Nymphon

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

Cobbles

Vulnerable

Other: Crustacea

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

“Short Range Mobility” “Sedentary”

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

“Short Term Planktonic” “Brooded or Laid Eggs”

Lifespan
  • 1-2 years
  • >10 years
  • 3-10 years
  • 1-2 years
  • <1 year
Maturity
  • <1 year
  • >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: Nymphon © MES

Vulnerability

Nymphon is a genus of very small sea spiders belonging to the Family Nymphonidae. The size rarely reaches 1cm & the sea spider lives associated with epigrowths such as hydroids & algae. It has very limited mobility & is moreover dependent on sessile epigrowths as a habitat. It is likely to be vulnerable to dredging & to alteration of its habitat if significant deposition of material mobilised by dredging occurs.

 

Recoverability

The life-span of this genusis thought to be about 1 yr. The sexes are separate & sexual maturity is attained in less that 12 months. There is an annual episodic breeding period from February-March at which time the female releases 30-40 eggs of about 0.12mm diameter. These are fertilised internally & later transferred to the male during the winter migration. Up to 300-400 embryos may be carried as a brood by the male. These are then released in a short planktotrophic larval phase before settlement in April. The fecundity is relatively low & the juvenules are unlikely to disperse far from the site of release. Recolonisation from outside sources following disturbance is likely to be slow & the genus has a low recoverability.

 

References

  • Biology

    • Jarvis & King, 1978
    • King & Jarvis, 1970
  • Reproduction

    • Fish & Fish, 1996
    • Jarvis & King, 1978
    • King & Jarvis, 1970