• Skip to main content
AlgaeBarn

AlgaeBarn

Marine Aquariums Made Easy!

    • Shop See All
      • Ultimate Packs See All
      • Ultimate Refugium Starter
      • Clam Keeper Kits
      • Ultimate Ecopack
      • Mandarin Feeder Kit
      • Hair Algae Killer Kit
      • See All Ultimate Packs
      • Live Foods See All
      • Copepods
        • Ecopods
        • 5280 Pods
        • Galaxy Pods
        • Poseidon's Feast
        • Tisbe Pods
        • Tig Pods
      • Food Combos
        • Ecopods & Phyto
        • Galaxy Pods & Phyto
        • Poseidon's & Phyto
        • Tig Pods & Phyto
        • Tisbe Pods & Phyto
      • Phytoplankton
        • Oceanmagik
      • Brine Shrimp
        • Simple Brine
        • Nano Brine Shrimp
        • Premium Brine Shrimp Eggs
        • Magnetic Brine Shrimp Eggs
      • Most Popular Products
        • Galaxy Pods 5 Species Copepod Blend

          Galaxy Pods

          $66 – $229
          Shop Now This product has multiple variants. The options may be chosen on the product page
        • Ecopods 4 Pack Special

          $99
          Shop Now
        • Galaxy Pods & Phyto Combo

          $80
          Shop Now
        • 5280 Pods

          $45
          Shop Now
      • Macroalgae See All
      • Clean Macro Series
        • Clean Chaeto
        • Clean Sea Lettuce
        • Clean Green Ogo
        • Clean Mocha Ogo
        • Clean Mocha Spike Sphere
        • Pom Pom
        • Red Ogo
        • Red Spike Sphere
        • Red Spaghetti
        • Red Mangrove
      • Premium Rare Macro
        • Leafy Ogo
        • Blue Hypnea
        • Dragon's Tongue
        • Thick Ogo
      • Most Popular Products
        • Clean Chaeto

          $40 – $125
          Shop Now This product has multiple variants. The options may be chosen on the product page
        • Clean Sea Lettuce

          $30 – $95
          Shop Now This product has multiple variants. The options may be chosen on the product page
        • Red Ogo

          $30 – $80
          Shop Now This product has multiple variants. The options may be chosen on the product page
        • Red Mangrove

          $13
          Shop Now
      • Captive Bred Fish See All
      • Gobies
        • Green Mandarin
        • Court Jester Goby
        • Watchman Goby
        • White Spotted Goby
      • AngelFish
        • Biota Coral Beauty
        • Maculosus Angel
        • Majestic Angel
        • Swallowtail Angel
      • Tangs
        • Yellow Tang
        • Blue Tang
      • More Species
        • Grammas
        • FileFish
        • Blennies
        • Damsel
        • ClownFish
        • RabbitFish
      • Most Popular Products
        • Blue Mandarin

          BIOTA Green Mandarin

          $99 – $209
          Shop Now This product has multiple variants. The options may be chosen on the product page
        • ORA Neon Goby

          $35
          Notify Me When in Stock
        • Captive Bred Yellow Tangs by BIOTA

          BIOTA Yellow Tang

          $250
          Shop Now
        • ORA Premium Picasso

          $145 – $300
          Shop Now This product has multiple variants. The options may be chosen on the product page
      • Captive Bred Invertebrates See All
      • Clams
        • Ora Derasa Clam
        • Squamosa Clam
        • Ora Gigas Clam
        • Ora Maxima Clam
        • Ora Hippopus Clam
      • Shrimp
        • Ora Peppermint Shrimp
        • Harlequin Shrimp
      • Snails
        • Cerith Snails
        • Trochus Snail
        • Nassarius Snails
      • Urchins
        • Ora Tuxedo Urchin
        • Ora Pincushion Urchin
      • Most Popular Products
        • Animated gif of peppermint shrimp

          Peppermint Shrimp

          $49 – $119
          Shop Now This product has multiple variants. The options may be chosen on the product page
        • 10 Cerith Snails

          Cerith Snail

          $25 – $79
          Shop Now This product has multiple variants. The options may be chosen on the product page
        • pincushion urchin lytechinus variegatus reef safe and captive bred by ora for sale at algaebarn

          Pincushion Urchin

          $29 – $99
          Shop Now This product has multiple variants. The options may be chosen on the product page
        • Gold Maxima Clam Bed

          ORA Maxima Clam

          $80 – $150
          Shop Now This product has multiple variants. The options may be chosen on the product page
      • Corals See All
      • LPS Corals
        • Biota Pearl Bubble
        • ORA Pearl Bubble
        • ORA Marshall Island Goniopora
        • ORA Marshall Island Hammer
      • SPS Corals
        • ORA Pearlberry Acropora
        • ORA Micronesian Imperial Acropora
        • ORA Turquoise Acropora
        • ORA Micronesian Yellow Porites
      • Soft Corals
        • BIOTA White Polyp Toadstool
        • ORA Long Polyp Leather Coral
        • ORA Silver Xenia
        • ORA Pulsing Xenia
      • Frag Packs
      • Most Popular Products
        • Biota Pearl Bubble Coral

          $65
          Notify Me When in Stock
        • ORA Pearlberry Acropora

          $290
          Notify Me When in Stock
        • BIOTA White Polyp Toadstool

          $70
          Shop Now
      • Additives & Bacteria See All
      • Live Cultures & Bacteria
        • Turbostart 900 Saltwater
        • Aquarium Cycle Kit
        • Coralline Algae
        • PNS Yellosno
        • PNS Probio™
      • Additives & Chemicals
        • Nitrocycle
        • Clarifier
        • Fritz A.C.C.R
        • Fritz RPM Salt
      • Most Popular Products
        • Mandarin Feeder Kit™

          $66
          Shop Now
        • Coralline Algae in a Bottle, In Pink or Purple!

          Coralline Algae

          $22 – $44
          Shop Now This product has multiple variants. The options may be chosen on the product page
        • MarinePure 10 Cubes

          2″ Cubes

          $5 – $99
          Notify Me When in Stock This product has multiple variants. The options may be chosen on the product page
        • Ultimate EcoPack

          $100
          Shop Now
      • Aquarium Supplies See All
      • Fuge Lighting
        • AI Fuge 16HD Light
        • Kessil A360X Fuge Light
        • Kessil H160
        • Kessil H80
        • Chaetomax
      • Biomedia
        • Marinepure Gems
        • Marinepure Rocks
        • Marinepure Plate
        • Marinepure Cubes
        • Marinepure Spheres
      • Foods
        • Dragon Roe
        • Simple Brine
        • Can'O Cyclops
        • Benereef™
        • Fresco Cyclops
      • Rock & Sand
        • Dry Rock
        • Clam Rocks
      • Most Popular Products
        • Mandarin Feeder Kit™

          $66
          Shop Now
        • Coralline Algae in a Bottle, In Pink or Purple!

          Coralline Algae

          $22 – $44
          Shop Now This product has multiple variants. The options may be chosen on the product page
        • MarinePure 10 Cubes

          2″ Cubes

          $5 – $99
          Notify Me When in Stock This product has multiple variants. The options may be chosen on the product page
        • Ultimate EcoPack

          $100
          Shop Now
      • CADE Aquariums See All
      • Reef Series
        • CADE REEF 500 S2
        • CADE REEF 600 S2
        • CADE REEF 900 S2
        • CADE REEF 1200 S2
        • CADE REEF 1500 S2
        • CADE REEF 1800 S2
        • CADE REEF 2100 S2
      • Frag Series
        • CADE Frag 600 S2/F
        • CADE Frag 900 S2/F
        • CADE Frag 1200 S2/F
        • CADE Frag 1500 S2/F
      • Peninsula Series
        • CADE Peninsula 1200 S2/P
        • CADE Peninsula 1500 S2/P
        • CADE Peninsula 1800 S2/P
      • Most Popular Products
        • CADE REEF 2100 S2

          $7,225
          Shop Now This product has multiple variants. The options may be chosen on the product page
        • CADE Peninsula 1500 S2/P

          $5,525
          Shop Now This product has multiple variants. The options may be chosen on the product page
        • CADE REEF 1200 S2

          $4,125
          Shop Now This product has multiple variants. The options may be chosen on the product page
        • CADE Frag 900 S2/F

          $3,275
          Shop Now This product has multiple variants. The options may be chosen on the product page
  • Blog
  • Shipping
  • Our Guarantee
  • Help
  • Deals
  • Sign In
  • Cart
You are here: Home / Captive Bred Fish & Inverts / Captive Bred Fish / Biota Court Jester Goby
Court Jester Goby
8 reviews

Biota Court Jester Goby

  • BIOTA
  • Shipping Days
    Wednesdays
  • Free Overnight
    Transport at $249+

$45

Suitable for a tank as small as 10 gallons, the colorful and peaceful court jester goby (Koumansetta rainfordi) is perfect for many marine nano-tanks. They have been documented eating red cyanobacteria. These captive bred specimens are much hardier and easier to feed than wild individuals.

**Fish are Shipped Directly from BIOTA Facilities and not from AlgaeBarn**

 

 

    • Purchase Size: ~2″ (length)
    • Max Size: 3″ (length)
    • Water Parameters:~78° F, dKH 8-12, pH 8.0-8.4, s.g. 1.021-1.023
    • Color: Green and orange stripes with black and white spots
    • Reef-Safe: Yes
    • Feeding: Omnivorous

 

***Fish appearance and size may vary due to factors like lighting, genetics, and growth rates. Fish received may differ slightly from the specified size.***

In stock

Save Buying in Bulk:

Earn up to 45 PodPoints.


Quantity

Save with Subscription:

Total:

$45

Saved

-

  • Description
  • FAQ

Description

Court Jester Goby (Koumansetta rainfordi)

The court jester goby (also known as Rainford’s goby) is an attractive little fish that is suitable for any nano- or large-scale marine aquaria. In fact, they’re fairly social and get along well in small groups when housed together in larger tanks. These fish are known (and appreciated) for their habit of nibbling on hair algae. Wild caught court jesters can sometime have a difficult time adjusting to aquarium life, particularly because of their tendency to refuse prepared foods. They often are shy when first introduced to the aquarium and can become targets to aggressive tankmates. They are much easier to feed, as they usually accept items such as small pellets, frozen mysis shrimp, brine shrimp, etc. See below for more information.

Size and Care Requirements

  • Purchase Size: ~2″ (length)
  • Max Size: 3″ (length)
  • Water Parameters:~78° F, dKH 8-12, pH 8.0-8.4, s.g. 1.021-1.023
  • Color: Green and orange stripes with black and white spots
  • Reef-Safe: Yes
  • Feeding: Omnivorous

Species Information

Koumansetta rainfordi occurs in Western Pacific Ocean coral reefs. This smallish, wary fish prefers water depths of 2-30 m (6.6 to 98.4 ft).

Benefits of Aquacultured Marine Aquarium Livestock

Aquacultured fishes offer a huge advantage over wild-caught specimens. For example, when bred and raised under captive conditions, they adjust more easily to aquarium life. They are also less likely to carry disease. Even more, aquacultured specimens can better tolerate shipping stress. Most notably, by purchasing aquacultured fish you support the aquaculture of marine organisms and help to make our hobby more sustainable!

100% Alive on Arrival (AoA) Guarantee

We guarantee that every court jester goby we sell will be Alive On Arrival and in good health. Should it arrive in any other state, we will either replace it free of charge (including shipping) or issue store credit if the total livestock loss is less than $40. For more information, please also visit our 100% Alive On Arrival Guarantee page.

**Fish are Shipped Directly from BIOTA Facilities and not from AlgaeBarn**

FAQ

Weight 1 lbs
Dimensions 3.5 × 3.5 × 5 in

Customer Reviews

Based on 8 reviews
Write a review
75%
(6)
0%
(0)
13%
(1)
0%
(0)
13%
(1)
P
Paul Pronsati
Beautiful

Great fish, very curious. Fits right in my tank

E
Eskew
Court jester

I received him healthy, but ight and he ate pellets immediately. He’s a sort of trouble maker burrowing tunnels under my rock work and make sand dust but he is just doing his thing and is fun to watch.

A
Anthony Mutti
Quality fish, good size, multiple levels of maturity, only eat pellets

Pros: I ordered four fish to put in a 120 gallon system with plenty of rock work. Three of the fish arrived VERY healthy. Two were pretty large. They did eat some very tiny pellet food I had that's designed for young saltwater fish.

Cons: Two fish were much larger than the other two. This caused some real aggression issues in the quarantine tank. I had to setup a divider. I don't suspect it will be an issue in the large tank, but it did complicate quarantine. They are only eating micro pellets. That's great now, but not practical in the large tank. I will fatten them up and grow out before adding. I'll also work on transitioning to frozen food. One of the fish had a sunken stomach when compared to the others and was clearly malnourished. It is getting better now that I'm target feeding. Finally, I made sure I had hair algae for the quarantine tank because it's supposedly part go their diet - so far none of them have eaten any.

Over all happy, but figured I'd share.

A
April

I do not a problem with the fish. It is small bit that is what I expected so far doing well. My rating is based on the fact that
I ordered a pair and only received one. I have attempted to contact customer service multiple times with no response. Very disappointed with my experience.

C
Chris Dunbar

My family and I are really enjoying this little fella. It took him a couple of days to settle in and start eating. You could tell he was curious about what the other fish were eating, but couldn't quite figure out what he wanted. Despite spending a ton of money on fancy frozen foods and live artemia, in the end he was happiest with TDO pellets and some flake food I "borrowed" from my son's guppy tank. The description says they can be kept together, and I am thinking about adding a second one.

12

Latest News from the AlgaeLab

Our team is hard at work studying how marine ecosystems behave so that you can build your tank with the perfect components!

PNS Deep Cycle

Harnessing the Power of PNS Deep Cycle for a Thriving Reef Aquarium

Reef aquariums are a testament to the beauty and complexity of marine ecosystems. Yet, one fundamental difference sets them apart from natural coral

Read More about Harnessing the Power of PNS Deep Cycle for a Thriving Reef Aquarium

How hard is it to keep a refugium?

Adding a refugium to the reef tank system can be a game changer for some reef keepers! Most experienced hobbyists agree that a refugiums’ natural

Read More about How hard is it to keep a refugium?

Keeping the Gigas Clam

There is something almost archetypal in the legend of man-eating clams. Perhaps this evokes allegorical imagery of a greedy or overly plucky sort of fool

Read More about Keeping the Gigas Clam

More Great Products

  • The Fun and playful Striped Blenny

    BIOTA Striped Blenny

    $35
    Notify Me When in Stock
  • Incredible Goldline Rabbitfish

    BIOTA Goldline Rabbitfish

    $50
    Shop Now
  • Placeholder

    Biota Queensland Dwarf Goby (Eviota queenslandica)

    $30
    Notify Me When in Stock
  • BIOTA Aiptasia-Eating Filefish

    $50
    Shop Now

Company

  • About Us
  • The AlgaeLab Blog
  • Our Team
  • Careers
  • FAQ

Get in Touch

  • Contact Us
  • AOA Claim Form
  • Press Inquiries
  • Call Us: 772-444-7637

Policies

  • Legendary AOA Guarantee
  • Terms & Conditions
  • Privacy Policy
  • Accessibility Statement

Other

  • Store Locator
  • Wholesale & B2B inquired
  • Business Location

Subscribe to our Newsletter

Join our mission to build a more sustainable aquarium hobby, one tank at a time!

Copyright 2025, AlgaeBarn LLC - Live Copepods and Phytoplankton