It is widespread on islands in Western Pacific Ocean, including Hawaii, and presents combinations of unusual features which make easily recognizable for field workers.

This feature is shared only by Rehderella belyaevi, but in latter species, scutum and tergum can be distinguished by raised ridge replacing old articular margin.

Unworn specimens are dirty white, and show vertical ribbing, prominent growth ridges, and wavy or chevroned sutures between shell plates.

As calcification proceeds, outer parts of the animal are raised off substrate, showing convex, saucer-shaped side view.

[4]: 33 Nesochthamalus can be found in mid-littoral environments, and does not generally form densely packed colonies as are characteristic of Chamaesipho.

Other reports include Indonesia, Philippine Archipelago (type area), Taiwan, Japan, Okinawa, Ryukyu Islands, Fiji, Tuamotu, and Hawaii.