Abstract:Based on the continuous samples of the larvae development of Harpiosquilla annandalei Kemp, the morphology and the development features were observed under microscope and dissecting microscope and their pictures were drawn. The result showed that after experiencing 11 molts at water temperature 24 - 27 ℃ and salinity 25.4 - 29.0, the pseudozoea of H. annanda/ei. . metamorphose into juvenile squilla and this process takes 49 days to complete. The body length at pseudozoea Ⅰ is 1.75 - 1.83 mm. Its head has a long rostrum. The shape of the carapace with one pair of ventral teeth in edge, a spine in each comers and a long spine in the middle of retral part is similar to a turtle shell. At pseudozoea stage Ⅵ, the carapace with 5 pairs of lateral abdomen teeth in edge gradually developed, and then looks like a trapezium. The mesial flagellum bud appears on the first antenna and the endopodite in the second antenna develops into a short bud. The telson appendage presents when the larva develops into pseudozoea Ⅶ. The two edges of carapace begin to bend and cover downwards when the larva is pseudozoea Ⅶ. At pseudozoea Ⅺ, its body length is 15.10- 17.20 mm. The endopodite in the second antenna develops and become a long flagellum divided into 14- 16 segments. The exopodite of telson has 2 segments and the endopodite has 1 segment. The body length of juvenile squilla at stage I is 14.5 - 16.10 mm. The long rostrum disappears and the carapace is still in trapezium shape while smooth and without ventral teeth. Its anterior cumu is rounded and its posterior comu has two nicks which are the distinguishing feature for this species. Then the mid spines in the retral carapace disappear. The rate of carapace length compared to body length decreases obviously. The larvae in this stage look like a miniature adult squilla. The larval morpha of H. annandaiei has some differences from those of O. kempi and O. oratoria. The differences can be identified by the rate of the carapace length compared to the body length, the rate between the length and width of carapace, the scale seta numbers in the second antenna and the lateral, mid, sub-mid tooth numbers in the telson.