A Bright and Shiny Beauty: The Sunshine Pleco

Author: Alex Kantor

The aptly named sunshine pleco (Scobinancistrus aureatus) has been a favorite among aquarists for many years. This can be largely attributed to the beautiful color pattern the fish sports, which changes somewhat between the juvenile and adult stages, but stays quite attractive throughout the fish’s life.

The body pattern of juveniles is made up of large-ish yellow/orange spots, which can be irregular, coupled with orange fins. The orange caudal and dorsal fins are particularly impressive and eye-catching in young fish.

The body spots reduce in size and increase in number as the fish matures, and this pattern extends into the fins, which subsequently become less orange, generally speaking, as time goes by. The adult phase of this species is perhaps not as exquisitely colored as the juvenile, but it is still quite attractively colored.

Sunshine plecos are incredibly greedy eaters, making feeding unproblematic, and their general disposition is fairly outgoing once they have settled into the aquarium. Good looking, outgoing, and unfussy—sounds like the perfect pleco!

The Sunshine Pleco Tank

As with the vast majority of plecos, Scobinancistrus aureatus requires a good amount of cover in the aquarium in order to feel secure. Cover and hiding places can be provided through the use of driftwood, rocks, and purpose-built pleco caves. The more cover that is provided to these fish, the safer and more comfortable they will feel. 

A pleco that feels comfortable and safe in its surroundings will be far more likely to make a daytime appearance than one that does not feel secure. This is often counterintuitive to what a new keeper might otherwise assume: For the uninitiated, the notion that giving a fish more hiding places means that you will see it out and about more often can take a little bit of time to get your head around. 

Due to this species’ relatively large eventual size and robust build, care should be taken when aquascaping your aquarium, ensuring that heavy rocks or wood cannot become dislodged and topple, posing a potential hazard to your tank or its inhabitants. 

Substrate is a matter of visual preference, but as this species hails from the fast-flowing Xingu River, in order to emulate the sunshine pleco’s natural environment, even if it’s not absolutely crucial, a reasonable amount of flow should be provided. And in such conditions, it can often be difficult to keep fine substrate in place—you may get bare areas of glass within the aquarium due to the increased flow. This can be avoided by using a larger-grain substrate like gravel, or by placing wood or rocks in areas where the substrate has blown away and left exposed glass. Careful consideration given to the placement of powerheads, filter returns, and wavemakers should also help to remedy any such issues.

Tankmates

You will get the most out of this species (and most other pleco species) if it is the star of the show, rather than an afterthought to an already stocked aquarium. The sunshine pleco does best at the higher end of its temperature range, something that should be considered when selecting suitable tankmates. This fish does well with most suitably sized South American cichlids, and it is robust enough to be kept with all but the most aggressive Central American cichlids, temperature considerations aside.

However, again, if you want to get the most out of your sunshine pleco(s), you should stock the tank around the species’ habits and needs. An aquarium with a group of these fish with some schooling tankmates (tetras or something similar) to provide midwater movement would be an ideal situation. It should be noted that very small tetra species, and especially ornamental shrimp, can and will fall prey to this carnivorous pleco, so both should be avoided when selecting tankmates. 

Much has been said over the years regarding the use of dither fish in pleco aquariums and whether their addition has any positive influence on the behavior of these loricariids during the daytime. My experience, specifically with sunshine plecos, is that adding dither fish does encourage this species to be more active during daylight hours. My group of four adult sunshine plecos became noticeably more active when a group of schooling fish was added to their aquarium. If nothing else, you will be adding some eye-catching midwater movement to an aquarium that may have otherwise been devoid of it.

Feeding

Scobinancistrus aureatus is a carnivorous species that does best on a diet high in protein. A quality sinking cichlid pellet is usually a good starting point for a staple portion of this fish’s diet, as are pellets intended for carnivorous catfishes. I personally have used these pellets as the staple portion of my group of sunshine plecos’ diet for the last 12 months to excellent effect.

I supplement these pellet feedings with feedings of frozen foods twice a week, alternating between whitebait/silversides and prawns. I also do a supplementary feeding of zucchini once a week to add some roughage and greens to their diet. Zucchini can be substituted for almost any other popularly used vegetables fed to plecos, including squash, cucumber, pumpkin, etc. Use whatever vegetable your fish prefer.

Adding a vegetable feeding once a week gives their gut a break from a constant high protein diet and acts as a cleanse, which is evident by the speed at which this food type passes through their digestive systems. I tend to schedule water changes for the day after the vegetable feed so as to quickly remove any added waste that this feeding may produce. I can also confirm other reports that this species tends to first eat the skin of vegetables offered, a trait that sunshine plecos share with their wood-eating cousins of the genus Panaque. 

The timing of feedings can also be important, depending on your setup and tankmates. My group of fish only share their aquarium with a group of schooling dither fish and a handful of other plecos. My group is incredibly active during daylight hours and has relatively little competition for food that is added to the aquarium. As such, I generally feed my group during daylight hours, when I can enjoy watching them come out and Hoover up their offerings.

Alternatively, if your Scobinancistrus aureatus are not as active or have an increase in food competition, it is often wise to add some food to the aquarium just before lights-out or approximately an hour after the lights have been turned off in order to ensure that they are receiving enough food. 

I have kept a lot of different pleco species over the last 30 years and one thing in particular stands out with this species: their appetite. I have never seen a pleco as greedy as a well-settled sunshine pleco. These fish will eat to the point of concern if given the opportunity. They are the food-eating champions of the pleco world and are equipped with the jaw muscles and dentition to take on almost any food item. 

While they are not known to be wood eaters, my group of fish can often be seen rasping on the driftwood in their aquarium. Whether they are feeding on the biofilm present on the wood or not, I cannot be entirely certain, but it seems providing this opportunity for additional nutrition can only be a good thing.

Sexing and Breeding

 

Mature males will develop a more squarish, angular head when viewed from above in comparison to the females, which have a more pointed head. This difference in head shape is generally only evident in fully mature individuals, and it may not be as evident in subadult fish. 

Males will also develop a more bristled appearance on the leading spine of the pectoral fins, as well as a more whiskered appearance to the face. Females will only develop slightly in these areas. Males will also develop some odontode growth on the last third of the body toward the caudal. As with head shape, this is generally only a feature of mature fish and may not be as obvious in growing fish.

This odontode growth toward the back end of males may also appear as a shine on the fish in the early stages of development, and it is particularly easy to notice under natural sunlight. As with most plecos, females will also appear more round through the midsection when viewed from above.

This is not a commonly spawned species of pleco, with only a few documented reports available online. That can be attributed to a number of factors, including:

• Their relatively large adult size and the respective large aquarium requirements
• A group of adult fish can be cost-prohibitive to purchase, and growing out a group of young individuals can take some years to achieve a mature breeding size
• Relatively few genuine breeding attempts—most keepers will keep this species as a single specimen rather than as part of a larger colony 

While there have not been a huge number of breeding reports for this species (nor for the genus Scobinancistrus), I feel that this will change moving forward. Previously there were relatively few breeding reports for the cactus pleco genus Pseudacanthicus, but now fishes of that genus are spawned in large numbers globally, with many species being bred in captivity. This can largely be attributed to concerted efforts to breed those species rather than keeping single specimens for display. Knowledge sharing once the first few successful breeding attempts and fry raising have been accomplished also aids in the future captive reproduction of the species. 

While I have not been fortunate enough (or perhaps smart enough) to get a spawn out of my young group of adults to date, based on my own keeping notes, the few reports available, and speaking with other pleco breeders, the following would be a good starting point with this species:

Reduce Lighting and Leave Them Alone

Adult sunshine plecos hail from the deep waters of the Xingu, and this area of the river is dark. It may be best to replicate this lack of light for breeding purposes. And as most pleco breeders will tell you, one cardinal rule is don’t mess around with your fish too much when you are trying to breed them!

Constantly trying new things and continual tinkering is often counterproductive. How often have you heard that someone’s fish have finally spawned for them when they gave up? This probably coincided with the time that they stopped messing around with their fish. Keep your arms out of the tank as best you can, reduce foot traffic around the tank, and put away the flashlight. This could potentially be of even greater importance with a species like this that comes from a very dark home.

Ensure You Have Both Sexes

While this may seem like a “no-brainer,” as per the sexing section of this profile, some of the distinguishing sex features of this species may not be entirely obvious unless you are dealing with fully mature fish. Sexing juveniles and subadults may be problematic, especially to the untrained eye.

Buying large, mature fish can remedy this problem, as can starting with a larger group of young fish than you eventually would like in order to ensure that both sexes are present. There are few things more frustrating in this area than investing a huge amount of time and effort into a species only to later discover that you only have one sex, or a very poor sex ratio.

Provide Breeding Sites

A genuine breeding attempt is going to require a suitable spawning location. This is a large pleco species, so an average-sized pleco cave will not suffice. Instead, the keeper will either need to be more inventive (I have seen octopus pots used as pleco caves) or buy some caves from a specialist vendor.

Increase Water Flow

As with most things pleco-related, the link between flow and breeding success is hotly debated. I keep my group of sunshines in an aquarium with what would be considered a high flow. This is due to two separate factors: It replicates the fast-flowing waters of the Xingu, and since my aquarium is bare-bottomed, the high flow ensures any waste is kept in suspension, sucked into my overflows, and sent down into my sump where it is removed by the filter wool, helping to ensure pristine water quality

Let a Little Sunshine In

With its lovely spotted pattern, beautifully colored fins, general hardiness, and outgoing behaviors, the sunshine pleco is a wonderful fish for larger aquariums. Just give them a good amount of cover and hiding places, adequate water flow, and proper nutrition, and they will give you years of enjoyment. For those who can provide them the proper setup, Scobinancistrus aureatus may just be the perfect pleco.

Maybe it’s time to let a little sunshine into your aquarium!