In 2011, I was working at a LFS and caring for a breeding trio of Gobiesox punctulatus. When they laid eggs and those eggs hatched, I took home the larvae to attempt to raise this species for the first time in captivity (Matt Wittenrich first raised the similar Gobiesox strumosus some years prior). CORAL magazine published my article in their
March/April 2012 issue.
I've learned a lot in the last 7 years since attempting to raise this species, and I would do things differently today. Although I didn't have large numbers of fry make it to adulthood, Sustainable Aquatics saw how easy it was to raise these fish and produced them commercially. They make lovely pets, and will often
learn to eat food from the aquarist's hand.
We are not Plecos!
Captive breeding of Gobiesox punctulatus
When customers first come upon the
Stippled Clingfish, Gobiesox punctulatus, at the fish store where I work, they almost always ask: "Is it like a Pleco? Does it eat algae?"
“No,” I tell them. “They are carnivores.”
The response is usually, "Oh, nevermind."
Of course, that response represents the dashed hopes of a hobbyist who momentarily thought the little brown fish might be the solution to the all-too-common algae woes of a modern reef aquarist. These aquarists must already be familiar with the group of suckermouth catfish belonging to the genus
Plecostomus as well as many related genera, all collectively known as “Plecos” in the freshwater aquarium vernacular.
While Plecos are often marketed as algae consumers, many Plecostomus are no better at algae control than the Stippled Clingfish would be in a marine tank, but Plecos still have a strong fanbase. If the Stippled Clingfish isn’t going to mow down your hair algae, and it’s going to be what many potential owners might consider rather “ugly”, why even bother to keep this fish at all?
This curious relative of the goby is truly an oddball, but it has earned a special place in my heart, being part of the small percentage of saltwater species that can currently be spawned and raised in captivity. This flat fish with a bullet-shaped head resembles a tiny, 2-1/2” skillet. In the wild Gobiesox punctulatus lives in the Western Atlantic from Florida to Northern South America. They prefer tidal zones where the current and wave action is strong. Similar to their cousins the gobies, they have modified pectoral fins that form a suction cup. With this they are able to suction themselves to rocks and leaves of plants to prevent being swept away in the current. Should they find themselves out of water when the tide withdraws, They can survive by breathing water stored in their suction cup. Their main diet is small, demersal crustaceans like amphipods and isopods, but they are also known to eat worms, crabs, and small shrimps. They also have the ability to gracefully snatch floating zooplankton from the water column before returning to the substrate.
In the home aquarium clingfish seem to be on the semi-aggressive side of peaceful.They reside peacefully with the host of other aquatic life in my setup, including a fairy wrasse, filefish, tilefish, curious wormfish, and countless small gobies, but appear to be territorial with the other clingfish. As their name suggests, they spend all of their time clinging to surfaces and rocks in the aquarium, endearingly wagging their white-edged, paddle-shaped tails. But during feeding time, they are quick to abandon their cling post and dart around the tank wildly, swimming after their favorite food - thawed frozen mysis shrimp.
The three clingfish in my aquarium are a little unique, being captive-bred rather than wild-caught, the product of a fishy love story which, of all days, started on Valentine’s Day 2011.
Gobiesox punctulatus: A love story
The store where I work (
The Hidden Reef, located in Levittown, PA) was housing a trio of clingfish in a 29-gallon tank for about a month when they decided to spawn during the night/early morning. The male spawned with the larger female first on February 14th, 2011, and then guarded the approximately 150 eggs on his own, constantly fanning and watching over them. Just two days later, the other female laid a smaller clutch of eggs just under the first clutch. It was decided that I would be in charge of raising the baby clingfish because of my previous experience with seahorse and clownfish breeding (and I was already equipped with all the necessary fry-raising foods and gadgets).
It was interesting to watch the development of the clingfish embryos inside the clear eggs. Not long before hatching, they started developing black pigment. It took eleven days for the first clutch of eggs to hatch during the night or early morning. I should note that the store is not completely dark at night; there is always a dim fluorescent sign lit, but it didn’t seem to affect the clingfish hatching. The trio of adult clingfish sold on the fifth day after the eggs were laid (a hazard of the job when you work in a fish store), which led me to worry about the future of the eggs. Having seen clownfish egg masses being artificially incubated with an air stone in the past, I added one to the tank to gently create current over the egg masses, simulating the way the father would fan water over the eggs. Since the father was gone, I removed the hang-on-the-back filter at this point so the newly hatched larvae would not be destroyed.
Mama I’m Coming Home
On February 25th, eleven days after the eggs were spawned, over a hundred delicate,
Pelagic clingfish larvae the size and shape of mosquito larvae were darting about the tank. I carefully collected the clingfish with a specimen container and transported them home. Their new home was to be my trusty set of empty salt buckets on a metal baking rack that I’d used to raise my seahorses last year. Filtration was a small air driven sponge filter, and 75 percent water changes were made daily. Lighting was provided by a small LED light that I left on 24 hours a day to allow more opportunity for the clingfish to eat.
I noticed that the clingfish larvae were running into the walls of their tank, and my initial reaction was that they were eating copepods off the walls. Dr. Matthew L. Wittenrich, an expert marine fish breeder, informed me that it was common for pelagic larvae to run headfirst into the walls and “gulp” or “gasp,” as pelagic creatures are not accustomed to encountering obstructions. He recommended adding “greenwater” (phytoplankton) to the rearing vessel. I remembered from previously working with clownfish that dosing “greenwater” into the rearing vessel could help prevent the larvae from bumping into things. It can also help the larvae see their food, make the Artemiamore nutritious by being gut-loaded with the phytoplankton, and in the case of live phytoplankton, can reduce ammonia.
The first foods consumed by the larval clingfish were a very small amount of rotifers and newly-hatched decapsulated Artemia. My rotifer culture crashed the same day I brought the clingfish home, so I had to quickly decide what other foods might work. Luckily I keep cultures of Tigriopus copepods on my windowsill and had enough that I could supplement the clingfish larvae diet with those. However, the bulk of their diet would have to be twice daily feedings of newly hatched Artemia. (I buy the convenient, already decapsulated bottled Artemiafrom SeahorseSource.com) I was concerned that the larvae would not be able to eat the Artemia, but on day four of the life of the larvae I photographed one of the larvae with my 10x magnified macro diopter, and could clearly see the orange Artemia in its gut. When I was certain they could consume two day old Artemia (around day seven post hatch), I began enriching the Artemia with Selco from Brineshrimpdirect.com and Dan’s Feed with Beta Glucan. Both are types of highly unsaturated fatty acid (HUFA) enrichments, which is required by most marine species for nutrition and proper development, especially during the larval stage.
At two weeks of life, it was clear that the smallest, weakest clingfish hadn’t gotten enough nutrition; many had died, and there was a major difference in growth and development between the largest and smallest siblings.
Settling In
Settlement day was highly anticipated, especially with one big mystery to solve: I was still unsure if the clingfish were Gobiesox strumosus or G. punctulatus.
According to Wittenrich, who had raised G. strumosus and G. punctulatus, the date of settlement would help us determine the species, since G. strumosus takes 16-18 days to metamorphose, while G. punctulatus takes 20-25 days. Day 16 passed. Day 18 passed. Still the larvae had not settled. On Day 23, all the fins including the individual pelvic fins that would eventually fuse to form a suction cup were clearly visible, but still the larvae had not settled. It wasn’t until Day 25 that I woke up to find the largest of the clingfish suctioned to the bottom of the bucket.
The newly settled clingfish was flat, unlike its smaller, bullet-shaped siblings. The transformation literally happened overnight. At this point I increased the amount of Tigriopus copepods, trying to encourage the rest to grow and settle. A quick word of caution to anyone attempting to raise clingfish - be careful when doing water changes, as these fish are very “sticky”! I nearly lost the first clingfish to settle when I dumped the water out of the bucket to switch them to a clean bucket. I didn’t notice that it was still clinging to the inside of the bucket until about 30 seconds after it had already been completely out of water. I could’ve lost it down the drain!
It took more than a week for the smaller, weaker siblings to settle. There were only eight clingfish of extremely varying sizes left by Day 38. As soon as all the clingfish settled, I decided it was time to start training them to frozen foods. I began feeding frozen CYCLOP-EEZE® in addition to the live enriched Artemia, since I’d had so much success training seahorse fry to eat CYCLOP-EEZE®. After adding frozen food to the juvenile clingfish’s diet, their growth rate skyrocketed. By Day 46, they were all big enough to eat frozen mysis shrimp, which started another growth spurt. Their behavior and appearance was now exactly like the adult clingfish. At this point the largest clingfish started harassing its next largest sibling. It would have been wise to separate the clingfish into their own tanks, and I regret not doing that now. I ended up with only three clingfish 60 days post-settlement; I believe this was due partly to insufficient nutrition during the first week of life and aggression between siblings after settlement.
On June 3rd, less than 3 ½ months after hatching, the clingfish were nearly full grown at two inches and eating mysis shrimp. I decided it was time to move them into my main display aquarium with all my other fishes. Within a few days each of the three had set up their own territory within the tank - one in the front left corner, one in the middle of the back, and one in the front right corner. Now over 6 months after hatching, they ignore each other even during feeding time, but I’m hoping this is a trio of one male and two females so I can spawn and raise them again, this time with a higher survival rate.
Raising Gobiesox punctulatus was a fantastic journey of discovery, one that I might have missed out on had I, like many aquarists, dismissed this fish...which is most certainly not a Pleco. ----
References
http://www.montereybayaquarium.org/animals/AnimalDetails.aspx?enc=n3f4wmcSJaPX3odIshZgyg==
http://www.marinebreeder.org/forums/viewtopic.php?f=141&t=9182
http://www.mbisite.org/Forums/tm.aspx?&m=50975&mpage=1http://www.fishbase.org/Summary/speciesSummary.php?ID=3077&genusname=Gobiesox&speciesname=punctulatushttp://www.fishbase.org/Summary/speciesSummary.php?ID=3079&genusname=Gobiesox&speciesname=strumosus ----
