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are Acoel flatworms a separate phylum?

are Acoel flatworms a separate phylum?. YES!! no gut (syncytial digestive tissue, vacuolar digestion) DNA evidence, with caveat unique form of spiral cleavage almost no extracellular matrix (ECM), no basement membrane in epithelia unique ultrastructure of cilia NO! biflagellate sperm

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are Acoel flatworms a separate phylum?

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  1. are Acoel flatworms a separate phylum? YES!! no gut (syncytial digestive tissue, vacuolar digestion) DNA evidence, with caveat unique form of spiral cleavage almost no extracellular matrix (ECM), no basement membrane in epithelia unique ultrastructure of cilia NO! biflagellate sperm hermaphroditic, complex reproduction, direct development http://www.umesci.maine.edu/ biology/labs/platyhelm.htm other turbellarians (Neodermatida) have a statocyst (gravity sensor), though a bit different and a somewhat similar ciliary ultrastructure and reduced ECM

  2. Science, vol 283 19 March 1999 Platyhelminthes acoel flatworms

  3. Barbara C. Boyer, Jonathan J. Henry and Mark Q. Martindale (1998) The Cell Lineage of a Polyclad Turbellarian Embryo Reveals Close Similarity to Coelomate Spiralians, Developmental Biology, Volume 204, Pages 111-123

  4. acoel "duet" spiral cleavage Jonathan Q. Henry, Mark Q. Martindale and Barbara C. Boyer (2000) The Unique Developmental Program of the Acoel Flatworm, Neochildia fusca, Developmental Biology, Volume 220, Issue 2, Pages 285-295

  5. Matthew D. Hooge, a graduate student at the University of Maine, wins AMS 2002 Photomicrography Contest with epifluorescence image of musculature in an acoel flatworm

  6. Columbian mangroves http://www.earthisland.org /map/mgim2.htm Mangrove basic biology photo by K. Veach “mangrove” is a descriptive, not a taxonomic term - i.e. a great example of convergent (“parallel”, technically) evolution coastal communities in the tropics, extending a bit into the sub-tropics often found upland, and lining the lagoons inland, of coral reefs many contain breathing pores in roots called “lenticels”; closed at high tide some can excrete salt through their leaves; others can ultra-filter the salt out during uptake of water into the roots many are “viviparous”: i.e. embryos are “brooded” on the plant seeds use water for dispersal

  7. worldwide mangrove distribution (32° North to 38° South)

  8. Invertebrate communities in mangrove swamps high abundances of zooplankton (including micro- and macro-zooplankton) - many are mangrove specialists sponges and ascidians - notably grow on (encrust) the roots rich fauna of sediment, “infaunal” and “epifaunal” dwellers - notably many species of nematodes and annelids (esp. oligochaetes) prawns and shrimp - especially important as “nurseries” (also true for spiny lobsters) barnacles and ispopods (these tend to be destructive) crabs - including many mangrove specialists - important, predators, herbivores, detritovores, diggers, scavengers... insects (herbivores, parasites, predators, leaf & stem borers...) molluscs - bivalves and snails Kathiresan and Bingham (2001) Biology of Mangroves and Mangrove Ecosystems.Adv. Mar. Biol. 40: 81-251

  9. sponges and ascidians protect mangrove roots from isopod damage roots without sponges/ascidians had more damage and 55% lower growth rates in places where, because of local conditions, roots were not covered by sponges/ascidians, 100% of roots showed isopod damage Ellison and Farnsworth (1990) JEMBE142: 91-104

  10. Aaron M. Ellison, Elizabeth J. Farnsworth, Robert R. Twilley (1996) Facultative Mutualism Between Red Mangroves and Root-Fouling Sponges in Belizean Mangal Ecology, Vol. 77, pp. 2431-2444.

  11. Aaron M. Ellison, Elizabeth J. Farnsworth, Robert R. Twilley (1996) Facultative Mutualism Between Red Mangroves and Root-Fouling Sponges in Belizean Mangal Ecology, Vol. 77, pp. 2431-2444.

  12. Aaron M. Ellison, Elizabeth J. Farnsworth, Robert R. Twilley (1996) Facultative Mutualism Between Red Mangroves and Root-Fouling Sponges in Belizean Mangal Ecology, Vol. 77, pp. 2431-2444.

  13. “rootlets” (root hairs) result in increased C uptake by sponges (“epibiont”; particularly Haliclona) associated with mangroves (Rhizopora) -- no change in C uptake in plant tissues with or without root hairs (this shows one advantage to the sponge of the association with mangroves, resulting from root hair production) Aaron M. Ellison, Elizabeth J. Farnsworth, Robert R. Twilley (1996) Facultative Mutualism Between Red Mangroves and Root-Fouling Sponges in Belizean Mangal Ecology, Vol. 77, pp. 2431-2444.

  14. shrimp ("prawn") aquaculture may represent the biggest modern threat to the world's mangroves the giant tiger shrimp, Penaeus monodon www.cmfri.com/cmfri_cfd.htm members.aol.com/brosenberr/ Species.html

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