Description: Order Canalipalpata are the bristle-footed Annelids or fan-head worms. They have no jaws or teeth. Most have grooved, ciliated tentacles with which they feed. Terebellids are mostly sessile tubeworms. Family Alvinellidae is found in the deep sea at hydrothermal vents. They usually build mucus tubes and feed with flattened, ciliated tentacles, plus obtain nutrition from episymbiotic bacteria living on their surface. Paralvinella palmiformis has a body with 100-118 segments, which gradually taper posteriorly (see photo above). The prostomium is reduced in its middle portion. A set of many smooth, grooved tentacles forms the buccal apparatus. Males also have two robust peribuccal tentacles that end in three rounded lobes bordered with papillae, and two blind cavities on the ventral side of the peristomium. The featherlike branchiae (gills) fan out anteriorly, dorsal to the feeding tentacles. The first 20-31 chaetigerous segments have only notopodia (no neuropodia), and segment 7 is highly modified. Color pinkish when preserved in alcohol, brownish red in life. Length up to 8 cm.
How to Distinguish from Similar Species: Of other species that may be found at Pacific Northwest hydrothermal vents, P. pandorae has only about 60 chaetigerous segments and only the first 3 chaetigerous segments have only notopodia. It is light brown to pink in alcohol. P. sulfincola has only about 54-68 chaetigerous segments, and the first 24-30 have only notopodia. Its body doesn't taper much until the last 10 segments. It may turn chocolate brown when preserved in formalin.
Geographical Range: Deep-sea hydrothermal vents in the NE Pacific: Gorda Ridge, Explorer Ridge, Juan de Fuca Ridge
Depth Range: Deep sea, about 2000 m
Habitat: The sulfide chimneys of hydrothermal vents.
live with caudal end coiled around other worm tubes or attached to the
surface of sulfide chimneys. They are a deposit feeder and
themselves with mucus. Paralvinellids also are symbiotic with
bacteria which live on the mucus. Can withstand rather high
(up to 45 C, Rinke and Lee 2009), but not as high as its
sulfincola can. At its highest
temperatures it increases
heat-shock protein levels (Dilly et al., 2012). Glycine is
osmolyte, and it contains less thiotaurine, which may be used in
detoxification, than does P.
sulfincola. The species contained no
et al., 2009). Aerobic metabolism appears to dominate in the
while anaerobic metabolism (glycolosys) appears to be more prominent in
the body wall (Rinke and Lee, 2009).
Dilly, Geoffrye F., C. Robert Young, William S. Lane, Jasmyn Pangilinan, and Peter R. Girguis, 2012. Exploring the limit of metazoan thermal tolerance via comparative proteomics: thermally induced changes in protein abundance by two hydrothermal vent polychaetes. Proceedings of the Royal Society B-Biological Sciences 279:1741 pp 3347-3356
Juniper, S. Kim, and Pascale Martineu, 1995. Alvinellids and sulfides at hydrothermal vents of the eastern Pacific: A review. American Zoologist 35:2 pp 174-185
Rinke, C. and R.W. Lee, 2009. Pathways, activities, and thermal stability of anaerobic and aerobic enzymes in thermophilic vent paralvinellid worms. Marine Ecology Progress Series 382: pp 99-112
Yancey, Paul H., Joanna Ishikawa, Brigitte Meyer, Peter Girguis, and Raymond W. Lee, 2009. Thiotaurine and hypotaurine contents in hydrothermal-vent polychaetes without thiotrophic endosymbionts: correlation with sulfide exposure. Journal of Experimental Zoology Part A-Ecological Genetics and Physiology 311A:6 pp 439-447
General Notes and
abundances, unusual behaviors:
My thanks to Kirt Onthank for providing me the preserved specimens photographed on this page.
This view of the head of a preserved specimen shows the
used for feeding, plus the bushy gills dorsal to them. In
animal would be
A view of the dorsal (gill) side of the head. The
segment (setiger), with a parapodium
can be seen near the bottom center. A small amount of debris
become attached to the tops of the
In this view of the first several segments, dorsal is right,
is left, and the head is downward. The bumps along the sides
This closeup of the parapodia
on a posterior section of the body shows the well-developed notopodium
Authors and Editors of Page:
Dave Cowles (2014): Created original page
CSS coding for page developed by Jonathan Cowles (2007)
Salish Sea Invertebrates web site provided courtesy of Walla