Gari

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

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)
  • Long Term Planktonic (Estimated)
  • Long Term Planktonic
  • Short Term Planktonic
  • Brooded or Laid Eggs

“Long Term Planktonic” (estimated)

Lifespan
  • 3-10 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 (Estimated)
  • 1 - 10
  • 10 - 100
  • 100 - 1000
  • 1000 - 10000
  • 10000 - 1 million
  • > 1 million

estimated

Image: Gari © MES

Vulnerability

Gari is a small-medium sized bivalve mollusc belonging to the Family Psammobiidae. The shell length is 5-6cm & the bivalve lives in sand & sandy gravel deposits in a shallow burrow where it filters plankton from the water column. It has limited powers of movement, but can re-bury itself after disturbance. It is likely to be vulnerable to the effects of dredging, but probably has the ability to resurface through sediments mobilised by the dredging process.
 

Recoverability

In common with many bivalve molluscs, Gari has a relatively long life-span of 6-10yrs, with an age at reproductive maturity of 1-2yrs. Yolk-filled eggs of about 0.15mm are released annually between spring to summer & are fertilised externally in the water column. Little is known of the fecundity or larval settlement time & dispersion potential for this genus. The relatively long life-span suggests that restoration of biomass would take several years after initial recolonisation. This genus probably has a low-intermediate recoverability.

 

References

  • Biology

    • Hayward & Ryland, 1990
    • Urban & Campos, 1994
  • Distribution

    • Hayward & Ryland, 1990
  • Reproduction

    • Brown et al., 2002
    • Urban & Campos, 1994