Animalscaretips
- Do annelids have internal or external segmentation?
- Do annelids have an external covering?
- Do annelids have internal organs?
- What is the characteristics of annelids?
- Which phylum has internal and external segmentation?
- Which phyla has both internal and external segmentation?
- What is the internal compartment of an annelid lined with?
- Do annelids have a cuticle?
- In which of the phylum Metamerism is observed internally as well as externally?
- Do annelids have an exoskeleton?
- What sensory structures do annelids have?
- Is a leech fertilization external or internal?
- What are the excretory organs of annelids called?
- Do the annelids have tissues?
Do annelids have internal or external segmentation?
In Summary: Phylum Annelida
Phylum Annelida includes vermiform, segmented animals. Segmentation is seen in internal anatomy as well, which is called metamerism. Annelids are protostomes.
Do annelids have an external covering?
Annelids have a body covered by an external cuticle that is never shed or molted. Epidermal microvilli secrete a network of fibers that are in part collagenous and also contain scleroprotein.
Do annelids have internal organs?
The internal organs of annelids are well developed. They include a closed, segmentally-arranged circulatory system. The digestive system is a complete tube with mouth and anus. Gases are exchanged through the skin, or sometimes through specialized gills or modified parapodia.
What is the characteristics of annelids?
Characteristics of Phylum Annelida
They have a long and segmented body. Annelids are bilaterally symmetrical. They are triploblastic. Also, they exhibit organ system grade of organisation, showing organ differentiation.
Which phylum has internal and external segmentation?
Annelids are often called “segmented worms” because they possess true segmentation of their bodies, with both internal and external morphological features repeated in each body segment.
Which phyla has both internal and external segmentation?
The annelids also known as the ringed worms or segmented worms, are a large phylum, with over 17,000 extant species including ragworms, earthworms, and leeches. Members of Annelida have both internal and external segmentation.
What is the internal compartment of an annelid lined with?
Tissues and fluids
The body cavity of annelids is lined by epithelium. Successive body segments are separated by walls that correspond to the external rings. In grooves between the segments of some oligochaetes are dorsal pores through which coelomic fluid may be discharged.
Do annelids have a cuticle?
The collagenous cuticle of annelids overlies the epidermis and, together with it, lines the gut, genital and excretory openings to various degrees, and also the chaetal follicles in polychaetes and oligochaetes. ... The annelid cuticle is unpigmented and the iridescence of many annelids is caused by interference effects.
In which of the phylum Metamerism is observed internally as well as externally?
In Annelids, the metamerism is clearly visible both externally and internally. Externally it is marked by the constriction on the skin of the body and internally it is marked by the partitions (septa). 7.
Do annelids have an exoskeleton?
The hardness of various parts of the exoskeleton in different arthropods is related to the thickness and degree of hardness of the cuticle. ... Annelids have a thin chitinous cuticle covering their bodies but it is not as well developed as in arthropods.
What sensory structures do annelids have?
Along with their centralized nervous system, annelids have a number of different sensory organs that help them to determine what is going on in their environments. These organs include the eyes, palps, and antennae located in the head region, which we discussed earlier.
Is a leech fertilization external or internal?
Leeches carry out a slight variation on this process by using the sperm to fertilize the eggs while they are still within the body. Once they are fertilized, the eggs are then deposited into the cocoon. Therefore, leeches have internal fertilization.
What are the excretory organs of annelids called?
Earthworms (annelids) have slightly more evolved excretory structures called nephridia, illustrated in Figure 2b. A pair of nephridia is present on each segment of the earthworm. They are similar to flame cells in that they have a tubule with cilia.
Do the annelids have tissues?
Like flatworms and roundworms, annelids are bilaterally symmetrical and have three tissue layers. However, the tissue layers are organized differently in each of the three groups of worms (Figure 23.16). ... The body cavity of annelids (as well as many other animals you will read about later) is called a coelom.
