Nematode trapping fungi

Question 1

What phylla contain carnivorous fungi

Answer 1

• over 150 described species
• Chytridiomycota
• Oomycota
• Zygomycota
• Basidiomycota
• Deuteromycota

Question 2

How many times did carnivory in fungi evolve

Answer 2

• at least 5 times
• very convergent/parallel
• similar morphological adaptations

Question 3

What 3 problems must a fungi overcome to prey upon an animal

Answer 3

• catch
• immobilize
• efficiently exploit

Question 4

Who was Charles Drechsler

Answer 4

• PhD student of Roland Thaxter
• studied plant disease/fungi associated with the USDA
• Led to carnivorous fungi

Question 5

What are the two main types of carnivorous fungi (non-taxonomic)?

Answer 5

• Those that capture small, slow “animals” like amoebae/protzoans
• Those that capture large, quick animals like nematodes and rotifers

Question 6

What three types of nematophagous fungi are there?

Answer 6

• Predatory with hyphae extending into substrate
• Endoparasitic
• Parasite of eggs or cysts

Question 7

What are common traits of predatory fungi

Answer 7

• extensive hyphal development away from host
• Amount of growth reliant upon frequency of successful captures
• wide variety of capture organs

Question 8

What are the capture organs of predatory fungi

Answer 8

• Adhesive hyphae
• Adhesive branches
• Adhesive nets
• Adhesive knobs
• Non-constricting rings
• Constricting rings

Question 9

What are adhesive hyphae in predatory fungi

Answer 9

• Non sophisticated trapping device
• characteristic of non-septate zygomycetes
• adhesive produced directly on hyphae along the whole length at any point in response to nematode contact

Question 10

What are traits of the genus Stylopage in the genera of zygomycota

Answer 10

• Following capture, appressorium
• long, slow death
• penetration, absorptive hyphae
• migration of fungal protoplast with septal construction

Question 11

What are adhesive branches

Answer 11

• found in asexual fungi
• very simple, works well for small nematodes
• a few erect cells lateral to hyphae, often in close proximity
• simplest and most primitive organ of capture in higher fungi

Question 12

What are adhesive nets

Answer 12

• more common and widespread than any other trapping device
• 2 or 3D loops with adhesive on surface
• restricted to deuteromycetes

Question 13

What are adhesive knobs

Answer 13

• like branches, but with a single swollen cell at the end

- evolved independently in deutero and basidiomycetes

Question 14

what are non-constricting rings

Answer 14

• often associated with adhesive knobs
• only in dueteromycetes
• ring can detach and germinate once host reaches new env

Question 15

what are constricting rings

Answer 15

• common in deuteromycetes
• most sophisticated
• when nematode enters the 3 celled ring, there is rapid expansion
• takes .01s for cells to inflate to max size and 3x increase in cell volume

Question 16

What are endoparasitic fungi

Answer 16

• Ecologically obligate parasites

- Conida can be ingested or attach to cuticle, then germinate and digest host