This white patch deep blade shrimp (Spirontocaris prionota) was resting on a cluster of old barnacles, and keeping an eye on me as I took the photo. All deep blade shrimps have a very obvious sawtooth edge to their vertically compressed head spike (rostrum). It is amazing to me the extreme variability of pattern and colour of this species. Deep blade shrimps often like to live in the fine shell litter that collects at the base of walls. I’ve had good luck finding these small slow moving shrimps during night dives. Deep blade shrimps can grow to 1.5 inches (4 cm) long, and have a range that includes Japan, as well as northern Alaska to northern Mexico.