Are polychaetes predatory?
Polychaetes also include active predators, scavengers and grazers of algae.
How do bristle worms defend themselves?
Likely this speed and agility is used to avoid their predators, but they have another defense when needed: These worms are among the few species on the planet known to produce yellow bioluminescent light. When threatened, they shoot glowing sparks from their parapodia to distract predators as they make a getaway.
How do polychaetes avoid predators?
Some polychaete worms have developed a different strategy to avoid being eaten—they live inside a tube, which they make themselves. Most of these tube- dwelling worms are small and threadlike in appearance.
What are the major characteristics of polychaetes?
Class Polychaeta
- Metamerically segmented.
- Bilateral symmetry.
- Chitinous setae called parapodia.
- Schizocoelic.
- Closed circulatory system.
- Complete digestive system.
- Respiration through skin, gills or parapodia.
- Nephridia for excretion.
What are the ecological roles of polychaetes?
Polychaetes are extremely abundant in some areas. They play essential ecological roles, serving on one hand as predators on small invertebrates, and on the other as food for fish and large invertebrates.
What eats a bristle worm?
Fish and invertebrates that hunt bristle worms down and eat them include Arrow crabs, Coral Banded Shrimp, Wrasses, Flame and Long Nose Hawkfish, Orchid Dottyback and Neon Dottyback, Gobbies, Copperband Butterflyfish, Goatfish, Horseshoe crabs, and some Pufferfish species.
How do polychaetes feed?
The nereid polychaetes are free-moving predators that will consume large and small invertebrates using large proboscis jaws; they will also consume large amounts of detritus in the absence of prey items (Figure 5). Other families have filter-feeding and deposit-feeding representatives.
How do polychaetes breathe?
The smallest species, and those adapted to burrowing, lack gills, breathing only through their body surfaces. Most other species have external gills, often associated with the parapodia. A simple but well-developed circulatory system is usually present.
What is unusual about the jaws of some polychaetes?
In general, however, they possess a pair of jaws and a pharynx that can be rapidly everted, allowing the worms to grab food and pull it into their mouths. In some species, the pharynx is modified into a lengthy proboscis.
How do polychaetes reproduce?
On the other hand, polychaetes, which are mostly marine, reproduce asexually. One way they might do this is by fission, which is when the worm makes an exact copy of its DNA and then splits into two. It basically clones itself into a new individual!
Will wrasse eat bristle worms?
Are polychaetes free living predators?
About half the known polychaeta are free living predators or scavengers – and the other half live permanently in burrows. This has resulted in the polychaeta being divided into two ecological groups: the active forms that move around searching for food (called the Errantia)
What are polychaetes?
Pelagic polychaetes: They are also known as planktonic polychaetes. These kinds of polychaetes are adapted to live in open sea and are semi-transparent in appearance. They swim near the surface of the sea where the danger of predators and solar radiation is excessive.
How are polychaetes adapted to live in open sea?
These kinds of polychaetes are adapted to live in open sea and are semi-transparent in appearance. They swim near the surface of the sea where the danger of predators and solar radiation is excessive. Hence, their semitransparent body that imparts them near invisibility and thus protects them from predators.
Are Polychaeta worms marine or terrestrial?
The Polychaeta: Worms, Worms and More Worms. The Polychaeta is the largest and the most diverse of the Annelid groups. Most species are marine, but some have adapted to brackish or even fresh water and a very few are terrestrial.