Gnathiferans

Question 1

how does a pseudocoelomate cross section compare to that of an Annelid?

Answer 1

• walls that divide coelom broke down
• pseudocoelom consists of blastocoelic material

Question 2

what features did pseudocoelomates lose secondarily?

Answer 2

• coeloms and all derived functions
• blood vessels
• metanephridia

Question 3

what classes are within Rotifora?

Answer 3

Monogononta, Bdelloidea, Seisonidae

Question 4

what does Rotifora mean?

Answer 4

“wheel bearers”

Question 5

what are the traits of Rotifora?

Answer 5

• corona (ciliated ring) for feeding
• straight digestive tract
• “toes” for attachment
• gonochoristic
• syncytial cuticle (plasma membranes of cells merge together into one cytoplasm)
• eutely (fixed number of cells at maturity)

Question 6

describe trophi and their purpose

Answer 6

• secreted from pharynx
• hardened biting structures for grasping, crushing or piercing prey
• connected to muscle that can contract or extend trophi

Question 7

what are Acanthocephalans?

Answer 7

spiny headed parasitic organisms

Question 8

what traits does Acanthocephala have?

Answer 8

• no corona
• no digestive tract (ends at pharynx)
• no trophi
• spiked proboscis
• especially large reproductive system

Question 9

what traits does Gnathostomulida have?

Answer 9

• marine
• benthic
• no corona
• trophi
• deposit feeders
• eutelic

Question 10

what phyla are under Gnathifera?

Answer 10

• Rotifora
• Gnathostomulida
• Micrognathozoa
• Acanthocephala

Question 11

What are two other phyla similar to these groups of animals?

Answer 11

Cycliophora and Gastrotricha

Question 12

what features does Cycliophora have?

Answer 12

• straight digestive system
• suspension feeders using buccal funnel (cilia ring)
• adhesive disc on posterior
• niche is on crustacean mouths
• males are ectoparasites on females

Question 13

what features does Gastrotricha have?

Answer 13

• deposit feeders
• ciliated anterior end for feeding
• uses cilia on ventral to crawl