The rainbow goby (Stiphodon ornatus) is named for its brilliant coloration, which is particularly noticeable in males of the species. Though vibrantly colored by nature, rainbow gobies only look their best when they’re cared for properly. In addition to building a suitable habitat for your fish, you also need to think about providing a healthy diet.
Here we explore what rainbow gobies eat, both in the wild and in captive environments. You’ll learn what to feed a rainbow goby and how to build a balanced diet for these fascinating fish.
Natural Diet of Rainbow Gobies
Like most gobies, rainbow gobies are bottom dwellers. They typically inhabit the lowest level of the water column, using their fan-shaped pelvic fins to grip onto rocks and other surfaces. As they pull themselves along, they’ll graze on biofilm, algae, and other natural growths. These foods make up the majority of a natural rainbow goby diet.
Something worth remembering about rainbow gobies in particular is that much of their development takes place in a marine environment. Native to the coastal streams of Sumatra, rainbow gobies spawn in fresh water, but the larvae are carried downstream into the ocean after hatching from eggs. There they spend a few months growing before they begin their journey back upstream to spawn.
In their larval state, rainbow gobies feed primarily on plankton as they float around in the ocean. Once their fins develop and they’re able to control their own movement, other options like microalgae and biofilm become obtainable.
What to Feed Rainbow Gobies in Aquariums
Because rainbow gobies haven’t been bred successfully in captivity, most specimens available in the aquarium trade are wild-caught. As such, it’s important to provide as natural a diet as possible. In the aquarium, rainbow gobies will still feed primarily on natural growths of biofilm and algae, though some may learn to accept commercial foods.
It’s important to keep in mind that rainbow gobies are bottom-dwellers. If you’re planning to supplement their diet, stick to sinking foods like wafers or pellets. Powder-based gel foods also tend to work well for grazing species. To encourage vibrant coloration, offer nutrient-dense live or frozen foods like baby brine shrimp and daphnia on occasion but stick primarily with vegetable-based foods.
To ensure your rainbow gobies have an adequate supply of natural biofilm to eat, make sure your tank is fully cycled and mature before introducing the fish. Provide plenty of textured, porous surfaces like driftwood, lava rock, and leaf litter for microorganisms to colonize. Decorating your tank with live plants can help too, as long as you’re able to find the right balance with lighting and nutrients to avoid green algae blooms.
Feeding Schedule & Portion Tips
Keeping your rainbow gobies well-fed is a must if you want them to be healthy. It’s also essential for helping them achieve full coloration, particularly in males of the species. This can be a challenge with wild-caught specimens that have been affected by the stress of transit, but establishing a consistent feeding schedule can help.
Here are some simple tips for developing a feeding schedule for rainbow gobies:
● Ensure your tank has an ample supply of biofilm and microalgae before introducing your rainbow gobies.
● Build a nursery tank to cultivate biofilm, algae, and other edible microorganisms you can use to supplement the natural growth in your goby tank.
● Swap out porous rocks and other items from the nursery tank into your goby tank regularly to keep the supply of edible biofilm steady.
● Offer small, vegetable-based supplemental foods on a daily basis (things like algae wafers, spirulina flakes, and blanched vegetables).
● Keep your portions of supplemental foods small, removing leftovers of larger foods like wafers before they fully break down.
Assess the condition of your rainbow gobies on a daily basis to determine whether they’re getting enough to eat. Depending on the biofilm supply in your tank, you may need to offer supplemental foods twice a day or reduce supplemental feeding to a few times a week. A healthy, well-fed goby should have a plump, slightly rounded belly without visible ribs or backbone.
Foods to Avoid
As long as you build your rainbow goby diet around natural growths and commercial foods formulated for fish, there isn’t much to worry about. When rainbow gobies have adequate access to biofilm and algae, they may be less likely to show interest in dried foods anyway.
If you plan to offer supplemental foods, prioritize vegetable-based foods over high-protein options. Rich foods like baby brine shrimp, frozen bloodworms, or daphnia may be accepted but should be fed sparingly.
Keep in mind as well that because rainbow gobies are bottom-dwellers, floating foods are unlikely to reach the lower level of the tank where your fish can find them.
Tips for a Balanced Goby Diet
No matter what species you’re stocking your home aquarium, a varied diet is essential. In the wild, rainbow gobies feed on a wide range of microorganisms, and your goal is to mimic their natural diet as closely as possible. Here are some simple tips:
● Cultivate a supply of microorganisms in a separate nursery tank. The variety of microorganisms may differ from what’s in your tank.
● Mix up the formulas and brands of commercial foods you offer, as each one will have a different nutrient profile.
● Stock a few different varieties of frozen foods and offer them on a rotating basis, thawing them in a cup of tank water so the food spreads and sinks.
● Provide small portions of blanched vegetables once a day, weighing them down with a veggie clip to make sure your rainbow gobies can easily access them.
As you’re feeding your rainbow gobies, take note of which foods they accept most readily. If your fish start to show signs of weight loss, you can always increase the frequency of offering that particular food until they regain healthy condition.
Final Thoughts
A nutritious diet is crucial for keeping your rainbow gobies in good condition and bringing out their most stunning coloration. Dietary variation is key, so make sure to keep an assortment of goby-friendly foods in stock.
Shop the fish food selection at Shrimpy Business to build a better diet for your gobies, with options ranging from floating flakes to slow-sinking pellets and wafers.