How are earthworms and leeches alike?
leeches. Leeches are segmented, and thus annelids, and like earthworms they lack the parapodia found in polychaetes and possess a clitellum for reproduction. They differ from earthworms in that they are flatter and actually lack a complete coelomic cavity; which most annelids do have.
What do leeches and Oligochaetes have in common?
The Acanthobdellae are considered to be the link between the oligochaetes and leeches because they possess setae and walls between segments; the order contains only one known species, however. The three remaining orders of leeches evolved into two lines based on whether or not the animals have jaws.
What are some unique features only found in leeches?
Regardless of how you view the leech, this relative of the humble earthworm has a fascinating array of physical features.
- Cylindrical Body. Like all members of the family Allenida, or “ringed worm,” leeches have cylindrical bodies.
- Segments. The leech’s body is segmented.
- Suckers.
- Proboscis.
- Five Pairs of Eyes.
What is the difference between Polychaetes and Oligochaetes?
Polychaetes refer to the marine annelids, with unsegmented swimming appendages with many chaetes. Meanwhile, oligochaetes refer to the hermaphroditic terrestrial or aquatic annelids that lack a specialized head.
What is the largest annelid class?
polychaetes
Are segmented worms the most advanced group of worms?
Annelids show the presence of a true coelom, derived from embryonic mesoderm and protostomy. Hence, they are the most advanced worms. A well-developed and complete digestive system is present in earthworms (oligochaetes) with a mouth, muscular pharynx, esophagus, crop, and gizzard being present.
Why are earthworms classified as oligochaeta?
Earthworms (Oligochaeta) The subclass Oligochaeta contains all the animals commonly thought of as ‘earthworms’. Long thin worms with no obvious appendages to their bodies and greatly reduced heads, so that when the animal is still it is not always obvious which end is the head and which is the tail!
Do leeches have tongues?
About three quarters of leech species are parasites that feed on the blood of a host, while the remainder are predators. Leeches either have a pharynx that they can protrude, commonly called a proboscis, or a pharynx that they cannot protrude, which in some groups is armed with jaws.