Created for a contest over at World-Craft [link] Boukalizoans (so named because many of them resemble oddly-shaped bottles) are small, planktonic organisms that drift in the upper atmosphere of a gas giant similar to Jupiter. Boukalizoans come in a bewildering variety of shapes and colors, but the traits that unite them all are:

1.) Four outgrowths—termed labria (singular labrum)-- surrounding the mouth. These are often modified into bulbous, gourd-like crops for holding food.

2.) Four primary eyes (usually) situated at the junction of two labria.

3.) Two smaller ocelli-like eyes behind each primary (eight ocelli in all)

4.) A gas-filled bladder that helps them stay afloat. Filled primarily with hydrogen that has been slightly heated above ambient temperatures.

5.) A “germ-sac” at the posterior end. Young develop within the sac and migrate to the surface where they form buds and feed until they are large enough to separate from the parent.

Most boukalizoans, by the way, have an alternating life cycle similar to Earthly cnidarians (which alternate between polyp and medusa stages) and nematodes (which often alternate between free-living and parasitic generations). Boukalizoans of the alternate generation (termed helicozoans—not to be confused with Earth's heliozoans) are quite different structurally from their bottle-shaped parents. I’ll have more on this group soon.

The Species

A.Spotted Hookgourd Nodophoramorphis maculosus
Although it is not yet clear why the tail and tip of the crop have hooked together in this group, such an arrangement seems to be ecologically important, since the hookgourds are one of the most highly-diverse planktonic species on the planet. Since this arrangement prevents the hookgourds from opening their mouths, these animals have developed a symbiotic relationship with several phyla of photosynthetic “bacteria”, which are visible on its skin as the patches of black and yellow.

B. Harlequin Berry-eye Dichtyoderma megalomatia
Although this boukalizoan has been observed to snack on other, smaller organisms, the majority of its food comes from its large photosynthetic eyes. Instead of chlorophyll, Berryeyes use a form of retinal (a photosensitive protein that is also found in the eyes of most Earth animals) to capture light.

C. Blue-faced Corpseflower Floricorpus caeruleus
The corpseflowers are believed to closely resemble the boukalizoan ancestral form, with four separate labria and a bulbous germ-sac (shown here with several budding helicozoans). F. caeruleus is an active, voracious predator that feeds by enveloping prey in its labria and liquefying them with regurgitated stomach acids.

D. Wulandari’s Tanglegourd Nodophora oculocaulis
Close relatives of the hookgourds, tanglegourds have taken the elongated, entangled tail-and-crop complex to an extreme. Also like the hookgourds, Nodophora gain most of their nutrition from symbiotic black and yellow bacteria living in their skin. The stalked eyes of this species are believe to give it binocular vision, though to what purpose is not known since it is not a predator.