The squat lobsters include six recognized families (Chirostylidae, Eumunididae, Kiwaidae, Galatheidae, Munididae and Munidopsidae) in two super families (Chirostyloidea and Galatheioidea) of decapods crustaceans within the infraorder Anomura (Ahyong., et al. 2010; Schnabel and Ahyong, 2010). Most of Genus Munida, Munidopsis, Eumunida and Agononida are from shelf and slope depths. The approximately 930 described species of squat lobsters are known form a wide range of depths (littoral to abyssal) and exhibit a worldwide distribution (Macpherson., et al. 2010). The present investigations of squat lobster have recorded and report for the first time in Indian Coast of Gulf of Mannar, off Thoothukudi (Figures 1, 2), Southeast coast of India. The dataset for the two squat lobster super families Galatheoidea and Chirostyloidea (Taxonomy and Phylogeny) and highlights the utility of these groups to global diversity and diversification. Squat lobsters are sporadic, widespread and biological diverse, and, importantly, are well-resolved taxonomically, with recent documentation of all published records for all known genus and species (Family Chirostylidae (9 Species) and Galatheidae (43 species) (Table 1).

Status and Conservation
Crustacean taxonomical studies on the Chirostylid and Galatheid lobsters of India are dealt with by Alcock (1894 & 1901), Alcock & Anderson (1895), Doflein & Balss (1913a), George and Rao (1966), Rao (1974), Tirmizi & Javed (1993), Thirumilu, (2011), Vaitheeswaran and Venkataramani (2012); Vaitheeswaran, (2014; 2015; 2016, 2017, 2018). A total of 52 species (9 from Family Chirostylidae and 43 from Family Galatheidae) are recorded, mostly from the deeper waters of Lakshadweep Sea, Arabian Sea, Bay of Bengal and Andaman Sea, while a single galatheid lobster Munidopsis regia Alcock & Anderson, 1894, Eumunida funambulus (Gordon, 1930),Agononida eminens (Baba, 1988), M. curvipes (Benedict, 1902), Munida heteracantha(Ortmann, 1892), M. semoni (Ortmann, 1894), Munidopsis cylindrophthalma (Alcock, 1894), M. scobina (Alcock, 1894) and Munida andamanica(Alcock, 1894) has been reported from Gulf of Mannar by Vaitheeswaran and Venkataramani (2012); Vaitheeswaran, (2014; 2015; 2016, 2017, 2018). While examining the crustacean catches landed by larger trawlers (more than 400 horse power), which operated in deeper waters off Thoothukudi waters, the number of specimen of squat lobster was obtained from Southeast and west coast of India. Thus, the total number of squat lobsters from India now rose to 52. Ongoing collections continue to explore new offshore regions, between the longitude and latitude, off Thoothukudi region, South India (08° 22.871’N 78° 22.409’E -08° 31.912’N 78° 25.327’E) at a depth of 185 to 318 M and habitats with the discovery of new species and genera continuing unabated. The average depth has calculated from minimum and maximum depth where two depths were available in straight line curve of southeast coast of India; otherwise the single depth record was used for only seasonal occurrence of this species. Depth classes were defined as follows: 0–199 m shelf; 200–899 m upper slope; 900–1999 m lower slope; 2000–3999 m continental rise; and >4000 m abyssal (Macpherson., et al. 2010). In order to cover as much available information as possible, different sources were used to extract distributional information for squat lobsters. The crustacean of squat lobster study revealed that the further stressed that strict management measures need to be undertaken to conserve deep sea fauna and flora species from further to avoid exploitation and to restore or sea ranching and enhancement of population of stock assessment of the particular crustacean group, the biodiversity of squat lobster population of Gulf of Mannar in general and Thoothukudi coast in particular, India.

Acknowledgements
The author is thankful to Thiru M. Kathirvel, former Principal Scientist of Central Institute of Brackishwater Aquaculture (I.C.A.R.), Chennai, for critical reading of the manuscript and helpful suggestion for its improvement. Dr. K. Baba, Professor, Kumamoto University, Japan, has provided me with literature on squat lobsters taxonomy. I wish to thank Thiru. K. Deenadhayalan, my dear friend and Professional photographer, Trichy, India, for their photograph of this specimen.