Crepidula onyx

Overview

Scientific Name: Crepidula onyx

Phylum: Mollusca

Class: Gastropoda

Order: Littorinimorpha

Family: Calyptraeidae

Genus: Crepidula

Species:

onyx [Describe here as A. iricolor]

Native Distribution

Origin Realm:

Temperate Northern Pacific, Tropical Eastern Pacific, Temperate South America

Native Region:

Origin Location:

CONFLICT: Northeast Pacific, Northwest Pacific Temperate Northern Pacific Eastern Pacific: from Southern California to Peru (NEMESIS 2016) STATED Native to central and southern California, down to Panama; reports of C. onyx south of Panama may be another species, requires additional study (Lee II and Reusser 2012) STATED It ranges from southern California in the north to Chile in the south. (Abbott & Haderlie 1980, in cited Woodruff et al. 1986) STATUS NOT STATED Kii Peninsula, Japan (Ohgaki 2010) STATUS NOT STATED Islets of Namuseom and Bukhyeongjeseom off Busan, South Korea (Hwang et al. 2014) STATUS NOT STATED Tropical Eastern Pacific Puntarenas, Costa Rica to San Pedro, California (Hoagland 1977, cited in Huang et al. 1983) STATED Eastern Pacific: from Southern California to Peru (NEMESIS 2016) STATED Native to central and southern California, down to Panama; reports of C. onyx south of Panama may be another species, requires additional study (Lee II and Reusser 2012) STATED It ranges from southern California in the north to Chile in the south. (Abbott & Haderlie 1980, in cited Woodruff et al. 1986) STATUS NOT STATED Temperate South America Eastern Pacific: from Southern California to Peru (NEMESIS 2016) STATED It ranges from southern California in the north to Chile in the south. (Abbott & Haderlie 1980, in cited Woodruff et al. 1986) STATUS NOT STATED

Geographic Range:

geographic coverage: -119.700004577637 -41.6000022888184,142.200012207031 34.5 (Ocean Biogeographic Information System) Eastern Pacific: from Southern California to Peru (NEMESIS 2016)

General Diversity:

Genetic analysis showed that the Hong Kong population was likely more closely related to populations from San Diego, than from populations near Los Angeles (Woodruff et al. 1986, cited in NEMESIS 2016) Reports of C. onyx south of Panama may be another species, requires additional study (Lee II and Reusser 2012) [China] Woodruff et al. (1986), in a comparative study of the population genetics of a number of California and Hong Kong sample of C. o., concluded that the Chinese colonists were derived originally from San Diego rather than Los Angeles with the presence of six alleles found in Hong Kong and San Diego, but not Balboa Island.

Non-native Distribution

Invasion History:

Yes (NEMESIS 2016)

Non-native Region:

Northeast Pacific, Northwest Pacific, Central Indo-Pacific

Invasion Propens:

CONFLICT: Northeast Pacific, Northwest Pacific Temperate Northern Pacific First collected in Japan in 1968 (Asakura 1992; Iwasaki 2006), now its range extends from Hokkaido (Iwasaki 2006) to Hong Kong (Morton 1987); introduced to Puget Sound, near Bremerton, Washington in 2004 -2005, now the range of C. onyx in Puget Sound extends about 20 km (Holm 2006; USGS Nonindigenous Aquatic Species Program 2008, cited in NEMESIS 2016) *Introduced Established in Victoria Harbour, Hong Kong, most likely introduced from Japan sometime before 1979; from 1979-1982 it became firmly established (Huang et al. 1983) *Introduced and ESTABLISHED Northwest Pacific: first recorded in 1968 in Miura Peninsula, Japan; established (Lee II & Reusser 2012) *Non-indigenous Northeast Pacific: first recorded in 2005 in Puget Sound, Washington; established (Collin et al., 2006, cited in Lee II & Reusser 2012) *Non-indigenous [Japan] First record of C. o. in Japan is 1968 at Iwabu, Miura Peninsula, Kanagawa Prefecture. After the first record, the species spreaded its distribution to Tokyo Bay. The distribution continued to spread from Miyagi Prefecture, northern Japan, to Osaka Bay along the Pacific coast. Furthermore, the distribution spreaded via Seto Inland Sea to the Ariake Bay, Kyushu, and it appeared at Toyama Prefecture and Hokkaido at Japan Sea side after 2000. (Egawa 1985, Iwasaki et al. 2004) *Introduced Central Indo-Pacific [China] First record of the species is 1975 in Hong Kong. (Morton 1987) *Introduced

Status Date Non-native:

collected in Puget Sound, Washington in 2004 -2005 (NEMESIS 2016) Hong Kong: sometime before 1979 (Huang et al. 1983) in Japan in 1968, reached Hong Kong sometime before 1979 (Huang et al. 1983) in Japan in 1968 (Asakura 1992), reached Hong Kong by 1975 (Morton 1987), South Korea by 1982 (Choe and Park 1992), and Hokkaido, Japan in 1984 (Ekawa 1985), west coast of Japan (Sea of Japan) in 2000 (Iwasaki 2006) (NEMESIS 2016) Kii Peninsula, Japan: collected May to June in 2007 and 2008 (Ohgaki 2010) Islets off the coast of Busan, South Korea: collected on September 27 and 28, 2013 (Hwang et al. 2014) [Japan] After 2000, the species is known to be distributed from Miyagi Prefecture to Ariake Bay, Kyushu, along the Pacific coast and via Seto Inland Sea. At the same period, it was distributed to Toyama Prefecture and to south and middle Hokkaido at Japan Sea side. (Iwasaki et al. 2004)

Vectors and Spread

Initial Vector:

Ballast water, Hull fouling (military; not specified)

Second Vector:

NF

Vector Details:

probably introduced to Puget Sound, WA through ballast water or hull fouling of naval ships (Holm 2006, cited in NEMESIS 2016) established in Victoria Harbour, Hong Kong, most likely introduced from Japan sometime before 1979; from 1979-1982 it became established in Victoria Harbour, which is one of the busiest ports in the world, with around 10,000 vessels arriving and departing per year; good chance that C. onyx will continue to spread (Huang et al. 1983) Hull fouling (Lee II & Reusser 2012) [Japan] Hull foulng (Otani 2004) and ballast water (Egawa 2002) [China] Thinking of long term of food-deprivation in ballast water, it would be unlikely to survive a long transoceanic journey in ballast water between Hong Kong and US West Coast. This means that juvenile or adult attachment to ship hulls is likely sole means for the invasion of Hong Kong waters. (Zhao et al. 2003)

Spread Rate:

in Japan in 1968, reached Hong Kong sometime before 1979 (Huang et al. 1983) in Japan in 1968 (Asakura 1992), and spread rapidly around ports of eastern Japan, China, and Korea: reached Hong Kong by 1975 (Morton 1987), South Korea by 1982 (Choe and Park 1992), and Hokkaido, Japan in 1984 (Ekawa 1985), west coast of Japan (Sea of Japan) in 2000 (Iwasaki 2006) (NEMESIS 2016) [Japan] Mean speed for the dispersion at all around Japan coast is 26.4 km/year (Iwasaki & Kinoshita 2004)

Date First Observed in Japan:

1968: Tokyo Bay, Japan (Habe & Maze 1970, cited in Huang et al. 1983) 1968 (NEMESIS 2016) 1968: Miura Peninsula (Lee II & Reusser 2012) First record in Japan is 1968 at Iwabu, Kanagawa Prefecture. (Egawa 1985)

Date First Observed on West coast North America:

Not applicable, Native to WCNA

Impacts

Impact in Japan:

[Japan][Competition] may have negative effects in introduced range by growing on native mollusks; can interfere and compete with native species for food; in Japan, C. onyx attaches to other mollusks, and is probably interfering with their behavior and growth; 'But the ecological impacts seems not so large' (National Institute for Environmental Studies 2013, cited in NEMESIS 2016) C. o. is known to cover the host shellfish exhaustively and to prevent its movement. They compete with cultured oyster for food. However, there is little influence on growth of the host shellfish because they don't prey on their host species nor intercept the food of that. (Egawa 2002)

Global Impact:

[Puget Sound, Washington] No impacts reported from the localized introduction of C. onyx (Holm 2006, cited in NEMESIS 2016) [Japan] competition: may have negative effects in introduced range by growing on native mollusks; can interfere and compete with native species for food; in Japan, C. onyx attaches to other mollusks, and is probably interfering with their behavior and growth; 'But the ecological impacts seems not so large' (National Institute for Environmental Studies 2013, cited in NEMESIS 2016) In its introduced range it may be having adverse effects by growing on native mollusks, thereby interfering and competing with native species for food. (NEMESIS 2015)

Tolerences

Native Temperature Regime:

Mild temperate, Warm temperate, Subtropical, Tropical

Native Temperature Range:

Warm temperate - Tropical (NEMESIS 2016) Mild temperate, Warm temperate, Subtropical, Tropical (M. Otani, pers. comm.)

Non-native Temperature Regime:

Mild temperate, Warm temperate, Subtropical, Tropical

Non-native Temperature Range:

[China] Average temperature is 18.6 - 27.5 ºC at bottom water of victoria Harbour in Hong Kong. (Morton 1984) Mild temperate, Warm temperate, Subtropical, Tropical (M. Otani, pers. comm.)

Native Salinity Regime:

Mesohaline, Polyhaline, Euhaline

Native Salinity Range:

Polyhaline - Euhaline (NEMESIS 2016) observed at 15 - 34psu, prefers 32 - 34psu (Lee II and Reusser 2012)

Non-native Salinity Regime:

Polyhaline, Euhaline

Temperature Regime Survival:

Cool temperate, Mild temperate, Warm temperate, Subtropical, Tropical, See details

Temperature Range Survival:

warm temperate - tropical; native and introduced range indicate a probable sensitivity to low temperatures; presence in Puget Sound may be dependant on shallow, warmer waters in the estuary (NEMESIS 2016) [China] Average temperature is 18.6 - 27.5 ºC at bottom water of victoria Harbour in Hong Kong. (Morton 1984) Cool temperate, Mild temperate, Warm temperate, Subtropical, Tropical (M. Otani, pers. comm.)

Temperature Regime Reproduction:

Cool temperate, Mild temperate, Warm temperate, Subtropical, Tropical, See details

Temperature Range Reproduction:

eggs can hatch into veligers in 12-20 days at 15-21°C; which can settle after 5 days at 15-23°C (Collin 2003; Zhao et al. 2003, cited in NEMESIS 2016) [Hong Kong] In the laboratory, C. onyx juveniles can reach maturity in 8 weeks, at 23 °C with abundant food (Zhao et al. 2003) [China] Average temperature is 18.6 - 27.5 ºC at bottom water of victoria Harbour in Hong Kong. (Morton 1984) Cool temperate, Mild temperate, Warm temperate, Subtropical, Tropical (M. Otani, pers. comm.)

Salinity Regime Survival:

Mesohaline, Polyhaline, Euhaline

Salinity Range Survival:

Polyhaline - Euhaline (NEMESIS 2016)  Observed at 15 - 34psu, prefers 32 - 34psu (Lee II and Reusser 2012) [China] Average salinity is 24.9 - 30.6 psu at the bottom water of Victoria Harbbour in Hong Kong. (Morton 1984) Larvae and adults can not survive when the salinity drops below 10 psu. (Zhao et al. 2003)

Salintiy Regime Reproduction:

Polyhaline, Euhaline

Salinity Range Reproduction:

Larvae of C. onyx tolerate short (12 hour) exposures to 15 PSU (Diederich et al.2011, cited in NEMESIS 2016) [China] Average salinity is 24.9 - 30.6 psu at the bottom water of Victoria Harbbour in Hong Kong. (Morton 1984)

Depth Regime:

Lower intertidal, Shallow subtidal, Deep subtidal

Depth Range:

Intertidal and shallow subtidal (NEMESIS 2016) Observed 0-200 m, but prefers 0-29 m; intertidal- deep subtidal (Lee II and Reusser 2012) Sample depth: 0 - 20 m (Ocean Biogeographic Information System 2016) [Japan] Lower intertidal to 60 m deep. (Inaba 1982, Egawa 1985)

Non-native Salinity Range:

Native Abundance:

NF

Reproduction

Fertilization Mode:

Internal

Reproduction Mode:

Hermaphrodite/ monoecious

Spawning Type:

None

Development Mode:

Planktotrophic planktonic larva (feeding)

Asexual Reproduction:

Does not reproduce asexually

Reproduction Details:

protandrous hermaphrodites, start as male then turn female; on soft substrates often found stacked upon eachother, from 2 up to 16 animals, with the large, older females on bottom, intermediates in the middle, and smaller young males on top; males are somewhat mobile and copulate with nearby females, or below them on the stack; male sex change can occur at 10-20 mm for solitary males, and 25-30 mm for an attached male in a stack (Coe 1938; Henry et al. 2010, cited in NEMESIS 2016) On hard substrates: C. onyx is often solitary or forms stacks 2-4 animals high (Coe 1938); males turned female at 10-15 mm at both rocky intertidal sites in Panama (Collin et al. 2005) and on gastropod shells in Korea (Son 2003); solitary males typically transition within 100 days, but in the presence of a female, males in Panama delayed their sex change to over 100-400 days (Collin et al. 2005) eggs are laid in capsules on the front edge of the foot: each capsule can have 24-135 eggs; in South Korea, 27 females laid 7-38 capsules and 294-4455 eggs in a single spawning (Son 2003); eggs can hatch in 12-20 days at 15-21°C, and hatch into swimming, planktotrophic veligers, which settle after 5 days at 15-23°C (Collin 2003; Zhao et al. 2003, cited in NEMESIS 2016) protandric hermaphrodite; females brood egg capsules under the foot; forms mating stacks up to 17 individuals; after a period of time, male penis starts to reduce (Coe 1942, cited in Huang et al. 1983) sexual reproduction; sequential hermaphrodite; planktonic larvae (Lee II and Reusser 2012) [Crepidula cf. onyx] females undergo periods of temporary or permanent immobility during the time they are brooding their young (Chaparro et al., 1998) C. onyx juveniles can reach maturity in 8 weeks (at 23 °C with abundant food {Isochrysis galbana}); fertilized eggs are brooded for about 10 days, after which the veliger larvae are released into the water; veligers develop for about 5 days before able to settle; the larval stage may be the most critical period for the successful colonization and establishment of a C. onyx population; feeding is important for the growth and reproduction of the adult too, however adults kept in still water can survive about 1 month of food deprivation (Zhao et al. 2003) [China] Protandric hemaphroditism. In the obtained sample, individuals up to 4 - 5 mm long were all sexually undifferentiated juveniles. All individuals of shell length 9 - 16 mm were males. Individuals larger than 17 mm possess a developing ovary, while some individuals larger than 21 mm are found to be brooding egg masses. Females brood egg masses beneath the head-foot. The egg mass is made up of egg caplules attached to the substrate by a capsular thread (Morton 1984). Internal fertilization; does not spawn; does not reproduce asexually (M. Otani, pers. comm.)

Adult Mobility:

See details

Adult Mobility Details:

Lives attached to solid substrates; Males are somewhat mobile; females are sedentary, they grow to fit the surface to which they are attached (Coe 1938; Henry et al. 2010, cited in NEMESIS 2016) Limpet-form species that moves less actively than snails (Ohgaki 2010) Surficial non-motile (Lee II and Reusser 2012) [Crepidula cf. onyx] females undergo periods of temporary or permanent immobility during the time they are brooding their young (Chaparro et al., 1998, cited in Martinelli et al. 2013) [Japan] Except for juvenile stage, they don't move after attaching to the substrata. (Egawa 2002)

Maturity Size:

male maturity can occur as small as 5 mm in size (NEMESIS 2016) male sex change (or female maturity) can occur at 10-20 mm for solitary males, and 25-30 mm for an attached male (Coe 1938; Henry et al. 2010, cited in NEMESIS 2016) [Korea] [Panama] males turned female at 10-15 mm size at rocky intertidal sites in Panama (Collin et al. 2005) and on gastropod shells in Korea (Son 2003); solitary males typically transition within 100 days, but in the presence of a female, males in Panama delayed their sex change to over 100-400 days (Collin et al. 2005, cited in NEMESIS 2016) [China] Individuals Larger than 17 mm possess ovary. (Morton 1984)

Maturity Age:

[Panama] solitary males typically transition within 100 days, but in the presence of a female, males in Panama delayed their sex change to over 100-400 days (Collin et al. 2005, cited in NEMESIS 2016) C. onyx juveniles can reach maturity in 8 weeks (at 23 °C with abundant food {Isochrysis galbana}) (Zhao et al. 2003) Less than one year (Coe 1942, cited in Woodruff et al. 1986)

Reproduction Lifespan:

[Japan] All year round (Egawa 2002)

Longevity:

[China] Three or more years. (Morton 1984)

Broods per Year:

[Hong Kong] In the laboratory (at 23 °C with an abundant diet of Isochrysis galbana at 10^6 cells /ml concentration) females deposited egg capsules about every 2 weeks; fertilized eggs were brooded for about 2 weeks (Zhao et al. 2003) When we suppose that they lay eggs 7 times in a year and the longevity is 3 years based on Coe (1949), cited in Morton (1984), we get the result -0.89.

Reproduction Cues:

[Hong Kong] In the laboratory (at 23 °C with an abundant diet of Isochrysis galbana at 10^6 cells /ml concentration) females deposited egg capsules about every 2 weeks; fertilized eggs were brooded for about 2 weeks (Zhao et al. 2003)

Reproduction Time:

[Japan] All year round. (Egawa 2002)

Fecundity:

Each capsule can have 24-135 eggs; in South Korea, 27 females laid 7-38 capsules and 294-4455 eggs in a single spawning (Son 2003, cited in NEMESIS 2016) [China] Fecundity of individual is mean: 2,610 eggs per individual, min.: 872, max: 14,560. (Morton 1984) [California] 5,000 - 20,000 per individual. (Coe 1949, cited in Morton 1984)

Egg Size:

NF

Egg Duration:

eggs can hatch in 12-20 days at 15-21°C (Collin 2003; Zhao et al. 2003, cited in NEMESIS 2016) fertilized eggs are brooded for about 10 days (Zhao et al. 2003)

Early Life Growth Rate:

eggs can hatch in 12-20 days at 15-21°C, and hatch into swimming, planktotrophic veligers, which settle after 5 days at 15-23°C (Collin 2003; Zhao et al. 2003, cited in NEMESIS 2016) [Hong Kong] In the laboratory, C. onyx juveniles can reach maturity in 8 weeks (at 23 °C with abundant food {Isochrysis galbana}); fertilized eggs are brooded for about 10 days or 2 weeks, after which the veliger larvae are released into the water; veligers develop for about 5 days before able to settle (Zhao et al. 2003)

Adult Growth Rate:

feeding is important for the growth and reproduction of the adult, however adults kept in still water can survive about 1 month of food deprivation (Zhao et al. 2003) Shell length attains to 6 - 60 mm in a year. (Coe 1949, cited in Woodruff et al. 1986)

Population Growth Rate:

NF

Population Variablity:

Genetic analysis showed that the Hong Kong population was likely more closely related to populations from San Diego, than from populations near Los Angeles (Woodruff et al. 1986, cited in NEMESIS 2016) [China] Population density is the largest at Victoria Harbour with the high concentration of nutrient and is small in western and eastern waters with hyposaline condition and with unfavorable environment condition respectively. (Zhao et al. 2003)

Habitat

Ecosystem:

Tide flats, Rocky intertidal, Rocky subtidal, Mussel reef, Oyster reef, Fouling, Other

Habitat Type:

Epibenthic, Epizoic

Substrate:

Mud, Mixed sediments, Cobble, Rock, Biogenic, Artificial substrate

Exposure:

Semi-exposed, Protected, Very protected

Habitat Expansion:

NF

Habitat Details:

habitat: rocky, oyster reef, marinas and docks, unstructured bottom; epibenthic; substrate: attach to rocks, mud, shells of live and dead mollusks, bottles, cans; often live stacked upon eachother, from 2 up to 16 animals (NEMESIS 2016) often found attached to living mollusks, like the bivalve Perna viridis in Hong Kong (Morton 1987) or gastropods Rapana venosa, Batillus cornutus, or Kelletia lischkei in South Korea (Choe and Park 1992; Son 2003, cited in NEMESIS 2016) [Victoria Harbour, Hong Kong] found attached to various gastropods and the bivalve Perna viridis (Huang et al. 1983) prefers estuary and coastal bays, but observed in nearshore and shelf; ecosystem: found in unvegetated tidal flat (estuarine), unvegetated subtidal (estuarine or oceanic), rocky intertidal, tide pools, subtidal rocky, oyster/mussel reef, fouling; epibenthic on consolidated substrate; epizoic; substrate: rocky, cobble, mixed sediments, oyster, pilings, hull/ballast (Lee II and Reusser 2012) [Argentina] [Crepidula cf. onyx] has been shown to favor eutrophic environments (Zhao et al. 2003, cited in Martinelli et al. 2013) [Parasites] C. onyx can act as a parasite through indirect kleptoparasitism: indirectly steals food by intercepting the feeding currents of a bivalve host; C. onyx is believed to occasionally engage in indirect kleptoparasitism with a bivalve host (Peterson 1983, cited in Iyengar 2008) [Epibionts] [Hong Kong (Victoria Harbour)] C. onyx usually attach to the shells of the green mussel Perna viridis (Zhao et al. 2003) *not specified whether parasitic They are found on rocks, shell of variable mollusks such as Repana venosa, Holiotis, Turbo, Mytillus, and etc., and pilings. (Egawa, 1985, 2002) Semi-exposed, Protected, Very protected (M. Otani, pers. comm.) RELATED: [Crepidula] Crepidula may be found in the apertures of hermit crab shells (Carlton 2007) * not specified whether sp. or spp.

Trophic Level:

Suspension feeder

Trophic Details:

Suspension feeder; filter-feeder (NEMESIS 2016) suspension feeder (Lee II and Reusser 2012) C. onyx may occasionally engage in indirect kleptoparasitism: indirectly stealing food by intercepting the feeding currents of its bivalve host (Peterson 1983, cited in Iyengar 2008) in the lab, larvae were fed a single-cell alga Isochrysis galbana (Zhao et al. 2003) They can be reared by single-cell alga like Isochrysis galbana in the laboratory. (Zhao et al. 2003) RELATED: [Crepidula (genus)] uses ciliary-mucous feeding: as water is moved left to right in mantle cavity, diatoms and other small food particles are trapped in mucus-coated ctenidia; the string of mucus travels in a ciliated groove to the mouth; mucous strands also prevent large particles from entering the mantle cavity (Kozloff 1990)

Forage Mode:

Selective

Forage Details:

traps phytoplankton and detritus in strings of mucus on its gills, which are conveyed to its mouth (Henry et al. 2010, cited in NEMESIS 2016) C. onyx may occasionally engage in indirect kleptoparasitism: indirectly stealing food by intercepting the feeding currents of its bivalve host (Peterson 1983, cited in Iyengar 2008) Their food is an excrement of mollusks they attached to and detritus. (Egawa 2002) RELATED: [Crepidula (genus)] uses ciliary-mucous feeding: as water is moved left to right in mantle cavity, diatoms and other small food particles are trapped in mucus-coated ctenidia; the string of mucus travels in a ciliated groove to the mouth; mucous strands also prevent large particles from entering the mantle cavity (Kozloff 1990)

Natural Control:

PREDATION [Predation] [Argentina] [Crepidula cf. onyx] eaten by muricids; drill holes found in dead shell assemblage (Martinelli et al. 2013) FOOD ABUNDANCE [Food Abundance] [Victoria Harbour] C. onyx has high density populations, but only in the harbor: the eutrophic environment of Victoria Harbour stimulates the growth of phytoplankton, which provides an abundant food source for C. onyx. Food may be a control on C. onyx densities in its native habitat, and areas outside of Victoria Harbour; larval stage is reliant on a good food supply; may be the most critical period for the successful colonization and establishment of a C. onyx population (Zhao et al. 2003)

Associated Species:

NF

References and Notes

References:

Association for the Research of Littoral Organisms in Osaka Bay (2012) Rocky shore macrobiota of southeastern Osaka Bay. Results of surveys carried out in the years 2006-2010. Shizenshi-Kenkyu 211-224. (in Japanese with English abstract) Carlton, JT (2007) The Light and Smith manual: intertidal invertebrates from central California to Oregon. London, England: University of California Press, Ltd Egawa K (1985) The distribution and dispersion of Crepidula onyx in Japan. Chiribotan 16: 37-44. (in Japanese) Egawa K (2002) Crepidula onyx. Introduced snail covers on host shellfishes exhaustively. In Handbook of alien species in Japan. The Ecological Society of Japan ed. Chijinshokan Inc., Tokyo: 185 p. (in Japanese) Horikoshi A & Okamoto K (2007) Present structure of sessile organisms communities of lighted buoys in Tokyo Bay. Sessile Organisms 24: 21-32. (in Japanese with English abstract) Huang ZG, Morton B, Yipp MW (1983) Crepidula onyx introduced into and established in Hong Kong. Malacological Review. 16:97-8. Hwang H, Kang J, Cho IY, Kang DW, Paek WK, Lee SH (2014) Benthic invertebrate fauna in the islets of Namuseom and Bukhyeongjeseom off Busan. Journal of Asia-Pacific Biodiversity. 7(2):e206-12. Inaba A (1982) Molluscan fauna of the Inland Sea, Japan. Hiroshima shell club, Hiroshima: 181pp. (in Japanese) Iwasaki et al. (2004) Human-mediated introduction and dispersal of marine organisms in Japan: Results of a questionnaire survey by the Committee for the Preservation of the Natural Environment, the Japanese Association of Benthology. Japanese Journal of Benthology 59: 22-44. (in Japanese with English abstract) Iwasaki & Kinoshita (2004) Range expansion of non-indigenous marine benthos introduced into Japan through human activities. Bulletin of the Plankton Society of Japan 51: 132-150. (in Japanese with English abstract) Iyengar EV (2008) Suspension feeding and kleptoparasitism within the genus Trichotropis (Gastropoda: Capulidae). Journal of Molluscan Studies. 74(1):55-62. http://mollus.oxfordjournals.org/content/74/1/55.full.pdf+html Kozloff EN (1990) Invertebrates. Philadelphia, PA: Saunders College Publishing Lee II H and Reusser DA (2012) Atlas of Nonindigenous Marine and Estuarine Species in the North Pacific. Office of Research and Development, National Health and Environmental Effects Research Laboratory, EPA/600/R/12/631. Martinelli JC, Gordillo S, Archuby F (2013) Muricid drilling predation at high latitudes: Insights from the southernmost Atlantic. Palaios. 28(1):33-41. Morton B (1984) The distribution and ecological-biological features of Crepidula onyx in Hong Kong. ACTA Oceanologica Sinica 3: 263-275. Morton B (1987) Recent marine introductions into Hong Kong. Bulletin of Marine Science 4: 503-513. NEMESIS 2015: Fofonoff PW et al. (2003) National Exotic Marine and Estuarine Species Information System. http://invasions.si.edu/nemesis/browseDB/SpeciesSummary.jsp?TSN=-72639. Access Date: 23-Oct-2015 NEMESIS (2016) Fofonoff PW, Ruiz GM, Steves B, & Carlton JT (2003) National Exotic Marine and Estuarine Species Information System. http://invasions.si.edu/nemesis/. Access Date: 22-Mar -2016 Ocean Biogeographic Information System. Crepidula onyx. http://iobis.org/mapper/.  Access Date: 22-Mar-16 Ohgaki SI (2010) List of shore molluscs along the south-west coast of the Kii Peninsula, 2007–2008. Argonauta. 18:31-49. Otani M (2004) Introduced marine organisms in Japanese coastal waters, and processes involved in their entry. Japanese Journal of Benthology 59: 45-57. (in Japanese with English abstract) Woodruff et al. (1986) Population genetics of Crepidula onyx: variation in a Californian slipper snail recently established in China. Veliger 29: 53-63. Zhao B, Qiu JW, Qian PY (2003) Effects of food availability on larval development in the slipper limpet Crepidula onyx (Sowerby). Journal of experimental marine biology and ecology. 294(2):219-33. http://www.sciencedirect.com/science/article/pii/S0022098103002703

Literature:

Moderate level of information; data from comparable regions or older data (more than 10 years) from the area of interest

Notes:

NA