No. 07 Pterophyllum scalare · Var. Black Lace (D/+)

Black Lace Angelfish: One Dark Gene, and Why It Shows Lace

A single copy of the Dark gene (D/+) makes the fish dusky without making it opaque — and that leftover translucency is the whole reason the structure inside the fins reads as lace. Two copies, and the lace disappears.

Black Lace Angelfish — quick facts
Scientific namePterophyllum scalare (Var. Black Lace)
GenotypeSingle Dark Gene (D/+)
Adult sizeUp to 6 in long, 8+ in tall with fins
Minimum tank29 gal tall (18 in) for a pair; 55+ gal for a community
Water76–82°F (24–28°C), pH 6.0–7.5, hardness 3–10 dGH
TemperamentSemi-aggressive
DietOmnivore; varied diet of flakes, pellets, and frozen foods
Lifespan10–15 years with proper care

The Black Lace Angelfish is one of the oldest and most well-known color morphs of Pterophyllum scalare. Its appearance comes from a single copy of the "Dark" gene (genotype D/+), which gives the fish a dusky black coloration that's dark but not completely opaque — the translucency lets the skeletal structure and patterns within the fins remain visible, creating the "lace" effect for which it's named.

Where this page comes from, because it should affect how much weight you give it: I have never kept a Black Lace. This one is common enough that I cannot blame availability the way I can with the Double Dark — I simply never had one. What follows is the genetics, which is checkable and which I have taken care to get right, plus the general scalare care that applies to every variety on this site. What it is not is an account of watching the lace sharpen or fade as a fish matured, or the wild barring surface when one was stressed — the two claims here a keeper could check and I cannot. Weigh it against them.

Diagram: three angelfish showing the Dark gene at nought, one and two copies. The first, plus over plus, is pale with its wild vertical barring and every fin ray visible. The second, D over plus, is dusky but still translucent, so the fin rays read through it as lace. The third, D over D, is opaque black with both the barring and the fin structure covered over. Below, a Punnett square for two Black Lace parents gives one silver to two black lace to one double dark black.
One copy is the whole story on this page: dark enough to read as black, translucent enough that the structure underneath still shows. Add the second copy and the lace goes.
Side-by-side comparison of the two varieties. Left: a black lace angelfish, its dark body still showing a visible lace pattern through the fins. Right: a double dark black angelfish, a solid opaque black with the fin pattern obscured.
Left: Black Lace (D/+), one dark gene — the lace pattern stays visible in the fins. Right: Double Dark Black (D/D), two dark genes — solid and opaque, the pattern obscured.

Black Lace vs. Double Dark Black (Velvet) Angelfish

This fish and the Double Dark Black are both sold as a black angelfish, which is where most of the confusion about either of them starts.

  • Black Lace (D/+): one dark gene; body is smoky dark grey to near-black; the "lace" pattern in the fins is visible; may show faint vertical barring from wild ancestors when stressed.
  • Double Dark Black / Black Velvet (D/D): two dark genes; deeper, more solid, opaque black; fin patterns are almost completely obscured for a uniform, velvety appearance.

Appearance & Identification

The primary identifier is the combination of a dark body and detailed fins. Body color ranges from deep grey to rich black, covering most of the fish. Under good lighting, the dorsal, anal, and caudal fins reveal an intricate network of fine lines and swirls — the signature "lace."

Temperament & Behavior

As a cichlid, the Black Lace Angelfish is semi-aggressive, consistent with other P. scalare varieties: generally peaceful community residents that establish a pecking order, becoming territorial as they pair off for breeding.

Tank Requirements & Habitat

A tall tank is non-negotiable. A 29-gallon tall aquarium (18 in of height) is the minimum for a pair, with 55 gallons or larger ideal for a small group or community. Their dark, elegant coloration looks particularly striking against a backdrop of bright green live plants like Amazon Swords, Anubias Nana, and Java Fern, with tall driftwood for security and spawning surfaces. A lighter-colored sand or fine gravel substrate helps the dark fish stand out.

Water Parameters

Stable, clean water is paramount: 76–82°F (24–28°C), pH 6.0–7.5. Use a high-quality filter with adjustable flow.

Diet and Feeding

Black Lace Angelfish are omnivores that thrive on a varied diet: a high-quality tropical flake or small cichlid pellet as the base, supplemented with protein-rich frozen or live brine shrimp, mysis shrimp, and bloodworms 2–3 times per week to encourage healthy growth and breeding behavior.

Breeding Black Lace Angelfish

Breeding follows the same process as other angelfish — a pair cleans a vertical surface and guards their eggs and fry — but the genetic outcomes are what make it fascinating. Breeding two Black Lace Angelfish (D/+ × D/+) predicts, by Mendelian genetics:

  • 25% Silver Angelfish (+/+)
  • 50% Black Lace Angelfish (D/+)
  • 25% Double Dark Black Angelfish (D/D)

See our full breeding guide for the general process.

Related Angelfish

Frequently Asked Questions

What is the difference between a Black Lace and a Black Velvet Angelfish?

A Black Lace has one dark gene (D/+), resulting in a dark body with visible 'lace' patterns in the fins. A Black Velvet has two dark genes (D/D), making it a deeper, solid black with little to no visible fin pattern.

Why does my Black Lace Angelfish sometimes show stripes?

The single dark gene in a Black Lace doesn't always completely mask the underlying wild silver pattern. When the fish is stressed, young, or in certain lighting, these faint vertical bars can become visible.

Are Black Lace Angelfish harder to care for?

No. Their care requirements are identical to other common varieties of freshwater angelfish. Their hardiness makes them a great choice for beginners with an appropriately sized tank.

Do they lose their color as they age?

No, a healthy Black Lace Angelfish should maintain its dark coloration throughout its life. Fading color is typically a sign of stress, poor water quality, or illness.

What happens when you breed two Black Lace Angelfish?

Due to their genetics (D/+), breeding two Black Lace Angelfish will result in a mix of offspring: approximately 25% will be Silver Angelfish (+/+), 50% will be Black Lace Angelfish (D/+), and 25% will be Double Dark Black Angelfish (D/D).

What is the best tank setup to show off a Black Lace Angelfish?

To make their dark coloration stand out, use a light-colored substrate (like white sand) and a background of vibrant green, live plants such as Amazon Swords or Anubias. Good lighting is also key to revealing the intricate 'lace' pattern in their fins.