Fisch: How to Get Abyssal Bio-Fluid and Bio-Fluid Fast

Abyssal Bio-Fluid and its more common counterpart, Bio-Fluid, are crafting materials in Fisch that both come from a single deep-sea target. The fastest way to stockpile them is to fish the Lower Deep and catch the Luminous Hake, a mythical fish that glows red in the dark trench.

Quick answer: Travel down into the Lower Deep, find the red-glowing Luminous Hake, and catch it. Each Luminous Hake has a 20% (1 in 5) chance to drop Abyssal Bio-Fluid and frequently gives Bio-Fluid as extra finds. Repeat until you have enough.

How to reach the Lower Deep in Fisch

The Lower Deep sits below the main hub area near the Nereus main quest statue. You reach it by diving down through the trench behind the large king statue that holds a trident.

Head to the statue of the king holding a trident and swim into the dark blue portal located directly behind its pedestal.

Swim downward past the white-domed buildings and continue into the dark trench below them.

Watch for the on-screen label reading “Lower Deep” and confirm the area by its purple-colored ground and glowing purple crystals. That is your signal that you are in the right zone.

Note: Deep-diving carries pressure and air limits, so bring your diving gear before you descend.

Catch the Luminous Hake for both materials

The Luminous Hake is the single source that supplies both Bio-Fluid and Abyssal Bio-Fluid in this zone. It is a mythical fish, so it does not appear on every cast, but it is easy to spot once it does.

Look through the Lower Deep for a fish giving off a distinct red glow. That glow is the Luminous Hake.

Cast your line toward the red-glowing fish and complete the reeling mini-game to land it.

Check your catch notifications. Landing the Hake can trigger the Abyssal Bio-Fluid drop along with one or more Bio-Fluid extra finds.

Repeat the loop in the same area. The more Luminous Hake you catch, the more Abyssal Bio-Fluid rolls you get.

Luminous Hake drop rates

Detail	Value
Fish rarity	Mythical
Zone	Lower Deep
Spawn chance	4.1%
Sparkling chance	0.2%
Abyssal Bio-Fluid drop	20% (1 in 5) per catch
Bio-Fluid	Frequent extra find on catch

Tip: Totems that shift the celestial cycle, such as the Sundial Totem, and days with bonus luck can help your farming session. Rods that grant extra catch abilities also improve your material yield over time.

How to confirm you got the drop

When a Luminous Hake catch produces the rare material, you will see a chat message reading “Rare Find! You just caught a Abyssal Bio-Fluid! (1/5)”. Bio-Fluid arrives through “Extra Find!” messages on the same catch, and you can often collect several at once.

Both items land in your inventory under the ingredients tab, so you can open your bag at any time to verify your current count.

What Abyssal Bio-Fluid is used for

Abyssal Bio-Fluid is a crafting component, so the reason to farm it is the recipes it unlocks. Two recipes call for it directly.

Cusk Purger
Cusk-Shot

Bio-Fluid, the more plentiful drop, stacks up quickly while you chase the Abyssal version, so a single farming run in the Lower Deep tends to leave you with a healthy supply of both.