From June 2014 to May 2015, 10 sampling stations were set up in the north of Hangzhou Bay. Monthly collections were held by a larvae net. 120 trawls were carried out and 1 972 ind. of Salanx ariakensis were collected. The development of the vertebral column and the appendicular skeleton of the larvae and juveniles of S. ariakensis was described. A series of wild specimens of 9.7-34.2 mm in body length were cleared and stained for both cartilage and bone. The dorsal, anal, pectoral and pelvic fins supports, neural arches and haemal arches were cartilage. The cleithrum, supracleithrum, posttemporal, hypurals, urostyle and uroneural were bone. All the skeletons developed in the following sequence:pectoral girdle, anal fin supports and hypurals, dorsal fin supports, haemal arches and neural arches, pelvic fin supports and epurals. According to the observation,the postcleithrum was absent in S. ariakensis. The number of neural arches was 73, haemal arches was 22, hypurals (including parhypural) was 7, pterygiophore of anal fins was 27 and dorsal fins was 13. This showed that S. ariakensis had the phenomenon of neoteny that the ossification of the skeletal system was not all bone, which was similar to other salangid fishes.