Size ranges of zoea stages based on measurements of P. japonicus
Z1
  1. Body length 0.86 -1.32 mm
  2. Body flattened; carapace distinct
  3. Sessile eyes present
  4. First and second maxillae and first and second maxillipeds functional
  5. Furcal processes present
  6. Digestive tract visible
Z2
  1. Body length 1.33 - 2.13 mm
  2. Stalked eyes present
  3. Rostrum developed
  4. Supraorbital spines developed
  5. Abdominal segmentation apparent
Z3
  1. Body length 2.14 - 2.70 mm
  2. Abdominal segmentation distinct; dorsal and/or lateral spines present on most somites
  3. Rudiments of uropods present

(Treece & Yates, 1988)