Bathochordaeus stygius are filter feeders closely related to sea squirts in the phylum Chordata, the same phylum to which humans belong. These tadpole-shaped animals are typically 1.5 inches (4 cm) long and can spin complex mucus nets that reach up to 3 feet (or 1 meter) across. They build an inner and outer mucus “house” that both traps savory small particles and keeps bigger unwanted particles out. When the tunicate is ready to feast, it shakes the innermost filter net to loosen the catch and sucks it in. Bathochodeus stygius builds two complete “houses” per day on average. See more images of mid-water creatures in our slideshow.