abdomen(11) = 20 segments
In Adult stage head (1) + thorax (3) + abdomen(10) =14 segments
Sclerites of head fused fully to form head capsule (formed by the
fusion 6 segments).
name of different chitinous plates
Exoskeleton of chitin plates occurred in each segment. Chitin plates called
“sclerites”.
Sclerites of dorsal side - tergum or tergite.
Sclerites of ventral side - sternum or sternite.
Sclerites of lateral side - pleurons or pleurites.
Sclerites joined each other by “membrane” called “articular or arthrodial
membrane.”
explain the mouth parts of the cockroach
A cavity formed due to presence of mouth parts called pre-oral
cavity. 5 types of mouth parts-
Labrum or Upper Lip - Dorsally overhangs the mouth. Holds the
food for feeding & has gustato-receptor (tasting).
- Mandibles or Jaw (1-pair) - They form the lateral wall of pre-oral
cavity. Grinding of food. - First maxillae (1-pair) - Putting the food in oral cavity. Also used
as brush to clean antenna and wings. - Second Maxillae or Labium or lower lip - It forms the floor of
pre-oral cavity and covers ventral side. - Hypopharynx or lingua or tongue - Non-chitinous flexible
structure. Common salivary duct opens at the base.
where are the legs present and what are their parts?
5 segments are present in legs known as Podomeres
(i) coxa
(ii) trochanter
(iii) femur
(iv)tibia
(v) tarsus
(vi) pretarsus
(vii) claw
what are th 2 types of wings
Forewing or Mesothoracic
wing or Elytra or Tegmina-
long, narrow, thick, leathery,
dark, opaque, covers body.
Hindwing or Metathoracic
wings- small, broad, thin,
membranous, transparent,
helpful in flight
what are the abdomen
10 segments are present in male and female.
10th tergum bowl shaped and bifurcated and has 1 pair
”Anal cerci - Sound receptor” bear in both male and
female.
7th tergum is largest in male and female and covers 8th
and 9th tergites.
Stink gland present in between 5th and 6th tergum its
smell repels enemies.
Sternum : In male- 9 sternum and in female- 7 sternum.
Anal or caudal style – 1 pair from 9th sternum only in male,
non segmented structures → Help in copulation.
what is haemocoel
Also known as Haemocoel
Haemocoel is not true coelom
All arthopodes are true coelomates but coelom is highly
reduced and found only in the form of the cavity of gonads
called Gonocoel.
Lagre fat bodies (corpora adiposa) present in haemocoel
Fat bodies are analogous to liver of higher animals
what are the salivary glands
Consists of salivary glands and alimentary canal
Salivary glands secretes → Saliva
which contain amylase, cellulase,
chitinase.
It is attached to crop
3 parts of the alimentary canal
A) FOREGUT-Ectodermal in origin- cuticle layer present
B) MIDGUT-Endodermal in origin- cuticle layer absent
C) HINDGUT-Ectodermal in origin- cuticle layer present
foregut parts:
(i)- gizzard: helps in grinding of food with cuticular teeth/ cavity is called armarium
(ii) sieve platE: filtering of food due to cuticular hair
(iii)stomodeal valve: prevent backflow of blood/ junction of fore and midgut
foregut is formed by invagination of body wall. the cuticle is present in the inner wall/
midgut or mesenteron parts:
(i) Anterior top part: cardia- secrete peritropic memebrane m/o glyocgen and protein beacsue midgut do not have cuticle layer
stomodeoal valve opens onto cardia into the midgut
bacetria and symbiotic protozoa present whichhelp in the digestion
mesenteron is muscular
Hepatic caeca is derives from mesenteron
hind gut parts
(a) 100-150 yellow colored thin tubules attached at the junction of
hind gut and mid gut called “Malpighian tubules” → Removal
of excretory products from haemolymph)
(b) Hind gut has three parts :
(i) Ileum - Its wall is thin and internally folded. Its cuticle bears
minute spines, which serve to break the peritrophic
membrane.
(ii) Colon - Longest and broader part
(iii) Rectum - Last part, oval shaped. Its wall has 6 folds - called
Rectal papillae which absorb water.
Anus - At the end of 10th abdominal segment.
wat are some other excretory structure except malphigiain tubules
Urate cell : Storage excretion
Nephrocytes and fat bodies: Storage excretion
Body wall : Absorbs excretory materials from Haemocoel and store in
cuticle. Then at the time of moulting excretory substances and cuticle
separate out from body
Uricose glands : These help in excretion in male cockroach.
whereare the spiracles are present
(d) 10- pair spiracles, 2-pairs on thorax and 8-pairs on
abdomen.
(e) 1st thoracic and 1st abdominal spiracle - Always open
f) All spiracles :- on “Pleurone” (Lateral side of body)
what does blood do
Open type or Lacunar type
(i) Colourless plasma
(ii) WBC (Haematocytes)
BLOOD VASCULAR SYSTEM
Blood vessel are poorly developed and open into
space called – HAEMOCOEL
Phagocytosis of bacteria
Related with blood clotting
In BLOOD → RBC, Haemoglobin ABSENT
BLOOD works as HYDRAULIC SKELETON
BLOOD is not related with respiration because respiratory pigment
absent
BLOOD helps in the transportation of nutrients, hormones and
excretory wastes
Blood contains trehalose sugar disaccaride.
what are the 2 diaphragms in cockroach
Two horizontal septa/diaphragm divides haemocoel in to
3 chambers. These septa are -
1-Dorsal diaphragm2-Ventral diaphragm
These have pores called “fenestrae”
Diaphragms divides the HAEMOCOEL in to three chambers :
Peri cardial sinus (DORSAL) : has heart chambers
Perivisceral sinus (MIDDLE) : has alimentary canal and fat body.
Perineural sinus (VENTRAL) :has nerve cord.
how is the flow of blood between the sinuses
first the blood is pumped from the anterior aorta into the head sinus from where it goes to the perineural sinus(ventral) then it moves to perivisceral sinus and then it moves to pericardial sinus where it goes into the heart through ostia.
explain heart of cockroac
(a) Heart is divided into 13 inverted funnel like chambers
.
(b) First chamber of heart in the form of long tubule called “anterior
aorta” It opens into head sinus
(c) Each chamber connected with Pericardial sinus by 1-pair of pores,
called “Ostia”. These pores act as valve.
(d) Blood enters from Pericadial Sinus to heart through Ostia.
(e) Each posterior chamber of heart connected/related with anterior
chamber by a valve like pore.
(f) These pore help in flow of blood from posterior to anterior part.
the heart is neurogenic( under nervous control)
theheart chambers are connected by 12 fan shaped alary muscles. when they contract, the diaphragms flatten, bp dicreases casuing blood to enter heart
what are nephrocytes
Special type of cells attached with heart wall called “Nephrocytes-
Storage excretion in the form of “Uric acid”.
what are the 3 types of galglion
supraoesophageal ganglion amd sub oseophageal ganglion RE CONNECTED BY CIRCUM OESEOPHAGEal connectives to form nerve ring.
there 3 ganglion in thorax and 6 ganglion in the tb
wha are the sense organs
Antennae → Tactile receptors, Olfactory receptors, detect
vibrations.
*Compound eyes → Each compound eye is made up of 2000
units called Ommatidia.
*Mosaic Vision or Apposition vision has more sensitivity but less
resolution.
*Simple eye or Ocelli → Photoreceptor (to detect light), No image
formation.
Maxillary and Labial Palps → Tactile receptors and Gustato
receptors
*Anal Cerci → Sound receptors( antennae also detect sound)
*Legs → Gustato-receptors
male repro system
(
(a) 1-pair of testis in “4-6” abdominal segment. Each testis formed
of “3 or 4 lobes” each lobe divided into many lobules
(b) Vasa deferentia - A vasa deferens arises from each testis these
open in an ejaculatory duct.
c) Ejaculatory duct opens outside by male genital pore. Seminal
vesicle in form of vesicles located upon ejaculatory duct.
(d) Spermatogenesis→ Completely in testis.
(e) Seminal vesicle :- Stored the sperms. All sperms glue together’s
to form a ball called “sperm ball”.
(f) A gland associated with seminal vesicles called Mushroom gland
or Utricular gland is present in the 6th - 7th abdominal segment
as an accessory reproductive gland.
Having two types of tubules-
Small tubules on inner side - Utriculi brevivores → Nutritive fluid in
spermatophore.
Long tubules outside - Utriculi majores → Secrete a membrane
around sperm ball. Tips of long tubules called “Uricose gland” →
These absorb excretory material from haemocoel.
(g) Ejaculatory duct secrete another coat on spermatophore.
spermatophore - ”Double layered.”
(h) A gland located on mushroom gland called phallic gland or
congloblate gland. It opens out side by a long duct “Phallic
aperture”.
When they go out side from male genital pore then phallic gland
secretes another layer, so spermatophore becomes three layered.
(j) Chitinous structures associated with phallic aperture and male
genital pore called “Phallomeres” or “Gonapophysis”.
Phallomeres
(1) Left phallomere
(2) Right phallomere
(3) Ventral phallomere
