Annelids, Onychophora, Tardigrades Flashcards
Annelids are known as ______ and live in what habitats
Segmented worms
Marine, freshwater and terrestrial
Annelida general characteristics
- body
- body wall
- coelom
- worm-like body that is divided both externally and internally into a series of repeating segments
- anterior segments of the body commonly unite to form a “head”
- body wall typically consists of a thin cuticle, glandular epidermis and two layers of muscle
- may have bristle-like setae protruding from body wall
- large coelom which is divided by transverse septa
Class-Polychaeta
-type
Annelids
Class-Polychaeta characteristics
- body
- organs
- sex types
- body consists of numerous segments. Each segment have have a pair of fleshy outgrowths of the body wall. These appendages are known as parapodia and often carry many setae.
- usually have a distinct head with eyes. Sense organs such as antennae, palps, and tentacles
- gonochoristics (separate sexes)
Nereis virens
- type
- body segments
- what toes of sense organs are on head
- what are parapodia used for?
- feeding habits
- phylum Annelida
- class-Polychaeta
- as many as 200 segments
- antennae, palps and tentacles
- feeding, locomotion, breathing
- predators and scavengers, carnivorous but can be omnivorous. Use proboscis with jaws
How do parapodia help Nereis sp. lifestyle
Parapodia aid in swimming, can extend/retract to aid in burrowing
Aphrodita sp.
- type
- how are setae arranged
Phylum Annelidia
Class-Polychaeta
Soft, hairlike setae all over back and form a felt. Also have smaller, stiffer setae for defence
Sabella sp.
- type
- what structural adaptations do these animals have associated with sedentary lifestyle
- phylum annelida
- class-polychaeta
-tube selling so it has feeding radioles for feeding and respiration
Class Clitellata
- habitat
- reproduction
- lacks which features
- Annelid
- freshwater and terrestrial
- hermaphroditic and have reproductive structure called clitellum
- head appendages and parapodia are absent
Subclasses of clitellata
Oligochaeta
Hirudinea
Most famous member of subclass Oligochaeta
Earthworm
Subclass Oligochaeta characteristics
- body
- head
- setae
- body plan is uniform with distinct segmentation
- head is poorly developed and lacks conspicuous sense organs
- very few setae per body segment
Lumbricus terrestris
- type
- is segmentation visible
- can use determine mouth easily
- where are setae
- phylum annelida, class Clitellata, subclass Oligochaeta
- yes
- on anterior end
- 2 rows on each segment
Lumbricus terrestris longitudinal section
- cuticle
- muscle layers
- are septa visible
- what is advantage of segmental septa in locomotion
- thin cuticle, must keep moist with mucus
- circular muscle loop around each segment and longitudinal along length of body
- allow flexibility and anchoring on some parts, while other move
Subclass-Hirudinea characteristics
- commonly known as
- body
- setae
- suckers
- leeches (blood sucking ectoparasite)
- bodies are not separated into compartments by septae
- small body segments have been modified to form anterior and posterior suckers
- most don’t have setae
Hirudo medicinalis
- type
- are locomotory appendages visible
- do they have body segments
- where is mouth located
Phylum annelida, class Clitellata, subclass Hirudinea
- no
- yes (34)
- mouth located in small anterior sucker
Hirudo sp. cross section
-how have the coelom and septa been modified
- no large and developed coelom, is partially divided by septa into small channels
- moves by musculature
Phylum Onychophorans
- habitat
- example
Terrestrial in moist areas
Velvet worms
Onychophoran characteristics
- body
- annelid characteristics
- arthropod characteristics
- worm-like and carried many short walking legs. Head has pair of antennae, pair of mandibles and a pair of oral papillae
- worm-like body with no joints on appendages, body wall with unspecialized layers of smooth muscle
- thin chitinous cuticle (exoskeleton), circulatory system is open and has a hemocoel, gas exchange via spiralled and a tracheal system
Peripatus sp.
- type
- papillae
- how many antennae
- what type of feeding habits
- are the legs jointed
- phylum Onychophorans
- small, wart like bumps that cover body
- 2 (1 pair)
- mandibles lacerate prey to eat sallee invertebrates like termites, and spiders
- NO JOINTS
What similarities do Peripatus and Lumbricus have in their cross sections
- Less space, lots of infolding
- worm-like appearance with segmentation
- no joints
- smooth muscle
Phylum Tardigrada
- also known as
- size
- habitat
- Water Bears
- microscopic
- surface film of freshwater that clings to terrestrial plants, or between sand grains on ocean floor
General characteristics of phylum Tardigrada
- mouthparts
- cryptobiosis
- temperature
- respiration
- larval stage
- shared arthropod characteristic
- stylet that can piece cell wall of plants
- dehydrate and reduce metabolic rate to very low levels to withstand bad environmental conditions (live for 10-100 years)
- can tolerate high temperatures, pressures or UV radiation, even vacuum
- no larval stage=mini adults
- chitinous cuticle which is she’s periodically, and claws (unjointed)
Class Polychaeta habitat
Range from highly active and free living (errant) to those that spend their lives in protective tubes
