Phylum Annelida
Annelids are worms with segmented bodies. They have a true coelom lined with tissue derived from the mesoderm. Internal walls between the segments is called the septa. The satae is the bristles attached to the segments.
These can eat decaying vegetation, they can be predators, or filter feeders. They use their pharynx to collect food. Filter feeders fan water through tube-like burrows and catch food particles in a mucous bag.
They typically have a closed circulatory system. It is where blood is kept in a network of blood vessels. Aquatic annelids use gills for respiration. Land annelids take in oxygen through their skin.
Annelids excrete through the anus. Cellular waste with nitrogen is eliminated through the nephridia, which is the organs that filter fluid in the coelom.
Many have well developed nervous systems with a brain and nerve cords. There are different adaptions for detecting stimuli: sensory tentacles, chemical receptors, statocysts, and two or more pairs of eyes.
Burrowing annelids use circular and longitudinal muscles to force their way through heavy sediment. Marine annelids have paddle-like appendages, parapodia, on each segment, which they use to swim and crawl.
They mainly use sexual reproduction. A few are hermaphroditic, and others use external fertilization. The clitellum is a band of thicker specialized segments that secrete a mucous ring where eggs and sperm are released.
There are three groups of annelids. Oligochaetes typically have streamlined bodies and a few satae. Most live in soil or fresh water. Leeches are external parasites that suck blood from the host. Polychaetes are marine dwellers that have paddle-like appendages with satae.
These can eat decaying vegetation, they can be predators, or filter feeders. They use their pharynx to collect food. Filter feeders fan water through tube-like burrows and catch food particles in a mucous bag.
They typically have a closed circulatory system. It is where blood is kept in a network of blood vessels. Aquatic annelids use gills for respiration. Land annelids take in oxygen through their skin.
Annelids excrete through the anus. Cellular waste with nitrogen is eliminated through the nephridia, which is the organs that filter fluid in the coelom.
Many have well developed nervous systems with a brain and nerve cords. There are different adaptions for detecting stimuli: sensory tentacles, chemical receptors, statocysts, and two or more pairs of eyes.
Burrowing annelids use circular and longitudinal muscles to force their way through heavy sediment. Marine annelids have paddle-like appendages, parapodia, on each segment, which they use to swim and crawl.
They mainly use sexual reproduction. A few are hermaphroditic, and others use external fertilization. The clitellum is a band of thicker specialized segments that secrete a mucous ring where eggs and sperm are released.
There are three groups of annelids. Oligochaetes typically have streamlined bodies and a few satae. Most live in soil or fresh water. Leeches are external parasites that suck blood from the host. Polychaetes are marine dwellers that have paddle-like appendages with satae.