The UCSB Oakley Evolution Lab seeks to investigate the evolutionary history of bioluminescence courtship signaling of small crustaceans called ostracods. Such emissions occur after nightfall when there is no moonlight and are characterized as pulses that vary in temporal and spatial patterns between species. We created a camera and DNA collection system named Stereovideographic & Macromolecular Acquisition of Low-Light Emitters (small-e), for deployment at the bottom of the Caribbean Sea. Small-e captures stereo-vision video that is stereo-rectified to create 4D models of the courtship patterns. Small-e is compact and supports new features compared to previous camera systems, such as time-precise light intensity measurements, time correspondent eDNA collection, and a 12-hour runtime. 

Small-e has three main systems controlled by a Jetson Nano, a small single-board computer capable of controlling multiple systems that has a dedicated hardware video encoder/decoder.  The Stereo Camera System consists of two low-light sensitive cameras (Watec) that interface with the Jetson via ethernet using the RTSP protocol. The received video is processed by the Jetson’s dedicated hardware encoder/decoder. The Light Intensity Measurement System consists of two light sensors. The first is a Silicon Photomultiplier (SiPM) which is designed to capture light intensity levels at high precision time intervals. This is crucial for characterizing the dynamics of the ostracod courtship light pulses with precision similar to that of the ostracod’s visual system. The second is an ambient light intensity sensor used to turn on the SiPM when it is dark enough. A separate environmental eDNA (eDNA) Collection System has three filters to collect water samples that contains the ostracods' DNA. The subsystem will gather water samples at user-set intervals. Solenoid valves are used to isolate and select a filter for DNA collection. A flow rate sensor verifies the amount of water sampled during a collection bout. The eDNA system captures biomaterial data during courtship signaling with minimal interference and is synchronized with the SiPM light intensity data and stereo video footage. 

With all these features, Small-e will aid in investigating the evolution history of bioluminescence courtship signaling in ostracods.