ADAPTIVE RADIATION IN POLYCHAETA PDF

ADAPTIVE RADIATION IN POLYCHAETA PDF

ideal for examining adaptive radiations in extreme environments. Did dorvilleid northern California and Oregon, dorvilleid polychaetes. Polychaeta is the largest class of phylum Annelida. The following is the discussion of the adaptive diversity of polychaetes, swim near the surface of the sea where the danger of predators and solar radiation is excessive. Phylogeny and Adaptive Radiation, Segmented Worms in The Diversity of On the other hand, polychaetes with well-developed parapodia are generally.

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A cone of mucous is secreted on the anterior side for trapping food particles. These worms are carnivorous and extend out from the tube openings to catch the prey. Pectinaria, Owenia, Diopatra, Clymenella, Sabella. Nereis, Aphrodite, Polynoe, Eunice etc. Lizards in an Evolutionary Tree: Locomotory organs or parapodia bear setae which can be retracted and protruded out in various directions for crawling among rocks and stones.

These Madagascan examples are significantly older than most of the other examples presented here: The following is the discussion of the adaptive diversity of polychaetes. Their setae have become hook-like to anchor in the burrow.

They are also known rxdiation planktonic polychaetes. The beating of these ;olychaeta produces water current which enters the tube from the anterior end and flows out of the posterior end. Describe the Modes of life of Polychaetes. Most of the sedentary and tubicolous polychaetes are filter feeders. Crawling polychaetes belong to order Errantia which includes marine, freely moving animals that crawl on sea bottom. Their body is elongated, prostomium is reduced or absent.

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Polychaete Diversity

Lake Victoria’s cichlids are also a species flock, once composed of some or more species. Sabella or the peacock worm lives in vertical parchment tube and projects the fan-like tentacles which are covered with sticky mucous to which the minute food particles get attached and are carried to mouth through the ciliated groove.

Head bears sense organs such as eyes, tentacles, antennae, cirri and palps. They generally have polychaefa body that imparts them near invisibility. Radides are used in food collection. These tubes may measure about 70 cm long and 2. These polychaetes polyhcaeta well developed prostomium sense organs and parapodia.

Much like in the case of the cichlids of the three largest African Great Lakes, each of these islands is home to its own convergent Anolis adaptive radiation event. The cichlids of Lake Malawi constitute a “species flock” of up to endemic species.

Adaptive radiation – Wikipedia

Body segments are generally similar Ex: Eyes, tentacles and palps are also usually absent. Mouth has eversible pharynx. Tubicolous annelids are capable of secreting mucous or other adhesive substance to which sand and shell particles get attached and make the tube strong, e. Hawaii has served as the site qdaptive a number of adaptive radiation events, owing to its isolation, recent origin, and large land area.

Adaptive radiation is not a strictly vertebrate phenomenon, and examples are also known from among plants. In Arenicola posterior part of body is without parapodia and tentacles and palps are also reduced because of mud-ingesting habit.

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In these animals water current carries micro-organisms inside the burrow and then tentacles move the food towards the mouth. Retrieved from ” https: The Beak of the Finch: Vanadis, Tomopteris Burrowing polychaetes: The Ecology of Adaptive Radiation.

Today represented by approximately 15 species, Darwin’s finches are Galapagos endemics famously adapted for a specialized feeding behavior although one species, the Cocos finch Pinaroloxias inornatais not found in the Galapagos but on the island of Cocos south of Costa Rica. They swim near the surface of the sea where the danger of predators and solar radiation is excessive. This mucus bag ends in a ciliated food cup where the food is rolled up into a ball and passed forward to the mouth along the ciliary groove.

The food particles in this water current are filtered out into the mucous bag formed by ciliated glandular epithelium.

Adaptive radiation tends to take place under the following conditions: Malawi Cichlids in their natural habitat, 5th edition. Arenicola, Glycera, Amphitrite and Terebella Tubicolous polychaetes: Calcareous tubes- These tubes are made up of calcium. Sense organs on prostomium and peristomium are well developed due to the free swimming and crawling habit. Victoria is famously home to a large number of piscivorous cichlid species, some of which feed by sucking the contents out of mouthbrooding females’ mouths.