Record of imposex in Cronia konkanensis (Gastropoda, Muricidae) from Indian waters

This study for the first time records the phenomenon of imposer in gastropo ds from Indian waters. The gastropods were collected from three stations lo cated in Goa: Marmugao harbour, Dona Paula and Arambol. Imposer was recorde d in a muricid neogastropod species Cronia konkanensis(Melvill, 1893) (Fa, Muricidae) collected from Goa waters located along the west coast of India. The frequency of imposer was found to be in the range of 90-100% in the an imals collected from Marmugao harbour while this value reduced to 0-7% at D ona Paula, whereas no imposer could be recorded at Arambol. The vas deferen s sequence (VDS) stages ranged from Stages 0 to 4 in which VDS index of Sta ges 2 and 3 were predominant in the imposer-affected population. An average VDS index of 2.7 +/- 1.0 with an average relative penis size (RPL) index o f 67.2% was recorded in Marmugao harbour snails. The cubed relative penis s ize (RPS) index was 11.72% so in Stage 2 which increased to 55.81% in Stage 4 female snails collected from Marmugao harbour. (C) 1999 Elsevier Science Ltd. All rights reserved.