Alcyonidium

A Vulnerable genera from the “Other: Bryozoa” group, mostly found in Cobbles

Cobbles

Vulnerable

Other: Bryozoa

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

“Sedentary”

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

“Brooded or Laid Eggs” (estimated)

Lifespan
  • 3-10 years
  • >10 years
  • 3-10 years
  • 1-2 years
  • <1 year
Maturity
  • 1-2 years (Estimated)
  • >4 years
  • 3-4 years
  • 1-2 years
  • <1 year

estimated

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

estimated

Image: Alcyonidium © MES

Vulnerability

Alcyonidium is an erect bryozoan which grows attached to hard substrates including stones, boulders & shells. Like all bryozoans this genus is sedentary & is therefore unable to evade the direct effects of dredging or deposition of sediment mobilised by the dredging process.
 

Recoverability

There is little information on the reproduction & life history of Alcyonidium. Some species of the genus are known to brood their larvae which, once released, settle within a matter of hours. The dispersal potential is therefore limited & is reliant on an adjacent colony. Recovery of adult biomass is difficult to assess, but since this colonial organism reaches sexual maturity after only 2 months local recolonisation may be achieved relatively rapidly if the substratum remains suitable for settlement.

References

  • Biology

    • Hayward, 1985
    • Pathmanaban et al., 2005
  • Taxonomy

    • Hayward & Ryland, 1995b
    • Hayward et al., 1996
    • Hayward, 1985
    • Howson & Picton, 1997
    • Pathmanaban et al., 2005
  • Distribution

    • Hayward & Ryland, 1995b
    • Hayward et al., 1996
    • Hayward, 1985
    • NBN, 2002
    • Pathmanaban et al., 2005
    • Picton & Costello, 1998
    • Porter et al., 2001
    • Porter et al., 2002