Boltenia villosa is a species of tunicate, a marine invertebrate of the family Pyuridae. Common names include spiny-headed tunicate, hairy sea squirt, stalked hairy sea squirt and bristly tunicate. Th
The intertidal zone, or foreshore, is the area above water level at low tide and underwater at high tide; in other words, it is the part of the littoral zone within the tidal range. This area can incl
The rocky shoreline of Saint-Malo, northwestern France, with a stripe of the black lichen Hydropunctaria maura at the high tide line
Tide pools at Pillar Point showing zonation on the edge of the rock ledge
A rock, seen at low tide, exhibiting typical intertidal zonation, Kalaloch, Washington, western United States
A California tide pool in the low tide zone