240 critically endangered Black Softshell Turtle hatchlings were released into a protected waterbody in Assam, boosting recovery efforts for the species. Guwahati: In a significant boost to the conservation and recovery of the critically endangered Black Softshell Turtle (BST), locally known as Bormuria Kaso (Nilssonia nigricans), 240 hatchlings were released on Saturday into a protected waterbody under the Biswanath Wildlife Division in Assam.