Transcript Major Divisions of Life

Phylum Onychophora The Velvet
Worms
Characteristics of the Phylum Onychopora
Characteristics of the Phylum Onychopora
• Bilaterally symmetrical with a through gut.
Characteristics of the Phylum Onychopora
• Bilaterally symmetrical with a through gut.
• Body with 14-43 pairs of un-jointed fleshy legs.
Characteristics of the Phylum Onychopora
• Bilaterally symmetrical with a through gut.
• Body with 14-43 pairs of un-jointed fleshy legs.
• Well developed hemocoelic body cavity with a
open circulatory system.
Characteristics of the Phylum Onychopora
• Bilaterally symmetrical with a through gut.
• Body with 14-43 pairs of un-jointed fleshy legs.
• Well developed hemocoelic body cavity with a
open circulatory system.
• Cuticle covered epidermis, with ecdysone
mediated molting (ecdysis).
Characteristics of the Phylum Onychopora
• Bilaterally symmetrical with a through gut.
• Body with 14-43 pairs of un-jointed fleshy legs.
• Well developed hemocoelic body cavity with a
open circulatory system.
• Cuticle covered epidermis, with ecdysone
mediated molting (ecdysis).
• Gaseous-exchange organs simple tubular
tracheae issuing in tufts from small spiracles.
Anatomy
Legs with claws
Anatomy
Anatomy
Oral Papilla
Lips and Jaws
Well Developed Eyes
Circulation and Gas Exchange
Circulatory system is an
open and very similar to
the arthropod hemocoel
circulatory system.
Gas exchange is by
tracheae.
Reproduction
• Accept for one species all dioecious.
• Males deposit spermatophor around or
on the female. (ovoviviparous and
viviparous)
Viviparous species have a “placenta”
like structure.
About 110 species all terrestrial
However their fossils have been found
in the Middle Cambrian marine
faunas.
Hallucigenia sparsa an Onychophoran from the Burgess
Shale deposits of Canada
Aysheaia, from the Middle Cambirian
Phylum Tardigrada the Water Bears
Characteristics of the Phylum Tardigrada
Characteristics of the Phylum Tardigrada
• Bilaterally symmetrical; minute, squat. 0.3-0.5
mm.
Characteristics of the Phylum Tardigrada
• Bilaterally symmetrical; minute, squat. 0.3-0.5
mm.
• A through straight gut.
Characteristics of the Phylum Tardigrada
• Bilaterally symmetrical; minute, squat. 0.3-0.5
mm.
• A through straight gut.
• Body monomeric although with four pairs of
short un-jointed claw-bearing legs.
Characteristics of the Phylum Tardigrada
• Bilaterally symmetrical; minute, squat. 0.3-0.5
mm.
• A through straight gut.
• Body monomeric although with four pairs of
short un-jointed claw-bearing legs.
• Coelom has been thought to be a pseudocoelom
however, more recently they think it is a
reduces hemocoel.
Characteristics of the Phylum Tardigrada
• Bilaterally symmetrical; minute, squat. 0.3-0.5
mm.
• A through straight gut.
• Body monomeric although with four pairs of
short un-jointed claw-bearing legs.
• Coelom has been thought to be a pseudocoelom
however, more recently they think it is a
reduces hemocoel.
• Ecdysone mediated molting like arthropods.
Anatomy
Well Developed Stylet For Feeding
Reproduction
• Sexual and parthenogenesis are the
reproductive modes exhibited in the
Tardigrada.
Reproduction
Most lay Ornamental eggs.
Reproduction
Reproduction
Biology
• Scientists have reported tardigrades in hot springs, on
top of the Himalayas, under layers of solid ice, and in
ocean sediments.
• Many species can be found in milder environments
such as lakes, ponds, and meadows, while others can be
found in stone walls and roofs.
• Most tardigrades live in the water/air
interface.
Biology
• Tardigrades are one of the few groups of species that are
capable of reversibly suspending their metabolism and going
into a state of cryptobiosis.
• Several species regularly survive in a dehydrated state for
nearly 10 years. Depending on the environment, they may
enter this state via anhydrobiosis, cryobiosis, or other ways.
• Their metabolism lowers to less than 0.01% of normal and
their water content can drop to 1% of normal. Their ability
to remain desiccated for such a long period is largely
dependent on the high levels of sugar which protects their
membranes.
Tardigrades Produce Tuns
Tardigrade Tun