Nephasoma

A Vulnerable genera from the “Other: Sipuncula” group, mostly found in Muddy Sandy Gravel

Muddy Sandy Gravel

Vulnerable

Other: Sipuncula

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

“Brooded or Laid Eggs”

Lifespan
  • 1-2 years (Estimated)
  • >10 years
  • 3-10 years
  • 1-2 years
  • <1 year

estimated

Maturity
  • 1-2 years (Estimated)
  • >4 years
  • 3-4 years
  • 1-2 years
  • <1 year

estimated

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

estimated

Image: Nephasoma © MES

Vulnerability

Nephasoma is a small sipunculid ‘worm’ belonging to the Family Golfingiidae. It reaches a body length of 1-2cm & lives in shallow burrows under stones in sand & muddy substrata & in rock crevices.It is a deposit-feeder exploiting mainly detritus in the sediments. It has some mobility but is likely to be vulnerable to dredging. It may have some capacity to survive small quantities of deposition of material mobilised during the dredging process.

 

Recoverability

Little is known of the longevity & age at maturity for this genus. Reproduction is from November-January by hermaphrodite adults that produce eggs of 0.2-0.28mm diameter. Development is direct from yolk-filled eggs following external fertilisation & there is no larval phase. This genus probably has low recoverability.

 

References

  • Biology

    • Fish & Fish, 1996
    • Hayward & Ryland, 1995b
  • Taxonomy

    • Howson & Picton, 1997
  • Distribution

    • Fish & Fish, 1996
    • Foster-Smith, 2000
    • Hayward & Ryland, 1995b
  • Reproduction

    • Fish & Fish, 1996