Male Morphological Description: Valves oval in shape with deep incisur. Valve length = 1.98-2.20 mm. Valve height = 1.13-1.30 mm. Color: Mostly transparent, except for rich yellow light organ and brown to tan-brown gut. Eye: brown to maroon-brown color with 16 ommatidia. Infold setae: Rostral Row (RR) with about 13-19 bristles; 1-9 bristles anterior to RR. Anteroventral Row (AVR) with 24-39 bristles; 1-9 bristles anterior to AVR; 0-7 bristles posterior to AVR. # of tiny suckers on 1st antenna: 3-6 on proximal filament of b-bristle; 3-7 on distal filament of b-bristle; 3-5 on proximal filament of c-bristle; 3-6 on distal filament of c-bristle. 7th limb: with 9-14 bristles. Furca: with 9 claws (few with 8 or 10 claws). Only claw 2 is fused to lamella.
Male Bioluminescent Display: Produce downward displays 45 min after sunset. Display start 0.5-2 m above the bottom. Displays consist of 3-5 medium bright pulses and are sometimes followed by a dim trill of about 10-15 closely spaced pulses. Train duration is about 14-15 s. Train length is about 13 cm, and trill length is about 10-20 cm more.
Female Morphological Descriptions: Valves are egg-shaped with a dorsal margin that is steeply sloped posteriorly. Valve length = 2.92-2.96 mm. Valve height = 1.82-2.00 mm. Infold setae: Rostral Row (RR) with about 18-24 bristles; 7-12 bristles anterior to RR. Anteroventral Row (AVR) with about 41-48 bristles; 12-20 bristles anterior to AVR; 7-12 bristles posterior to AVR. 7th limb: with 23-29 bristles. Furca: with 9 claws (few with 8 or 10 claws). Only claw 2 is fused to lamella.