AquaNISInformation system on aquatic non-indigenous and cryptogenic species |
Species | Mercenaria mercenaria [WoRMS] | |
Authority | (Linnaeus, 1758) | |
Family | Veneridae | |
Order | Venerida | |
Class | Bivalvia | |
Phylum | Mollusca | |
Synonym (?) | Mercenaria cancellata (Gabb, 1860) Mercenaria fulgurans (Tryon, 1865) Mercenaria rutila (Sternheimer, 1957) Mercenaria rutila rarilineata (Sternheimer, 1957) Venus mercenaria (Linnaeus, 1758) |
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Sub-species level (?) | Not entered |
Native origin (?) | Ocean: Atlantic --> Ocean region: NW Atlantic References (not structured): Brown A, Heilmayer O, Thatje S (2010) Metabolic rate and growth in the temperate bivalve Mercenaria mercenaria at a biogeographical limit, from the English Channel. Journal of the Marine Biological Association of the United Kingdom, 90(5), 1019–1023 Comments: North-west Atlantic, North America, from Prince Edward Island. |
Life form / Life stage (?) |
References (not structured): Brown A, Heilmayer O, Thatje S (2010) Metabolic rate and growth in the temperate bivalve Mercenaria mercenaria at a biogeographical limit, from the English Channel. Journal of the Marine Biological Association of the United Kingdom, 90(5), 1019–1023 Huiping Yang, Ximing Guo (2006) Tetraploid Induction by Inhibiting Mitosis I with Heat Shock, Cold Shock, and Nocodazole in the Hard Clam Mercenaria mercenaria (Linnaeus, 1758) Biotechnol (NY) 8(5):501-10 |
Sociability / Life stage (?) |
References (not structured): Carter M.,2005. Mercenaria mercenaria. Hard-shell clam. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 07/06/2012]. Available from: |
Reproductive frequency (?) | Iteroparous References (not structured): Huiping Yang, Ximing Guo (2006) Tetraploid Induction by Inhibiting Mitosis I with Heat Shock, Cold Shock, and Nocodazole in the Hard Clam Mercenaria mercenaria (Linnaeus, 1758) Biotechnol (NY) 8(5):501-10 Hoffman EE, Klinck JM, Kraeuter JN, Powell EN, Grizzle RE, Buckner SC, Bricelj VM (2006) A population dynamics model of the hard clam, Mercenaria mercenaria: development of the age- and length-frequency structure of the population. Journal of Shellfish Research. pg(s) 417-444 |
Reproductive type (?) | Sexual References: Huiping Yang, Ximing Guo (2006) Tetraploid Induction by Inhibiting Mitosis I with Heat Shock, Cold Shock, and Nocodazole in the Hard Clam Mercenaria mercenaria (Linnaeus, 1758) Biotechnol (NY) 8(5):501-10 Judge LM, Coen DL, Heck LK (1993) Does Mercenaria mercenaria encounter elevated food levels in seagrass beds? Results from a novel technique to collect suspended food resources. MARINE ECOLOGY PROGRESS SERIES Vol. 92: 141-150 Whetstone JM, Sturmer NL, Oesterling MJ (2005) Biology and Culture of the Hard Clam (Mercenaria mercenaria). Southern Regional Aquaculture Center. SRAC Publication No. 433 Comments: Mercenaria mercenaria is a protandric hermaphrodite, with the male line developing first. Approximately 98% of all juvenile clams begin life as males; however, with increased age and size, sex ratios in the population even out, and approximately half of the males later change to females. |
Developmental trait (?) | Planktotrophy Spawning References: Carriker, M.R. 2001. Embryogenesis and organogenesis of veligers and early juveniles. In J.N. Kraeuter & M. Castagna (eds.), Biology of the hard clam. pp 77-112. Elsevier, New York, USA. Comments: Eggs of M. mercenaria measure approximately 70 - 90 um in diameter and are surrounded by a gelatinous envelope. Fertilized eggs become trochophore larvae within the first 12 hours; shells develop within 26-30 hours. The veliger stage is reached in another 8-12 hours. Veligers are planktonic for approximately 12-14 days before settling. Larvae that are competent to settle measure approximately 200-210 um. With settlement, the velum disappears and use of the foot shifts from aiding in swimming to burrowing and crawling. |
Characteristic feeding method / Life stage (?) |
References (not structured): Alatalo P (1980) Yeast utilization in oysters and clams. Masters thesis, Univ. Del., Newark, DE 19716, 44 p. Carriker, M.R. 2001. Embryogenesis and organogenesis of veligers and early juveniles. In J.N. Kraeuter & M. Castagna (eds.), Biology of the hard clam. pp 77-112. Elsevier, New York, USA. Whetstone JM, Sturmer NL, Oesterling MJ (2005) Biology and Culture of the Hard Clam (Mercenaria mercenaria). Southern Regional Aquaculture Center. SRAC Publication No. 433 Comments: Hard clams filter the water to obtain phytoplankton and other suspended particles that they use as food. Juvenile clams, Mercenaria mercenaria were fed one of three diets consisting of the flagellate Isochrysis galbana, the torulan yeast Candida utilis. The free swimming larvae feed on phytoplankton and other organic materials in the water. |
Mobility / Life stage (?) |
References (not structured): Carter M.,2005. Mercenaria mercenaria. Hard-shell clam. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 07/06/2012]. Available from: Comments: The hard clam, Mercenaria mercenaria, burrows shallowly in sediments of either mud or sand. |
Salinity tolerance range (?) | Exact range: 21 - 30 References: Eversole, A.G. 1987. Species profiles: life histories and environmental requirements of coastal fishes and invertebrates (South Atlantic)--hard clam. U.S. Fish Wildl. Serv. Biol. Rep. 82(11.75). U.S. Army Corps of Engineers, TR EL-82-4. 33 pp. Comments: the tolerance of M.mercenaria to decreases in salinity increases with the age of the clam, and its inversely proportional to temperature. Eggs develop normally within the range of 20-32,5 ppt; over 35 ppt, only 1% of eggs develop, at salinity below 17,5 ppt none do. Maximum growth of larvae os achieved at salinities between 21-30 ppt. Adult Mercenaria mercenaria are able to withstand long periods of low salinity due primarily to their valves. Adults survive at salinity as low as 10 ppt for up to 4-5 weeks, and are able to balance their internal osmotic conditions with that of the external medium. |
Habitat modifying ability potential (?) | OLD VALUE Comments: --/OLD VALUE/-- Perennial habitat former |
Toxicity / Life stage (?) | Not relevant |
Bioaccumulation association (?) | Anthropogenic chemical compounds References: Larsen, P. F. 1979. The distribution of heavy metals in the hard clam, Mercenaria mercenaria, in the lower Chesapeake Bay region. Estuaries, 2, pp. 1-8. |
Known human health impact? | Known References: Hadley, N., Coen L. 2015. Hard clams. Supplemental Volume: Species of Conservation Concern. Available at: (https://dc.statelibrary.sc.gov/server/api/core/bitstreams/bfebd132-b921-42f9-9f66-1a2e19eb7584/content) Comments: A large adult clam filters an average of seven to eight liters per hour. They also readily ingest bacteria, viruses and other water-borne pathogens that can cause human health problems. |
Known economic impact? | Known References: Hadley, N., Coen L. 2015. Hard clams. Supplemental Volume: Species of Conservation Concern. Available at: (https://dc.statelibrary.sc.gov/server/api/core/bitstreams/bfebd132-b921-42f9-9f66-1a2e19eb7584/content) Comments: Hard clams are harvested both recreationally and commercially and are the most valuable commercially harvested clam in the United States. In South Carolina, the hard clam also supports a mariculture industry producing an estimated ‘farmgate’ value of 6.5 million dollars. |
Known measurable environmental impact? | Known References: Smithsonian Environmental Research Center. (n.d.). Nemesis species summary: Mercenaria mercenaria. Retrieved from https:https://invasions.si.edu/nemesis/species_summary/-57 Comments: M. mercenaria to small, confined estuaries has probably limited its impact. However, dense populations of these clams could have substantial impacts by filtering phytoplankton and excreting nutrients, as was seen in the Colorado Lagoon, California.In the Gulf of Mexico, widespread plantings and aquaculture of M. mercenaria has resulted in hybridization with the native M. campechiensis. In five estuaries on the Gulf Coast of Florida, near early planting and present aquaculture sites, hybrids comprised 13-45% of the Mercenaria sampled. |
Included in the Target Species list? | No References: HELCOM, 2009. Alien Species and Ballast Water [PDF]. Available at: (https://archive.iwlearn.net/helcom.fi/stc/files/shipping/Table_2_Alienspecies_%20lists_2009.pdf) |
Association with vessel vectors (?) | Unknown Comments: Not available. |
Molecular information | Available NCBI (http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=6596&lvl=0) |
Last update by | Sandra Gečaitė, 2024-07-16 |