Candystick goby

Where they come from

Candystick gobies (Vanderhorstia delagoae) come from sandy, rubble-y lagoon and reef areas in the Indo-Pacific. You will usually find them posted up at the mouth of a burrow, often paired with a pistol shrimp. That partnership is basically their whole lifestyle: shrimp digs, goby stands guard.

In tanks, they do best when you lean into that natural setup instead of trying to make them live like a rock-perching goby.

Setting up their tank

Think sand first, rocks second. This fish wants a burrow and a clear line of sight from the entrance. If you give them a deep, mixed-grain sand bed and a few stable rocks to tuck a tunnel under, they settle way faster.

• Tank size: 20 gallons is workable for a single, but I like 30+ so you can give them a quiet zone and still keep other fish.
• Sand: 2-3 inches minimum. Mix fine sand with a little rubble/crushed coral so the shrimp (if you add one) can reinforce the burrow.
• Rockwork: set rocks on the glass or on acrylic supports, then add sand around them. Do not balance rocks on sand if a shrimp will be digging.
• Flow: moderate. Too much direct flow at the burrow entrance can make them give up and relocate constantly.
• Cover: tight lid. They can jump, especially during the first week or if spooked at night.
• Lighting: they do not care much, but bright lights with no shaded spots can make new arrivals hide longer. A couple overhangs helps.

What to feed them

The hardest part with candysticks is getting them eating confidently. They are not grazers. They are little ambush pickers that want small meaty stuff drifting by the burrow. Once established, they are great eaters, but they can be shy at first and lose weight quickly if you assume they will figure it out.

• My go-to foods: frozen mysis (small), enriched brine, finely chopped shrimp, calanus, and quality micro pellets (0.5-1 mm) once they recognize pellets as food.
• Feeding style: small portions 2-3 times a day at first beats one big dump. Target feed near the burrow entrance so they do not have to compete in open water.
• Enrichment: soak frozen foods in a vitamin/HUFA supplement a few times a week if the fish came in thin.
• Watch the belly: you want a gently rounded belly after meals, not pinched-in sides.

How they behave and who they get along with

Most of the day you will see a head poking out of a burrow, doing quick little darting grabs for food and then reversing back inside. They are peaceful, but they are not bold. If your tank is full of fast, pushy eaters, the goby will starve while everyone else gets fat.

• Good tankmates: other calm community reef fish (clownfish that are not jerks, firefish, small fairy wrasses, cardinals, chalk bass in larger tanks), and of course a pistol shrimp partner.
• Avoid: aggressive dottybacks, big hawkfish, most triggers, larger wrasses that hunt the sand bed, and anything that likes to rearrange the substrate.
• With other sand gobies: mixed results. A big sand bed helps, but they can squabble over burrow spots. I would not do two in a small footprint tank unless they are a known pair.
• Corals/inverts: reef-safe. They can bury frags placed on the sand, and their digging can undermine rock if your base is not stable.

Breeding tips

They can spawn in captivity, usually in the burrow. In a calm tank with a settled pair, you may see them disappear for longer stretches and get a bit more defensive of the entrance. Eggs are typically laid on the burrow wall or ceiling, and the male often guards.

Raising the larvae is the real challenge. They are tiny planktonic larvae that need live foods (rotifers, then copepods) and stable rearing conditions. If you are not already set up for marine larval rearing, treat spawning as a fun bonus rather than a project you can casually wing.

Common problems to watch for

Most issues with candystick gobies come down to stress, shipping weight loss, and being outcompeted at mealtime. They are advanced mostly because they punish sloppy acclimation and impatient stocking.

• Not eating and wasting away: very common in new imports. Offer small meaty foods near the burrow multiple times a day and reduce competition.
• Jumping: they can bolt through the tiniest gap. Cover overflows, cable cutouts, and mesh tops that do not sit flush.
• Burrow collapse and constant relocating: usually from sand too shallow, grains too fine with no rubble, or flow blasting the entrance.
• Getting bullied: if they stay pinned in the burrow all day and only peek out after lights out, something in the tank is stressing them.
• Parasites (ich/velvet) and bacterial issues after import: watch for rapid breathing, flashing, heavy slime, or refusing food. These fish do not handle 'wait and see' well.
• Pistol shrimp mismatch: some shrimp species are less likely to pair, and a very large shrimp can intimidate a small goby. Size-match when you can.