Download Zoology Ch. 14 Arthropods Arthropods and annelids are closely

Zoology Ch. 14 Arthropods
Arthropods and annelids are closely _____________ animals. _______________ arthropods are divided into _________
subphyla: Chelicerata, Crustacea, Hexapoda, and Myriapoda. __________ members of a fifth subphylum , Trilobitomorpha
are ____________. _________________ are one of many groups of animals belonging to the phylum Arthropoda. Crayfish,
________________, spiders, mites, scorpions, and _______________ are also arthropods. Zoologists have described around
________ million species of arthropods with an estimated _________ to _________ million species yet to be described.
Characteristics of Arthropoda include: 1. ___________________ modified by the specialization of body regions for specific
____________. 2. ______________ exoskeleton that provides support and protection and is modified to form __________
structures. 3. Paired, ______________ appendages. 4. Growth accompanied by _____________ or molting. 5. __________
nervous system 6. Coelom ____________ to cavities surrounding ______________ and sometimes excretory organs. 7.
____________ circulatory system in which blood is released into tissue spaces, _____________ derived from the blastocoel.
8. ______________ digestive tract. 9. _______________________ often present; reduces _________________ between
immature and adult stages.
Metamerism and Tagmatization
____________ aspects of arthropod biology have contributed to their success. One of these is _________________, which is
most evident ______________ because the arthropod body is often composed of similar ______________, each having a pair
of _________________. Internally, ___________ do not divide the body cavity of an arthropod, and most organs are not
metamerically arranged. Metamerism _______________ the specialization of regions of the body for specific ____________.
This regional specialization is called _________________________. In arthropods, body regions, called _______________,
are specialized for ______________ and ________________ perception, locomotion, and visceral functions.
The Exoskeleton
The _____________ aspect for success is the external, jointed skeleton called the ____________________ or cuticle that
encloses the arthropod. It provides structural ______________, protection, impermeable surfaces for the prevention of
____________ loss, and a system of levers for muscle ___________________ and ___________________. The exoskeleton
has ________ layers. The _________________ is the outermost layer and is made of a waxy _______________, it is
impermeable to water and a ________________ to microorganisms and pesticides. The bulk of the exoskeleton is below the
epicuticle and is called the ________________. The procuticle is composed of ___________, a tough leathery
polysaccharide, and several kinds of _______________. The ____________ of an arthropod would be impossible unless the
exoskeleton were periodically ________, in a process called ___________. Ecdysis is divided into __________ stages: 1.
____________________ secreted from hypodermal glands begin _____________ the old procuticle to separate the
hypodermis and the exoskeleton 2. __________ procuticle and epicuticle are secreted 3. the __________ exoskeleton
_____________ open along predetermined ecdysal lines when the animal stretches by air or ____________ intake; _______
In the procuticle secrete additional epicuticle and 4. __________ ________________ deposits and or __________________
harden the new exoskeleton.
The Hemocoel
The __________ aspect of arthropod success is the presence of a ______________. The hemocoel is derived from an
embryonic cavity called the _______________ that forms in the blastula. The hemocoel provides an ____________ cavity
for the ___________ circulatory system of arthropods. Internal organs are bathed by ________________ fluids in the
hemocoel to provide for the exchange of _____________, wastes, and sometimes gases. The ___________ which forms by
splitting blocks of ________________ later in the development of most protostomes was reduced in ancestral arthropods.
The presence of the ___________ exoskeleton and body wall means that the coelom is _______ longer used as a hydrostatic
compartment. In modern arthropods, the coelom forms __________ __________ around the gonads.
Metamorphosis
The ____________ aspect of arthropod success is ______________ which has caused a ____________ of _____________
between adults and immature stages. Metamorphosis is a radical ______________ in body form and physiology as an
________________ stage, usually called a ____________, becomes an ___________.
Subphylum Trilobitomorpha
Members of the subphylum Trilobitomorpha were a _____________ form of life in the ____________ from the Cambrian
period to the Carboniferous period. They __________ along substrate feeding on annelids, mollusks, and decaying organic
matter. The trilobite was ___________, flattened, and divided into ____________ tagmata: _________, thorax, and
pygidium. All body segments articulated so that the trilobite could ________ into a __________ to protect its soft ventral
surface. Trilobite appendages consisted of ________ lobes or __________, and are all biramous appendages. The ________
lobe was a _____________ leg, and the _____________ lobe had ___________ or teeth that may have been used in digging
or swimming or as ___________ in gas exchange.
Subphylum Chelicerata
This group of arthropods includes ____________, mites, ____________, horseshoe crabs, and sea spiders. These animals
have __________ tagmata. The _____________ or __________________ is a sensory, feeding and locomotor tagma. It
usually has __________, but unlike other arthropods, never has _______________. ____________ appendages attach to the
Prosoma. The first pair, called _______________ are pincerlike and used for ________________. They may also be
specialized as __________ ____________ for other functions. The second pair, called ______________, are usually for
___________ but may also be used in feeding, locomotion, or _______________. Paired _____________ legs follow
pedipalps. Posterior to the prosoma is the _________________, which contains ______________, reproductive,
____________, and respiratory organs.
Class Merostamata
Members of the class Merostamata are divided into _________ subclasses. The Xiphosura are the _____________ _______,
and the Eurypterida are the giant ____________ _________________. The later are _____________, having lived from the
Cambrian period to the Permian period. Only _________ species of horseshoe crabs are living today. One species is known
to exist in the _______________ Ocean and the ___________ of ________________. Horseshoe crabs _____________
sandy and muddy substrates for annelids, small mollusks, and other ______________. Their body form has remained
______________ for over ________ million years. The horseshoe crab prosoma is covered by a _______________. The
chelicerae, pedipalps, and the first _____________ pairs of walling legs are _____________ and are used for walking and
____________ handling. The ________ pair of appendages has leaflike plates at their tips and are used for ______________
and digging. The _________________ of a horseshoe crab includes a long ________________ telson. The _________ pair
of opisthosomal appendages cover genital pores and are called ____________ ______________. The remaining ______ pairs
of appendages are ___________ ____________ for gas exchange. Horse shoe crabs are ______________. During
reproductive periods ___________ and ____________ congregate in intertidal areas. The male ____________ the female
and ___________ her with his pedipalps. The female excavates shallow _______________ in the sand, and as she sheds eggs
into the depressions the male __________________ them. Fertilized eggs are ________________ with sand and develop
unattended.
Class Arachnida
Members of the class Arachnida are some of the most _______________________ members of the animal kingdom. Their
reputation as fearsome and grotesque creatures is very __________________, because the majority of spiders, mites, ticks,
scorpions, etc. are either ________________ or very _______________ to humans. Most zoologists believe that arachnids
arose from the __________________ and were early ________________ inhabitants.
Form and Function
Most arachnids are _____________________. They hold small arthropods with their ______________ while ____________
from the gut tract pour over the prey. Partially digested food is taken into the _____________. Others ___________ enzymes
into prey through _____________ chelicerae and __________ partially digested animal tissue. The gut tract of arachnids is
divided into ___________ regions. The anterior portion is the ______________, and the posterior portion is the __________.
Both develop infoldings of the ______________ _________ and are lined with ____________. A portion of the __________
Is modified into a _______________ stomach and the hindgut is a site of ___________ reabsorption. Arachnids use
________ glands and/or _______________ tubules for ____________ nitrogenous wastes. Coxal glands are ___________,
thin-walled spherical ________ bathed in the blood of body _____________. The nitrogenous wastes are _____________
across the wall of the sacs and transported to __________, and excreted through an excretory _____________ at the base of
the posterior appendage. Arachnids in ________ environments use malpighian tubules to absorb waste materials from the
__________ and empty them into the __________ tract. Excretory wastes are then eliminated with ________________
wastes. The major excretory product of arachnids is ___________ _________, which is a _____________ and has little water
________. Gas exchange also occurs with ___________ water loss because arachnids have few _____________ respiratory
surfaces. Some arachnids have structures called __________ ____________, that are modifications of the book gills. Book
lungs are ______ invaginations of the ____________ body wall that fold into a series of leaflike lamellae. Air enters the book
lung through a slitlike opening and ______________ between the lamellae. Respiratory gases ____________ between the
blood moving among the lamellae and the air in the lung chamber. Other arachnids have a series of ____________, chitinlined tubules that deliver air directly to body tissues. These tubule systems called _____________ open to the
______________ through openings called ________________ along the ventral side of the abdomen. The circulatory system
of arachnids is an ______ system in which a _________ contractile vessel (heart) pumps blood into tissue ___________ of
the hemocoel. Blood _____ the tissues and then returns to the dorsal ___________ through openings in the aorta called
________. Arachnid blood contains the dissolved respiratory pigment _________________ and has amoeboid cells that aid
in ____________ and body defenses. The nervous system of all arthropods is ____________ and is laid out in a pattern
similar to the _____________. With the exception of the ____________, the nervous system is centralized by the
______________ of _____________. The body of the arachnid has a variety of __________ structures. Most
mechanoreceptors and chemoreceptors are modifications of the ________________, such as projections, ____________, and
slits, together with sensory and accessory cells. All together these are known as ___________. Examples of these structures
include: __________ hairlike structures that initiate nerve impulses, _____________ receptors, spiders use ____________ to
capture prey and the size to capture is determined by the vibrations of the insect. Chemical receptors stimulate ________
cells. Arachnids have _________ or more pairs of _________, which they use for detecting ____________ and ___________
in light intensity. Arachnids are ____________ with paired ____________ openings on the ventral side of the ____________
abdominal segment. Sperm transfer is __________ and the sperm is packaged in a spermatophore, then transferred to the
___________. Courtship rituals take place with individuals of the same ___________ by attraction to a female who is
positioned to ___________ the spermatophore. _______________ does occur in some species where sperm is transferred via
___________. Development is ___________, and the young ___________ from eggs as _______________ adults.
Order Scorpionida
Members of the order Scorpionida are the __________________, which are common from _____________ to warm
______________ climates. Scorpions are ________________ and __________________, hiding during the day under logs
and stones. Scorpions have a _______________ that is ______________ into a shield-like carapace, and small ___________
project anteriorly from the front of the carapace. They have a pair of posterior enlarged chelate _____________, and the
opisthosoma is ________________. They have a preabdomen with __________ __________ and chemical receptors called
________________, and genital openings. They have a postabdomen or ____________ with a ___________ that contains
___________-producing glands. Prior to _________________, male and female scorpions have a period of courtship that
lasts from _________ minutes to several hours. Male and female scorpions face each other and extend their ___________
high in the _______. The male seizes the female with his pedipalps, and they repeatedly walk ______________ and then
_________________. The _____________ portion of the male reproductive tract forms a spermatophore that is __________
on the ground. During courtship the male ______________ the female so that the genital opening on her abdomen is
positioned over the __________________. Downward ______________ of the female’s abdomen on a triggerlike structure
of the spermatophore releases __________ into the female’s genital chamber. Most arthropods are _______________,
females lay eggs that develop _____________ of the body. Many scorpions and some other arthropods are
___________________, development is ____________ and the yolk provides nourishment for development. Some scorpions
are ______________, meaning that the mother provides nutrients to nourish the embryos. Eggs develop in the __________
in association with the digestive tract. Nutrients pass from the digestive tract to the embryo, where development requires up
to _________ years, and _________ to ___________ young are brooded. After birth, the young ________ onto the mother’s
__________ where they remain for up to a ____________.
Order Araneae
There are about _______________ species of order Araneae, the _____________ group of arachnids. The prosoma bears
chelicerae with ____________ glands and __________. Pedipalps are leglike, and in males are modified for ____________
transfer. The ____________ anterior margin of the carapace usually has ________ to ___________ eyes. They have a
_________ pedicel attached to the prosoma, and the abdomen is ____________ and contains openings to the reproductive
tract, _________ __________, and trachea. It also has ___________ projections called ______________ associated with
__________ glands. The protein that forms silk is emitted as a _______________, but ______________ as it is drawn out.
Spiders produce different kinds of ___________ for different uses. Most spiders feed on _________ and other arthropods that
they hunt and capture in ____________. Spiders bite their prey to ____________ them and then __________ them in their
silk. They puncture the prey’s body wall and inject _____________. The spider’s _____________ stomach then
___________ predigested prey products into the spider’s ____________ tract. The ____________ of most spiders is
______________ to humans. _____________ widow and the __________ recluse spiders are exceptions with _______
venom to humans. Mating of spiders involves ______________ behaviors that include chemical, ___________ and/or visual
signals. Females deposit chemicals called ___________________ on their webs or bodies to attract males. A male may
attract a female by plucking the strands of a female’s __________. The pattern of plucking is species __________ and helps
to identify and locate potential ________ and prevents the male spider from becoming the female’s next _________. The
male has an ____________ that is a penislike structure that is inserted into the female’s reproductive opening and sperm are
discharged. The female deposits up to __________________ eggs in a silken egg _______________, which she seals and
attaches to webbing and then _____________ with her.
Order Opiliones
Members of the order Opiliones are the ____________ or daddy longlegs. The prosoma joins the opithosoma, and legs are
very _________ and ___________. Most daddy longs legs are ______________, and other are strictly ___________. They
seize prey with their __________ and ingest prey as other arachnids described before. Digestion is both _____________ and
_____________. Sperm transfer is ___________ with the male penislike structure. Females have a tubular ______________
that projects from a sheath at the time of egg laying. Females deposit _____________ of eggs in ___________ locations on
the ground.
Order Acarina
Members of the order Acarina are the __________ and _________. Many are ____________ on humans and domestic
animals. Others are free-living in both _______________ and ______________ habitats. Of all arachnids, acarines have had
the greatest impact on human __________ and welfare. Mites are ________mm or less in length. The prosoma and
opisthosoma are __________ and covered by a _______________. An anterior ____________ carries mouthparts. Chelicerae
are modified for ____________, biting, anchoring,and ______________, and adults have ________ pairs of walking legs.
Free- living mites may be ______________ or scavengers. These mites damage ________________ products. Parasitic mites
usually do not ____________ attach to their hosts, but __________ for a few hours or days and then drop to the ground. A
few mites are ______________ ectoparasites. Itch mites cause scabies in humans and other animals by tunneling in the
_____________ of the skin, eggs are deposited and ____________ of the mites irritate the skin, and ___________ occur.
Ticks are ectoparasites during their __________ life. They may be up to _________ cm in length. Hooked mouthparts are
used to attach to their hosts and to feed on ___________. Copulation occurs on the _________, and after feeding, females
drop to the ground to __________ eggs. Eggs hatch into _____-_________ seed ticks that feed on host blood. Some ticks
transmit _______________ to humans and domestic animals, like Rocky Mountain spotted fever.
Class Pycnogonida
Members of the class Pycnogonida are the __________ spiders. All are __________ and worldwide, but most common in
________ water. Pycnogonids live on the ocean __________ and feed on cnidarian polyps. Sea spiders feed by ___________
prey tissues through a proboscis or ______________ are prey with their first pair of appendages called
__________________. Pycnogonids are _________________ with ______-shaped gonads that branch to the __________.
As the female releases eggs, the male _____________ them, then ____________ them into a round mass and attaches them
the appendages of the
Male called _____________, where they brood until hatching.
Subphylum Crustacea
The subphylum Crustacea includes many different organisms such as _____________, shrimp, lobsters, crabs, copepods,
cladocerans, fairy shrimp, isopods, amphipods, and _____________. Except for some isopods and crabs, all crustaceans are
______________. Crustaceans __________ from other living arthropods in _________ ways. They have ________ pairs of
antennae, whereas all other arthropods have __________ pair or _________. Crustaceans possess ______________
appendages, each consists of a basal segment called the __________________, with two rami attached. The medial ramus is
the _______________ and the lateral ramus is the _____________. Trilobites had ______________ structures which is
evidence for close relation to ancestral crustaceans. There are _________ classes of crustaceans and many orders.
Class Malacostraca
Malacostraca is the _______________ class of crustaceans that includes _________, lobsters, crayfish, shrimp, mysids,
shrimplike krill, isopods, and amphipods. The order ______________ is the ______________ order of crustaceans and
includes shrimp, crayfish, _____________, and crabs. ____________ have a laterally compressed muscular abdomen and
pleopods for _______________. Lobsters, crabs, and crayfish are adapted to ________________ on the surface of the
substrate. The body of the crayfish is divided into ________ regions. The crayfish has a ________________, fused head and
and chest which is anterior and a posterior ____________ or tail. Paired appendages are ____________ in _________ body
regions. The first two pairs of cephalothoracic appendages are the first and second _______________. The third and fifth
pairs of appendages are associated with the ____________. During crustacean evolution, the __________ pair of appendages
became modified into chewing and grinding structures called ____________. The fourth and fifth pairs of appendages are for
food handling and are called _______________. The sixth through the eighth appendages are called
______________________ and are accessory _____________ and food handling appendages. The _________ two pairs of
maxillipeds have __________. Appendages __________ to _________ are thoracic appendages called ______________. The
first periopod is the cheliped and enlarged pincer used for ________________. All but the last pair of appendages of the
abdomen are called ______________ (swimmerets) used for swimming. In females developing eggs attach to the
________________ and the embryos are brooded until hatching. In males the ________ two pairs of pleopods are modified
into gonopods used for __________ transfer during copulation. The abdomen ends in a median extension called the
_____________. The telson bears the __________ and is flanked by the biramous appendage of the last segment called
____________. The telson and uropods are effective ____________ used in swimming and escape. Crayfish prey upon other
invertebrates, eat __________ matter and scavenge __________ and ____________ animals. The foregut includes an
enlarged _____________ which is used for ________________. A digestive gland secretes digestive _____________ and
______________ products of digestion. The midgut extends from the stomach and is called the __________. A short hindgut
ends in an ___________ and is important in _________ and _________ regulation. Gills are in a branchial chamber, and
oxygen and carbon dioxide are exchanged between ______________ and ____________ across the gill surfaces, and a
respiratory pigment, ____________ carries oxygen in blood plasma. Circulation in crayfish is similar to that of most
arthropods. Dorsal, anterior, and posterior arteries lead ___________ from a muscular __________. Branches of these
vessels empty into ___________ of the hemocoel. Blood _______________ to the heart __________ in a ventral sinus and
enters the gills before returning to the pericardial sinus, which ______________ the heart. Crustacean nervous systems show
trends similar to those in ____________ and arachnids. Crayfish have supraesophageal and subesophageal __________ that
receive sensory input from receptors in the ________ and control the head appendages. The ____________ nerves and
segmental ganglia _________, and ___________ neurons in the ventral nerve cord function in __________ responses. In
addition to antennae, the sensory structures of crayfish include __________ and ____________ eyes, statocysts,
chemoreceptors, proprioceptors and tactile setae. Chemical receptors are distributed all over the appendages and __________.
When a crustacean is crawling or resting, stretch receptors at the joints are _____________. The endocrine system of a
crayfish controls functions such as ecdysis, ______ determination and color change. Endocrine glands release chemicals
called _____________ into the blood, where they circulate and cause responses at certain ___________ tissues. The
excretory organs of crayfish are called _________________ glands (green glands) because they are at the bases of the second
antennae and are ____________. Excretory products form by the filtration of ___________. Ions, sugars, and amino acids are
_________________ in the excretory tubule before the diluted ______________ is excreted. ____________ is the primary
excretory product. Gill surfaces are also important in ______________ excretion and water and ion regulation. Crayfish and
all other crustaceans except the ______________ are _____________. ___________ are in the dorsal portion of the thorax
and gonoducts open at the base of the ___________ (____________) or ___________(_____________) periopods. Mating
occurs just after a female has _____________. The male turns the female onto her ____________ and deposits nonflagellated
sperm near the openings of the female gonoducts. Fertilization occurs after copulation as the eggs are _________. The eggs
are __________ and fasten to the female’s pleopods. The development of crayfish embryos is _____________ with young
hatching as miniature _________.
Two other orders of malacostracans are the ____________ which include ___________. Isospods are dorsoventrally
flattened and may be aquatic or terrestrial, and __________ decaying plant and animal material. Terrestrial isopods live under
rocks and logs and in ___________ ____________. Members of the Amphipoda have a laterally compressed body that gives
them a ________________ appearance. Amphipods move by ____________ or _____________ on their sides along the
substrate. Some species burrow, climb or jump. Amphipods are _______________ and some are parasites.
Class Branchiopoda
Members of the class Branchiopoda live in _________________ and have flattened leaflike appendages used in
________________, filter feeding, and locomotion. Fairy shrimp and brine shrimp comprise the order Anostraca. Fairy
shrimp usually live in temporary ____________ that spring thaws and rains form. Eggs are brooded and hen the female
_______, and the temporary pond begins to __________, the embryos become _______________ in a resistant capsule.
Embryos lie on the forest floor until the ponds ____________ again the following spring when they hatch into larva. Brine
shrimp also form _____________ embryos and live in __________ lakes and ponds. Members of the order Cladocera are
called _________ _________. A large _________ covers their bodies and they _____________ by repeatedly thrusting their
__________ antennae downward to create a jerky upward locomotion. Females reproduce parthenogenitically in spring and
summer and can _______________ populate a pond or lake. Eggs are brooded in an _________ _________, and at the next
_________ the egg case is released and either floats or sinks.
Class Maxillopoda
Members of the class Maxillopoda are ___________ crustaceans that recognized by their __________ bodies and the unique
combination of __________ head, ____________ thoracic, and ___________ abdominal segments plus a telson.
Pentastomida is made up of ______________ of the _____________ passages of reptiles, birds and mammals.
Subclass Copepoda
Members of the subclass Copeopoda include some of the most ___________ marine and freshwater crustacean species.
Copepods have a _____________ body, and the first antennae are modified for ________________, and the _____________
is free of appendages. Most copepods are planktonic and ________________ ____________________.
Subclass Thecostraca
The barnacles are members of the infraclass Cirripedia that _____________, and highly modified as adults. They are all
__________ with about ________ thousand species. Most barnacles are _________________. Barnacles attach to a variety
of substrates including _________, ship bottoms, whales, and other animals.