Male Morphological Description: Valves are oval in shape with deep incisur. Valve length = 2.18-2.30 mm. Valve height = 1.25-1.33 mm. Color: Slightly opaque valves with dirty-yellow to brown light organ and dark brown gut. Eye: brown to maroon-brown color with 16 ommatidia. Infold setae: Rostral Row (RR) with 15-22 bristles; 0 or 1 bristle anterior to RR. Anteroventral Row (AVR) with 24-34 bristles; 0 bristles anterior to AVR; 1-5 minute bristles posterior to AVR. # of tiny suckers on 1st antenna: 6-8 on proximal filament of b-bristle; 6-8 on distal filament of b-bristle; 4-7 on proximal filament of c-bristle; 5-8 on distal filament of c-bristle. 7th limb: 11-15 bristles. Furca: with 9 claws (few with 8 or 10). Only claw 2 fused to lamella.
Male Bioluminescent Display: Produce vertical upward displays. Displays occur 5-25 cm over the bottom about 45 min after sunset. Composed of 4 or 5 (but up to 7) bright pulses and is occasionally followed by a rapid trill of 7-15 dim pulses. Train length is about 25 cm (trill length is 6-10 cm more), and train duration is 9-16s.
Female Morphological Description: Valves are egg-shaped with a dorsal margin that is steeply sloped posteriorly. Valve length = 3.10 mm. Valve height = 2.01 mm. Infold setae: Rostral Row with 14-22 bristles; 0 bristles anterior to RR. Anteroventral Row (AVR) with 34-36 bristles; 0 bristles anterior to AVR; 15-17 minute bristles posterior to AVR. 7th limb: 25 or 26 bristles. Furca: with 9 claws (few with 8 or 10). Only claw 2 fused to lamella.