Morphological variation in three species of Alpheid shrimps in Palk Bay

Abstract

Morphological characterization and morphological variation studies between and within species is very important to assess the biodiversity in a particular geographical area. In this work, we have collected three Alpheus species from Palk Bay region and measured the morphometric characters and ana-lysed subsequently. Based on the standard identification keys, the collected specimens were identified as Alpheus serenei, A. strenuus and A. parvirostris. Among the fourteen morphometric characters, ocular hood width (OW) in relation to abdominal length (AL) and dactyl length of the major chela (MdL) in relation to propodus length of the major chela (MpL) are showed no sig-nificant variation in all the three species. Most of the characters like AI2 (%ASL), AI3 (%ASL), TIP (%TIL), TID (%TIL), MpH (%MpL), MhH (%MdL), NpH (%NpL) and NdL (%NpL) are significantly similar in A. serenei and A. strenuus. The first and second principal component loading value confirmed more pos-itive weights for AI2 (%ASL), AI3 (%ASL), TIP (%TIL), TID (%TIL) and MdL MpL) in all the three species. The outlier values of some individual specimens of A. serenei and A. strenuus on the first and second principal components have over lapped on the score plot. Further research is warranted to confirm these species using molecular tool like DNA barcoding.