Sertularella mutsuensis


Scientific Name: Sertularella mutsuensis

Phylum: Cnidaria

Class: Hydrozoa

Order: Leptothecata

Family: Sertulariidae

Genus: Sertularella


mutsuensis [Describe here as A. iricolor]

Native Distribution

Origin Realm:

Temperate Northern Pacific

Native Region:

Origin Location:

Temperate Northern Pacific Mutsu Bay, Japan (Choong & Calder 2013) *Type locality Mutsu Bay (Suzu-uchi-Mura Village (Stechow 1931)) , Japan (Choong & Calder 2013) *Type locality Sea of Japan; Sea of Okhotsk; Pacific side of the southern Kuriles (Naumov 1969, cited in Choong & Calder 2013) STATUS NOT STATED Russky Island, Russia (Ivanova et al. 2008, cited in Choong & Calder 2013) STATUS NOT STATED Dokdo, Republic of Korea (Ryu et al. 2012) STATUS NOT STATED Peter the Great Bay, Japan Sea (Ivanova & Tsurpalo 2013) STATUS NOT STATED Russky Island, Peter the Great Bay, Sea of Japan (Ivanova et al. 2009) STATUS NOT STATED Mutsu Bay, Japan (Ruthensteiner et al. 2008) STATUS NOT STATED Pacific coast of Kunashir Island. (Kussakin 1975) STATUS NOT STATED

Geographic Range:

Sea of Okhotsk (Naumov 1969, cited in Choong & Calder 2013) to Dokdo, Republic of Korea (Ryu et al. 2012)

General Diversity:


Non-native Distribution

Invasion History:

No records of invasion (Global Invasive Species Database 2016)

Non-native Region:

Northeast Pacific

Invasion Propens:

Temperate Northern Pacific Not previously known from the northeast Pacific; collected from Agate Beach, Newport, Oregon (Choong and Calder 2013) *Status not known

Status Date Non-native:

Agate Beach, Newport, Oregon: June 2012 (Choong and Calder 2013)

Vectors and Spread

Initial Vector:


Second Vector:


Vector Details:

Introduction vector: Found on tsunami debris. Long range dispersal by rafting (Choong and Calder 2013)

Spread Rate:


Date First Observed in Japan:


Date First Observed on West coast North America:



Impact in Japan:


Global Impact:



Native Temperature Regime:

See details

Native Temperature Range:

[Russky Island] Water temperature during low tides ranged from 20ºC in Ajaks Bay to 25.5ºC in Melkovodnaya Bay (Voevoda Bay) (Ivanova et al. 2009) [Kunashir Island] Average water temperature at the Pacific coast of Kunashir Island in Kurile Islands is 16ºC, accoding to the Marine Atlas (1953) (cited in Kussakin 1975) and in the Sakhaline Region Atlas (1967) (cited in Kussakin 1975) . In winter an abrupt water chilling down to 0°C and even lower is observed all over the Kuriles. (Kussakin 1975)

Non-native Temperature Regime:


Non-native Temperature Range:


Native Salinity Regime:

Polyhaline, Euhaline

Native Salinity Range:

[Russky Island] Maximum salinity was 30‰ in Karpinsky Bay and 25‰ in Novik and Voevoda Bays. The highest salinity for the area (35‰) was recorded in a shallow lagoon at Cape Akhlestysheva (Ivanova et al. 2009)

Non-native Salinity Regime:


Temperature Regime Survival:


Temperature Range Survival:

RELATED: [Sertularella spp.] -1.022 - 26.618ºC (OBIS 2016)

Temperature Regime Reproduction:


Temperature Range Reproduction:


Salinity Regime Survival:


Salinity Range Survival:

RELATED: [Sertularella spp.] 27.473 - 38.933 PPS (OBIS 2016)

Salintiy Regime Reproduction:

Polyhaline, Euhaline

Salinity Range Reproduction:


Depth Regime:

Lower intertidal

Depth Range:

Littoral zone (Ivanova & Tsurpalo 2013) Intertidal (Ivanova et al. 2009) Intertidal (Kussakin 1975, Ivanova et al. 2009)

Non-native Salinity Range:

Native Abundance:



Fertilization Mode:


Reproduction Mode:

Gonochoristic/ dioecious

Spawning Type:


Development Mode:

Lecithotrophic planktonic larva (non-feeding)

Asexual Reproduction:

See details

Reproduction Details:

RELATED: [Sertularella turgida] Releases sperm into the water but retains its eggs for fertilization (Sept 1999) [Obelia sp. as a representative example of class Hydrozoa] Medusae have separate sexes. Males release sperm; eggs are fertilized while still in the gonads. Planula lavae (Kozloff 1990) *Note: entered as lecithotrophic because planula larvae are non-feeding and planktonic; other sources for Obelia spp. contradict where eggs are fertilized (see two Obelia entries) [Hydroids] Rapidly colonize through asexual proliferation (Denny & Gaines 2007)

Adult Mobility:


Adult Mobility Details:

RELATED: [Hydroids] Sessile (Denny & Gaines 2007)

Maturity Size:


Maturity Age:


Reproduction Lifespan:




Broods per Year:


Reproduction Cues:


Reproduction Time:




Egg Size:


Egg Duration:


Early Life Growth Rate:


Adult Growth Rate:


Population Growth Rate:


Population Variablity:




Rocky intertidal, Flotsam, Fouling

Habitat Type:

Epibenthic, Epizoic, Epiphytic


Rock, Biogenic, Artificial substrate



Habitat Expansion:


Habitat Details:

Found on tsunami debris: on a barnacle, Semibalanus cariosus, attached to a floating dock (Choong and Calder 2013) Rocky littoral zone (Ivanova & Tsurpalo 2013) Attached to algae (Ruthensteiner et al. 2008)

Trophic Level:

Suspension feeder

Trophic Details:

RELATED: [Hydroids] Suspension-feeding or carnivorous (Denny & Gaines 2007)

Forage Mode:


Forage Details:

RELATED: [Hdroids] They consume completely small animals like small crustacea, mollusc, annelida and juvenile fish. (Uchida 1961)

Natural Control:

RELATED: PREDATION [Hydroids] [Predation] Hydranths may be eaten by nudibranchs, pyconogonids, fish, and the polychaete Procerastea halleziana (Denny & Gaines 2007)

Associated Species:

RELATED: EPIBIONT [Hydroids] [Epibiont] Act as microhabitats for many other species, including other hydroids, gammarid amphiods, and mussel recruits (Denny & Gaines 2007) PARASITES [Hydroids] [Parasites] Pycnogonid larvae may parasitize and develop in hydranths (Denny & Gaines 2007)

References and Notes


Calder DR (2013) Some shallow-water hydroids (Cnidaria: Hydrozoa) from the central east coast of Florida, USA. Zootaxa 3648(1): 001-072. Choong HHC & Calder DR (2013) Sertularella mutsuensis Stechow, 1931 (Cnidaria: Hydrozoa: Sertulariidae) from Japanese tsunami debris: systematics and evidence for transoceanic dispersal. BioInvasions Records 2(1): 33-38. Denny MW & Gaines SD (2007) Encyclopedia of Tidepools and Rocky Shores. Berkeley and Los Angeles, California: University of California Press Global Invasive Species Database. Access date: 06-01-2016 Kozloff EN (1990) Invertebrates. Philadelphia, PA: Saunders College Publishing Kussakin OG (1975) A list of the macrofauna in the intertidal zone of the Kurile Islands, with remarks on zoogeographical structure of the region. Publications of the Seto Marine Biological Laboratory 22: 47-74. Ivanova MB, Belogurova LS, Tsurpalo AP (2009) Composition and distribution of benthos in the intertidal zone of Russky Island (Peter the Great Bay, Sea of Japan). Ecological Studies and the State of the Ecosystem of Amursky Bay and Estuarine Zone of the Razdolnaya River (Sea of Japan), 2, 87-146. Ivanova MB & Tsurpalo A (2013) Composition and distribution of macrobenthos communities in the intertidal zone of Putyatin Island (Peter the Great Bay, Japan Sea). News TINRO 172: 149-160. OBIS. Ocean Biogeographic Information System. Access date: 30-08-2016 *Note: genus level data Ruthensteiner B, Reinicke GB, Straube N (2008) The Type Material of Hydrozoa described by Eberhard Stechowin the Zoologische Staatssammlung München. SPIXIANA 31(1): 3-27. Ryu SH et al. (2012) Biodiversity of marine invertebrates on rocky shores of Dokdo, Korea. Zoological Studies 51(5): 710-726. Sept JD (1999) The Beachcomber's Guide to Seashore Life in the Pacific Northwest. Madeira Park, BC: Harbour Publishing Stechow E (1931) Neue hydroiden von der Mutsu-Bai, Nordjapan. Zoologicher Anzeiger 96: 177-178. (in German) Uchida T (1961) Coelenterata. In: Animal systematics. Uchida T (ed.) Nakayama-shoten Co. Ltd., Tokyo: 55-204. (in Japanese)




I can't get access to a full version of Choong HHC (2015) Hydroids of the genus Sertularella (Cnidaria: Hydrozoa: Sertulariidae) from the Pacific coast of Canada in the collection of the Royal Ontario Museum, with descriptions of four new species. Zootaxa 3925(3): 387-408. Should be useful for related information