Vinay, T.N., Raymond, J.A.J; Katneni, V.K.; Aravind, R.; Balasubramanian, C.P.; Jayachandran, K.V.; Shekhar, M.S., and Vijayan K.K., 2019. Mitochondrial DNA study reveals the cryptic species Penaeus japonicus (form-II) in Indian waters. In: Jithendran, K.P.; Saraswathy, R.; Balasubramanian, C.P.; Kumaraguru Vasagam, K.P.; Jayasankar, V.; Raghavan, R.; Alavandi, S.V., and Vijayan, K.K. (eds.), BRAQCON 2019: World Brackishwater Aquaculture Conference. Journal of Coastal Research, Special Issue No. 86, pp. 149–155. Coconut Creek (Florida), ISSN 0749-0208.
Kuruma shrimp (Penaeus japonicus), is the most high-valued penaeid shrimp species due to its high market demand in Japan and other countries, and the most widely distributed penaeid shrimp across Indo-West Pacific. Kuruma shrimp was considered as a single species under the subgenus Marsupenaeus; however, recent studies have shown the existence of cryptic species within kuruma shrimp, with a slight variation in banding pattern on carapace with no other noticeable morphological differences. The form-I, is confined to Japan, Korea and China, including Taiwan and dominates the East China Sea and north of the South China Sea. The form-II is widely distributed in South-East Asia, Australia, the western Indian Ocean, the Red Sea and the Mediterranean with type locality being South Africa (Great fish point). Kuruma shrimp is distributed along both coasts of India. However, there is no genetic data available to conclude whether the species available in India is P. japonicus form-I or form-II. The morphological observations made in this study confirms its similarity with form-II along with the analysis of 16S rRNA (423 bp) and cytochrome c oxidase subunit I (COI) (419 bp) gene sequences which revealed that the species is phylogenetically more closely allied to form-II. This study indicates that P. japonicus form-I is not naturally present in India and the cryptic species in Indian waters is P. japonicus form-II.