Gnathifera Flashcards
Gnathifera Taxonomy
Phylum Gnathostomulida
Phylum Rotifera
Phylum Acanthocephala
Phylum Micrognathozoa
Phylum Gnathostomulida Characteristics
80 species Small, intestinal, parasitic worms Pharynx with unique jaws Monolayered, monociliated epidermis for protection No circ or resp systems Protonephridia Hermaphroditism
Phylum Micrognathozoa Characteristics
Single species
Complex body (head, thorax, abdomen)
Thorax has plates for protection
Unique adhesive pad to attach to structures
Parthenogenesis reproduction: polar bodies act like sperm to restore diploid
Found on moths in Greenland
Gnathifera Common Name
Jawed Animals
Phylum Acanthocephala Characteristics
1200 species Obligate intestinal parasite Eversible proboscis (retracts inside out) with proboscis receptacle Syncytial body wall with lacunar canals Ligament sac Gonochoristic
Acanthocephala Males
Cement gland: covers cloaca to stop any other mating
Acanthocephala Females
Ovary balls: float freely in ligament sac fluid
Acanthocephala Ligament Sac
Extends from posterior end of proboscis receptacle to near genital pore, subdividing pseudocoel
Contains ovarian balls
Acanthor Stage: Acanthocephala
Following copulation and fertilization, fertilized eggs develop into acanthors to be released to exit host encased in protective shells
Develop further only when in invertebrate host = intermediate host
Phylum Rotifera
Wheeled animals Bio indicator Triploblastic Bilateral symmetry No respiratory or circulatory systems FW, marine, semi-terrestrial, few parasitic Omnivores Pelagic- external body moves independent of body
Rotifera Defining Characteristics
Corona: feeding structure
Pseudocoelom
Glycocalyx: carb structure surrounding body for protection
Lamina Layer: thick, protective fluid filled cavity
Mastax: grinds food
Rotifera Musculature
Muscles in defined muscle bands
Hydrostatic skeleton
Rotifera Digestion/Feeding
Mastax: grinds food Complete digestive system Stomach uses enzymes to break down food Intestine absorbs nutrients Omnivores Corona: outer ring; collection of cilia to move water and catch food to bring to mouth
Rotifera Foot and Toes
Annulated: ringed/body broken into rings which allows for telescoping movement
Cement glands: allow to cement in place to hold on
Rotifera Nervous System
Collection of nerve cell bodies to control movement
Antenna: sensory structures for muscles
Rotifera Excretion
Protonephridia:
Rotifera Reproduction (Cl. Monogononta)
Parthenogenesis: diploid females produce diploid eggs by mitosis and develops into diploid female = amictic females
Mictic females: produce haploid eggs through meiosis that turn into haploid males to mate with females to introduce genetic differences; promoted by change in environment
Rotifera: Cl. Monogononta Characteristics
Sessile: many have protective tube
Lorica: protective outer cuticle (hinders telescoping)
Sticky mucus: catches stuff for tube such as fecal pellets for protection
Polymorphic Development: change morphologically in response to predator
Rotifera: Monogononta–Polymorphic Development
Change morphology in response to predators
