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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Nereis, Phyllodoce, Colycera Pelagic polychaetes: Sense organs on prostomium and peristomium are well developed due to the free swimming and crawling habit.
Crawling polychaetes belong to order Errantia which includes marine, freely moving animals that crawl on sea bottom. The Hawaiian honeycreepers are known for their beaks, which are specialized to satisfy a wide range of dietary needs: Its parapodia are modified for clinging and mouth parts transform into piercing stylets for sucking blood. Body is covered with stiff and iridescent setae for protection. Lake Victoria Rock Cichlids: Feeding is done by the peristomial funnel, mouth, ciliated groove and three fans on segments Direct deposit feeders include burrowing and tube-dwelling species.
Based on the form and construction the tubicolous burrows are of following types:. Darwin’s finches are an often-used textbook example of adaptive radiation.
ln Modes of life of Polychaetes Posted on: Tanganyika Cichlids in their natural habitat, 3rd Edition. The cactus finches Geospiza sp. Locomotory organs or parapodia are large, they bear setae which can be retracted and protruded out in various directions for crawling among rocks and stones. Genesis, explosive speciation, key-innovations and phylogeography of the haplochromine cichlid fishes”. And accordingly they show great adaptive diversity.
Polychaete diversity | Zoology for IAS, IFoS and other competitive exams
They are also known radiatiion planktonic polychaetes. 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.
Malawi Cichlids in their natural habitat, 5th edition. Parapodia are reduced as they do not find any use.
This page was last edited on 26 Novemberat Class Polychaeta shows the greatest diversity in Phylum Annelida. This organically rich sand is then ingested by the worm.
Explain adaptive radiations in Polychaeta –
This causes the sand to cave in forming a funnel-shaped depression at the surface. Adaptive radiation is not a strictly vertebrate phenomenon, and examples are also known from among plants.
Cirri are generally longer as they carry tangoreceptors and help in locating food. The most famous example of adaptive radiation in plants is quite possibly the Hawaiian silverswordsnamed for alpine desert-dwelling Argyroxiphium species with long, silvery leaves that live for up to 20 years before growing a single flowering stalk and then dying.
Pectenaria, Owenia, Diopatra, Clymenella. In Myxicolathe gill filaments are joined by a thin sheet and form a semicircle at the apex, in which polychaetx is captured. The giant or emperor cichlid Boulengerochromis microlepis is a piscivore often ranked the largest of all cichlids though it competes for this title with South America’s Cichla temensisthe speckled peacock bass.
These tubes act as protective covering. Parchment tubes- These kinds of tubes are membranous, usually U-shaped. Majority of the species of polychaetes are marine and exhibit a variety of habits and habitats. The three most radiaiton examples of these radiations are presented below, though insects like the Hawaiian drosophilid flies and Hyposmocoma moths have also undergone adaptive radiation.
These are tube dwelling polychaetes. Hawaii has served as the site of a number of adaptive radiation events, owing to its isolation, recent origin, and large land area.