1 / 43

Phylum Annelida

Phylum Annelida. Phylum Annelida. Terrestrial, marine, freshwater. Repeating segments. Triploblastic. True coelomates – complete gut. Closed circulatory system. Well developed nervous system. Respiratory organs. Protostome development. Metamerism (unspecialized) segmentation.

duncan
Download Presentation

Phylum Annelida

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Phylum Annelida

  2. Phylum Annelida Terrestrial, marine, freshwater. Repeating segments. Triploblastic. True coelomates – complete gut. Closed circulatory system. Well developed nervous system. Respiratory organs. Protostome development. Metamerism (unspecialized) segmentation. One or more pairs of setae.

  3. Phylum Annelida • Ancestral Traits • Coelomate • Lophotrochozoan- non-molting protostomes • Protostome • Closed circulatory system • Cephalization • Derived Traits • Segmentation • Metamerism • Septa • Setae • Bristles • Myelinated neurons Spirobranchus giganteusChristmas tree worm ~ 40K species of annelids

  4. Systems • Integument- epidermis is one cell layer with mucous gland that secrete a moist cuticle. • Skeletal -hydrostatic (using coelom) • Muscle- longitudinal and circular muscles Each segments muscles are independent of the other segments. • Digestive- complete, complex, with absorption and digestive glands and excretory cells.

  5. Systems (continue) • Excretory- a pair of nephridia per segment. • Respiratory -through skin, some through parapodia; tubeworms have gills. • Circulatory- closed system, use hemoglobin as oxygen carrier. • Nervous- dorsal brain; ventral, double, solid nerve cord, with gangliain each segment. • Endocrine- hormones secreted by nervous system. • Reproductive- • Dioecious in Polychaeta; no special organs, posterior end becomes gonads. • Monoecious in Oligochaeta and Hirudinea; Clitellium.

  6. Annelid Taxonomy • Phylum Annelida (an-nel-i-da) • Class Polychaeta (poly-key-ta) • Nereis, Aphrodita, Chaetopterus, Arenicola, Amphitrite • Class Clitellata • Subclass Oligochaeta (ol-e-go-key-ta) • Lumbricus, Tubifex • Subclass Hirudinea (hi-ru-din-e-a) • Hirudo, leech • Earthworm dissection

  7. Annelid Taxomony • Class Polychaeta (many bristles) • most numerous # species • marine Hermodice crunculata

  8. Annelid Taxomony • Class Polychaeta • Class Clitellata • Subclass Oligochaeta (few bristles) • Freshwater, marine & terrestrial Lumbricus terrestris

  9. Annelid Taxomony • Class Polychaeta • Class Clitellata • Subclass Oligochaeta • Subclass Hirudinea • Fixed # segments (34) • Setae absent Hirudo medicinalis

  10. Annelid Phylogeny

  11. Annelid Body Plan Setae

  12. Class Polychaeta • Highly specialized head regions • Antennae • Sensory palps • Feeding appendages • Paired extensions of body(parapodia) • Often tube-dwelling • Burrow into substrate and secrete mucus/ CO3 materials Bispira bunnea sabellid worm Spirobrancheus giganteus

  13. Polychaete Anatomy http://www.telegraph.co.uk/news/picturegalleries/picturesoftheday/9093134/Pictures-of-the-day-20-February-2012.html

  14. Parapodia with setae

  15. Polychaete Anatomy (cross section)

  16. Polychaeta Amphitrite

  17. Polychaeta Lugworm (Arenicola sp)

  18. Polychaeta

  19. Polychaeta Parchement worm

  20. Clade-Siboglinidae Riftia pachyptila Ridgea sp

  21. Giant tube worms (Vestimentifera) trophosome Riftia pachyptila http://www.bbc.co.uk/nature/life/Polychaete/by/rank/all

  22. Polychaete Reproduction • Most are dioecious-few monoecious • Some asexually but sexually more common • Trochophore larvae • Some species develop specialized segments containing gametes • Epitokes • Segments are released and gametes burst out

  23. Polychaete Asexual Reproduction • Epitokes are essentially buds • Clues to ancestral origin of segmentation • Segmentation may have been derived from incomplete budding processes

  24. Typosyllis nipponica Samoan palolo worm Palola viridis

  25. Class Oligochaeta

  26. Class Oligochaeta • Defining characteristics • Pronounced cylindrical glandular region of the body = clitellum • Second largest class in the phylum Annelida • Most spp. are earthworms, very few are marine Phylum Annelida

  27. Polychaetes and Oligochaetes • Oligochaetes differ from polychaetes in several ways: • No parapods, fewer setae (if at all) • Hermaphroditic with sex cells produced in a separate section • No larval stages Giant Gippsland earthworm Phylum Annelida

  28. Oligochaete Anatomy

  29. Oligochaete Anatomy

  30. Setae: a.k.a. Bristles

  31. Oligochaete Reproduction

  32. Oligochaete Development • For terrestrial oligochaetes, development is direct without any larval forms • Some aquatic oligochaetes retain a trochophore-like larval stage Site for earthworm anatomy: http://www.naturewatch.ca/english/wormwatch/resources/anatomy.html

  33. Quick and Easy Earthworm Morphology Guide -Earthworms can be classified by size, burrowing habits, and color -Number, location and pattern of genital tumescences (GT) and tubercular pubertatis (TP) -Location & shape of clitellum Aporrectodea turgida Lumbricus rubellus

  34. Common Terrestrial Oligochaetes: Earthworms Octagonal Tail Worm Dendrobaenaoctaedra Eisenia foetida Redworm http://www.earthlife.net/inverts/oligochaeta.html This link shows diversity of Oligochaetes!

  35. Earthworm Dissection Return to taxonomy Cross section

  36. Aquatic Oligocheates

  37. Subclass Hirudinea • Defining characteristics • Posterior sucker • Predominately freshwater, but do occur in all seas and moist soil • Leeches do not burrow, lack parapods and setae • Clitellum only visible during breeding Phylum Annelida

  38. Horse leech-actually feeds on small worms Haemopis sanguisuga Great Amazon Leech Haementaria ghiliani

  39. Subclass Hirudinea

  40. Leech Anatomy • Anterior sucker is small and contains the mouth • Anterior sucker creates a wound with saw like jaws • Leeches drink other animals’ blood, usually vertebrates • Can be carnivores, or scavengers; leeches are not set in their feeding habits Phylum Annelida

  41. Hirudo medicinalis More leech info: http://www.earthlife.net/inverts/hirundinae.html

  42. Leech Reproduction • Leeches are simultaneous hermaphrodites that lack a free-living larvae stage • Fertilization is internal through copulation • Development occurs in a cocoon similar to the Oligochaetes Phylum Annelida

More Related