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Horsetail hydroid
Sponge & Cnidarian
Horsetail hydroid
Rhizocaulus verticillatus (Linnaeus, 1758)
WoRMS AphialID
117399
Sample IDs
HMSC174_01031 https://bench.boldsystems.org/index.php/MAS_DataRetrieval_OpenSpecimen?selectedrecordid=ATCCN035-24; HMSC174_01044 https://bench.boldsystems.org/index.php/MAS_DataRetrieval_OpenSpecimen?selectedrecordid=ATCCN036-24; HMSC174_03218 https://bench.boldsystems.org/index.php/MAS_DataRetrieval_OpenSpecimen?selectedrecordid=ATCCN140-25; HMSC174_01973 https://bench.boldsystems.org/index.php/MAS_DataRetrieval_OpenSpecimen?selectedrecordid=ATCCN150-25; GM2024_03 https://bench.boldsystems.org/index.php/MAS_DataRetrieval_OpenSpecimen?selectedrecordid=ATCCN195-25
Collected
Quebec (Les Escoumins, Cap de Bon-Desir) and Bay of Fundy (Grand Manan, The Wolves).
Distinguishing Features
• Colonies up to 15 cm high. Single stems or sparsely branched.
• Stem and main branches polysiphonic.
• Hydrothecae in whorls on stem, 4–5 hydrothecae per whorl.
• Hydrothecae cup shaped, 0.9–1.2 mm deep, with 12–14 low teeth on the cup margin.
• Gonothecae bottle-shaped with long tubular neck.
Habitat
Attaches to shells, cobbles, boulders, and bedrock. Associated with areas of high current movement with mobile sand and gravel. Very common in the Bay of Fundy. Found from 15-680 m.
Geographic Range
Arctic and both sides of the north Atlantic Ocean.
Fun Fact
The Latin name comes from Verticillatus meaning whorled and refers to the arrangement of the hydrothecae on the stem and branches.
Barcode Distribution
BOLD: ACY4073. This BIN contains specimens from the Netherlands and Sweden. Two of our specimens, both from the Wolves, belong to this BIN. BOLD: AGX7072. Most of our specimens belong to this BIN, it is a private BIN.
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