Tiny in stature but huge in character, Alex explains why he believes the goldstreak blenny (also known as the tailspot blenny) is one of the most entertaining fish available to reefkeepers and remains a firm favourite of his.
My love of small fish is well known among my fishkeeping friends and family. It is a running joke that I don’t actually have any fish in my aquariums as they are too small to see.
For a long time now, I have only kept freshwater fish, but back when I worked in the trade, I had a reef tank. I had easy access to RO water, discount on equipment, and sometimes first pick on livestock; it was impossible to resist setting up my own slice of the ocean. And guess what? All of my favourite marine fish were just as tiny as my current favourite freshwater fish.
Fast forward to present day and whenever I visit a store that sells marine livestock, it is still the little fish that catch my eye over the characterful species like large puffers, terrific triggers, and enormous eels.
I regularly find myself mentally planning my return to the salty side, and there are a couple species that always make the list. One of which is the focus of this feature: the goldstreak blenny.
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All photos by Shutterstock
Goldstreak Blenny Fact File
Scientific name: Ecsenius stigmatura
Size: up to 6 cm (2.4 in)
Origin: Western Pacific around the Philippines and Indonesia.
Habitat: They occur in shallow waters in coastal lagoons and sheltered coral reefs.
Tank size: 60 x 30 x 30 cm (24 x 12 x 12 in)
Water requirements: Standard reef parameters, a pH 8.1-8.4, 1.023-1026 SG.
Temperature: 23-27°C (74-81°F)
Temperament: Territorial towards similar fishes. Confirmed pairs can live together but generally keeping just one is the safer option. Not totally reef safe as reports of nipping corals exist.
Feeding: An unfussy omnivore, feeding on filamentous algae and microorganisms on the rocks. Supplement this with the prepared foods, frozen and live fare, and some plant based foods.
Availability & cost: Fairly common, expect to pay upwards of £25.
Descriptive names
This delightful nano fish is commonly known by two monikers: the goldstreak blenny and the tailspot blenny. Both names describe this fish perfectly, but they focus on the opposite ends of the fish’s body.
The goldstreak common name refers to the small orange-gold stripe that sits just posterior to the pectoral fins. In some specimens this streak extends to almost below the eye, while in others a thinner blue line that sits just above the golden stripe is more noticeable.
The tailspot name refers to the black mark at the base of the tail. This spot is separated from the orange-brown body by a small white mark which helps to really highlight it. This is important for the fish, as the spot is thought to form part of its predator avoidance strategy, potentially encouraging predators to target the tail rather than the more vulnerable head.
The descriptive name theme continues into its scientific name: Ecsenius stigmatura. The species name stigmatura is derived from the Greek words stigma, meaning 'spot', and oura, meaning 'tail'.
Yet neither the gold streak nor the tail spot is the fish's most captivating feature – its eyes steal that honour in my opinion. Large relative to its body size, with a bright yellow iris encircled by a red ring, the eye contributes greatly to the goldstreak blenny's alert and expressive appearance.
Combined with the false eyespot on the tail, it creates a fish that is both attractive and cleverly adapted to life on the reef. All that is missing is another common name which focuses on this third striking characteristic.
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A fish packed with character
If you have ever had the pleasure of watching any species of blenny for a while, you’ll know how much personality they have. This personality is evident not only in their expressive, almost comical, faces, but also in their behaviour.
Many species love posing on rocky outcrops around the aquarium, watching the world around them, or popping up from small crevices and hidey-holes, with just their beady eyes appearing initially. It is worth aquascaping your marine tank with these behaviours in mind.
This personality may not surprise you when it comes to the larger blenny species like the lawnmower blenny and Midas blenny. However, the goldstreak has the same playful character, but in a tiny package growing to just 6 cm (2.4 in). Many people wrongly assume small fish don’t have the ability to become “pet-like”, but these miniature blennies certainly prove them wrong.
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Life with corals
This endearing personality isn’t just for the benefit of us humans; it has a real-world use on the sheltered coral reefs around the Philippines and Indonesia, where they originate. The small size of goldstreak blennies makes them easy pickings for the larger piscine predators that inhabit the region. Their constant perching and scanning of their surroundings enables them to dive back into dense coral growth and rocky networks at the first sign of danger.
When these blennies aren’t on high alert, they spend their days utilising their comblike teeth to scrape algae and encrusting organisms off rocks.
While generally considered reef-safe, some individuals may occasionally move from grazing on the rocks to nipping at SPS corals, clam mantles, or certain LPS species. This behaviour appears to vary between specimens and is often more common in tanks with limited natural grazing opportunities.
A mature tank with plenty of rockwork that features some filamentous algae can help reduce the risk, and their small size rarely poses too much threat to any one coral in a large system. However, adding one to a fairly new nano tank with SPS corals may be a recipe for constant frustration.
Is a goldstreak right for you?
If you are happy to risk a few nips at your prized corals, you’ll be rewarded with a stunning and entertaining fish in your reef. Not only that, they will even help out with janitorial duties, tidying up some algae from the rockwork. However, before you head to your local store to see if they have one in stock, there are a few additional considerations to keep in mind.
Their small size makes them vulnerable to larger fish. If you have or plan to add any predatory species, you should avoid keeping a goldstreak blenny.
Similarly, overly boisterous or territorial tankmates may cause your blenny to spend much of its time hiding, meaning you miss out on many of its entertaining behaviours. In fact, the blenny itself is territorial and will not appreciate any similar looking fish, although compatible male-female pairs can work well in larger aquariums. Cardinalfish, common clownfish, and small wrasses would all be appropriate, as would any of the non-predatory ornamental crustaceans.
Tank size is unlikely to be an issue, unless you have a very small desktop reef. Aquariums measuring 60 x 30 x 30 cm (24 x 12 x 12 in) will suffice long-term, but larger tanks will reduce the risk of one coral colony getting the brunt of the blenny’s grazing.
Similarly, feeding is also unlikely to cause you headaches, with goldstreak blennies being unfussy omnivores. Supplement their natural grazing with frozen and live foods, quality prepared diets, and the occasional sheet of nori or other vegetable matter.
Despite their diminutive size, goldstreak blennies have the charm, character, and presence of a much larger marine fish. Their inquisitive nature and attractive appearance are what captivated me initially, but their manageable care requirements are the cherry on top. Just don't be surprised if this tiny blenny ends up becoming the fish you spend the most time watching.