Male Morphological Description: Valves oval in shape with deep incisur. Valve length = 1.773-1.825 mm. Valve height = 0.950-1.050 mm Color: Mostly transparent, except for brown to orange-brown gut and yellow-brown to dirty yellow light organ. Eye: dark brown to maroon-brown with 16 ommatidia. Infold setae: Rostral Row (RR) with 9-14 double bristles; 1-2 double bristles posterior to RR. Anterovenrtal Row (AVR) with 24-36 bristles; 0 bristles anterior to AVR; 0-2 double bristles posterior to AVR. 7th limb: with 8-11 bristles. Furca: with 9 claws. Claws 2 and 4 fused to lamella; claw 3 more slender and the same length or slightly longer than claw 4.
Male Bioluminescent Display: Downward display occurs 1-4 m above coral reefs about 45 min after sunset. Train starts 1-3m above reef. Pulse distance: 5-8 cm between first two pulses; 4-5 cm between the 2nd and 3rd pulses; 3 cm between 3rd and 4th pulses; remaining pulses are about 2 cm apart. Total train duration about 10 s. Displays are synchronous. Downward display type is more widespread and abundant than the upward type.
Upward display occurs 20-46 min after sunset. Train is comprised of 10-20 widely spaced vertically upward pulses over a distance of 100-250 cm. Pulse distance: the first pulse is 1.5-3 m above the bottom; the 2nd pulse is 15-70 cm (avg. 40 cm)above the 1st pulse; the 3rd pulse is 10-40 cm (avg. 25 cm) above the 2nd pulse; the 4th pulse is 8-25 cm above the 3rd pulse; the fifth pulse is 6-15 cm above the 4th pulse; the remaining 5-15 pulses are about 6-10 cm (avg. 8 cm) apart. Total train duration is 10-22 s.
Female Morphological Description: Valves are an elongated oval shape. Valve length = 2.20-2.33 mm. Valve height = 1.31-1.41 mm. Lateral eye diameter = 0.25-0.27 mm. Infold setae: Rostral Row (RR) with about 10-15 bouble bristles. Anteroventral Row (AVR) with 34-43 double bristles. 7th limb: distal comb with 2 or 3 bristles; terminal comb with 5 or 6 bristles; distal peg with 2-4 bristles; terminal peg with 4 or 5 bristles. Furca: with 9 claws. Claws 2 and 4 fused to lamella; claw 3 more slender and the same length or slightly longer than claw 4.