News and New Research on Seahorses and Seadragons (Family Syngnathidae)

Seahorses have much to attract aquarists – armor plated and prehensile tailed, and with independently-moving eyes and wing-like fins, they can also change color as well as grow and discard filamentous appendages. And, of course, the males become “pregnant”.

My first contact with seahorses came in the mid 1960’s when my grandfather, long in awe of these unusual fishes, mail-ordered a group of dwarf seahorses, Hippocampus zosterae, from a dealer in Florida. The shipment included several males carrying eggs, and I was hooked – so much so that I wound up writing a book on seahorses.

Texas A&M researchers are now learning the male seahorse’s pouch is far more than a mere container for eggs, and are trying to discover just how such a unique organ managed to evolve. Tissue from within the pouch actually grows around the eggs and functions in a similar manner to a mammalian placenta. Through it the seahorse father is able to keep blood flowing around the eggs, and to provide them with oxygen and nutrition. Amazingly, he also makes minute adjustments to the salinity of the water within his pouch, gradually increasing it as the embryos’ needs change. By hatching time, the salinity of the pouch water matches precisely the salinity of the surrounding ocean.

The male seahorse fertilizes the eggs once they have been deposited into his pouch by the female. From that point on, the reproductive roles of the sexes are reversed. The researchers at Texas A&M are also looking into the effect this has had on mate selection and other aspects of seahorse reproductive behavior. In certain species of pipefish (close relatives of the seahorses) females have the bright coloration usually associated with male fishes, and they compete for access to the egg-incubating males. Seahorses are, as far as we know, monogamous. They form long-term pair bonds which are reinforced, in many species, with daily “greeting” rituals (the pair clasps tails, swims together, etc.), but much about how role-reversal has affected mate selection is unknown.

In other related news, the Georgia Aquarium has announced that one of its male weedy seadragons is carrying eggs, only the third time such has been recorded in a US aquarium. Weedy seadragons, and the larger and even more flamboyantly decorated leafy seadragons, are close relatives of the seahorses and pipefishes and also exhibit similar reproductive strategies.

You can read more about the Georgia Aquarium’s seadragon breeding program and see a seadragon video at:

Please also take a look at my seahorse book if you have a chance (see above) – I would greatly appreciate your feedback.

I’ll write more about keeping seahorses and their relatives in aquariums in the future. Until then, please forward your comments and questions.

Thanks, Frank.

Carnival fish part 2: The Betta

Crowntail Betta

The Betta fish, Betta splendens, is another commonly found “prize fish” that you may have the pleasure of become the new owners of. Bettas are one of the most beautiful freshwater fishes that are available in the aquarium hobby; their striking color and ornate finnage are quite remarkable.
Bettas are often chosen as prizes because of their ease of care, and ability to do well in very small amounts of water. The Betta is native to areas of Thailand, where they are exposed to times extreme rainfall and drought, which during times of drought can result in little more than a puddle to live in. Unlike most fish, the Betta does not solely rely on oxygen from the water it resides in, it has the ability to breathe air. Bettas are members of a group of fishes called Labyrinth fishes. Labyrinth fishes have a specialized breathing organ, called the labyrinth, which allows them to breathe air at the waters surface, somewhat like a primitive lung. The ability to breathe air allows the Betta to survive in very warm water with little or no dissolved oxygen. This is how Bettas are able to cope with very small fish bowls, and is often how they are displayed and sold.
PLEASE do not use this as an excuse to keep a Betta in extremely small environments for extended periods: although they can survive in only a few ounces of water, they will not be happy and comfortable.
Bettas can be kept in unfiltered bowls, provided adequate water changes are maintained (at least 20% per week), and water quality is monitored. Larger aquariums of at least several gallons are preferred, the bigger the better. There are a number of small desktop aquariums that are ideal for Betta keeping.
There is another side of the Betta fishes heritage that there is much controversy surrounding. Another common name for the Betta, is the fighting fish, or Siamese fighting fish. This name comes from the aggressive nature that these fish have towards one another, especially two males. The Thai name for these fish is”pla-kat”, which means biting and tearing fish. When placed in the same tank, two male Betta fish will literally fight to the death. There is a whole world of fighting and gambling involving the Betta in other cultures. Fighting Bettas is not considered an appropriate practice in the hobby.
There are many commercially produced Betta foods, in pellet, flake and freeze dried forms. A good varied diet is best. Feed only as much as the fish will eat in a few minutes, take extra care not to overfeed, especially in unfiltered bowls. Bettas prefer warm water, 72-78 degrees, so avoid cool areas like window sills, and hallways when possible. Direct sunlight should also be avoided; this will lead to unwanted algae growth, and temperature fluctuations during the day. While you can not keep bettas together, they can be kept in peaceful community tanks, with other types of fish.
If you have any futher questions about bettas or other carnival fish, post them and I’ll be sure to answer.
Until next time,

Fish for the Cold Water Aquarium – the Oriental Weatherfish, Misgurnus anguillicaudatus & European Weatherfish Part II

Please welcome back Frank Indiviglio with a continuation of his earlier article on weatherfish
Care in Captivity

Space and Other Physical Requirements
Although they adapt fairly well to smaller aquariums, weatherfishes are large and active, and adults should be given a tank of 20 gallons or more. They are also ideally suited to outdoor ponds and are finding increasing favor among koi and goldfish keepers. The aquarium’s lid and any spaces around filter intake tubes must be secured tightly, as these alert fellows are accomplished escape artists.

In the wild, weatherfishes spend a good deal of time buried in the substrate, with just their heads protruding. In contrast to most other burrowing fish, they become quite bold in the aquarium and quickly abandon their secretive ways. Still, a soft substrate is appreciated, and it is quite amusing to see them burst forth from the sand when they detect food. I suggest Aqua Terra sand. If you do use gravel, be sure it is a smooth variety, such as walnut gravel, so that the delicate skin will not be damaged.

Always hungry, weatherfishes spend a good deal of time foraging – and in doing so are likely to uproot growing plants. However, well-rooted aquarium plants should be included in the aquarium when possible, as the fish seem to favor resting among plant leaves and stems.

Although weatherfishes get along quite handily without much aeration, their tank should be have a good aquarium filter as these ravenous feeders produce a good deal of waste.

Temperature and Other Water Parameters
The European species is adapted to cool and cold climates, and does best if water temperatures are kept below 75F. Oriental weatherfishes are far more adaptable, and inhabit areas where the water temperatures range from 36 -86F. They become inactive when temperatures dip below 50F or so, and are best kept at 66-75F.

Weatherfishes are undemanding as regards pH and water hardness, but do best at a pH of 7 or slightly below and in soft water.

Weatherfish do a fine job of consuming food missed by tank-mates. Armed with sensory barbels, they miss little and will even root below gravel and rocks for food trapped there. However, they have quite large appetites and should by no means be expected to get by on leftovers.

Both species do best when offered a variety of foods. Although primarily carnivorous, weatherfishes should also be given food preparations that contain some plant material, such as flake fish food and Tetra tablets. A variety of freeze dried fish food, such as bloodworms and krill, should also be offered.

Free-living weatherfishes feed largely upon insects and other invertebrates, and captives do best when given ample live food. They particularly favor crushed crickets, blackworms, brine shrimp and small earthworms, and will take bits of fish and wild-caught insects as well. I have kept a number of individuals of both species for decades (see below) and attribute some of my success to a diet high in a variety of live foods.

Social Grouping/Compatible Species
Weatherfishes seem quite social by nature, and often rest in physical contact with others of their kind. You may even see them “exploring” one another with their barbels. They are sturdy enough to be kept with fairly large fish, and do not bother smaller animals (however, they will consume fish eggs and, possibly, fry). I have successfully kept them with fairly aggressive animals such as American eels and African clawed frogs without incident.

Captive Longevity
An Oriental weatherfish in my collection lived for 21 years. Longevities of 10-15 years are regularly reported.

Breeding can be induced in both species by gradually lowering the water temperature to 60-65F while simultaneously dropping the water level to ½ the usual level and shortening the light cycle to 8 hours. After 2-4 weeks (longer periods may be required by fish from certain populations), water of approximately 10F warmer than ambient should be added to raise the water level back to normal. The temperature should be maintained at 72-75F and the light cycle increased to 14 hours.

The greenish eggs are attached to plants and the substrate following a “mating dance” of sorts. The males, distinguishable by their slightly larger and triangularly shaped pectoral fins, fertilize the eggs externally. It is best to remove the eggs (or adults) for hatching, which occurs in 3-5 days. The fry readily accept Daphnia, newly hatched brine shrimp prod, chopped blackworms and other live foods, and there are reports that they will take flake fish food and finely chopped frozen bloodworms as well.

Weatherfishes are exceptionally responsive to food and take readily to hand feeding – they will even wiggle onto a palm held partially out of water for a favored treat. To encourage hand feeding, try using freeze-dried or fresh prawn.

As mentioned in Part I of this article, I have encountered Oriental weatherfishes of 12-13 inches in food markets in two of NYC’s Chinese communities. The fish I found were in poor shape, but you may wish to keep an eye out for others in food markets – those I saw were much larger than pet trade animals, and would have made spectacular additions to any collection.

Please be aware that weatherfishes, like eels, catfishes and other scale-less species, are sensitive to many fish medications. Be sure to read the label carefully, or write in to this blog for more information.

I look forward to hearing about your experiences with weatherfishes, and to addressing any questions you might have. Thanks. Until next time, Frank.

Further information about weatherfishes is available at:

Thanks Frank
Until Next Time,

Red Sea Test Kits On Sale at

Steven Pro

Please welcome back aquarium expert Steven Pro to tell you about the Red Sea test kits now on sale at That Fish Place.
When I was originally approached to write a blog entry for test kits, I was somewhat at a loss. What do I say about test kits? A test kit is a test kit, right? You put water into a vial, follow the directions, add some drops, and read the results. Well, not all test kits are created equal. There are some important differences when one sits down and evaluates them all.

First of all, Red Sea makes a kit for almost anything a hobbyist could desire to test for. They have test for standards such as ammonia, nitrite, and nitrate, to reef kits such as pH, alkalinity, calcium, magnesium, and phosphate, to ones for more obscure parameters like silica, dissolved oxygen, and residual ozone. Red Sea also makes a full range of test kits for freshwater, as well, including important tests for freshwater planted aquariums like carbon dioxide, iron, and both general hardness and carbonate hardness. To do them all justice would take pages and pages, but I want to point out a few test kits and their particulars that might not be as well known or recognized yet.

I have written and given presentations on marine fish diseases extensively. Inevitably the use of copper comes up. One drawback to using copper is certain test kits only accurately report the values of certain formulations of copper, so one must take special care to properly match the test kit with the medication being used. Red Sea eliminates that confusion by packaging both the copper test kit and the medication in one box for ready-made use. This falls in line with Red Sea’s motto of “making it easy”. By the way, the copper medication (Paracure) is also available individually for those that require additional copper for dosing larger tanks or for repeated usage.

Most titration style test kits, such as those for calcium, usually tell the hobbyist to watch for a color change from pink to blue. But, Red Sea goes a step further by including a color chart with their titration test kits which demonstrates both the starting and ending colors so the user does not have to guess which shade of blue is the proper end point of the titration.

With the color matching style of test kits, those in which the hobbyist must match the color of the reagent in the vial to a color bar, Red Sea has gone to great lengths to make their tests have very distinct color changes. Some other brands of test kits I have used have color bars that change from yellow, to darker yellow, to still darker yellow, to yellowish-green, to green with a hint of yellow. Very much ever changing shades of grey which make accessing parameter values somewhat difficult. Red Sea’s tests have very dramatic color changes which provide easy to interpret results.

Thanks Steven,
Until next time,

New Aiptasia-X from Red Sea

Steven Pro

I’m pleased to welcome Steven Pro: Aquarium hobbyist and coral propagation expert, to That Fish Blog. Steven is here to review the new Aiptasia-X product just put out by Red Sea.

I have tried most every method of eliminating pest anemones such as Aiptasia and the so-called Anemonia majano over the years and really did not have a favorite. There are some techniques that I don’t like and won’t use, but there are several methods that work ok. Although, none of these methods really stood out over the others. That is until now. I love this stuff! I have been using Red Sea’s Aiptasia-X all over the Northeast US for about a month now leaving a trail of dead pest anemones in my wake. You can practically hear the Aiptasia shriek in horror when they see me enter their store to demo Aiptasia-X. Ok, not really, but it is a fabulous product!

Red Sea’s Aiptasia-X has a number of attributes which distinguishes it from the competition. It comes in a large 60 milliliter bottle, enough to treat even they largest, most infected displays. You also get the syringe and two stainless-steel applicators included in the package. This makes it a very good value for the price since you have a large supply of the liquid and you don’t have to buy all these items separately.

And that is not all that is different. The product itself is very different from others in that it is non-caustic. The pest anemones don’t retract into a small hole in the liverock when exposed to Aiptasia-X. In fact, in most instances the anemones actually feed upon the Aiptasia-X liquid. Ingesting the Aiptasia-X exposes any planulae (baby anemones inside the parent polyp) to the product killing them as well.

You will also notice that the Aiptasia-X liquid is very sticky. This minimizes the chances of it being blown all around the aquarium. Because it is so sticky, it tends to stay on the target animal. But, even if a little blows away, don’t worry. It is completely safe to the rest of the display inhabitants.
When applying Aiptasia-X, you don’t have to inject the pest. You merely gently squirt the liquid near the mouth of the polyp of the Aiptasia. It sticks to the mouth, the tentacles enclose the liquid, the product gets eaten, and after about fifteen seconds or so, splat, the target anemone is dead and starts to disintegrate. It is as simple as that. They do twitch for a little while in their death throws. I have found it helps to have an evil laugh as they are dying. Ok, again, not really, but it might help your mental outlook if you have suffered any coral losses to these pest anemones.

Click below to see Aiptasia-X in action!
Thanks Steven, sounds like a cool product. And for a limited time, Aiptasia-X is 20% off at That Fish Place. Now’s your chance to give it a shot.

Until next time,