Definition - What does Mermaid Pose mean?
Mermaid pose is an advanced posture that involves a deep backbend. This is a variation on the traditional one-legged king pigeon pose (eka pada rajakapotasana).
Mermaid pose provides a deep and energizing stretch for the chest and shoulders, as well as for the groin and thighs. In addition, this asana stimulates the internal organs and works the core muscles. As with any of the different backbend and hip-opening asanas, it is advisable to warm up properly with preparatory poses such as warrior pose, extended triangle pose and low lunge pose.
Yogapedia explains Mermaid Pose
A good starting point for mermaid pose is in downward-facing dog pose. The spine is then lengthened and the hips lifted. Then the right knee is bent and brought forward between the hands. The right ankle is placed down close to the left wrist and the right knee placed close to the right wrist. The left leg is extended out behind with the knee and top of the foot resting on the floor
The front of the body is then lengthened, with the torso moving away from the thigh. The spine is now gradually lifted higher and the right hand placed on the right thigh. By bending the left knee the foot on this side can be grasped by the left hand.
The left foot is then brought in toward the body until it is cradled in the left elbow. The left foot is pressed in and the right arm lifted up over the head. The right arm is bent and this hand moves behind the head to grab the left hand
Finally, the hips are then squared and the torso moved forward. The gaze should be upward and the breathing steady.