Invasion History

First Non-native North American Tidal Record: 1978
First Non-native West Coast Tidal Record: 1978
First Non-native East/Gulf Coast Tidal Record:

General Invasion History:

Haplosyllis ohma is native to the Northwest Pacific. It is known from a few specimens in its native range, including Shirikishinai, southern Hokkaido, Japan and the Kurile Islands, Russia, where it is found from the littoral zone to 120 m (Imajima 1966e, Lattig and Martin 2009). It has been collected three times from California waters. Little is known about its natural history, but it seems to be associated with sponges and hydroids on hard substrates (Leslie Harris. personal communications 2008, 2014).

North American Invasion History:

Invasion History on the West Coast:

Haplosyllis ohma was collected from Newport Bay and Los Angeles Harbor, California in the late 1970s or early 1980s (Leslie Harris. personal communications 2008, 2014). A more recent specimen was collected off Bird Rock, Santa Catalina Island in 2007 (Leslie Harris. personal communication 2014).

Other records of Haplosyllis ohma are doubtful or erroneous. This polychaete was reported by Kudenov and Harris (1995, cited in Lattig and Martin 2009) from surveys of the Santa Barbara basin, but these specimens were all juveniles, probably belonging to another species (Lattig and Martin 2009; Leslie Harris, personal communication 2014). A 1999 record in Discovery Bay, Washington (Wilson and Partridge 2007), from a soft-sediment grab-sample is questionable on the basis of habitat, while a specimen in the BOLD database from the Kenai Peninsula, Alaska (Canadian Centre for DNA Barcoding 2014) does not match the description of the species (Leslie Harris. personal communication 2014). The occurrence of established populations of H. ohma in North American waters is unverified.


Haplosyllis ohma is a syllid polychaete. The syllid family is extremely diverse and taxonomically difficult, including more than 700 described species (San Martin et al. 2014). Subfamily and generic assignments within the family are in a state of flux (Blake and Ruff 2007; Lattig and Martin 2009). Family characteristics include: a relatively small and slender body; a prostomium with two pairs of eyes (and sometimes a couple of eyespots); three antennae and paired palps; an eversible pharynx; the anterior-most segment (peristomium) lacking chaetae, but bearing 1-2 pairs of tentacles; uniramous parapodia (biramous in reproductive individuals); dorsal and ventral cirri on each chaetiger (except in the Autolytinae subfamily); and a pygidium (anal segment) with 2-3 anal cirri (Pettibone 1963; Blake and Ruff 2007).

Very few specimens of Haplosyllis ohma have been studied. This worm has a roughly cylindrical, elongated body. Two specimens, the holotype and paratype, respectively, have 82 and 65 chaetigerous segments (Imajima 1966c; Lattig and Martin 2009). The prostomium is pentagonal, lacks a median cleft, and has four small red eyes arranged in a trapezoid. The pharynx contains a circlet of 10 triangular teeth (with an additional tooth inside the circle, mid-dorsal), surrounded by 10 soft papillae. There are three antennae, with the median one having 30 annulations, located between the posterior pair of eyes. The lateral antennae have 25 annulations and are located at the anterior margin of the prostomium. The palps are broad, thick, and roughly triangular. The dorsal tentacular cirri, on the peristomium, have about 30 annulations, while the ventral cirri have only 12. The proventricle extends from segment 12 to 21 (Imajima 1966c; Lattig and Martin 2009).

On the anterior chaetigerous segments, the first cirri are longest (30-36 annulations) and generally decrease in length to the posterior. The parapodia are short, each having 5-8 chaetae in a bundle. The chaetae have two teeth, at the tip. The ventral cirri are finger-like and slightly longer than the parapodial lobes (Imajima 1966c; Lattig and Martin 2009). The pygidium has long anal cirri. The largest specimen was 32 mm long. The overall color is pale yellow with red eyes (Imajima 1966c; Lattig and Martin 2009).


Taxonomic Tree

Kingdom:   Animalia
Phylum:   Annelida
Class:   Polychaeta
Subclass:   Palpata
Order:   Aciculata
Suborder:   Phyllodocida
Family:   Syllidae
SubFamily:   Syllinae
Genus:   Haplosyllis
Species:   ohma


Geminosyllis ohma (Imajima, 1966)
Haplosyllis ohma (Lattig & Martin, 2009)
Typosyllis ohma (Imajima & Hartman, 1964)
Syllis (Haplosyllis) spongicola (Uschakov, 1955)
Trypanoseta ohma (Aguado, San Martin, & Nishi, 2008)

Potentially Misidentified Species

Haplosyllis cf. spongicola
Haplosyllis spongicola (Grube 1855), described from the Mediterranean, is listed for the California coast (Blake and Ruff 2007), but these worms probably belong to an undescribed species.



Haplosyllis ohma, like many other members of the Syllidae, probably reproduces by epitoky, in which the worm undergoes stolonization, and these segments of the body become modified for carrying gametes and swimming (modified setae, enlarged eyes). In Haplosyllis, the posterior segments are modified and budded off. The epitokous section breaks off, swarms at the surface, and releases eggs and sperm. In some species, the epitokes are acephalous and lack a head, but have eyespots on each segment. In other species, the epitoke develops a distinct head, with cephalic appendages (Lattig and Martin 2009).

Little is known about the habitat of Haplosyllis ohma, but it has been collected from the shallow subtidal to 120 m off Japan. It appears to be associated with hard substrates and was collected among sponges, gorgonians, and bryozoans off Santa Catalina Island, California (Leslie Harris, personal communication 2014). Haplosyllis spp. are often found inside sponges, or associated with gorgonians or other polychaetes (Lattig and Martin 2009; Martin et al. 2002; Sarda et al. 2002).

Trophic Status:




General HabitatMarinas & DocksNone
General HabitatRockyNone
Salinity RangePolyhaline18-30 PSU
Salinity RangeEuhaline30-40 PSU
Tidal RangeSubtidalNone
Vertical HabitatEpibenthicNone

Tolerances and Life History Parameters

Maximum Length (mm)32Largest specimens examined (Imajima 1966c)
Broad Temperature RangeNoneCold temperate
Broad Salinity RangeNonePolyhaline-Euhaline

General Impacts

No impacts are reported for Haplosyllis ohma.

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
NEP-VI Pt. Conception to Southern Baja California 1978 Def Unk
NWP-5 None 0 Native Estab
NWP-4b None 1964 Native Estab
P040 Newport Bay 1978 Def Unk
P058 _CDA_P058 (San Pedro Channel Islands) 2007 Def Unk
P050 San Pedro Bay 1980 Def Unk

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude


Aguado, María Teresa; San Martín, Guillermo; Nishi, Eijiroh (2008) Contribution to the knowledge of Syllidae (Annelida, Phyllodocida) from Japan with descriptions of three new species, Systematics and Biodiversity 6(4): 521-550

Blake, James A.; Ruff, R. Eugene (2007) The Light and Smith Manual: Intertidal invertebrates from Central California to Oregon (4th edition), University of California, Berkeley CA. Pp. 309-410

Canadian Centre for DNA Barcoding 2014 BOLD: The Barcode of Life Data System. <missing URL>

Imajima, Minoru (1966a) The Syllidae (polychaetous annelids) from Japan (IV)* Syllinae (1), Publications of the Seto Marine Biological Laboratory 14(3): 219-252

Imajima, Minoru (1966c) The Syllidae (polychaetous annelids from Japan (III) Eusyllidane., Publication of the Seto Marine Biological Laboratory 14(2): 85-116

Lattig, Patricia; Martin, Daniel (2008) A taxonomic revision of the genus Haplosyllis Langerhans, 1887 (Polychaeta: Syllidae: Syllinae), Zootaxa 2220: 1-40

Martin, Daniel; Núñez, Jorge; Riera, Rodrigo; Gil, João (2002) On the associations between Haplosyllis (Polychaeta, Syllidae) and gorgonians (Cnidaria, Octocorallaria), with the description of a new species, Biological Journal of the Linnean Society 77: 455-477

Pettibone, Marian H. (1963) Marine polychaete worms of the New England region. 1. Aphroditidae through Trochochaetidae., Bulletin of the United States National Museum 227(Part 1.): 1-356

San Martin, Guillermo; Aguado, Maria Teresa; Alvarez-Campos, Patricia (2014) Revision of the genus Megasyllis (Annelida, Syllidae) with descriptions of four new species, Journal of the Marine Biological Association 94(2): 331-351

Sardá, Rafael; Avila, Conxita; Paul, Valerie (2002) An association between a syllid polychaete, Haplosyllis basticola n. sp., and the sponge Ianthella basta, Micronesica 34(2): 165-175

Wilson, Sarah; Partridge, Valerie (2007) <missing title>, Washington State Department of Ecology, Olympia. Pp. 244