Dacruon bathynectes

The Voûlic Ocean located near- and on the south pole of Eryobis has, on average, the coldest waters in the world. Even though barely any permanent sea ice exists, surface temperatures are known to drop below 0°C in winter. The cold waters of the Voûlic however, are also very oxygen- and nutrient rich, resulting in the south polar ocean being some of the most productive waters on Eryobis. Many peculiar organisms can be found in the chilly depths at the southern end of the world, with some more rare than others. 

The waters are often too cold and potentially dangerous for human explorers to dive into, so ROVs are typically employed on expeditions here. ROVs often only ever encounter small invertebrates or small fish too slow to flee from the lights, but on occasion, the ROV may encounter something more rare.

On one such encounter, the ROV came across a kind of fish that had never been seen or heard of. Measuring between 3 and 4 meters long and shaped like long tailed tear drop, the Dacruon bathynectes, still lacking a common name, is very large kind of bunnyfish, as could be determined by the placement of its pectoral- and pelvic fins. 

The enormous fish was found at a depth of around 300 meters, just below the photic zone, slowly cruising with long movements of its tail. Because the fish moved so sluggishly, the ROV was able to place a tracker on its dorsal fin, which revealed that D. bathynectes performed vertical migration; spending the day time hours at depths between 200 and 500 meters and moving up around 30 meters deep during the night.

Footage of the fish's head revealed that it large, flat and blunt teeth within its thick, but deep jaws. This points to D. bathynectes being a durophage, feeding on hard shelled prey like mollusks and crustaceans. While no footage of the act of feeding, or evidence from washed up specimens exist, it is thought that Dacruon most likely relies on pelagic pectinauts as its main food source. The slow swimming nectonic scallops are known to perform vertical migration in other parts of the world's oceans, so it is not unreasonable to assume they might do the same in the cold waters of the Voûlic.