Search results
Results from the WOW.Com Content Network
A few marine annelids that live in tubes lack cuticles, but their tubes have a similar structure, and mucus-secreting glands in the epidermis protect their skins. [8] Under the epidermis is the dermis , which is made of connective tissue , in other words a combination of cells and non-cellular materials such as collagen.
Trochophores exist as a larval form within the trochozoan clade, which include the entoprocts, molluscs, annelids (including echiurans and sipunculans) and nemerteans. Together, these phyla make up part of the Lophotrochozoa; it is possible that trochophore larvae were present in the life cycle of the group's common ancestor.
Lamellibrachia luymesi is a cold seep tube worm that reaches lengths of over 3 m and may be the most long-lived annelid, being over 250 years old. A still unclassified multilegged predatory polychaete worm was identified only by observation from the underwater vehicle Nereus at the bottom of the Challenger Deep , the greatest depth in the ...
In the most recent research, the three phyla Cycliophora, Entoprocta and Bryozoa makes up a single clade and are the first to branch off from the other lophotrochozoans. The second split is the molluscs, and the third consists of two sister phyla, annelids and nemerteans. Lastly remains the clade that consist of the phoronids and the brachiopods.
It is a muscular structure for suction on a host or substrate. In parasitic annelids , flatworms and roundworms , suckers are the organs of attachment to the host tissues. In tapeworms and flukes , they are a parasitic adaptation for attachment on the internal tissues of the host, such as intestines and blood vessels. [ 1 ]
Oligochaeta (/ ˌ ɒ l ɪ ɡ ə ˈ k iː t ə,-ɡ oʊ-/) [1] is a subclass of soft-bodied animals in the phylum Annelida, which is made up of many types of aquatic and terrestrial worms, including all of the various earthworms.
Molluscs are generally regarded members of the Lophotrochozoa, [28] a group defined by having trochophore larvae and, in the case of living Lophophorata, a feeding structure called a lophophore. The other members of the Lophotrochozoa are the annelid worms and seven marine phyla. [31] The diagram on the right summarizes a phylogeny presented in ...
Feather-duster worms have a crown of feeding appendages or radioles in two fan-shaped clusters projecting from their tubes when under water. Each radiole has paired side branches making a two-edged comb for filter feeding. Most species have a narrow collar below the head. The body segments are smooth and lack parapodia.