Invasion History
First Non-native North American Tidal Record:First Non-native West Coast Tidal Record:
First Non-native East/Gulf Coast Tidal Record:
General Invasion History:
None
North American Invasion History:
Description
A new hydroid was found in San Francisco and tentatively identified by Le-Anne Henry as Pachycordyle michaeli, a hydroid only known from Boothbay Harbor, Maine. This hydrozooan lacks a planktonic medusa. It consists of colonies spreading by stolons, with hydrocauli and stems covered by corrugated perisarc, terminating below the hydranths. The hydranths are club-shaped, and sit on pedicels. The hypostome is conical-to-dome-shaped, surrounded by 12-20 tentacles in 3 whorls. Spherical-to-ovoid gonophores, each with a conspicuous spadix, develop on stalks, on the pedicels of the hydranths. The hydroids are about 4 mm high. Colonies are diecious (either all male or female). Female gonophores contain about 6-10 eggs, which develop into planulae, which are released (Berrill 1948; Schuchert 2004; Schuchert 2007). This identification is tentative, and the systematics of the genus (~9 species, with many synonyms) are confused, and could be clarified by molecular studies. Pachycordyle michaeli could be conspecific with P. navis, described from South Africa, and introduced to Europe, or with other members of the genus (Schuchert 2007).
Taxonomy
Taxonomic Tree
| Kingdom: | Animalia | |
| Phylum: | Cnidaria | |
| Class: | Hydrozoa | |
| Subclass: | Hydroidolina | |
| Order: | Anthoathecatae | |
| Suborder: | Filifera | |
| Family: | Bougainvilliidae | |
| Genus: | Pachycordyle | |
| Species: | michaeli |
Synonyms
Pachycordyle michaeli (Schuchert, 2007)
Potentially Misidentified Species
Described from South Africa and introduced to Europe. This hydroid is very similar to P. michaeli and could be conspecific (Schuchert 2007). It is better known under its synonym Clavopsella navis.
Pachycordyle pusilla
Described from Mediterranean
Ecology
Food:
Zooplankton, small epibenthos
Trophic Status:
Carnivore
CarnHabitats
| General Habitat | Coarse Woody Debris | None |
| General Habitat | Marinas & Docks | None |
| General Habitat | Rocky | None |
| Vertical Habitat | Epibenthic | None |
Tolerances and Life History Parameters
| Maximum Duration | 1 | Time to settlement of planula larvae (Berrill 1948) |
| Minimum Height (mm) | 4 | Berrill 1948; Schuchert 2007 |
| Broad Temperature Range | None | Cold-Temperate |
| Broad Salinity Range | None | Poly-Euhaline |
General Impacts
Occurrence Map
| OCC_ID | Author | Year | Date | Locality | Status | Latitude | Longitude |
|---|
References
Berrill, N. J. (1948) The life cycle of Aselomaris michaeli, a new gymnoblastic hydroid, Biological Bulletin 95(3): 289-295Eno, N. Clare; Clark, Robin A.; Sanderson, William G. (1997) <missing title>, Joint Nature Conservation Committee, Peterborough. Pp. <missing location>
Faasse, Marco (2012) The exotic isopod Synidotea in the Netherlands and Europe, A Japanese or American invasion (Pancrustacea: Isopoda)?, Nederlandse Faunistiche Mededelingen 108: 103-106
Foss, Stephen (2011) <missing title>, California Department of Fish and Game, Office of Spill Prevention and Response, Sacramento. Pp. 54
Reise, K.; Gollasch, S.; Wolff, W.J. (1999) Introduced marine species of the North Sea coasts., Helgoländer Meeresuntersuchungen 52: 219-234
Schuchert, Peter (2004) Revision of the European athecate hydroids and their medusae (Hydrozoa, Cnidaria): Families Oceanidae and Pachycordylidae, Revue Suisse de Zoologie 111(2): 315-369
Schuchert, Peter (2007) The European athecate hydroids and their medusae (Hydrozoa, Cnidaria): Filifera Part 2, Revue Suisse de Zoolgie 114(2): 195-396
Wolff, W. J. (2005) Non-indigenous marine and estuarine species in the Netherlands., Zoologische Verhandelingen 79(1): 1-116