First observation of Alpheus soror Bruce, 1999 (Caridea: Alpheidae) from Gulf of Mannar, Southern India with notes on A. lottini Guérin, 1830 [in Guérin, 1829-1830]

Pistol shrimps Alpheus Fabricius, 1798 generally inhabit shallow depths of coral regions. A recent survey conducted at the Gulf of Mannar and Lakshadweep islands provided two species of Alpheus shrimps from the intertidal zone at 0.5 to 15 m depths. The study revealed that Alpheus soror Bruce, 1999 is a new report to the Gulf of Mannar and A. lottini Guérin, 1830 [in Guérin, 1829-1830] found in stony coral of genus Pocillopora sp. is a new report to Lakshadweep waters. The major intra and interspecific characters of these two species are described and discussed in detail.