Bio Lab Wksht & HW Questions 37

Bio Lab Wksht & HW Questions 37 - organs there They...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
32 Many platyhelminthes are internal parasites of vertebrates. Based on the specimens you observed, can you think of any specific adaptations they have for a parasitic lifestyle? Phylum Rotifera Rotifers are pseudocoelomate, free- living marine and freshwater animals that swim and feed with an anterior ciliated corona , and break up food particles with complex internal jaws (the mastax ). Unlike the Platyhelminthes, they have a complete digestive tract with mouth and anus. If living rotifers are on display, watch the action of these two structures. Phylum Annelida Members of this phylum are eucoelomate, segmented worms. The segments are usually divided internally by transverse septa (sing. septum ), membranous partitions that separate each segment. Most annelids show evidence of cephalization (development of an anterior head, and concentration of nervous system and sense
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: organs there). They have closed circulatory systems (i.e. distant from the heart, the arteries and veins are connected by capillaries), and a complete gut (mouth and anus present). Three classes, the Polychaeta, Oligochaeta and Hirudinea, will be examined. Class Polychaeta Members are marine. Polychaetes have lateral, fleshy parapodia beset with numerous setae , and well developed head appendages such as jaws, tentacles and eyes. What function(s) do you think parapodia serve? Polychaetes may be tube dwellers, bottom wanderers, or planktonic swimmers. Polychaetes include carnivores, herbivores, omnivores and scavengers. They are dioecious (have separate sexes). Sketch a representative polychaete and label the parapodia. Distinguish between setae and septa....
View Full Document

{[ snackBarMessage ]}

Ask a homework question - tutors are online