That Fish Blog That Fish Blog is the source for aquarium advice, information and interaction with the experts at That Fish Place

GloFish are some of the most popular, colorful and controversial fish to enter the aquarium trade in a long time. Their easy care, small size, peaceful nature and neon bright colors make them appealing to aquarists of all ages, but the modifications that cause these bright colors cause some debate among aquarists, scientists and environmentalists alike.

The original “GloFish” were not created for the aquarium trade. They came from a popular fish used in many different fields of research, the Zebra Danio (Danio rerio). Zebra Danios have been used in research for environmental studies, cancer research, genetics, reproductive biology, neuroscience and applications to other fields as well. They even made the trip to space in 1975 on the Russian “Salyut 5” space station. So what makes them such good research subject? Zebra Danios are easy to breed and it only takes hours for the internal organs to develop after the eggs have been fertilized (about 24-36 hours, depending on temperatures and conditions). During this time, it is easy for researchers to monitor the development of the embryo since the “shell” around the eggs is a clear membrane. The eggs can hatch about 12-36 hours after that (again, depending on the conditions). These variable time frames also mean that, while the development is being studied, conditions can be adjusted to slow down or speed up the development, depending on what exactly the researchers are trying to determine. The genetic sequence involving the structure of the Zebra Danio’s DNA and RNA is very well-known at this point and is comparable enough to our own that, by understanding how changes in this structure affect the fish, researchers are gaining more understanding into how changes in our genetic structure can affect our own health.

Originally, GloFish were being developed for two major fields: cancer research and pollution detection. In the late 1990′s/early 2000′s, researchers thought to develop a fish that would change colors when a certain pollutant was found in their water. The thought was to develop a fish that would appear normal in “ideal” conditions but when a specific chemical or type of chemical was present in the water, a “trigger” would be set off to cause the fish to “glow” with a fluorescent protein in their bodies. As a step in this direction, they began to develop a fish that would always have this flourescent “glow” in a reproducible and hereditary way that wouldn’t affect the ecosystem around them. To do this, scientists turned to a fluorescent protein naturally found in jellyfish, corals and anemones rather than potentially harmful chemical dyes. Around the same time, similar projects were using a fluorescent protein to “mark” specific genes that were thought to be a cause or sign of cancer. By pairing the fluorescent protein with the cancer-related gene, researchers could see the fluorescence increase or decrease along with the other gene and see if an increase or decrease in that gene was related to the cancer. Since the genes (and cancers) in these fish behave in much the same was as they do within ourselves, researchers are using this to develop a way to track, diagnose and treat cancer in people. Read More »

Hello, Frank Indiviglio here.  In habits, appearance, and evolutionary history, the African Butterfly Fish, Pantodon buchholzi, is one of the most unusual of all aquarium species.  Yet despite having been in the trade for over 100 years, this “freshwater flying fish” (a misnomer, see below) gets little attention.  Captive breeding is challenging but possible, and its fantastic hunting behaviors are thrilling to observe.  I helped to set up an African Butterfly Fish exhibit at the Bronx Zoo, and was not at all surprised when it became a great favorite.  Most of the visitors I spoke with were astonished to learn that such an “exotic” creature, worthy of a large zoo exhibit, was available at many pet stores! 

Description

The yellowish-green to silvery-tan body is marked with an intricate pattern of speckles and lines.  The huge pectoral fins, reminiscent of those of marine flying fishes, lend an uncanny resemblance to a dead, floating leaf when viewed from above.  Long rays extending from the tail and the pelvic fin add to its remarkable camouflage.

Uploaded to Wikipedia Commons by Toniher

The African Butterfly Fish’s mouth is noticeably upturned, an adaptation for feeding on insects at and above the water’s surface.  Less noticeable is the mouth’s large size and the many teeth it bears; although it tops out at 5 ½ inches, this specialized predator can take quite sizable insects and fishes.

Utilizing its wing-like pectoral fins and unique musculature, the African Butterfly Fish can explode from the water’s surface to snatch low-flying dragonflies, moths and other insects, and to escape predators.  It does not, as far as we know, glide above the water as do marine Flying Fishes (please see photo). Read More »

Hello, Frank Indiviglio here. In 2001, I wrote a book about the Natural History and Care of Seahorses. As I intended, many readers were discouraged, due to the demands involved in their care and the fragile state of wild populations. Today, I am happy to report that captive-born individuals of several species are regularly available, and that the task of feeding them (a major stumbling block) has been greatly simplified.  Still, they are not ideal for every aquarist. Following are some important points to consider before you decide to keep these intriguing but challenging fishes. 

Seahorses Need a Wide Variety of Small, Live Foods

The world’s 130+ seahorse species (Family Syngnathidae) are strict live food specialists. Brine shrimp, the most easily-obtained seahorse food, is suitable as a steady diet for only one, the Dwarf Seahorse, Hippocampus zosterae (please see this article). Most others avidly consume brine shrimp, but will not survive long without amphipods (scuds, side-swimmers), sand hoppers, tiny shrimp, Mysids and similar marine creatures. Read More »

Hello, Frank Indiviglio here.  The world’s 30-35 freshwater sunfish species (Family Centrarchidae) range throughout Canada, the USA and Central America.  Although popular among European aquarists, sunfishes have been largely been neglected in American aquaculture. This is a shame, as all are colorful, interesting and active, and most adjust well to aquarium life. From the tiny Black-Banded Sunfish to the 39 inch long Largemouth Bass, there is something for everyone.  I’ve had the good fortune of working with a “sunnies” ranging from the tiny Black-Banded Sunfish to the massive Largemouth Bass, and would enjoy hearing from readers who have also come to know them, or wish to (please post below).

Obtaining Sunfishes

Although rarely offered in the pet trade, many species are easily collected via seine net or minnow trap (check state regulations).  While their diversity is greatest in the southeastern USA (my friend in Louisiana collected 8 species in the lake behind his house!), sunfishes can be found most everywhere in the USA. New York, where I reside, is home to 14 species. Read More »

Well, hello! It has been awhile since I’ve blogged, but some current acquisitions have inspired a new post. Recently, one of our fish distributors informed me he had some Hericthys bartoni available. So for our anniversary sale I ordered 20 of them to offer for sale. A couple days later I was staring 20 fish each between 1 inch to 1.5 inches in length. We acclimated them into a 40 breeder and waited until the sale weekend to offer them, once we knew they were eating well in the store. The weekend came and went quickly, but I’ve knew this was a species I had to grab for myself. I’ve always wanted to breed them, from first time I saw a picture of one, and we carried them a long time ago and were able to get them to breed at around 3 inches. So I netted 7 of the remaining stock and placed them in holding, til I make some room for them.

Let’s talk a little about this gem from Mexico. Bartoni is restricted to the springs of Rio Verde. Water conditions may vary from place to place with pH ranging from 7.6 – 8.0 with a stable hardness (100 degrees German and a carbonate of 15 degrees). A robust male Bartoni can reach lengths up to 8 inches, while females reach a little over 4 inches. Males also develop a nice little forehead hump.

Their normal coloration is gray to light brown with a row of black blotches running from behind the eye to the base of the caudal fin. Some scales in the lower half of the body have a blue spot. But the breeding coloration is outstanding, and it’s also one of the main reasons I want to keep this fish. In both sexes, the upper half of the body turns white while the lower half becomes velvety black, including the fins.

In the wild, Bartoni mainly dine on algae, but so far they have done well on frozen cyclops and flakes while in holding. I would make sure that they get a flake high in veggie matter.

Pairs tend to either spawn in caves or beside rocks. The size of the clutch dependes on how old the female is, with an adult producing as many as a couple hundred eggs each spawn. At 84 F the eggs hatch in about two and a half days. In another five days, the fry should start to become free swimming after they consume their egg sacs. The females does most of the brood tending inside the cave while the male guards the perimeter. At any sign of danger, instead of running away like most Central American cichlids he will enter the spawning cave and wait with his mate until the danger goes away. Both parents take care of the fry when it comes to feeding time.

Bartoni generally tend to be very aggressive towards conspecifics, and sometimes their aggression may extend to other species in aquariums smaller than a 50 gallons. 

It is believed in many circles that this species and others may become endangered in the near future, due to the introduction of a tilapia to their native waterways. What a shame that would be! If you have room for a 30 or a 40 gallon aquarium, this would be an awesome fish to add to your collection, and you can do your part to conserve them through captive breeding. 

Until next time,    

Jose