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Didemnum vexillum - Sandwich, Massachusetts, Images



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October 4, 2004

Click here for video of Didemnum vexillum in tide pool at Sandwich, Massachusetts.

Video imagery DB_STP_MAvideo2. Tunicate colonies of Didemnum vexillum encrusting cobbles boulders and macro algae; shows typical colony growth upward from base of cobbles and boulders; also shows degenerating colony peeling off rock and being grazed by periwinkles (Littorina littorea). Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Video recorded at low tide. October 4, 2004. Video credit: Dann Blackwood (USGS). Location no. 1.
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June 2003
Image MC_STP_03, tunicate colonies of D. sp. in early stage of invasion of the Sandwich tide pool.
Image MC_STP_03

Image MC_STP_03. Tunicate colonies of Didemnum vexillum in early stage of invasion of the Sandwich tide pool. D. vexillum colonies are encrusting a boulder and overgrowing colonies of Botryllus schlosseri (dark green) and Botrylloides violaceus (small dark yellow colony in right center of the image). Boulder was lifted out of the water for photo; tunicate colonies are contracted. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. June, 2003. Collector: Mary Carman. Photo credit: Mary Carman, WHOI. Location no. 1.
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December 4, 2003
View of the Sandwich tide pool on the south side of the east entrance of the Cape Cod canal.
View of the Sandwich tide pool on the south side of the east entrance of the Cape Cod canal.

Image DB_STP_DSC0161. View of the Sandwich tide pool on the south side of the east entrance of the Cape Cod canal at low tide, looking east. Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
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Image DB_STP_DSC0132, tunicate colonies of the D. sp.  encrusting boulders, dark red algae, and the surrounding gravel seabed.
Image DB_STP_DSC0132

Image DB_STP_DSC0132. Tunicate colonies of Didemnum vexillum encrusting boulders, dark red algae, and the surrounding gravel seabed. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
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Image DB_STP_DSC0146, tunicate colonies of the D. sp.  encrusting a boulder and overgrowing dark red algae and pink calcareous algae.
Image DB_STP_DSC0146

Image DB_STP_DSC0146 Tunicate colonies of Didemnum vexillum encrusting a boulder and overgrowing dark red algae and pink calcareous algae. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
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Image DB_STP_DSC0149, tunicate colonies of the D. sp.  advancing over a boulder surface and overgrowing barnacles and a green encrusting sponge.
Image DB_STP_DSC0149

Image DB_STP_DSC0149 Tunicate colonies of Didemnum vexillum advancing over a boulder surface and overgrowing barnacles and a green encrusting sponge (cf. Halichondria sp.). Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
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Image DB_STP_DSC0155, tunicate colonies of the D. sp.  advancing up the side of a boulder and overgrowing barnacles, green algae, and dark red algae.
Image DB_STP_DSC0155

Image DB_STP_DSC0155 Tunicate colonies of Didemnum vexillum advancing up the side of a boulder and overgrowing barnacles, green algae, and dark red algae. D. vexillum is exposed here at low tide. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
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Image DB_STP_DSCN1840, tunicate colonies of the D. sp. encrusting the surface of a boulder and enveloping dark red algae.
Image DB_STP_DSCN1840

Image DB_STP_DSCN1840 Tunicate colonies of Didemnum vexillum encrusting the surface of a boulder and enveloping dark red algae. Note contrasting smooth and appendaged surfaces of the tunicate. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4 , 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
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Image DB_STP_DSCN1843, tunicate colonies of the D. sp.  overgrowing dark green algae (rockweed) attached to a boulder.
Image DB_STP_DSCN1843

Image DB_STP_DSCN1843 Tunicate colonies of Didemnum vexillum overgrowing dark green algae (rockweed) attached to a boulder. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
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Image DB_STP_DSCN1846, tunicate colonies of the D. sp. overgrowing dark red algae and green encrusting sponge attached to a boulder.
Image DB_STP_DSCN1846

Image DB_STP_DSCN1846 Tunicate colonies of Didemnum vexillum overgrowing dark red algae and green encrusting sponge attached to a boulder. Note contrasting smooth and appendaged surfaces of the tunicate. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
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Image DB_STP_DSCN1847, tunicate colonies of the D. sp. overgrowing dark green and dark red algae attached to a boulder.
Image DB_STP_DSCN1847

Image DB_STP_DSCN1847 Tunicate colonies of Didemnum vexillum overgrowing dark green and dark red algae attached to a boulder. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
Click here to download image.

Image DB_STP_DSCN1848, tunicate colonies of the D. sp.  growing out from the side of a boulder and displaying ropey or bearded morphology; and advancing over the adjacent seabed and displaying typical pancake batter morphology.
Image DB_STP_DSCN1848

Image DB_STP_DSCN1848 Tunicate colonies of Didemnum vexillum growing out from the side of a boulder and displaying "ropey or bearded" morphology; and advancing over the adjacent seabed and displaying typical "pancake batter" morphology. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
Click here to download image.

Image DB_STP_DSCN1852, tunicate colonies of the D. sp. growing on the sides of a boulder and beginning to display ropey or bearded morphology; and advancing over the adjacent seabed and displaying typical pancake batter morphology.
Image DB_STP_DSCN1852

Image DB_STP_DSCN1852 Tunicate colonies of Didemnum vexillum growing on the sides of a boulder and beginning to display "ropey or bearded" morphology; and advancing over the adjacent seabed and displaying typical "pancake batter" morphology. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
Click here to download image.

Image DB_STP_DSCN1854, tunicate colonies of D. sp.  encrusting the side of a boulder and overgrowing dark red algae.
Image DB_STP_DSCN1854

Image DB_STP_DSCN1854 Tunicate colonies of Didemnum vexillum encrusting the side of a boulder and overgrowing dark red algae. Note the contrasting "ropey" morphology on the boulder and the smooth morphology on the seabed below. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
Click here to download image.

Image DB_STP_DSCN1856, tunicate colonies of the D. sp. encrusting the sides of two boulders and overgrowing dark green and dark red algae.
Image DB_STP_DSCN1856

Image DB_STP_DSCN1856 Tunicate colonies of Didemnum vexillum encrusting the sides of two boulders and overgrowing dark green and dark red algae. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
Click here to download image.

Image DB_STP_DSCN1857,Tunicate colonies of the Didemnum sp.   encrusting the sides of two boulders and overgrowing dark green and dark red algae.
Image DB_STP_DSCN1857

Image DB_STP_DSCN1857 Tunicate colonies of Didemnum vexillum encrusting the sides of two boulders and overgrowing dark green and dark red algae. Close up of Image DB_STP_DSCN1856. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
Click here to download image.

Image DB_STP_DSCN1858, tunicate colonies of D. sp. encrusting the sides of two boulders and overgrowing dark green and dark red algae.
Image DB_STP_DSCN1858

Image DB_STP_DSCN1858 Tunicate colonies of Didemnum vexillum encrusting the sides of two boulders and overgrowing dark green and dark red algae. Close up of Image DB_STP_DSCN1856. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
Click here to download image.

Image DB_STP_DSCN1859, tunicate colonies of the D. sp. overgrowing dark green algae and displaying a ropey surface.
Image DB_STP_DSCN1859

Image DB_STP_DSCN1859 Tunicate colonies of Didemnum vexillum overgrowing dark green algae and displaying a "ropey" surface. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
Click here to download image.

Image DB_STP_DSCN1860, tunicate colonies of the D. sp. overgrowing dark green algae and developing a  surface.
Image DB_STP_DSCN1860

Image DB_STP_DSCN1860 Tunicate colonies of Didemnum vexillum overgrowing dark green algae and developing a "ropey" surface. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
Click here to download image.

Image DB_STP_DSCN1862, tunicate colonies of the D. sp. encrusting the sides of boulders and overgrowing dark red and dark green algae.
Image DB_STP_DSCN1862

Image DB_STP_DSCN1862. Tunicate colonies of Didemnum vexillum encrusting the sides of boulders and overgrowing dark red and dark green algae. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
Click here to download image.

Image DB_STP_DSCN1864, tunicate colonies of the D. sp. encrusting the sides of a boulder, overgrowing dark red algae, and beginning to advance over the adjacent seabed.
Image DB_STP_DSCN1864

Image DB_STP_DSCN1864 Tunicate colonies of Didemnum vexillum encrusting the sides of a boulder, overgrowing dark red algae, and beginning to advance over the adjacent seabed. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
Click here to download image.

Image DB_STP_DSCN1866, tunicate colonies of the D. sp. advancing over a boulder surface and overgrowing barnacles and a green encrusting sponge.
Image DB_STP_DSCN1866

Image DB_STP_DSCN1866. Tunicate colonies of Didemnum vexillum advancing over a boulder surface and overgrowing barnacles and a green encrusting sponge (cf. Halichondria sp.). Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
Click here to download image.

Image DB_STP_DSCN1871, tunicate colonies of the D. sp. on the side of a boulder  and overgrowing a green encrusting sponge.
Image DB_STP_DSCN1871

Image DB_STP_DSCN1871. Tunicate colonies of Didemnum vexillum on the side of a boulder and overgrowing a green encrusting sponge (cf. Halichondria sp.). Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
Click here to download image.

Tunicate colonies of the Didemnum sp.   encrusting the side of a boulder and showing the transition from the morphology on the boulder side to the smooth morphology on the seabed below.
Image DB_STP_DSCN1872

Image DB_STP_DSCN1872. Tunicate colonies of Didemnum vexillum encrusting the side of a boulder and showing the transition from the "ropey" morphology on the boulder side to the smooth morphology on the seabed below. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
Click here to download image.

Image DB_STP_DSCN1880, tunicate colonies of the D. sp. overgrowing the fronds of dark green algae.
Image DB_STP_DSCN1880

Image DB_STP_DSCN1880. Tunicate colonies of Didemnum vexillum overgrowing the fronds of dark green algae. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
Click here to download image.

Image DB_STP_DSCN1885, tunicate colonies of the D. sp.  encrusting the side of a boulder and overgrowing dark red algae.
Image DB_STP_DSCN1885

Image DB_STP_DSCN1885. Tunicate colonies of Didemnum vexillum encrusting the side of a boulder and overgrowing dark red algae. Note the red colony of the tunicate Botrylloides violaceus. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
Click here to download image.

Image DB_STP_DSCN1894, tunicate colonies of the D. sp. growing on the sides of a boulder and beginning to display  morphology; and advancing over the adjacent seabed and displaying typical  morphology.
Image DB_STP_DSCN1894

Image DB_STP_DSCN1894. Tunicate colonies of Didemnum vexillum growing on the sides of a boulder and beginning to display "ropey or bearded" morphology; and advancing over the adjacent seabed and displaying typical "pancake batter" morphology. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
Click here to download image.

Image DB_STP_DSCN1901, tunicate colonies of the D. sp. growing on the side of a boulder and overgrowing red and green encrusting sponges.
Image DB_STP_DSCN1901

Image DB_STP_DSCN1901. Tunicate colonies of Didemnum vexillum growing on the side of a boulder and overgrowing red and green (cf. Halichondria sp.) encrusting sponges. The leading edge of the tunicate colony is beginning to peel away from the upper edge of the boulder. Note the small colonies of D. vexillum beginning to grow on the upper surface of the boulder. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Collected at low tide. December 4, 2003. Collectors: Mary Carman and Page Valentine. Photo credit: Dann Blackwood, U.S. Geological Survey. Location no. 1.
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February 3, 2004
View of the Sandwich tide pool on the south side of the east entrance of the Cape Cod canal.
Image DB_STP_DSC0090

Image DB_STP_DSC0090. View of the Sandwich tide pool on the south side of the east entrance of the Cape Cod canal at low tide, looking east (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal, 11 foot (3.4 m) range. Water temperature 1 deg C. Observed at low tide. February 3, 2004. Photo credit: Dann Blackwood (USGS). Location no. 1.
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Image DB_STP_DSCN2010, Tunicate colonies of D. sp. encrusting a boulder and being preyed upon by the common periwinkle.
Image DB_STP_DSCN2010

Image DB_STP_DSCN2010. Tunicate colonies of Didemnum vexillum encrusting a boulder and being preyed upon by the common periwinkle, Littorina littorea. Note that the snails are numbered for comparison with the following images. Elliptical and subcircular holes in D. vexillum are interpreted to represent areas that have been grazed by the periwinkles. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Water temperature 1 deg C. Observed at low tide. February 3, 2004. Observers: Page Valentine (USGS) and Mary Carman (WHOI). Photo credit: Dann Blackwood (USGS). Location no. 1.
Click here to download image.

Image DB_STP_DSCN2011, tunicate colonies of D. sp. encrusting a boulder and being preyed upon by the common periwinkle.
Image DB_STP_DSCN2011

Image DB_STP_DSCN2011. Tunicate colonies of Didemnum vexillum encrusting a boulder and being preyed upon by the common periwinkle, Littorina littorea. Snail no. 1 has been removed to show area grazed through the D. vexillum colony. Elliptical and subcircular holes in D. vexillum are interpreted to represent areas that have been grazed by the periwinkles. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Water temperature 1 deg C. Observed at low tide. February 3, 2004. Observers: Page Valentine (USGS) and Mary Carman (WHOI). Photo credit: Dann Blackwood (USGS). Location no. 1.
Click here to download image.

Image DB_STP_DSCN2012, tunicate colonies of D. sp. encrusting a boulder and being preyed upon by the common periwinkle.
Image DB_STP_DSCN2012

Image DB_STP_DSCN2012. Tunicate colonies of Didemnum vexillum encrusting a boulder and being preyed upon by the common periwinkle, Littorina littorea. Snails no. 1, 2 and 3 have been removed to show areas grazed through the D. vexillum colony. Elliptical and subcircular holes in D. vexillum are interpreted to represent areas that have been grazed by the periwinkles. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Water temperature 1 deg C. Observed at low tide. February 3, 2004. Observers: Page Valentine (USGS) and Mary Carman (WHOI). Photo credit: Dann Blackwood (USGS). Location no. 1.
Click here to download image.

Image DB_STP_DSCN2015, tunicate colonies of D. sp. encrusting a boulder and being preyed upon by the common periwinkle.
Image DB_STP_DSCN2015

Image DB_STP_DSCN2015. Tunicate colonies of Didemnum vexillum encrusting a boulder and being preyed upon by the common periwinkle, Littorina littorea. Snails no. 1-6 have been removed to show grazed areas in the D. vexillum colony. Snails 1-3 have grazed through the tunicate, snail no. 4 has grazed the surface of the colony, and snails 5 and 6 were grazing the edges of a large hole in the colony when they were removed. Elliptical and subcircular holes in D. vexillum are interpreted to represent areas that have been grazed by the periwinkles. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Water temperature 1 deg C. Observed at low tide. February 3, 2004. Observers: Page Valentine (USGS) and Mary Carman (WHOI). Photo credit: Dann Blackwood (USGS). Location no. 1.
Click here to download image.

Image DB_STP_DSC0089, dead tunicate colonies of D. sp. peeling away from the top of a boulder exposed at low tide.
Image DB_STP_DSC0089

Image DB_STP_DSC0089. Dead tunicate colonies of Didemnum vexillum peeling away from the top of a boulder exposed at low tide. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Water temperature 1 deg C. Observed at low tide. February 3, 2004. Observers: Page Valentine (USGS) and Mary Carman (WHOI). Photo credit: Dann Blackwood (USGS). Location no. 1.
Click here to download image.

Image DB_STP_DSCN1994, dying tunicate colony of D. vexillum beginning to peel away from a boulder.
Image DB_STP_DSCN1994

Image DB_STP_DSCN1994. Dying tunicate colony of Didemnum vexillum beginning to peel away from a boulder. Colony surface shows a yellow discoloration; small dark spots are clusters of fecal pellets showing through the tunic. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Water temperature 1 deg C. Observed at low tide. February 3, 2004. Observers: Page Valentine (USGS) and Mary Carman (WHOI). Photo credit: Dann Blackwood (USGS). Location no. 1.
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Image DB_STP_DSCN1998, dying tunicate colony of D. vexillum peeling away from the side of a boulder.
Image DB_STP_DSCN1998

Image DB_STP_DSCN1998. Dying tunicate colony of Didemnum vexillum peeling away from the side of a boulder. Colony surface shows onset of yellow discoloration; small dark spots are clusters of fecal pellets showing through the tunic. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Water temperature 1 deg C. Observed at low tide. February 3, 2004. Observers: Page Valentine (USGS) and Mary Carman (WHOI). Photo credit: Dann Blackwood (USGS). Location no. 1.
Click here to download image.

Image DB_STP_DSCN1999, dying tunicate colony of D. vexillum peeling away from the side of a boulder.
Image DB_STP_DSCN1999

Image DB_STP_DSCN1999. Dying tunicate colony of Didemnum vexillum peeling away from the side of a boulder. Close-up of Image DB_STP_DSCN1998 showing ragged edge of colony with elliptical holes interpreted to represent areas that have been grazed by the common periwinkle Littorina littorea. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Water temperature 1 deg C. Observed at low tide. February 3, 2004. Observers: Page Valentine (USGS) and Mary Carman (WHOI). Photo credit: Dann Blackwood (USGS).Location no. 1.
Click here to download image.

Image DB_STP_DSCN2003, dying tunicate colony of D. vexillum peeling away from a boulder, exposing the underside of the colony.
Image DB_STP_DSCN2003

Image DB_STP_DSCN2003. Dying tunicate colony of Didemnum vexillum peeling away from a boulder, exposing the underside of the colony, which is being preyed upon by the common periwinkle, Littorina littorea. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Water temperature 1 deg C. Observed at low tide. February 3, 2004. Observers: Page Valentine (USGS) and Mary Carman (WHOI). Photo credit: Dann Blackwood (USGS).Location no. 1.
Click here to download image.

Image DB_STP_DSCN2001, dying tunicate colony of D. vexillum encrusting the side of a boulder.
Image DB_STP_DSCN2001

Image DB_STP_DSCN2001. Dying tunicate colony of Didemnum vexillum encrusting the side of a boulder. Colony surface shows a yellow discoloration; small dark spots are clusters of fecal pellets showing through the tunic. This colony shows little predation by the common periwinkle, Littorina littorea. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Water temperature 1 deg C. Observed at low tide. February 3, 2004. Observers: Page Valentine (USGS) and Mary Carman (WHOI). Photo credit: Dann Blackwood (USGS). Location no. 1.
Click here to download image.

Image DB_STP_DSCN2019, dying tunicate colony of D. vexillum encrusting the side of a boulder.
Image DB_STP_DSCN2019

Image DB_STP_DSCN2019. Image DB_STP_DSCN2019. Dying tunicate colony of Didemnum vexillum encrusting the side of a boulder. Colony surface shows a yellow discoloration; small dark spots are clusters of fecal pellets showing through the tunic. D. vexillum is being preyed upon by the common periwinkle, Littorina littorea. Elliptical and subcircular holes in the tunicate colony are interpreted to represent areas that have been grazed by the periwinkles. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Water temperature 1 deg C. Observed at low tide. February 3, 2004. Observers: Page Valentine (USGS) and Mary Carman (WHOI). Photo credit: Dann Blackwood (USGS). Location no. 1.
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Image DB_STP_DSCN1995, dying tunicate colony of D. vexillum encrusting the side of a boulder.
Image DB_STP_DSCN1995

Image DB_STP_DSCN1995. Dying tunicate colony of Didemnum vexillum encrusting the side of a boulder. Colony surface shows a yellow discoloration; small dark spots are clusters of fecal pellets showing through the tunic. D. vexillum is being preyed upon by the common periwinkle, Littorina littorea. Elliptical and subcircular holes in the tunicate colony are interpreted to represent areas that have been grazed by the periwinkles. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Water temperature 1 deg C. Observed at low tide. February 3, 2004. Observers: Page Valentine (USGS) and Mary Carman (WHOI). Photo credit: Dann Blackwood (USGS). Location no. 1.
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Image DB_STP_DSCN2006, dying tunicate colony of D. vexillum encrusting the sides of boulders.
Image DB_STP_DSCN2006

Image DB_STP_DSCN2006. Dying tunicate colony of Didemnum vexillum encrusting the sides of boulders. Small dark spots on the surface of the colonies are clusters of fecal pellets showing through the tunic. D. vexillum is being preyed upon by the common periwinkle, Littorina littorea. Elliptical and subcircular holes in the tunicate colony are interpreted to represent areas that have been grazed by the periwinkles. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Water temperature 1 deg C. Observed at low tide. February 3, 2004. Observers: Page Valentine (USGS) and Mary Carman (WHOI). Photo credit: Dann Blackwood (USGS). Location no. 1.
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Image DB_STP_DSCN2020, tunicate colony of D. vexillum encrusting a boulder and being preyed upon by the common periwinkle.
Image DB_STP_DSCN2020

Image DB_STP_DSCN2020. Tunicate colony of Didemnum vexillum encrusting a boulder and being preyed upon by the common periwinkle, Littorina littorea. Dark spots on the surface of the colony are clusters of fecal pellets showing through the tunic. At least 20 snails are present in the image Elliptical and subcircular holes in D. vexillum are interpreted to represent areas that have been grazed by the periwinkles. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Water temperature 1 deg C. Observed at low tide. February 3, 2004. Observers: Page Valentine (USGS) and Mary Carman (WHOI). Photo credit: Dann Blackwood (USGS). Location no. 1.
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July 26, 2011
Image KH_STP_MA001 tunicate colonies of Didemnum vexillum encrusting boulders and red algae in Sandwich tidal pool
Image KH_STP_MA001

Image KH_STP_MA001. Tunicate colonies of Didemnum vexillum encrusting boulders and red algae. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Observed at low tide. July 26, 2011. Observers: Kim Holzer (UVA), Page Valentine (USGS), and Mary Carman (WHOI). Photo credit: Kim Holzer (UVA). Location no. 1.
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Image KH_STP_MA002 tunicate colonies of Didemnum vexillum encrusting a boulder and red algae in Sandwich tidal pool
Image KH_STP_MA002

Image KH_STP_MA002. Tunicate colonies of Didemnum vexillum encrusting a boulder and red algae. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feel (3.4 m). Observed at low tide. July 26, 2011. Observers: Kim Holzer (UVA), Page Valentine (USGS), and Mary Carman (WHOI). Photo credit: Kim Holzer (UVA). Location no.1.
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Image KH_STP_MA003 Tunicate colonies encrusting a boulder and seabed with a common periwinkle present in Sandwich tidal pool
Image KH_STP_MA003

Image KH_STP_MA003. Tunicate colonies of Didemnum vexillum encrusting a boulder and pebble-cobble seabed below it. Common periwinkle, Littorina littorea, present. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Observed at low tide. July 26, 2011. Observers: Kim Holzer (UVA), Page Valentine (USGS), and Mary Carman (WHOI). Photo credit: Kim Holzer (UVA). Location no. 1.
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Image KH_STP_MA004. Tunicate coloneis encrusting a boulder, barnacles and green sponge in Sandwich tidal pool
Image KH_STP_MA004

Image KH_STP_MA004. Tunicate colonies of Didemnum vexillum encrusting a boulder and overgrowing barnacles and green encrusting sponge (Halichondria sp.). Common periwinkle, Littorina littorea, present. Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feel (3.4 m). Observed at low tide. July 26, 2011. Obervers: Kim Holzer (UVA), Page Valentine (USGS), and Mary Carman (WHOI). Photo credit: Kim Holzer (UVA). Location no. 1.
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Image KH_STP_MA004. Tunicate coloneis encrusting a boulder, barnacles and green sponge in Sandwich tidal pool
Image KH_STP_MA005

Image KH_STP_MA005. Tunicate colony of Botryllus schlosseri (and colonial bryozoan) encrusting a leaf of eel grass (Zostera). Sandwich tide pool (41 deg 46.42 min N lat, 70 deg 29.30 min W lon). Water depth, intertidal range to 11 feet (3.4 m). Observed at low tide. July 26, 2011. Observers: Kim Holzer (UVA), Page Valentine (USGS), and Mary Carman (WHOI). Photo credit: Kim Holzer (UVA) . Location no. 1.
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