Asian Clam

Studies on which abiotic habitat characteristics are most strongly associated with Asian clam population abundance have produced varying results. Brazilian habitats have been found to have support the largest abundances of invasive Corbicula spp. in areas with coarser dominant sediment fractions, while negatively correlated with increasing levels of organic matter. Other studies have shown abiotic habitat characteristics such as water redox potential, inorganic nutrient content, hardness, and organic matter content in tandem with the amount of very coarse sand combine to explain 59.3% of Corbicula population habitat association via statistical tests. Asian clam invasions seem to be limited by elevation (88% of the invaded range is below 500m elevation), latitude (90% lies between latitudes 30°and 55°) as well as the minimum winter temperature (−10 °C (14 °F)) of the ecosystem. In 2001 it was identified in Puerto Rico from a collected specimen back in 1998, 18° of latitude.

Right after reaching maturity, these clams produce eggs, followed by sperm. Throughout adult life, Corbicula is a self-fertile simultaneous hermaphrodite which can broadcast spawn up to 570 mucoid larvae per day per individual, and more than 68,000 per year per individual. Larvae are ~200 microns in length when discharged from an adult and dispersed through water until becoming sessile adults. Adults can reach a length of about 5 centimetres (2.0 in).

Corbicula fluminea enjoys several physiological capabilities which are advantageous in promoting its invasion of novel lentic/lotic environments including:

Rapid individual growth rate Short time to reach sexual maturity Short lifespan paired with high fecundity Fast rate of water filtration for suspension feeding Ability to broadcast gametes over a broad area by utilizing water flow (in rivers) Tolerance of a wide variety of substrate/habitat types Corbicula fluminea is a self-fertilizing, simultaneous hermaphrodite which can asexually produce internally-brooded, semi-buoyant planktonic larvae when spermiogenesis is induced at temperatures above 10 °C (50 °F). This allows C. fluminea to colonize novel habitats at an advanced rate.