Phylum Echinodermata II

Question 1

Holothuroidea Body Form

Answer 1

No arms 
Elongation along the oral-aboral axis 
Bivium: two tube feet on the upper side 
Trivium: 3 tube feet on the lower side 
Microscopic ossicles embedded in the dermis: flexible, muscular wall

Question 2

Holothuroidea feeding

Answer 2

Large buccal podia extending out the oral side used for feeding
Finely branched buccal podia used for suspension feeding
Truncated buccal podia used for deposit-feeding (mop like)

Question 3

Holothuroidea WVS

Answer 3

Bivium (dorsal)
Trivium (ventral)
Buccal podia
Suspension or deposit feeding
Internal madreporites: sits within the perivisceral coelom
Very large Polian vesicles (water resoivoire)

Question 4

Cuverian Tubules

Answer 4

Toxic and sticky

Contraction of circular body wall muscles eject these from the anus for defense

Question 5

Evisceration

Answer 5

The gut is connected within the body by mutable collagenous tissue
The organism chooses to fail the collagenous tissue at its connections
Circular body muscles contract to push gut outside the anterior end
Done in defence or some on a yearly basis

Question 6

Holothuroidea Distinctive Characteristics (6)

Answer 6

Sausage shape (no arms)
Microscopic Ossicles 
Muscular body wall 
Spacious perivisceral coelom 
Buccal podia for feeding 
Respiratory trees