Identifying features are:
- Multicellular heterotroph.
- embryonic development, preceded by heterogametic fertilization.
- Segmented body covered by chitinous cuticle.
- Body segment bear paired externally jointed appendages.
- Anterior photoreceptors are present.
- Carapace is covered the dorsal surface.
- Head bears a pair of compound eyes located on movable stalk.
- Two pairs of pre oral & Three pairs of post oral appendages are present on the head.
- Antennules are uniramous but other appendages are biramous.
- Phyllopodium or Stenopodium are biramous appendages.
- Stalked eye
- Eight segments are present in thorax & six or seven on abdomen.
- Fan like tail has uropod & telson.
- Compound eyes.
- Antenna without three flagella.
- Seventh abdominal segment lacking.
- Elongated spindle shaped body.
- Carapace well developed drawn anteriorly into a rostrum.
- Elongated rostrum.
- Presence of antennal & hepatic spine.
- 19 pairs biramous appendages (5 pairs cephalic,8 pairs thoracic,6 pairs abdominal)
- First & second thoracic legs chelate, second pair is larger.