Description

Synonymy- The validity of the species Demonax flecatus is uncertain. Specimens from Chesapeake Bay fouling plates, which were initially identified as this species, may actually be the native D. micropthalmus (Perkins 2000).

Potentially Misidentified Species- Demonax micropthalmus is the most widespread and abundant sabellid in the Chesapeake region (Wass 1972, as Sabella micropthalma), but D. leucaspis was also found on settling plates in the lower Bay in 1994-1996 (Ruiz et al. unpublished data). In addition, P. neglecta and F. sabella have been reported from the Bay (Wass 1972).

Taxonomy

Kingdom	Phylum	Class	Order	Family	Genus
Animalia	Annelida	Polychaeta	Canalipalpata	Sabellidae	Demonax

Synonyms

Parasabella flecata

Invasion History

Chesapeake Bay Status

First Record	Population	Range	Introduction	Residency	Source Region	Native Region	Vectors
1995	Established	Unknown	Native	Regular Resident	Western Atlantic	Western Atlantic	Shipping(Ballast Water, Fouling Community)

History of Spread

The tube-dwelling polychaete Demonax flecatus is a species of uncertain validity. It may represent a morphological variation of Demonax microphthalmus, a abundant sabellid polychaete which is considered native in Chesapeake Bay (Perkins 2000). If it is a valid species, we would consider it to be cryptogenic in our region, since its range and history are unknown.

Demonax flecatus was named by Hoagland (1919)., from two specimens collected in Puerto Rico by A. L. Treadwell. These specimens were re-examined by Knight-Jones (1983). No further published records of this species are known. In 1996, Phyllis Knight-Jones identified 5 specimens taken from our Marine Invasions Program settling plates as D. flecatus . These worms were collected in September, 1995 from Scotts Creek, a branch of the Elizabeth River, in Norfolk VA (Knight-Jones 1996; Ruiz et al. unpublished data). As a consequence of the paucity of records, the range, habitat, and life history of D. flecatus are unknown.

Re-examination of our specimens by Phyllis Knight-Jones and Thomas Perkins suggests that our specimens are actually D. micropthalmus (Perkins 2000). If this is confirmed, D. flecatus will be dropped from our species list.

History References - Hoagland 1919; Knight-Jones 1983; Knight-Jones 1996; Perkins 1984; Perkins 2000;Knight-Jones 1996; Ruiz et al. unpublished data

Invasion Comments

Vector(s) of Introduction- The most probable vector of introduction for Demonax flecatus would be ship fouling, since most sabellids either lack planktonic larvae, or have very short larval periods (McEuen et al. 1983).

Ecology

Environmental Tolerances

	For Survival		For Reproduction
	Minimum	Maximum	Minimum	Maximum
Temperature (ºC)
Salinity (‰)
Oxygen
pH
	Salinity Range	poly-eu

Age and Growth

	Male	Female
Minimum Adult Size (mm)
Typical Adult Size (mm)	25.0	25.0
Maximum Adult Size (mm)
Maximum Longevity (yrs)
Typical Longevity (yrs

Reproduction

	Start	Peak	End
Reproductive Season
Typical Number of Young Per Reproductive Event
Sexuality Mode(s)
Mode(s) of Asexual Reproduction
Fertilization Type(s)
More than One Reproduction Event per Year
Reproductive Startegy
Egg/Seed Form

Impacts

Economic Impacts in Chesapeake Bay

Demonax flecatus has no known economic impacts. If abundant, it could be an important food of some commercial fish species, but it may not differ in this regard from the native D. micropthalmus .

Economic Impacts Outside of Chesapeake Bay

Due to its apparent scarcity, among other factors, Demonax flecatus appears to have no important economic impact as a fouling organism.

Ecological Impacts on Chesapeake Native Species

The relative abundance of the different species of sabellids in Chesapeake Bay is unknown, but Demonax spp. are an important component of the fouling community (Lippson and Lippson 1984; Otsuka and Dauer 1982; Ruiz et al. unpublished data). Until now, the dominant form was generally assumed to be D. micropthalma (Lippson and Lippson 1984; Wass 1972), but D. flecatus appears to have made up a large proportion of voucher specimens at at least one location. However, interactions among Demonax spp. or with other fouling organisms, have not been well-studied. In Otsuka and Dauer's (1982) experiments, Demonax spp. (as Sabella micropthalma) became abundant when plates were enclosed by hardware cloth to screen out large predators. They are presumed to compete for space with other organisms, and to provide food for predators, but the relative importance of D. flecatus is unknown.

References - Lippson and Lippson 1984; Otsuka and Dauer 1982; Ruiz et al. unpublished data; Wass 1972

Ecological Impacts on Other Chesapeake Non-Native Species

The relative abundance of the different species of sabellids in Chesapeake Bay is unknown. Competition between D. flecatus and D. leucaspis is possible, but has not been studied. Otsuka and Dauer's (1982) experiments where plates were enclosed by hardware cloth to screen out large predators, suggested possible competition with the cryptogenic ascidian Botryllus schlosseri and Demonax (presumed then to be D. micropthalmus).

References- Otsuka and Dauer 1982

References

Barnes, Robert D. (1983) Invertebrate Zoology., , Philadelphia. Pp. 883

Furlani, Dianne M. (1996) A guide to the introduced marine species in Australian waters., In: (Eds.) . , Hobart, Australia. Pp.

Hoagland, Ruth A. (1919) Polychaetous annelids from Puerto Rico, the Florida Keys, and Bermuda, Bulletin of the American Museum of Natural History 23: 163-252

Knight-Jones, Phyllis (1983) Contributions to the taxonomy of Sabellidae, Zoological Journal of the Linnean Society 79: 245-295

February 11, 1996 <i>Demonax</i> spp., email. email

Lippson, Alice Jane; Lippson, Robert L. (1984) Life in the Chesapeake Bay, , Baltimore. Pp.

McEuen, F. S.; Wu, B.L.; Chia, F. S. (1983) Reproduction and development of Sabella media, a sabellid polychaete with extratubular brooding, Marine Biology 76: 301-309

Nelson-Smith, Anthony (1971) Annelids as fouling organisms., In: Gareth Jones, E. B. and Eltringham, S. K.(Eds.) Marine Borers, Fungi, and Fouling Organisms of Wood.. , Paris. Pp. 171-184

Otsuka, Cary M.; Dauer, Daniel M. (1982) Fouling community dynamics in Lynnhaven Bay., Estuaries 5: 10-22

Perkins, Thomas H. (1984) Revision of Demonax Kinberg, Hypsicomus Grube, and Notaulax Tauber, with a review of Megalomma Johansson from Florida (Polychaeta: Sabellidae), Proceedings of the Biological Society of Washington 97: 285-368

Novermber 9, 2000 Smithsonian Environmental Research Center specimens (<i>Demonax spp</i>). tom.perkins@fwc.state.fl.us Bureau of Marine Research, Florida Department of Natural Resources

Wass, Melvin L. (1972) A checklist of the biota of lower Chesapeake Bay, Special Scientific Report, Virginia Institute of Marine Science 65: 1-290

Demonax flecatus

Annelids-Polychaetes