Re:live rock

Dear Karen:

I don’t know much about pipefish at all. Right now, no one is culturing them so all the pipes are wild caught and they seemed to be a little more delicate than seahorses, in general.

However, I like to keep the small Gulf Pipefish (Syngnathus sp.) from Florida in my dwarf seahorse tanks. The pipes add a lot of interest to the aquarium because their behavior is so different from the dwarves (Giwojna, 2005). For example, when they’re just trying to blend into their surroundings, the pipes orient themselves vertically, heads up and tails down, and sidle up alongside a fake gorgonian or a tall clump of sea cactus, imitating one of the branches. It’s not a bad bit of camouflage, and once in a while one of the seahorses perches on a pipefish by mistake and gets taken for a wild ride, like a bareback bronco rider at a rodeo.

But when they’re hunting, the pipes slip into the beds of Caulerpa horizontally, and launch themselves like torpedoes at passing prey (Giwojna, 2005). Unlike the seahorses, which prefer to wait for their prey to come to them, the pipes dart out from hiding and snatch up brine shrimp right and left. It’s amazing how much faster and more agile they are than the pigmy ponies. At feeding time, the pipes go blasting around the tank like little guided missiles. Fortunately, with just two pipefish in the tank, they can’t make a serious dent in the swarms of Artemia.

Like the seahorses, these pipefish are livebearers and give birth to independent babies that are miniature replicas of themselves, except that the newborn pipes are totally transparent (Giwojna, 2005). They look like glass splinters or tiny transparent threads. Although I never made a serious attempt to raise them, a number of them survived for several weeks when left to their own resources in the dwarf tank. They were very good at concealing themselves amid the macroalgae, and especially liked to take refuge amongst the "bristles" of my Merman’s Shaving Brushes. The dwarf seahorses have no interest in them whatsoever, but I strongly suspect the parent pipes are cannibals. All in all, Gulf pipefish are inexpensive and entertaining additions to my dwarf seahorse setups.

But if you like big pipefish, Karen, then the alligator pipefish (Syngnathoides biaculeatus) is probably your best bet. Many specimens I have seen were eaten 11 or 12 inches in length (28 cm to 30.5 cm).

As I have said many times, my favorite subtropical or warm-water seahorses are Mustangs and Sunbursts (Hippocampus erectus). Commonly known as the Lined Seahorse, Hippocampus erectus was the first seahorse to be commercially raised for the aquarium hobby. They have been captive-bred and raised for more generations than any other seahorse, and have now achieved a level of domestication that makes them better adapted to aquarium conditions and life in captivity than other seahorses. The Ocean Rider aquaculture facility in Hawaii that raises H. erectus selects them for traits such as adaptability, vigor, disease resistance, fast growth and aggressive feeding habits — traits that increase the fitness of each line over time (Abbott 2003). After numerous generations of strengthening and improvement, the current breeds of farm-raised erectus are tough as nails. Very hardy and very impressive, yet affordable, CB Mustangs are a great choice for a novice seahorse keeper who is still learning the ropes (Abbott 2003). They are very adaptable and have led the on-going trend toward keeping captive-bred seahorses only (Abbott 2003).

Mustangs are impressive animals. They are large, robust, deep-chested seahorses that can reach well in excess of 7 inches in length when fully grown. They tend to be cryptically colored, and often show earth tones such as beige, russet, charcoal black, gray, brown, ochre or olive over an underlying pattern of fine parallel lines that run down their necks and across their chest (Giwojna, Jun. 2002). White blazes, blotches, saddles, triangles, and diamonds are common markings for captive-bred erectus (Giwojna, Jun. 2002).

The lighter specimens that show their stripes boldly can be very striking, and they are apt to express a wide range of color phases as time passes, including everything from yellow to yellow-green, green, lavender, purple, maroon, magenta, pink, red, and orange from time to time (Giwojna, Jun. 2002). Like all seahorses, the coloration expressed by Lined seahorses can vary with their mood, environment, and social activities.

The first pair of captive-bred seahorses I ever owned were Mustangs, and my ‘stangs quickly learned to recognize me as their feeder, whereupon they would often interact with me at dinnertime by turning on their greeting colors. As I mentioned, I prefer to target feed (i.e., handfeed) my seahorses, which allows me to observe them closely on a daily basis, monitor their health, keep track of exactly how much each specimen is eating, and remove any leftovers immediately.

Led by the female-by far the bolder and most outgoing of the two-the Mustangs were soon literally eating right out of my hands. (I know, I know-sensible aquarists should always strive to keep their mitts out the aquarium as much as possible, but handfeeding is a thrill I find difficult to resist, and hey — nobody ever said I was sensible!) Of course, I’m very well aware of the risks involved and extremely diligent about taking all the necessary precautions beforehand.

As much as feeding time brightens up my day, I have no doubt it livens things up for my seahorses even more. They genuinely appear to enjoy interacting with me, and I believe in enriching their captive environment as much as possible. No doubt it’s the food they’re looking forward to, not the food giver, but our daily encounters are always eagerly awaited and they like to linger on my hand long after all the food is gone. They would allow me to lift them out of the water when I withdraw my hand if I didn’t gently shoo them away first. There’s a lot of puppy dog in your average seahorse and no doubt that’s a big part of their appeal, too. One almost expects to see them wagging their tails as they beg for handouts.

After I’d had them a week or so, my Mustangs were beating me to their feeding station whenever I approached their tank, betraying their eagerness and excitement by flashing through a series of bright color changes as soon as I opened the aquarium cover. Needless to say, I was delighted to find my Mustangs were such aggressive feeders. They have never had a health problem, and I’ve been equally pleased with the results of Piscine Energetics frozen Mysis enriched with Vibrance as a long-term diet.

The only thing I don’t like about this extremely nutritious diet is the obligatory fast day. The problem with fasting is that the Mustangs don’t seem to realize it’s good for them-that it’s absolutely in their own best interests, essential for their long-term health. Whenever I make an appearance on fast day, they insist on parading back and forth in front of the glass in their greeting colors, begging for a handout. Before my butt hits the upholstery, both of them will be dancing at the feeding station, impatiently awaiting their gourmet shrimp dinner. When it doesn’t materialize, they forlornly abandon their post at the lunch counter, and come up to stare at me through the front glass. When I still don’t take the hint, the female paces back and forth at the front, looking her brightest and most conspicuous, as though trying to attract my attention, while the male reverts to his drab everyday attire and dejectedly resumes his futile vigil at the feeding station. If not for their well-rounded cross-sections, one would think they were dying of hunger, making it difficult to resist their puppy-dog antics. Just sitting there ignoring them makes me feel like a first-class heel. Sheesh–talk about your guilt trips Dang! I hate fast days.

My favorite temperate or cold-water seahorses are the potbelly seahorses (Hippocampus abdominalis), by far. Big, beautiful, boldly marked, and fairly easy to rear, they have a great deal to offer the hobbyist.

These magnificent fish deserve the title of world’s biggest seahorse. With a maximum size of over 14 inches (35 cm), Hippocampus abdominalis vies with H. ingens and H. kelloggi as the longest of all hippocampines, but abdominalis if far more robust than either of these and is certainly the heaviest seahorse in the world. A foot-long female may have a chest that’s 2-1/2 inches deep and a good 3/4 of inch thick (Warland, pers. comm.).

The base coloration of the head and body ranges from a pale, off white to variable brown or purplish to mottled yellow and shades of orange (Lourie, Vincent & Hall 1999). The dorsal fin is typically mottled. Large, dark spots and blotches adorn the head and trunk, and the tail is usually marked with alternating light and dark bands. Males typically sport more dark blotches than females (Lourie, Vincent & Hall 1999) and flaunt their pale, overdeveloped pouches marked with a yellow slash at the top during courtship displays, which make the aroused males looked like they were decked out for a formal dance, complete with broad white cummerbunds and yellow sashes! Well-marked males have a distinctly giraffe-like pattern of spots.

There are a number of color phases, including a beautiful golden color form and an amazing red-and-white color morph. The rare specimens colored like candy canes are among the most spectacular seahorses I have ever seen.

Potbelly seahorses are often further adorned with extravagant cirri on their heads and necks. In some case, this attractive feature is so extravagant it resembles an Indian Warbonnet.
When courting, Potbellies rely on pouch displays (ballooning) rather than color changes to impress prospective mates. This is how David Warland describes their courtship displays: " the article spoke of how seahorses change color so as to attract a mate. Well not so with abdominalis, they (he) just puffs himself up like a muscle bound beach jerk. The understanding is that he puffs his belly up so his prospective mate sees what a beaut breeder he is, I suppose the same as we look at a woman with good child-bearing hips. . . . I have 28 breeders in two tanks. . I sit and watch them for what seems like forever, the boys blow themselves up till you are sure that they will burst and just prance around in front of the girls. It is quite comical as the boys will fight for the right to be closest to the female, it’s most unviolent, just a bit of push and shove and occasionally a big male will grab a smaller male and tow him away. The interesting thing is that, of all the females in the tank, all the effort is given to one female at a time, and only when one male gets that glint in his eye and starts blowing himself up and approaching a female does one or more of the other males see this and think I better get in on this in case he gets lucky and I don’t (Warland, pers. comm.)."

Hippocampus abdominalis is very different from most seahorses. For example, while other seahorses are feeble swimmers that seldom stray far from home, H. abdominalis is a strong swimmer that ventures far and wide. Most hippocampines are strict homebodies — real stick-in-the-muds that are tied to a relatively small home base. Hence researchers refer to them as "site-faithful," meaning that divers find them day after day within a few feet of the same place on the substrate, as demonstrated by tagging studies that followed individual seahorses for an entire breeding season. But not abdominalis; compared with its conservative cousins, Potbelly seahorses are footloose and fancy free — regular nomads that can stand up to a stiff current and often travel long distances every day (Warland, pers. comm.).

As a rule, seahorses are very cryptic animals that rely on camouflage and concealment for their safety. Not so Hippocampus abdominalis. This large, boldly-marked seahorse apparently feels little need to blend into its background, for it is often seen in settings in which it is quite conspicuous: settling over bare, muddy bottoms in estuaries or clinging to the netting on tuna traps in the middle of nowhere, for instance. Its sheer size may be enough to deter some enemies, and its armor-plated exoskeleton no doubt provides additional protection, making an adult abdominalis a rather unpalatable package that faces little risk of predation compared to most seahorses.

The polygamous mating system seen in abdominalis is unusual as well. Potbellied seahorses congregate in loose groups and males compete vigorously for ripe females, with the female selecting the lucky winner from among the rival males. Interestingly, in the aquarium, all of the males will compete for the same female at the same time, regardless of how many other females may be available at the time. It seems likely that the males are able to recognize a female that has prepared her eggs (pheromones?) from all the other females with unripened eggs, and thus choose to concentrate their attention on the one which is ready to mate at any given moment. Stimulated by the ensuing mass courtship, it will take the female only a few hours to fully hydrate her eggs — ample time to select a suitable mate from her stable of stallions. It is the female who calls the shots under this nonmonogamous mating system, and more likely than not, she will choose a different stallion the next time she mates.

For best results breeding these polygamous ponies, David Warland recommends maintaining a skewed sex ratio in favor of females. He feels a ratio of 1 male for every 2-3 females is about right, noting that Potbelly stallions can look after between 2 and 3 mares (Warland, pers. comm.). The reason for this is that the females make a greater relative contribution to their offspring than the male who incubates the young. Therefore, if you want Potbelly mares to remain healthy and continue to produce large clutches of eggs, David suggests that broodmares should be given a rest between matings.

Best of luck with your custom-made seahorse tank, Karen!

Happy Trails!
Pete Giwojna