Lumikapis

Lumikapis is a fictional language that is used by a race of sea-dwelling squid-like lifeforms called Luminocapita, who inhabit the planet Derega in the fictional universe of “Empires of Land and Sea”, a franchise created only to accommodate this unique language.

The concept of this language is that it has no spoken and no permanent written form. Instead, the language is communicated by shaped emissions of light, transmitted between the Luminocapita using one of their four bioluminescent arms.

The inside of their arms are usually dim and emit a small, faint amount of light, but are covered by a layer of opaque skin. By opening the four flaps at the extremities of these arms, they are able to emit a bright light in a variety of colours, which changes depending on mood, their surroundings and current patterns of thought.

This allows them to create shapes of light that can be directed towards other members of their shoal to communicate ideas, ranging from basic utterances such as “danger” to more complex ideas such as “I think we should attempt to travel further towards the place with lots of kelp before the cover of night descends so that we may meet with Galefa and Jopuki tomorrow morning for some light hunting.”

Phonology
As the format of their language is so different from spoken or written forms of communication, there are no letters to make up words and there are no consonants or vowels to transcribe.

Instead, all concepts are communicated by shape and colour.

Also, as the “speaker” can transmit their light message from any direction in a 3D space, the shapes produced can be interpreted regardless of their rotation, i.e. they mean the same thing whether they are shone upside-down, at an angle or upright (relative to the "receiver" of the light message).

All “words” and “sentences” consist of a sequence of light patterns. For example, one word could be “red star, mauve triangle, pink square”, meaning “unexpected”.

Lexicon
As these lifeforms live exclusively underwater, they have no words for many concepts familiar to humans and things that only exist on land. For example, they do not have a word for structures, such as “bridge”, “house” or “building”. They do however have words for “home”, “family”, “current”, “rock”, “coral”, “kelp”, etc.