Submarine the Guppy Has a Passenger — And Neither of Them Seems to Mind

Submarine the Guppy Has a Passenger — And Neither of Them Seems to Mind

Dave didn't name him Submarine because he's fast. He named him that because the little guppy looks like a vessel with an extra hull: a second, partially-formed body fused to his belly, both of them cutting through the water column like some aquatic fever dream. The photos hit r/Aquariums yesterday and cleared 500 upvotes before most hobbyists had finished their morning coffee — commenters zooming in on the wild asymmetry, debating whether they were looking at a genuine parasitic twin or just a very unfortunate lump.

A vet in the thread settled it: classic parasitic twinning, where a second embryo attaches early in development and hitches a ride, never fully forming but never quite letting go. It sounds like a death sentence, but Submarine eats, colors up, and darts from tankmates like any guppy who knows he's the main character. Most fry with this kind of deformity vanish within hours. Submarine is out here rewriting the script.

Breed guppies long enough and you'll see everything — but most hobbyists go years without spotting a survivor like this.

Gobble's Take: Inspect your guppy fry closely — your next tank centerpiece might already have its own built-in co-pilot.

Source: r/Aquariums

50 Cichlid Fry, Day 10 — And Dad Is Already Flaring at Tetras

She spotted the first wiggle at dawn: 50 Ivanacara bimaculata fry, each barely the size of a peppercorn, schooling under mom's fin while dad patrolled the perimeter of a 20-gallon, flaring at anything that drifted too close. The macro shots posted to r/Aquariums yesterday show translucent bodies still pulsing with yolk sacs — but by day 10, these South American dwarf cichlids are already vacuuming infusoria off the glass and growing fins you can watch change by the hour.

This spawn didn't happen by accident. The keeper had been dosing Indian almond leaves for tannins, holding pH steady at 6.5, and feeding live blackworms exclusively in the week leading up to the spawn. Community veterans in the thread flagged Ivanacaras as one of the most underrated nano breeders going: peaceful enough to share a tank with shrimp, capable of producing 50–100 fry per clutch, and colors that rival discus at a fraction of the cost and footprint.

By week four, these fry will be out-eating their parents — and one clutch could quietly stock three tanks.

Gobble's Take: Want cichlid drama without a 200-gallon arms race? Ivanacara bimaculata will deliver it in a tank you can fit on a bookshelf.

Source: r/Aquariums

Your Local Fish Shop's "Rare" Fish Is a $3 Convict in a Trench Coat

He walked in expecting something special. The store clerk grinned, pointed to a barred cichlid with some attitude, said "rare bars, killer personality," and charged $25. He bought it. Then he posted the photos to r/Aquariums this morning, and the identification came back unanimous inside of ten minutes: Amatitlania nigrofasciata — the convict cichlid, one of the most prolific and indestructible fish in the hobby, a species so common that one commenter recalled seeing 10,000-plus in a single Florida pond.

Convicts earn the name. They pair up, excavate pits in your substrate, and guard fry with the territorial aggression of something three times their size — shredding shrimp, harassing tankmates, and generally restructuring the social order of any tank you put them in. One commenter shared a 75-gallon takeover story that took six months and ended badly for everyone else in the tank. The store's "rare" pitch is a classic upcharge on a bulletproof fish that breeds in buckets. The OP is debating a return, but veterans in the thread have a counter-offer: pair it up, collect 200 fry every quarter, sell half, and fund your next equipment upgrade.

Shops peddle convicts as special because new hobbyists haven't been burned yet — but now you have no excuse.

Gobble's Take: Before you hand over cash for an LFS "rarity," snap a photo and run it through Reddit — five minutes could save you $25 and a tank civil war.

Source: r/Aquariums

This 14-Gallon Planted Cube Has Run Itself for Five Years — No CO2, No Ferts, No Drama

Five years ago, someone filled a 14-gallon cube with dwarf hairgrass, Monte Carlo, and a single Anubias nana, capped a dirt substrate with gravel, set the lights on a cheap timer for six hours a day at 6500K, and basically left it alone. The update posted to r/PlantedTank yesterday shows zero algae, zero melt, and a carpet so thick and even it looks like a rendering. Cherry shrimp have colonized every surface — the population is now somewhere around 200 — and a betta and a small tetra group provide the fertilizer from above.

The only real inputs in year one were root tabs. After that, the shrimp handled detritus before it could brown a leaf, the fish waste fed the plants, and the bacteria did the rest. Low-tech planted tanks get dismissed constantly by the CO2 crowd, but this cube is a five-year argument that high-tech gear often fights the natural balance rather than improving it. Forum veterans in the thread weren't surprised — they were nodding.

Most planted tanks crash by year two from over-tinkering. This one thrived by being left alone.

Gobble's Take: Stock shrimp, plant once, set a timer, and resist the urge to "fix" it — your cube might still be running when your current CO2 regulator is in a landfill.

Source: r/PlantedTank

Quick Hits

• The juiciest bristle worm footage you didn't ask for: A reefer zoomed in on a 6-inch bristle worm working through a pile of detritus — the thread is split between "that's disgusting" and "that's the best cleanup crew member I've ever seen." r/ReefTank
• First planted tank, three months in: A beginner posted their very first planted setup at the 90-day mark, and the results are genuinely good — proof that patience beats expensive equipment for new hobbyists. r/PlantedTank

In Case You Missed It

Yesterday's top stories:

• PNW Custom Shrinks an Entire Reef Controller to 3×3.5 Inches — and It Drops Today
• Your LFS Has Been Misidentifying These Three Corals for Decades. Here's How to Tell Them Apart.
• One Hobbyist Added Six Cherry Shrimp. Months Later, They Own a Shrimp Farm.
• A 2007 Coral Frag Ad Just Surfaced. The Prices Will Make You Want to Cry.