Occurrence of Oratosquilla oratoria (De Haan, 1844) and Oratosquillina gravieri (Manning, 1978) from the trawl bycatches of Nagapattinam region, Tamil Nadu

Six species of mantis shrimps were recorded in the trawl catches of Nagapattinam region during January – December, 2018. The occurrence of two species namely Oratosquilla oratoria (De Haan, 1844) and Oratosquillina gravieri (Manning, 1978) were reported for the first time in the trawl bycatches of Nagapattinam region. The morphometrics of these two species is reported in this paper. Presence of inferodistal spine in the merus of the raptorial claw, rostral plate short and trapezoid to square in shape, 5th abdominal segment without submedian patch, 4th abdominal segment submedian carinae unarmed in Oratosquilla oratoria and rostral plate elongate and rectangle, lateral process of 6th thoracic somite with slender, triangular anterior lobe and dactylus of the raptorial claw with 6 teeth in Oratosquillina gravieri are chief characters to differentiate from other species