Monograph on the Planktonic Shrimps of the Genus Lucifer (Family Luciferidae) from the Indian EEZ

The decapod dendrobranchiate shrimps of the family Luciferidae De Haan, 1849 under the superfamily Sergestoidea Dana, 1852 were studied comprehensively to prepare a taxonomic monograph and thus to record the taxonomic placement, diagnostic characters and the distribution of each species of the family in the seas around India. The zooplankton samples of the first 44 cruises of FORV Sagar Sampada in the Indian EEZ and the collections made from the coastal sea off Cochin for a period of one year constituted the database of this investigation. These holoplanktonic pelagic shrimps were chosen for a detailed taxonomic study due to its importance in the coastal food web and the abundance in planktonic state throughout the year exhibiting peak dominance during the southwest monsoon and immediate postmonsoon months. The study brought to light the presence of all the seven world species of the genus Lucifer in the Indian EEZ and thus added three more new records, namely, L. chacei Bowman, 1967; L. intermedius Hansen, 1919 and L. orientalis Hansen, 1919 to the already known four species from Indian waters, viz., L. typus H.Milne Edwards, 1837; L. hanseni Nobili, 1905; L. penicillifer Hansen, 1919 and L. faxoni Borradaile1915. L.penicillifer Hansen, 1919 is the predominant species in the Arabian Sea and Bay of Bengal while L.typus H.Milne Edwards, 1837 in the island ecosystems. The neretic region of the Indian EEZ up to the 50 m depth support 51 % of these shrimps, mid shelf between 50 and 100m harbour 29%, whereas 12 % occur in the outer shelf between 100 and 200 m and 8 % in the deep zone beyond 200 m. In the fishery environment off Cochin up to 30 m depth zone L.hanseni is found to be the predominant species followed by three more species namely, L.typus H.Milne Edwards, 1837; L.penicillifer Hansen, 1919 and L. chacei Bowman, 1967 of which the last two are new records for the coastal area. Keys of the family and species of the genus are given. Each species is treated in detail giving prime importance to its taxonomic placement, diagnostic characters and distribution supported by descriptions and adequate illustrations in a simple manner making the identification process an easy task. Comparisons are made wherever possible followed by references from the Indian authors and the world over. Schematic representations of a penaeid prawn and its appendages are adapted and given with a view to get familiarized with the usage of updated terminology. References included in this monograph are those of a review nature, relating to a new geographic area of occurrence of the species or giving a link to the diagnosis and distribution of the species. The taxonomic placement of the family Luciferidae De Haan, 1849 under the superfamily Sergestoidea Dana, 1852 was under debate but Farfante & Kensley (1997) treated it as a separate family Luciferidae closely related to Sergestidae under the superfamily Sergestoidea and this pattern has been followed in this monograph