Gastromyzon sp. “Bloody Mary” (Hillstream Loach)
Gastromyzon sp. “Bloody Mary” (Hillstream Loach)
A striking and uncommon hillstream loach from Borneo, Gastromyzon sp. “Bloody Mary” is prized for its intense blood-red markings and rugged beauty. This micro-loach is a captivating choice for aquarists seeking both visual appeal and functional tankmates.
A striking and uncommon hillstream loach from Borneo, Gastromyzon sp. “Bloody Mary” is prized for its intense blood-red markings and rugged beauty. This micro-loach is a captivating choice for aquarists seeking both visual appeal and functional tankmates.
🧭 Overview & Origins
Belongs to the Gastromyzon fasciatus group, with bold red patches at the base of its dorsal fin and caudal peduncle
Wild-caught from Pangkalan Bun, southern Borneo—collected alongside the rare Gastromyzon sp. “Blue”
Unscientifically described; morphologically distinct from both G. fasciatus and G. praestans
🔍 Appearance & Behavior
Size: Reaches 5–6 cm (approx. 2–2.5 inches) as adults, though many imports arrive at 2.5–3.8 cm
Deep dark body with brilliant red markings that glow under strong oxygen flow
Courting males become almost black; females slightly smaller and more streamlined. Both sexes sport dermal tubercles (horny snout pimples)
🌿 Tank & Water Conditions
Tank size: Minimum 80 litres (~20 gallons). More space preferred for groups
Temperature: 20–24 °C
pH: 6.5–7.5, hardness 4–12 dGH, mimicking cool, oxygen-rich streams
Flow & Oxygen: High-oxygen, moderate-to-strong current is essential, provided via powerheads or strong filters
Substrate & Decor:
Use smooth stones, driftwood, caves and flat rocks for algae grazing stations.
Dense planting with riverine style structures adds both beauty and security.
🍽 Diet
Primary diet: Natural biofilm and algae growing on hard surfaces.
Supplemental foods: Algae wafers or spirulina tabs, blanched veggies (zucchini/spinach), and occasional live/frozen foods like daphnia or bloodworms
🧑🤝🧑 Social Behavior & Tankmates
Temperament: Calm, peaceful, best kept in groups of 3 or more to stimulate activity and reduce stress
Compatible species:
Small peaceful schooling fish (rasboras, danios, tetras)
Other hillstream loaches or bottom-dwellers (Otocinclus)
Shrimp and small snailsAvoid: aggressive, large, or fin-nipping species that may outcompete or harass them.
🧩 Breeding & Health Notes
Breeding: Rare or unconfirmed in home tanks; only glimpsed mating behaviors in tank studies and likely requires precise flow, tannin and substrate conditions
Found resilient in the wild—even surviving infections like Piscinoodinium without losses
✅ Summary: Why Keep Gastromyzon sp. “Bloody Mary”?
Stunning red–black contrast coloration makes this fish stand out
Hardy algae-eater suited for fast-current aquascapes
Peaceful and community-friendly when kept in groups
Rare, exotic, and visually compelling as a focal addition to river biotope tanks
🧾 Care Checklist (Metric Units)
| Parameter | Recommendation |
|---|---|
| Tank Size | ≥ 80 L |
| Temperature | 20–24 °C |
| pH | 6.5–7.5 |
| Hardness | 4–12 dGH |
| Flow | Moderate to strong |
| Substrate | Smooth rocks, driftwood, caves |
| Diet | Algae + wafers + veggies |
| Schooling | Keep at least 3 individuals |
| Compatible Fish | Rasboras, Danios, Otocinclus, shrimp |
Would you like help crafting a river-style aquascape or suggestions for ideal tankmates to pair with “Bloody Mary” loaches? 😊
Related Products
Racer Nerite Snails are stunning, algae-eating freshwater snails with unique striped and swirled shell patterns. They are excellent for keeping aquariums clean and are perfect for planted and community tanks.
5 in stock
Daisy’s Ricefish (Oryzias woworae) is a small, vibrant freshwater fish native to Muna Island in Southeast Sulawesi, Indonesia. Discovered in 2010, this species has gained popularity among aquarists for its striking coloration and peaceful demeanor.
All livestock has undergone a mandatory quarantine period of at least 2 weeks.
Livestock Policy
We are committed to providing healthy and thriving livestock to our customers. Here are some important details to keep in mind:
- We do not accept returns on any livestock (plants, aquatic animals, etc.) please see DOA Policy.
- We primarily sell juvenile livestock but may substitute adult specimens if available.
- We do not guarantee specific sexes for our livestock and may send a mix of males and females if available.
13 in stock
The Blue Dream Shrimp (Neocaridina davidi var. Blue Dream) is a stunning freshwater shrimp known for its deep blue coloration and ease of care. It’s a great choice for shrimp keepers of all experience levels and makes an excellent addition to planted aquariums.
20 in stock
Tanichthys micagemmae is a beautiful and peaceful freshwater fish closely related to the well-known White Cloud Mountain Minnow (Tanichthys albonubes), but rarer and even more vibrant. Native to the cool, clear streams of central Vietnam, this species features shimmering scales, metallic stripes, and striking red-orange fins — making it a fantastic choice for nano and planted aquariums.
20 in stock
BRED BY SHRIMP NATION
The Blue Bolt Shrimp is one of the most stunning Taiwan Bee varieties, prized for its striking icy blue coloration that intensifies with higher grades. High Grade Blue Bolts display a more solid, uniform sky-blue to deep turquoise body with minimal white patches, making them a true centerpiece in any shrimp collection.
20 in stock
BRED BY SHRIMP NATION
The Pure Red Line (PRL) Crystal Shrimp is a selectively bred strain of Crystal Red Shrimp that has been kept within dedicated PRL bloodlines for generations. Unlike standard CRS, which may have Golden Bee or other genes mixed in, PRL shrimp are guaranteed to produce only Pure Red Line offspring. This makes them highly prized by serious shrimp breeders and collectors.
20 in stock
The Military Helmet Nerite Snail is a striking freshwater snail species, valued for its unique, rugged shell pattern resembling a military helmet and its exceptional algae-eating abilities. Hardy and peaceful, it is a favorite among aquarists for both aesthetic and practical reasons.
All livestock has undergone a mandatory quarantine period of at least 2 weeks.
Livestock Policy
We are committed to providing healthy and thriving livestock to our customers. Here are some important details to keep in mind:
- We do not accept returns on any livestock (plants, aquatic animals, etc.) please see DOA Policy.
- We primarily sell juvenile livestock but may substitute adult specimens if available.
- We do not guarantee specific sexes for our livestock and may send a mix of males and females if available.
5 in stock
The Snowball Shrimp is a beautiful freshwater dwarf shrimp known for its bright, opaque white coloration — resembling tiny snowballs drifting through your aquarium. A selectively bred variant of Neocaridina davidi, Snowballs are easy to care for, peaceful, and excellent for beginner shrimp keepers and planted tanks.
20 in stock
The Celestial Pearl Danio, also known as the CPD or Galaxy Rasbora, is a stunning freshwater fish highly sought after for its vibrant coloration and peaceful nature. Native to shallow, vegetated ponds in Myanmar, this small and hardy species is perfect for nano aquariums and community tanks.
All livestock has undergone a mandatory quarantine period of at least 2 weeks.
Livestock Policy
We are committed to providing healthy and thriving livestock to our customers. Here are some important details to keep in mind:
- We do not accept returns on any livestock (plants, aquatic animals, etc.) please see DOA Policy.
- We primarily sell juvenile livestock but may substitute adult specimens if available.
- We do not guarantee specific sexes for our livestock and may send a mix of males and females if available.
20 in stock
The Guppy is one of the most popular and widely kept freshwater fish in the aquarium hobby, renowned for its vibrant colors, flowing fins, and hardy nature. Native to South America, Guppies have been selectively bred into countless varieties, each showcasing unique patterns and hues. They are small, peaceful fish ideal for community aquariums and are particularly well-suited for beginners.
All livestock has undergone a mandatory quarantine period of at least 2 weeks.
Livestock Policy
We are committed to providing healthy and thriving livestock to our customers. Here are some important details to keep in mind:
- We do not accept returns on any livestock (plants, aquatic animals, etc.) please see DOA Policy.
- We primarily sell juvenile livestock but may substitute adult specimens if available.
- We do not guarantee specific sexes for our livestock and may send a mix of males and females if available.
5 in stock
The Zebra Nerite Snail is a small, hardy, and strikingly patterned freshwater snail that is excellent for controlling algae in aquariums. Its black and yellow-striped shell resembles a zebra pattern, making it a popular choice for aquascaped tanks.
6 in stock
The Guppy is one of the most popular and widely kept freshwater fish in the aquarium hobby, renowned for its vibrant colors, flowing fins, and hardy nature. Native to South America, Guppies have been selectively bred into countless varieties, each showcasing unique patterns and hues. They are small, peaceful fish ideal for community aquariums and are particularly well-suited for beginners.
All livestock has undergone a mandatory quarantine period of at least 2 weeks.
Livestock Policy
We are committed to providing healthy and thriving livestock to our customers. Here are some important details to keep in mind:
- We do not accept returns on any livestock (plants, aquatic animals, etc.) please see DOA Policy.
- We primarily sell juvenile livestock but may substitute adult specimens if available.
- We do not guarantee specific sexes for our livestock and may send a mix of males and females if available.
4 in stock
Reviews
There are no reviews yet.