1.2 Internal morphology 1.2.1 Digestive system: mouth – esophagus – stomach – midgut – hindgut - anus 1.2.2 Circulation 1.2.3 Respiration system: podobrachiae 1.2.4 Excretory system: antennal glands 1.2.5 Reproductive system: ♀♂dioecious 1.2.6 Nervous system and sensory organ：compound eyes 1.2.7 Photophores
1.2 Internal morphology 1.2.1 Digestive system: mouth – esophagus – stomach – midgut – hindgut - anus 1.2.2 Circulation 1.2.3 Respiration system: podobrachiae 1.2.4 Excretory system: antennal glands 1.2.5 Reproductive system: ♀♂dioecious 1.2.6 Nervous system and sensory organ：compound eyes 1.2.7 Photophores
2 Classification Crustacea Malacostraca Eucarida Euphausiacea (2 families, 11 genera, 87 species) Family Bentheuphausiidae Family Euphausiidae
2 Classification Crustacea Malacostraca Eucarida Euphausiacea (2 families, 11 genera, 87 species) Family Bentheuphausiidae Family Euphausiidae
Order Euphausiacea 1a Photophores present only on abdominal segment one .Stylocheiron 手磷虾属 1b Photophores present on abdominal segments one to four .2 1c No photophores on abdomen or thorax . 3 1b 1a 1c
Order Euphausiacea 1a Photophores present only on abdominal segment one .Stylocheiron 手磷虾属 1b Photophores present on abdominal segments one to four .2 1c No photophores on abdomen or thorax . 3 1b 1a 1c