What's In the Tanks Right Now: New Tropical Fish Arrivals at MTF Aquatics

If you've been refreshing the MTF stock page waiting for something worth the tank space, this is the post for you. Below is an honest rundown of what's landed most recently — species, sizes, parameters, and a frank word on who each fish is actually suitable for. No filler, no hype.

Black Arowana (Osteoglossum ferreirai) — 12–13 Inches

Difficulty: Expert | In stock: 6 singles, 3 pairs | Price from: £250

The Black Arowana is the less-commonly-seen South American counterpart to the Silver (O. bicirrhosum), and arguably the more striking of the two in maturity. These are arriving at 12–13 inches — already past the fragile juvenile stage where feeding refusals and jump fatalities are most common. That matters: most losses with Osteoglossum happen in the first few weeks, and receiving a specimen that's already eating confidently is a meaningful advantage.

Parameters & Setup

A secure, heavy lid is non-negotiable. Arowana are surface predators with explosive lateral movement — a startled specimen will clear a gap most keepers wouldn't think twice about. They need calm surface access (they are obligate air-breathers), a long footprint rather than height, and ideally RO-conditioned or soft tap water. UK tap water in most regions runs too hard for long-term health; a RO unit is not optional equipment here.

Feed a varied diet: Hikari Massivore Delite, large frozen lance fish, and occasional whole prawns once settled. Live feeders carry parasite risk — if you're going to use them, quarantine first.

Pairs (2× Black Arowana, £450) are available for keepers with the tank footprint for two. Bear in mind that even juveniles from the same batch can develop aggression as they mature — a divider option is worth factoring into your setup.

Who this is for: Experienced keepers with an 8 ft+ tank, RO capability, and the patience to let a newly arrived specimen settle for 1–2 weeks before pushing feeding. Not a community fish. Not a beginner fish.

Snow White Pearl Stingray — 9–12 Inches

Difficulty: Expert | In stock: 1 male (11–12"), 1 female (9–10") | Price: £1,250 each

Freshwater stingrays are a serious commitment, and Snow Whites sit at the top end of the desirability spectrum within the Potamotrygonidae family. The colouration — a dense, pale white-cream disc with defined pearl spotting — is the result of selective line breeding, and the quality of patterning varies enormously between sources. Both the male (11–12") and female (9–10") currently in stock are large, well-grown specimens well past the most fragile juvenile phase.

Parameters & Setup

Substrate choice is critical. Rays spend the majority of their time disc-down on the bottom, and gravel or coarse substrate causes disc abrasions which rapidly become infected. Fine sand only. Filtration needs to be proportionally oversized relative to tank volume — rays produce significant bioload and are sensitive to ammonia spikes. Weekly 30–40% water changes are a baseline.

Feeding: bloodworm, earthworms, cockles, and mussel. Most captive-bred individuals will accept quality frozen food readily; wild-caught specimens can take several weeks to transition. These specimens are captive-bred, which matters.

A word on the sting: rays do not use the barb offensively, but a startled or cornered animal will. Use long-handled net equipment for any tank maintenance that requires reaching near the ray, and never use bare hands on or near the disc when the animal is unsettled. The venom causes significant local tissue damage and is medically serious.

Who this is for: Expert keepers who've kept Potamotrygonidae before, have the right substrate and filtration already running, and understand the welfare and safety obligations. A single Snow White Pearl is a centrepiece specimen. A pair in a large system is something genuinely extraordinary — and these two are a correctly-sexed match.

Rare Red Florida Gar (Lepisosteus platyrhincus) — 9–10 Inches

Difficulty: Intermediate–Expert | In stock: 13 singles, 5 pairs | Price from: £450 (single), £800 (pair)

The standard Florida Gar is already a visually compelling fish. The Red variant — a colour morph with vivid brick-red and amber hues across the ganoid-scaled body — is a genuine rarity, and stock at this size (9–10") and in these numbers is unusual. Marc sources selectively; when a run of this quality comes in, it's worth paying attention.

Gars are ambush predators with ancient lineage — they've been around, largely unchanged, for 100 million years. The ganoid scales (interlocking, enamel-coated, and almost impervious to puncture) are part of what makes them so striking under light. At 9–10", these fish have already developed their full scale patterning.

Parameters & Setup

One of the practical advantages of the Red Florida Gar over some of the more demanding exotics: they're relatively tolerant of UK tap water chemistry in most regions, don't require RO, and take to quality frozen food — large lance fish, whitebait, defrosted prawns — without much persuasion once settled. Hikari Massivore Delite works well for regular feeding.

Pairs are available at £800 and can be housed together successfully in a large system — Gars coexist well with conspecifics, which is not something you can say about every predator on this list. Avoid housing with anything small enough to be swallowed. The gape is considerable at this size.

A secure lid is not a suggestion. Like all obligate air-breathing fish, they come to the surface regularly, and that surface proximity combined with a powerful tail means escapes happen quickly.

Who this is for: Intermediate-to-expert keepers looking for a prehistoric centrepiece predator that doesn't require soft blackwater conditions. Pairs are suitable for keepers with a serious large tank setup. The Red colouration makes these standout even in a collection of oddballs.

Corydoras (Hoplisoma sp. aff. Concolor) — CW217 — 3–4 cm

Difficulty: Intermediate | In stock: 10 singles, 2 groups of 5 | Price: £75 (single), £300 (group of 5)

Not every arrival needs to be a 40-inch apex predator to be worth your attention. The CW217 is one of the rarer Corydoras assignments — Hoplisoma sp. aff. Concolor sits in the broader concolor complex and is infrequently available in the UK trade. If you keep South American blackwater communities, a group of wild-caught or selectively bred CW217s is worth far more than another batch of peppered Corys.

Parameters & Setup

Corydoras are shoaling animals — a single specimen or a pair will be chronically stressed and spend the majority of time hiding. Six is the working minimum; more is better. The CW217 specifically does well with softer, slightly acidic water and a well-planted setup. Fine sand substrate is non-negotiable: gravel erodes barbels within months, and eroded barbels are impossible to reverse.

Feed Repashy Soilent Green gel food, Hikari Sinking Wafers, and occasional frozen daphnia or bloodworm. They'll also clean up meaty scraps from larger tankmates in a community setup — useful if you're running a mixed South American system.

Groups of five are available at £300 — with ten singles in stock, there's enough to build a proper shoal.

Who this is for: South American blackwater community keepers, Corydoras species collectors, or anyone running a larger mixed system that needs a competent bottom-tier. Not a beginner fish in the sense that the care specifics (water chemistry, substrate, group size) are specific — but manageable for an intermediate keeper who does their research.

How MTF's Arrivals Work

All livestock coming through MTF Aquatics is health-checked and held before dispatch. Marc sources direct from Indonesian and South East Asian exporters, bypassing the UK wholesale chain — that's why you're seeing species like the CW217 here that simply don't appear in high-street trade. The transhipping service also lets you commission specific species not currently in stock: if you want something that isn't listed, that's the route.

Every fish ships with the Live Arrival Guarantee — photograph the fish in the sealed bag within two hours of delivery and you're covered. Dispatch runs Monday–Thursday before 2 pm for next-day specialist live-fish delivery.

If you have a question about suitability — tank size, tankmates, whether a pair will work in your specific setup — ask before you order. We're fishkeepers first. If a fish isn't right for your situation, we'll tell you.

Browse Current Stock

The full list of what's available right now — including multi-buy options for the Arowana, Red Florida Gar, and CW217 Corydoras — is on the shop page. Stock moves; the Snow White Pearl Stingrays in particular are one-of-a-kind specimens.

• Black Arowana (Osteoglossum ferreirai) — from £250
• Snow White Pearl Stingray Male (11–12") — £1,250
• Rare Red Florida Gar (9–10") — from £450
• CW217 Corydoras Hoplisoma sp. aff. Concolor — £75 each

All fish ship with our Live Arrival Guarantee. Questions? Check the FAQ or get in touch directly.