Gnathifera Flashcards
What are Gnathifera?
- group of 4 phylum that share a specific, unique trait (Eutely)
- Gnathifera = jaw bearers
What is Eutely?
- where the number of cells is fixed at adulthood. (at some point, cell division stops)
- growth of organism is done by increasing cell size, not cell number
What phylums are included in Gnathifera?
- rotifera
- Gnathostomulida,
- Micrognathozoa
- Chaetognatha
What are two implications of eutely?
- that they cant regenerate lost body parts
- they cannot perform asexual reproduction via fission
Some main morphological aspects of gnathifera?
- all have complex pharyngeal jaws
- are non-molting
- all have pseudocoelomate
What are the defining characteristics of rotifera?
- mastax and trophi
- ‘toes’ with adhesive glands
Rotifera ______ particulates
FILTER
What is the corona in rotifera?
- two lobes covered in cilia, which creates a water current
- has 4 main function
What are the 4 main functions of rotifera corona?
- bring food particles in
- aids in respiration, bringing oxygenated water into the body
- flushes away waste gases, other waste products
- used for mobility/locomotion
what is the syncytial epidermis in rotifera?
- a single, whole body continuous cellular space
- houses a lattice work of proteins that provides structural support and protection
What are trophi in rotifera?
- they are their jaws
- hard structure made of proteins/calcium used for feeding and grinding food
Trophi are ______ specific in rotifera
SPECIES
Rotiferans use the ______ as a hydrostatic skeleton
PSEUDOCOELOM
What are the three classes of rotifers?
- seisonidea
- bdelloidea
- Monogonata
are rotifers hermaphroditic or gonochoristic?
gonochoristic, have separate sexes
the rotifera class __________ only has females, which reproduce via ________
BDELLOIDEA, PARTHENOGENESIS
under stressful conditions, rotifera class _________ may switch from asexual reproduction to sexual
MONOGONATA
What is cryptobiosis?
function of rotifers where they try to withstand hard or stressful conditions by slowing their metabolism down so they appear dead
What are Phylum Acanthoceophala? defining characteristics?
- spiny-headed worms that are exclusively parasitic (endoparasites)
- defining characters: ligament sacs, proboscis with hooks
Ancanthoceophala are thought to be closely related to rotifers due to ….
them both having a syncytial epidermis
Acanthoceophala are ________, and after mating the male will create a ____ _____ so the female cant mate with other males
Acanthoceophala are GONOCHORISTIC , and after mating the male will create a SPERM PLUG so the female cant mate with other males
