BioLab7 Flashcards
Where are annelida found?
In moist terrestrial environments.
What are annelida?
Segmented worms.
What type of symmetry do annelids have?
Bilateral.
What type of digestive system do annelids have?
Tubular digestive tract.
What is the body plan of annelids?
Triploblastic coelomates.
How do annelids move?
Segmentation. Contractions of muscles against the fluid within the coelom allow for powerful forward locomotion.
What type of skeleton do annelids have?
Hydrostatic.
Where do Lumbricus live?
In burrows two metres deep within moist soil during the day, come out at night to feed on organic detritus.
What is the protective covering on the Lumbricus that must be kept moist and allows for respiration?
Cuticle.
What is the clitellum?
A structure that secretes a thick mucus to attach worms together while they exchange sperm. Later this structure produces a cocoon which houses the fertilized eggs until a young worm develops
How do Lumbricus reproduce?
Hermaphroditic; 3 large seminal vesicles that store sperm and two small seminal receptacles that receive sperm.
What is firmness in the earthworm due to?
Pressure of the coelomic fluid (hydrostatic skeleton).
How do earthworms move?
alternating waves of contraction muscles moving posteriorly along the worms body. Each segment has circular and longitudinal muscles which act against the fluid within the coelom of that segment antagonistically to each other.
Describe Lumbricus Ingestion and Digestion.
Pharynx takes food from mouth. Food goes through esophagus and is temporarily stored in the crop. It then passes to muscular gizzard to be ground up. It is digested and absorbed in the long intestine and undigested material is eliminated through the anus.
Who are friends of the Lumbricus?
Nereis (sandworm) and Leeches.
What does the phylum Mollusca consist of?
clams, oysters, squids, octopus, snails, and slugs.
What is a defining feature of Mollusca?
Their soft bodies.
What are the 3 common regions of the Mollusca body?
Foot, Visceral mass, and Mantl
What does the visceral mass contain?
The internal organs.
What is the mantle?
A fold of tissue which secretes the shell.
What is the symmetry of mollusks?
Bilateral.
What is the body plan of mollusks?
Triploblastic coelomate.
What is the digestive system of Mollusks?
Tubular digestive tract.
Are mollusks segmented?
No.
What is Pomacea commonly referred to as?
The apple or mystery snail.
Where does pomecea live?
Southern North America.
What do Pomacea feed on?
They are omnivorous and feed on algae, terrestrial plants, detritus, and decaying animals.
How do Pomacea reproduce?
Sexually. There are separate sexes. Sperm and egg fuse together to form zygotes which grow into new individuals.
Where are Pomacea egg masses laid?
Above the waterline to protect against predators.
What structures does the Pomacea use for respiration?
Gills and lungs
How does pomacea move?
Muscular contraction that pass down the length of the foot and the it glides on a film of mucus that is secreted from a gland at the anterior end of the foot.
What is the operculum?
A disc-shaped structure on the dorsal surface of the foot tat functions to cover the body of the snail when it retreats into its shell.
What is the radula used for?
It bears many teeth to eat plants and scrape food off of rocks.
Who are some friends of Pomacea?
Helix, Clam, Octopus, and Squid
What groups are included in Anthropoda?
Crustaceans, eight-legged arachnids, six-legged insects, centipedes, and millipedes.
What definable features do Anthropoda have?
Jointed appendages and an exoskeleton made of chitin.
What is molting?
A process where anthropods periodically shed their exoskeleton in order to grow.
What is the body plan of anthropods?
Triploblastic coelomate.
What are the three regions that anthropods are divided into?
head, throax, and abdomen.
How do Cambarus respirate?
Through gills located in their thorax.
What do Cambarus prey on?
Small aquatic animals, dead plant and animal matter. They are both predators and detrivores.
What structure protects and provides points of attachment for Cambarus?
Hard chitinous exoskeleton.
How does cambarus escape danger?
By quickly doing a tail flip, bending abdomen rapidly, and propelling itself backwards through the water.
Why can the crayfish move?
Because the exoskeleton has joints which attach to muscles and can extend and flex. Muscles act against each other and against hydrostatic pressure of body fluids.
What is the Cambarus’ body divided into?
Cephalothorax covered by carapace. Abdomen is posterior to this.
What are the antennae of the Cambarus?
There is a long pair and a short branched pair. They are sensory and are sensitive to tactile and chemical stimuli.
What are the cheliped used for?
They bear large pincers for defense, subduing prey, and sexual display.
What are the 6 pair mouthparts and how do they work?
3 pair maxillipeds and 2 pair maxillae to break up food particles and guide them to the mouth. The 1 pair of mandibles are for cutting up and grinding the food.
Where are the walking legs of the Cambarus attached?
The cephalothorax.
What are the pincers on the 2 anterior walking legs used for?
Searching for food and transferring food to the mouth
How does the Cambarus move water over its gills while it is resting?
It slowly moves its walking legs from side to side. This helps it obtain oxygen.
What do the telson and uropods of the Cambarus make up?
The tail fin.
What are pleopods?
Found on anterior abdominal segments and create a current of water that passes over gills and aids in respiration. Males have 3 pairs and Females have 5.
What are gonopods?
Transfer sperm in males to the seminal receptacle in females. Males have 2 pairs.
How do female cambarus reproduce?
Produce egg in internal ovaries. Release eggs and stored sperm. Fertilized eggs and newly hatched young are carried on pleopods.
What was a factor in the success of insects?
Diversification of the mouthparts.
What are some friends of cambarus?
Spiders, ticks, centipedes, grasshoppers, shrimp, and crabs
