Starlight Shrimp

Starlight Shrimp

The stars of the sea

In the deep, dark water beneath the ice, sometimes the only light is the sparkling of shrimp, dancing through the blackness like stars.
— Excerpt from an Eriasian folktale
  Starlight shrimp are small, transluscent crustaceans that live in the depths underneath The Expanse in the Frozen North. The bioluminescent algae on which they feed causes their bodies to grow a bright, eerie blue.   Colonies of starlight shrimp contain several million individuals. Though they serve as prey for many of the denizens of the water under The Expanse, they remain numerous.


The body of the starlight shrimp is split into two main parts: the cephalothorax, and an elongated abdomen split into six segments. The cephalothorax is protected by a solid carapace, whereas the abdomen is covered in thinner segmented sections. This armour, though strong, is transparent, which allows the shrimp to blend into their ocean surroundings.   There are eight pairs of appendages growing from the cephalothorax. The first three pairs are known as maxillipeds. As well as functioning as the shrimp's mouth, these are also used to both push water through their gills. The gills of the shrimp are protected by the carapace on the cephalothorax. The gills allow the shrimp to filter dissolved oxygen from the surrounding water, and to excrete carbon dioxide from their bloodstream.   The remaining five pairs of appendages are called the pereiopods - or legs. The first pair have claws, known as chela, which the starlight shrimp use to scrape algae from the surface of the ice. The other four pairs of legs are long, firm and slender. They are used for walking on the surface of the ice when the shrimp is not swimming.
  There are further pairs of appendages on the first five segments of the abdomen, known as swimmerets. These are shaped like paddles and are edged with fine, hair-like bristles. Whilst the main purpose of the swimmerets is to propel the shrimp around in the water, females of the species also use these to cradle their brood of eggs up against their body.   The last segment of the abdomen is a fan-shaped tail, made up of two conjoined appendages known as uropods. Whilst the main function of the tail is to act as a rudder, steering the shrimp through the water, it also allows them to launch themselves backwards at great speed if in danger.   Starlight shrimp each have a pair of compound eyes on stalks that grow from their heads. These allow them to more easily see movement in the dark waters where they. They also have two pairs of antennae that grow just in front of their eyes. One pair is short and is used for feeling for and sensing food. The other pair is as long as their bodies and is used for orienting them in their surroundings.  

Growth and Life Stages

Shrimplets hatch as fully-formed, though miniscule, versions of their parents. Each shrimplet is less than a millimetre long when it hatches. They spend the first three months of their life clinging to the ice and gorging on algae.   After three months, the shrimplets are officially juvenile shrimp. The juveniles are more adventurous than the shrimplets and often venture away from the safety of the ice columns into open water.   After six months, the shrimp are considered sexually mature adults. At this stage, all shrimp are male and will compete for the attention of the older, larger females.   A year to eighteen months into the life of the starlight shrimp, the testes morph and are replaced by ovaries. The starlight shrimp then completes its life as female.


Starlight shrimp live exclusively underneath the large landmass of ice known as The Expanse, being one of the only species of shrimp to have evolved to survive in such extreme cold. Under The Expanse are huge columns of ice that stretch down miles towards the sea floor, anchoring the continent above in place. The shrimp cluster near the top of these large pillars, out of the reach of the crushing pressure further down.   Most often, the shrimp stay clustered near or on the surface of the ice, but they swim into open water to mate.  


  Starlight shrimp are herbivorous. At all stages of their lifestyle, they feed exclusively on the bioluminescent algae that grows on the underside of the ice, and on the ice columns that reach down to the sea floor.   As the shrimp are transluscent, the algae in their stomach is visible as they digest, making them glow.


  Starlight shrimp choose when to mate due to fluctuations in water temperature. A raise of merely one degree is a sign to mate, as this usually precedes an algae bloom. The excess of food means that the shrimplets will have the best chance of survival.   Females of the species can store the sperm of multiple partners, meaning that a brood of starlight shrimplets from one female can have multiple paternities. The more genetically diverse the brood, the higher percentage tend to survive to maturity.   Starlight shrimp lay between 100-200 eggs at a time. Throughout gestation, which can take between 2-3 weeks, the mother cradles the eggs against her abdomen using her swimmerets. When it is time for the eggs to hatch, the mother lands on an ice column and allows the hatching shrimplets to cling to the algae growing there.  

Cultural Significance

The habitat of the starlight shrimp lies around a mile outside of the underwater merfolk city of Qasceile. Though they are not a particularly useful species to the polar merfolk who live there, their home is seen as a romantic destination for courtship. Couples will often travel outside the city to watch the shrimp glowing like stars in the darkness.
Tiny Pets
Children in Qasceile often keep starlight shrimp colonies as pets. This is easily achieved by setting up small ice formations and making sure they are kept coated with algae. Small groups of shrimp are captured and then released on these domesticated ice formations, where they will thrive if looked after well.   Some adults also enjoy keeping starlight shrimp colonies, though this is rather looked down upon in Qasceile society as an eccentric hobby.

Cover image: by Pexels


Author's Notes

The second article I wrote on World Anvil.   Starlight shrimp are currently disconnected from anything else I've written about, as they live way up in the Frozen North. I do love shrimp though, and had a lot of fun writing about them! :)

Please Login in order to comment!
Jun 30, 2020 10:58 by Laurabones

I just want to say, I will never get sick of the word shrimplet. Everything about it is adorable.

Jun 30, 2020 11:12 by Dr Emily Vair-Turnbull

Shrimplet is the best word, for sure! :D

Emy x   Etrea | Vazdimet
Jun 30, 2020 16:38 by R. Dylon Elder

Excellent work here! I love the theme as well!

Jun 30, 2020 20:13 by Dr Emily Vair-Turnbull

Thank you so much! :D

Emy x   Etrea | Vazdimet
Jul 3, 2020 16:12 by Elias Redclaw

I.... I’m in love. No seriously , I love it to the point that I’m obsessed with it. I just love how detailed you went into this article and honestly, I’m just fangirling over it. I’m sorry for not being able to control my emotions xD   This article has roused some incredible interest for your world on my behalf. I have now committed to reading every last article you have made and showering you with love as well as tearing apart ( I meant it as a compliment I swear!) your articles. I’m a sucker for all things cold, dark and honestly I’m obsessed with cold oceanic beings and geography so I’ll definitely love where this is going!   You keep rocking my friend! You have earnt a new fan in me!

Jul 3, 2020 17:46 by Dr Emily Vair-Turnbull

Aww, thank you so much! I'm pretty new to WA so haven't got many articles up yet, but I hope you like the content I produce. This comment has made my day. <3

Emy x   Etrea | Vazdimet
Jul 4, 2020 15:24 by Elias Redclaw

You’re welcome! I mean I’m already so much in love with this world! I’d love to chat with you more if you didn’t mind ( be it on discord or twitter or anywhere else!). Feel free to decline tho :)

Jul 4, 2020 15:54 by Dr Emily Vair-Turnbull

Thanks! I'm often hanging around in the World Anvil discord, but I don't do private messaging for personal reasons. :)

Emy x   Etrea | Vazdimet
Jul 4, 2020 17:07 by Elias Redclaw

It’s okies my friend! I’ll still love reading about this world!

Dec 29, 2020 21:24 by Eliora Yona

Oh so pretty! Starlight shrimp is a great idea. I dislike shrimp, but this makes me want some in an aquarium <3

Dec 29, 2020 21:26 by Dr Emily Vair-Turnbull

Aww thank you! I have shrimp in a couple of tanks in my house, and they're fascinating to watch. :)

Emy x   Etrea | Vazdimet
May 25, 2021 21:04 by Gilly-May Hartill

'Some adults also enjoy keeping starlight shrimp colonies, though this is rather looked down upon in Qasceile society as an eccentric hobby.'   Consider me eccentric!   This is an excellent article Emily! It's so detailed, especially the science, and the presentation is beautiful. Bravo :)

Gilly Hartill   Fantasy world builder, aspiring author & lover of all things RPG.
May 25, 2021 21:05 by Dr Emily Vair-Turnbull

As someone with my own shrimp colonies, same! XD   Thank you so much! <3

Emy x   Etrea | Vazdimet
May 25, 2021 22:20 by Fall

A gorgeous page that blens so elegantly with the theme! your layout is amazing too and really helps to break up the content. It's all really clear and well presented. Amazing job!

May 25, 2021 22:32 by Dr Emily Vair-Turnbull

Aww, thank you so much! <3

Emy x   Etrea | Vazdimet
May 29, 2021 13:42 by Amélie I. S. Debruyne

I'm finally reading those famous shrimps!   Great article, I absolutely love all those biological details :D

May 29, 2021 19:11 by Dr Emily Vair-Turnbull

Thank you! :D Yes, my placeholder shrimps hahahaha. <3

Emy x   Etrea | Vazdimet
Jun 2, 2021 23:27 by Starfarer Theta

What a pleasant article. :)

Jun 3, 2021 13:49 by Dr Emily Vair-Turnbull

Thank you! :D

Emy x   Etrea | Vazdimet
Jul 1, 2021 12:46 by Avalon Arcana

There is always something about little creatures that glow in the dark that I love, and these guys completely fit the bill. The attention to detail here is amazing, from the sheer amount of information on their anatomy to their significance. Oh, and I love that people keep them as pets 'cause I really want to.

You should check out the The 5 Shudake, if you want of course.
Jul 1, 2021 13:11 by Dr Emily Vair-Turnbull

Thank you! I would love to keep these as pets too! <3

Emy x   Etrea | Vazdimet
Jul 16, 2021 10:33 by David Alexander

Fab article! I'm loving the new theme by the way, but - now this could just be my colourblindness acting up - the tooltips were a tad hard to find though I did really appreciate their inclusion to tell a lowly non-shrimp-guy like myself what a compound eye was :D

Latha math leat! Sending praise from the Hebrides!
Jul 16, 2021 12:14 by Dr Emily Vair-Turnbull

Thank you! I'll try to work out how to make the tooltips a little brighter. <3

Emy x   Etrea | Vazdimet
Jul 16, 2021 12:18 by Dr Emily Vair-Turnbull

How's that? Brightened the colour so hopefully it is easier to see. :)

Emy x   Etrea | Vazdimet
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