Description
Threadfin Rainbow (Iriatherina werneri) – Graceful Beauty with Flowing Fins
The Threadfin Rainbow (Iriatherina werneri) is a delicate and elegant freshwater species admired for its long, flowing fins and shimmering iridescent body. Males are especially striking, displaying extended filament-like dorsal and anal fins and soft hues of gold, blue, and even red tones when fully mature and healthy.
Native to slow-moving streams and swamps in northern Australia and New Guinea, the Threadfin Rainbow thrives in peaceful, planted aquariums with gentle filtration and soft, acidic water. Though small in size, their unique appearance and graceful swimming make them stand out in nano and community tanks alike.
Key Features:
-
Latin Name: Iriatherina werneri
-
Common Name: Threadfin Rainbow
-
Coloration: Iridescent body with elongated, flowing fins (males); subtle colors with elegant form
-
Temperament: Peaceful and shy
-
Size: Up to 2 inches
-
Tank Requirements: Minimum 15 gallons, with dense plants, calm water, and low flow
-
Diet: Omnivorous—micro pellets, powdered flakes, live/frozen foods like baby brine shrimp and daphnia
-
Compatibility: Best with other peaceful, non-fin-nipping fish; ideal for planted nano tanks
Tips:
-
Keep in groups of 6 or more, with a good male-to-female ratio to reduce stress.
-
Avoid boisterous or aggressive tank mates that may nip their long fins.
-
Use sponge filters or gentle flow to protect their delicate fins.
-
Enhance colors with a protein-rich diet and stable water conditions.
Why Choose This Fish?
The Threadfin Rainbow offers a perfect blend of beauty, subtlety, and tranquility. Its feather-like fins and elegant movement make it an ideal choice for peaceful planted aquariums or aquascapes, especially for hobbyists seeking something graceful, refined, and utterly unique.
Click & Collect
Livestock will only be bagged once you arrive, or if you contact us in advance to request it ready beforehand.
Local Delivery
Order anything from our in-store range and have it delivered right to you.
-
Minimum spend: £50
-
Delivery up to 10 miles: £10
-
Delivery up to 25 miles: £20
Distances are measured “as the crow flies”, not by road.
Once your order is placed, we’ll be in touch to arrange a suitable delivery date and time.
Please note, delivery may take a little longer as we often group orders together to build an efficient delivery run.
Important: If you’re ordering a large aquarium, please ensure someone is available to help unload the van on arrival.
Dry Goods Delivery
-
DPD Next Day: 1 working day (order before 12 noon)
-
DX Next Day (Heavy Items & Small Aquariums): 1 working day (order before 12 noon)
-
Express Pallet: 1–3 working days
If you'd like to add more items to an existing order that hasn't yet been dispatched, please place a Click & Collect order and leave a note asking us to combine the orders.
Please note: We currently only dispatch parcels Wednesday to Friday.
Pre-Order
Want the full details? Check out our Terms & Conditions.
Livestock Delivery
Thursday Delivery – £24
-
Dispatched Wednesday afternoon
-
Delivered Thursday before 1pm
-
Order by Wednesday 12 noon
-
Minimum spend: £50
Friday Delivery – £24
-
Dispatched Thursday afternoon
-
Delivered Friday before 1pm
-
Order by Thursday 12 noon
-
Minimum spend: £50
Saturday Delivery – £29
-
Dispatched Friday afternoon
-
Delivered Saturday before 1pm
-
Order by Friday 12 noon
-
Minimum spend: £50
📦 Want to Add to an Existing Order?
No problem! Just place a Click & Collect order and leave a note asking us to link it with your original one (as long as it hasn’t been dispatched yet).
🛒 Dry Goods Now Included!
You can now include dry goods in your livestock delivery – perfect for topping up supplies in one go.
❄️ Please note: We can’t send frozen food with livestock – please order frozen items separately.
⚠️ Delivery Exclusions
Unfortunately, we’re unable to deliver livestock to the following postcodes:
Scotland & Isles:
AB30–AB56, DD8–DD10, DG3–DG9, DG12–DG14, FK17–FK21, KA18–KA19, KA26–KA30, PA20–PA38, PA80, PH3–PH40
Cornwall Isles: TR21–TR25
All of the following postcodes are excluded:
BT, HS, IM, IV, JE, KW
Plus Channel Islands and Shetland Islands
Payment & Security
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.