Hydrozoans

Hydrozoa Owen 1843

described accepted species

• Appeltans et al: 3426

known marine species

• Appeltans et al: 3426

number of new species decribed 1999-2008

• Appeltans et al: 304

percent of marine species currently described

• Appeltans et al: 69 (max)
• Appeltans et al: 46 (min)

percent surveyed species not yet known to science

• Appeltans et al: 0.64

percent synonyms among marine species

• Appeltans et al: 27

total species (expert opinion)

• Appeltans et al: 7526 (max)
• Appeltans et al: 4976 (min)

total unknown marine species

• Appeltans et al: 1550 (min)
• Appeltans et al: 4100 (max)

undescribed marine species present in museum collections

• Appeltans et al: 50 (min)
• Appeltans et al: 100 (max)

undiscovered marine morphospecies

• Appeltans et al: 1500 (max)
• Appeltans et al: 500 (min)

undiscovered species (molecular cryptic)

• Appeltans et al: 1000 (min)
• Appeltans et al: 2500 (max)