The Smooth-coated Otter is essentially a plains’otter. In the Indian subcontinent they are adapted to live even in the semiarid region of northwestern India and Deccan plateau (Prater 1971). Generally, the species uses large rivers and lakes, peat swamp forests, mangroves and estuaries, and also rice fields for foraging (Foster-Turley 1992). In Southeast Asia, rice fields appear to be one of the most suitable habitats in supporting its viable populations (Melisch et al. 1996). However, they were more abundant in the mangroves of Kuala Gula, Malaysia as compared to the rain forest rivers (Shariff 1984). In certain areas, such as Singapore, the species uses highly disturbed urban sites, with some populations showing a remarkable resilience in the presence of human activity (Theng and Sivasothi 2016, Khoo and Sivasothi 2018).

Along the large rivers in India, the Smooth-coated Otters prefer rocky stretches since these stretches provide sites for den and resting. River stretches with bank side vegetation and marshes are used in proportion to their availability especially in summer as they provide ample cover while travelling or foraging. Open clayey and sandy banks are largely avoided as they lack escape covers (Hussain 1993; Hussain and Choudhury 1995, 1997). In the Tarai areas of the upper Gangetic plains the Smooth-coated Otters use seasonally flooded swamps during monsoon (July-September) and in early winter (October-February). Winter being the breeding season, the swamps are extensively used as natal den sites and nursery. By February-March the swamps begin to dry and the fish biomass appears to be depleted, consequently the otters move to the perennial rivers (Hussain and Choudhury 1997). In west Java, the Smooth-coated Otters prefer mangroves and tidal stretches of the rivers and rice fields. Freshwater swamps and coastal stretches lacking vegetation are avoided (Melisch et al. 1996). In rice fields and pond areas they prefer sites having moderate diversity of vegetation. Rivers with moderate to slow or stagnant water and water bodies having a width of 10-40 m are preferred. In Huai Kha Khaeng, Thailand, the Smooth-coated Otters extensively use the slowly meandering river near the dam and the dam itself (Kruuk et al. 1994). In urban Singapore, in addition to natural sites, otters use human-made, concretized structures such as reservoirs and canals, and have adapted to use concrete and grass for grooming. Latrines, resting sites, and dens are present in areas with high human accessibility such as small gaps and crevices under bridges, and under metal beams and roads. They have been observed using stairs and ladders to access dry land in concrete canals with steep sloping walls (Khoo and Sivasothi 2018).

The Smooth-coated Otter is predominantly a fish eater, but supplements its diet with shrimp/crayfish, crab and insects, and other vertebrates such as frog, mudskippers, birds and rats (Prater 1971, Foster-Turley 1992, Hussain and Choudhury 1998). In general, its diet is similar to that of Eurasian Otter. The range of fish in the diet varies from 75% to 100% (Tiler et al. 1989, Foster-Turley 1992, Hussain 1993, Melisch et al. 1996, Hussain and Choudhury 1998, Nawab and Hussain, 2012b). The Smooth-coated Otters exhibit the typical opportunistic feeding behaviour similar to the Eurasian Otter. Along the major rivers in India they eat more fish, often making up to 94% of the total diet (Hussain and Choudhury 1998), while along the coast in mangrove habitats and in rice fields it ranges between 75-100% (Foster-Turley 1992, Melisch et al. 1996). In west Java otters inhabiting mangrove areas eat more of crustaceans, around 22% of the scats contain remains of crab and shrimp where as in the paddy fields in Malaysia, along with fish they tend to eat more rice field rats Rattus argentiventer, represented in 23% of the spraints (Foster-Turely 1992). In Singapore, along the mangrove habitats, prawn consisted 35% of their diets (Theng et al. 2016).

Hussain (1993) identified 12 fish species from the spraint of Smooth-coated Otter from the Chambal River, of which seven species were eaten throughout the year. Rhinomugil corsula (Mugilidae) and Rita rita (Bagaridae) were the preferred species. At least eight species of fish were identified from the spraints from Malaysia (Foster-Turley 1992). Some of these include Gourami (Trichogater spp.), Climbing Perch (Anabis testudineus), catfish (Clarius spp.), snakehead (Channa spp.) and mudskipper (Gobioidei). In the rice fields they ate large amount of most common fish (Trichogater and Anabis spp.). The size of the fish consumed varied from 5-46 cm, often ranging between 15-30 cm (Wayre 1978). No significant relationship was found between the calorific values of the fish and the quantities consumed. Thus, the prey selection by Smooth-coated Otter is mainly influenced by its availability (Hussain 1993). In Singapore, at least 12 fish species from 11 families were identified from spraints, with the highest occurrence of fish from the Cichlidae family (Theng and Sivasothi 2016). Diet of the Smooth-coated Otter in Periyar Tiger Reserve, India, predominantly consisted of the exotic Tilapia mossambicus (51.54%) and Cyprinus carpio communis (9.16%), which reveals that the otters may contribute in controlling the rapid expansion of invasive species (Anoop and Hussain, 2005).

The Smooth-coated Otter attains sexual maturity at twenty-two months in captivity (Desai 1974). Yadav (1967) observed first litter at four years of age. In captivity they mate during August to October in water followed by prolonged playful bouts between partners (Desai, 1974, Naidu and Malhotra 1989). Copulation takes place several times daily. Males are polygamous mating with up to four females (Desai 1974). In the wild in northern India mating occurs in August-September and littering in November-December (Hussain 1993). Desai (1974) observed litter size of 2-5 (mean = 3.25). Similarly, Naidu and Malhotra (1989) observed litter size 1-5. The breeding schedule of Smooth-coated Otters in the wild in India corresponds with the captive records (Hussain 1993, 1996). Evidences of littering have been recorded in October and the cubs were seen out of the den in February. The mean litter size along the Chambal River was three (Hussain 1996). In Singapore, litter size observed from two family groups over seven litters was 3-7 (mean = 4.86), with breeding being non-seasonal (Khoo and Sivasothi 2018).

Based on the percentage of active telemetry recordings, Hussain (1993) observed that the overall activity pattern of Smooth-coated Otters along the Chambal River in India was in the form of a bimodal curve in which two period of high activity were separated by a period of relative inactivity. This pattern of activity varied considerably among seasons. In summer, the relative period of inactivity was greater than in winter or monsoons. A significant difference was also found between day and night time activities in different seasons. Otters were more diurnal during winter than in summer or monsoon.

Hussain (1993) observed daily movements of four radio-implanted Smooth-coated Otters of different age and sex within their home range. Two types of movements were identified; small-scale movements associated with foraging in a restricted area close to dens, and more extensive travels between dens and foraging sites. Most of the movement was restricted between 250 to 1,500 m. A typical group of Smooth-coated Otter consisting of male, female, and up to four young ones require 7 to 12 km of river for their territory and an even longer stretch of shoreline if living along the coast (Wayre 1974). During a radio-tracking study along the Chambal River, India, the home range of all the otters tracked overlapped intensively. Among the radio-implanted otters, the maximum home range was observed in sub-adult male and the minimum in juvenile female and male. Among the non-tagged otters, the home range of female with cubs was estimated as 5.5 km. In case of the adult male it was estimated to be approximately 17 km (Hussain 1993). Along the Chambal River, the home range length and area of Smooth-coated Otter was less than that of Eurasian Otter, in Perthshire, Scotland and North American River Otter Lontra canadensis in Idaho (Melquist and Hornocker 1983), but larger than that of Eurasian Otter (Erlinge 1967) in Sweden.

The Smooth-coated Otter is distributed throughout South Asia and Southeast Asia. Its distribution is continuous from Indonesia, through Southeast Asia, and westwards from southern China to India and Pakistan, with an isolated subpopulation in Iraq (Pocock 1941, Medway 1969, Hussain 1993). Though its current status in the Middle East is not known, its presence has been confirmed from Pakistan, India, Nepal, Bhutan, Bangladesh, southwest China, Myanmar, Thailand, Singapore, Viet Nam, Malaysia (Penisular Malaysia, Sabah and Sarawak), and Indonesia (Kalimantan, Sumatra, Java) and Brunei (Mason and Macdonald 1986, Corbet and Hill 1992, Wozencraft 1993). Historically, the Smooth-coated Otter occurred in the Pearl River Delta of Guangdong Province and the international borders of the Red River and the Irrawaddy in Yunnan Province. The presence records from Guangdong Province suggest a disjunct distribution in the species' continental range at the easternmost limit. However, due to an upsurge in the pelt trade during the 1900s, otters have faced a massive decline in China. There are no recent records of the Smooth-coated Otter from China (Li and Chan 2018).

Smooth-coated Otter is a protected species in almost all the range countries which prohibits its killing. It has been up listed to Appendix I from Appendix II of CITES in 2019. However, most range countries are not able to control the clandestine trade leading to extensive poaching.

The Smooth-coated Otter, once common in the wetlands and low lying areas of south Asia, is now restricted to a few protected areas. Creation of networks of Protected Areas, identification of sites as wetlands of national and international importance under Ramsar Convention, has, to some extent, halted the degradation of its habitat.

Over the years the IUCN SSC Otter Specialist Group has developed a cadre of biologist across Asia to conduct field surveys and has popularize otter conservation by promoting otters as ambassadors of the wetlands. A global strategy for otter conservation was also published by the IUCN SSC Otter Specialist Group as a consolidated effort to identify and discuss the significant factors that influence habitat quality and the presence of otter in each region where they occur. However, concerted efforts to conserve this species are needed. For the long term survival of the species, policy based action, research on factors affecting its survival, habitat based action on creation and wherever required expansion of protected areas, and communication and awareness building actions are needed. The Global Otter Conservation Strategy for the species (Hussain et al. 2018) recommends priority actions that include:

• Monitor population status of Smooth-coated Otter in protected as well as non-protected areas in all range countries.
• Determine the status of L. p. maxwelli in the Iraqi marshes.
• Support existing laboratories, and creation of new research facilities dedicated to research on conservation genetics of the species.
• Support full-time research for otter conservation.
• Organise workshops for capacity building, conservation education, and awareness in all range countries.