Blue/Green Galaxy Boa

A black shrimp with a thick white hood over its head and shoulders, and legs that look painted.

It arrives young, showing only a hint of the metallic sheen. The sheen comes through and intensifies as the shrimp mature, blue on some and deep green on others. The white hood thickens over the same period.

Four price levels, set by how much white covers the head, how clean the body pattern is and how thick the shell is. All three are visible on arrival, and the dearer levels have more of each.

Caridina wants soft, slightly acidic water and a tank that has been running a while. It is not a first shrimp. Numbers in the FAQ.

The Blue/Green Galaxy Boa is a Caridina with two defining traits: the thick white “hood” spreading across the head and carapace and down the cheeks, and a metallic mutation that keeps working after that pattern sets. The black body never changes. As these shrimp grow and moult (shed their shell), the white pattern over it shifts to a metallic blue or a deep emerald, depending on the individual. Other sellers list the same line as the Black Base Galaxy Boa. We named it for the colour you end up seeing.

About the photo. The shrimp pictured is High or Collector grade. We ship unsexed juveniles, selected for early signs of metallic potential, so treat the photo as where they are heading. Coverage thickens, the body stripe sharpens and the metallic shift builds over successive moults. If you want the metallic look straight away, contact us about adults.

A true Boa has five traits, and each keeps developing after arrival.

• The hood: White spreading over the head and carapace, down to the cheeks. It is the defining hallmark.
• The body stripe: A thick “fishbone” stripe runs down the back and reaches close to the edge of the belly. It is either a clean, straight-cut “boa” look or a saw-edged “jagged” look. Both are correct, and the fewer breaks in it, the better.
• Shell thickness: A thick shell looks shiny and solid. A thin one looks dull, with see-through patches.
• Colour on the pattern: The black base stays black and only the tone of the white changes. At the size we ship there is already some blue in it, and it deepens and spreads from the head across the whole body pattern with age, blue on some and green on others. The strongest, most metallic tone typically arrives after a female has carried eggs (been “berried”) for the second time, at roughly three to four months old. Males colour up less than females.
• Spider legs: The body pattern carried onto the legs, with black patches and white. The white takes the same tone the body does, only subtler. Leg colour follows shell thickness, so the higher grades show it first.

The pattern keeps spreading and shifting with age, so a Boa improves over time. Every shrimp arrives pale from the trip and colours back up within hours to a few days.

We grade by the traits that genuinely vary within a batch. A Boa varies in five ways, and all five are readable at the size we ship, so the line sorts into four grades.

• Head coverage. How much of the head is covered in blue-green. Mid sits around 40 to 70%, High up to about 80%, and Collector 95% or the full head.
• Body pattern. Thick, in the boa look or the jagged look. The higher the grade, the fewer breaks and flaws.
• Shell thickness. High and Collector are thick throughout. Entry and Mid can be a mix of thin and thick.
• Colour. The higher grades show the blue or green tone earlier and over more of the pattern.
• Leg colour. It grows in with age on every grade. High and Collector already show strong spider legs at the size we ship. Entry and Mid may show none when young and may never fill the legs completely.

Entry has the lightest head coverage and the most flaws, with a mixed shell and legs. It is the same genetics at the lowest price. Mid has 40 to 70% head coverage with some flaws, a sound Boa base. High has up to 80% coverage with very few flaws, a thick shell and strong legs already. Collector is the best of each batch: a near-full head of blue-green, the cleanest pattern and the fullest legs. There are only ever a few.

Grading is done by eye at shipping size, on what the shrimp shows then. Shrimp rarely move a grade as they grow, but water matters: poor water costs colour and shell.