Nuculana

A Vulnerable genera from the “Molluscs” group, mostly found in Muddy Sandy Gravel

Muddy Sandy Gravel

Vulnerable

Molluscs

Genera Characteristics Recorded Traits Possible Values
Size in cm
  • 1-10 cm
  • <1 cm
  • 1-10 cm
  • 11-20 cm
  • >20 cm
Genera Characteristics Recorded Traits Possible Values
Motility (Adult)
  • Short Range Mobility
  • Adult
  • Short Range Mobility
  • Sedentary

“Short Range Mobility”

Motility (Larval)
  • Short Term Planktonic
  • Long Term Planktonic
  • Short Term Planktonic
  • Brooded or Laid Eggs

“Short Term Planktonic”

Lifespan
  • >10 years
  • >10 years
  • 3-10 years
  • 1-2 years
  • <1 year
Maturity
  • 1-2 years
  • >4 years
  • 3-4 years
  • 1-2 years
  • <1 year
Fecundity
  • 100 - 1000
  • 1 - 10
  • 10 - 100
  • 100 - 1000
  • 1000 - 10000
  • 10000 - 1 million
  • > 1 million

Image: Nuculana © MES

Vulnerability

Nuculana is a small bivalve mollusc of about 1-2cm in length that lives in muddy sands & gravels. It has very limited mobility & is likely to be vulnerable to dredging & to deposition of sediment mobilised during the dredging process.
 

Recoverability

The bivalve has a long life-span of about 15yrs. There is a protracted breeding season that extends throughout the year. Relatively small numbers of 175 eggs of about 0.12-0.14mm diameter are fertilised externally. They develop into lecithotrophic larvae that settle in less than 12 hours within 10m of the site of release without a pelagic phase. The low fecundity, low dispersal & slow growth of this bivalve suggest that it has a very low recoverability following disturbance.

 

References

  • Biology

    • Hutchings & Haedrich, 1984
    • Knudsen, 1979
  • Distribution

    • Hayward & Ryland, 1990
    • Thorson, 1946
    • Thorson, 1946
  • Reproduction

    • Ansell et al., 1978
    • Hutchings & Haedrich, 1984
    • Knudsen, 1979
    • Mackie, 1984
    • Mackie, 1984
    • Thorson, 1946
    • Thorson, 1946
    • Tyler et al., 1992