A new species of the amphipod genus Quadrivisio (Senticaudata, Maeridae) from Chilika Lagoon, India Author Bhoi, Gitanjali Department of Marine Sciences, Berhampur University, Bhanja Bihar, Odisha- 760007, India. Author Myers, Alan A. School of Biological, Earth and Environmental Sciences, University College Cork, Cork Enterprise Centre, Distillery Fields, North Mall, Cork, Ireland. Author Tarafdar, Lipika Department of Marine Sciences, Berhampur University, Bhanja Bihar, Odisha- 760007, India. Author Smita, Moili Department of Marine Sciences, Berhampur University, Bhanja Bihar, Odisha- 760007, India. Author Jena, Ajay Kumar Department of Marine Sciences, Berhampur University, Bhanja Bihar, Odisha- 760007, India. Author Patro, Shesdev Department of Marine Sciences, Berhampur University, Bhanja Bihar, Odisha- 760007, India. text Zootaxa 2023 2023-03-16 5256 1 36 42 http://dx.doi.org/10.11646/zootaxa.5256.1.2 journal article 10.11646/zootaxa.5256.1.2 1175-5326 7745263 534EEABE-292D-4E9D-B2DC-4FBAF0643D9A Identification key to species of Quadrivisio (updated after Gnohossou and Piscart, 2019 ) 1. Carina absent on pleonites or urosome in males and females.................................................... 2 – Carina present on pleonites or urosome in males and/or females................................................ 6 2. Male gnathopod 2 propodus palm without posterodistal shelf...................... Q. chevreuxi Gordon & Monod, 1968 – Male gnathopod 2 propodus palm with posterodistal shelf..................................................... 3 3. Male gnathopod 2 dactylus short, not reaching end of palm.......................... .. Q. aviceps (K.H. Barnard, 1940 ) – Male gnathopod 2 dactylus subequal to palm length.......................................................... 4 4. Urosome and telson covered in dense setae; male gnathopod 2 propodus anterior margin produced into lobe................................................................................................. Q. lobata Asari, 1983 – Urosome and telson without dense setae; male gnathopod 2 anterior margin not produced.............................5 5. Posterior margin of pereopod 7 basis regularly convex, telson with robust setae along inner margins of each lobe............................................................................... Q. sarina Lowry & Springthorpe, 2005 – Posterior margin of pereopod 7 basis not convex, telson without robust setae along innermargins of each lobe................................................................................. Q. laleyei Gnohossou and Piscart, 2019 6. Telson with robust setae along inner margins of each lobe............................. Q. bengalensis Stebbing, 1907 – Telson without setae along inner margin of each lobe......................................................... 7 7. Epimeron 3 margin smooth............................................................................. 8 - Epimeron 3 margin with several tooth..................................................................... 9 8. Antennae 2 flagellum is nearly twice the length of the fifth peduncle............................ Q. chilikensis sp. nov . – Antennae 2 flagellum is subequal to fifth peduncle...................................... Q. lutzi ( Shoemaker, 1933 ) 9. Accessory flagellum with 7 articles; mandibular palp articles 2–3 without setae.... Q. bousfieldi Karaman & Barnard, 1979 - Accessory flagellum with 9–10 articles; mandibular palp articles 2–3 with setae .......... Q. meufong Hughes & Haji, 2016