Mediomastus

A Intermediate genera from the “Annelids” group, mostly found in Muddy Sand

Muddy Sand

Intermediate

Annelids

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

“Long Term Planktonic” “Brooded or Laid Eggs”

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

estimated

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

estimated

Fecundity
  • 100 - 1000
  • 1 - 10
  • 10 - 100
  • 100 - 1000
  • 1000 - 10000
  • 10000 - 1 million
  • > 1 million

Image: Mediomastus © MES

Vulnerability

Mediomastus is a small-medium sized polychaete worm belonging to the Family Capitellidae. The worm is about 2-10cm in length & lives in permanent sandy tubes in fine sands & muds where it exploits subsurface diatoms & detritus. It has limited mobility & is likely to be vulnerable to dredging, but it may be capable of tolerating sand mobilised by the dredging process.

 

Recoverability

Little is known of the life-span or age at reproductive maturity for this genus. The adults spawn in April & eggs of about 0.1mm are fertilised externally then form gelatinous egg masses that containing about 500 eggs per individual. These hatch into planktonic larvae that spend about 4 weeks in the water column. The relatively large number of eggs & the occurrence of a planktonic dispersal phase suggest that this genus has a moderate-high recoverability following disturbance by dredging.
 

References

  • Distribution

    • Hansen, 1993
    • Hayward & Ryland, 1995b
    • Rasmussen, 1973
  • Reproduction

    • Hansen, 1993
    • Rasmussen, 1973
    • Warren, 1979