That Fish Blog – Aquarium Advice and Information

Hello, Frank Indiviglio here.  Seahorse husbandry has advanced quite a bit in recent years, with several species having now been bred in captivity.  One stumbling block, however, is the near impossibility of keeping Seahorses with other marine creatures.  Seahorses are slow, methodical hunters, and the live foods they require are also favored by other fishes.  In typical community aquariums, food is gobbled up by other species before the Seahorses even know its feeding time.  But there are some options…following are a few creatures that I’ve experimented with over the years.

Pipefishes

Pipefishes are classified with Seahorses in the order Syngnathiformes, and are also confirmed live-food specialists that hunt in a similarly slow manner.  They are the best choice as Seahorse companions –all those I’ve kept have gotten along very well with Seahorses.

The Banded Pipefish, Doryrhamphus dactyliophorus, strikingly marked in red and yellow, makes a spectacular tank mate for tropical Seahorses. Read More »

Hello, Frank Indiviglio here.  Seahorse identification is a tricky prospect, as most species can change color, and many even periodically grow and discard fleshy appendages known as cirri.  However, the husbandry needs of each species varies, so a proper ID is critical.  Fortunately, the Big-Bellied or Pot-Bellied Seahorse (Hippocampus abdominalis) is very distinct in appearance.

Description

At 12.5 inches in length, the Big-Bellied Seahorse is one of the largest (perhaps the largest) of the world’s 120+ seahorse species.  The body is noticeably deeper than that of other seahorses.  Males possess a huge brood pouch, which is usually white in color and bordered with yellow at the top.  Other distinguishing features are the number of dorsal fin rays (26-29), trunk rings (12-13) and tail rings (45-48), all of which exceed those of most other species. Read More »

Hello, Frank Indiviglio here. The biggest stumbling block in keeping the fascinating seahorses, pipefishes and seadragons (Family Syngnathidae) is providing them with a balanced diet – all are confirmed live-food specialists, and need a variety of prey items if they are to thrive.  However, once past that hurdle we are sometimes faced with a dilemma unique to these fishes – a buildup of gas in the male’s pouch.

Pouch Malady

Seahorse and their relatives are well known for their unusual reproductive strategy.  Females deposit eggs in the male’s special brood-pouch, where they develop and hatch.  Male seahorses have even been shown to adjust the salinity of the water in the pouch to meet the special needs of the incubating eggs.

For reasons not fully understood, gas sometimes accumulates in the pouches of male seahorses and related fishes.  Animals so afflicted float head down at the surface and soon expire. Read More »

Please welcome back Frank Indiviglio with another excellent article.

Introduction – A Most Captivating Fish
Seahorses, armor-plated and prehensile-tailed, and equipped with independently-moving eyes and fins that flutter like wings, seem to stretch the limit of what might conceivably be called “a fish”.  Add to this the phenomenon of “male pregnancy” (the male incubates the eggs in a pouch and adjusts the salinity of the water therein as needed; please see my article posted on this blog on June 27, 2008 for more details) and the fact that seahorses change color and can grow and discard filamentous appendages, and you can easily see why they have long attracted marine aquarists.  All of the nearly 130 species (Family Syngnathidae) are, however, strict live food specialists, and rarely thrive on the brine shrimp-based diet commonly offered to them in captivity.

The two species highlighted in this article (Please see Part I, The Atlantic Seahorse, published last week) were chosen because, of all, they are the most likely to do well on diets that are within the means of most aquarists.  Please do not be tempted to try other species until you are well-experienced with the following animals.  I will focus here on points unique to seahorse husbandry – water quality and filtration should be managed as for other marine fishes (please see related articles posted on this blog).
Dwarf Seahorse, Hippocampus zosterae

Description and Habitat
“Seapony” might be a more appropriate name for this diminutive creature, which, at an adult length of 0.9 inches, is only slightly larger than the smallest known species, Denise’s pygmy seahorse (please see below).  Ranging from Florida to the Bahamas, the dwarf seahorse may be white, yellow, green or black in color.  It dwells in sea grass beds, so much so that the species name, “zosterae”, is drawn from that of the plant with which it is most often associated.  Northern populations were formerly considered to be a separate species, H. regulus.

An Ideal “First Seahorse”
In sharp contrast to larger fishes, dwarf seahorses offer us the opportunity to observe nearly all of their natural behaviors in captivity.  Due to their small size, they adjust readily to the confines of aquarium life.  Three pairs in a 15 gallon tank will reward you with a display of activities not often observed among captive seahorses of other species.   As a consequence, their captive husbandry is well understood, and many specimens in the trade are commercially produced.  This is an important consideration at a time when many seahorse species are in sharp decline (please see below).

Interest in this charming creature peaked here in the 1960’s and early 70’s, when they were advertised for sale in the backs of magazines.  My grandfather, who kept marine fishes even before that time, so aroused my interest in them that I eventually wrote a book on the care and natural history of seahorses  (please see below).

The Key to Feeding Dwarf Seahorses
Dwarf seahorses are one of the only seahorse species that will thrive on a diet consisting solely of enriched brine shrimp.  They will, however, appreciate an occasional meal of tiny, wild caught invertebrates – thin meshed “plankton nets,” (available from biological supply houses) drawn through shallow marine waters will yield a wealth of valuable food items.  “Enriched” brine shrimp are those that have been allowed to feed for a few days before themselves being given to the seahorses.  This process increases the shrimps’ nutritional value, and is indispensable if one is to succeed in keeping dwarf seahorses.  Therefore, brine shrimp intended as seahorse food should be given Brightwell Aquatic’s Phyto-Green, or a similar product, for several days.

Breeding and Other Considerations
In common with all their relatives, dwarf seahorses require calm water and suitable “hitching posts” upon which to wrap their tails.  There is some evidence that wild seahorses consistently utilize the same hitching sites, so their aquarium’s décor should not be re-arranged once they have been introduced.  Captive reproduction is a definite possibility – the tiny young can take only newly-hatched brine shrimp, so be sure to set up a brine shrimp hatchery  in advance.

Tiny, Newly Discovered Specialists
The Pygmy Seahorse, Hippocampus bargibanti, first described in 1970, seems to live on only 2 species of gorgonians (soft corals) of the genus Muricella.  So closely does it resemble the coral’s polyps that the individual which led to the first description of the species was not discovered until it was seen on a coral that had been placed in an aquarium several days earlier!  At 0.8 inches in length, it was the smallest known species until the discovery, in 2003, of Indonesia’s Denise’s pygmy seahorse.  Adults of this minute creature are a mere 0.6 inches long.

As mentioned, I became so enamored of these unique fishes that I wrote a book on their care and natural history – if you have a chance to read it, please forward your thoughts and suggestions to me.   Until then, please write in with your questions and comments.  Thanks, until next time, Frank.

Project Seahorse is the world’s premier seahorse conservation and research organization.  A wealth of information is available at their web site:
http://seahorse.fisheries.ubc.ca/who.html

Thanks for the great article Frank,

Until Next Time,

Dave

Introduction
Today I would like to discuss a large, temperate water seahorse that can be kept and even bred in captivity by those willing to devote the necessary time and effort to its care.

Note: Please see my article posted on this blog on June 27, 2008 for information concerning new research into the phenomenon of “male pregnancy” in seahorses.

A Temperate Seahorse
Most people consider seahorses to be tropical in origin, and may be surprised to learn that the Atlantic seahorse ranges as far north as Nova Scotia, the waters of which are decidedly “un-tropical”.  It also occurs south to Venezuela, and it is the only seahorse to dwell north of North Carolina along our eastern seaboard.

Found from the shoreline to depths of over 230 feet, this weak swimmer somehow manages to survive in areas of strong tidal activity.  I have collected Atlantic seahorses attached to clumps of marine algae being swept along by very strong currents.  Mated pairs are believed to establish stable territories, but I cannot imagine how they can accomplish this in the turbulent waters they sometimes inhabit.  I imagine that individuals in such populations move to quiet bays during the breeding season – any information you might have concerning this would be most appreciated.

Feeding Atlantic Seahorses
The Atlantic seahorse’s rather large size, to 7.3 inches, allows it to take a wide variety of prey, including small shrimps, blackworms and fish fry. This, coupled with the fact that many individuals can be tempted to eat frozen foods moved about in a life-like manner, makes the Atlantic seahorse a good (but still delicate) candidate for experienced aquarists.

In addition to the foods mentioned above, Atlantic seahorses that I have kept were extremely fond of amphipods (scuds or side-swimmers), sand hoppers, seed shrimp and sand shrimp that I seined in local marine waters.  Their reactions to these food items were quite intense, much more so than to the fish fry, brine shrimp and opossum shrimp (Mysids) that made up the bulk of their diet.

I urge anyone attempting to keep seahorses to collect live foods whenever possible.  It is especially advantageous to maintain native species, as you have a better chance of providing these with a balanced diet based on natural, wild-caught prey (an extremely important consideration when keeping delicate live-food specialists).

Several specimens under my care also accepted frozen clams, shrimp and scallops.  This requires a conditioning period, and is best accomplished with young animals or long-term captives.  Frozen food is initially mixed in with live food, and kept in motion via the filter outflow (or, for the really dedicated, water squirted from a turkey baster).  You may also wish to experiment with freeze dried krill and similar foods.

Black mollies breed readily, and few pairs should be maintained as a food source for Atlantic seahorses.  Their fry, which will survive the transition to salt water if slowly acclimated, are usually readily consumed by the seahorses.

Other fresh-water food animals worth trying include fairy shrimp, bloodworms (midge larvae, Chironomus spp.), blackworms, micro-worms, grindal worms and white worms.  Please bear in mind that these animals expire and decompose rapidly in salt water, and that they do not likely provide complete nutrition in and of themselves.

Seahorse Companions
This species presents a limited exception to the general rule that seahorses should not be housed with other creatures.  Actively swimming fishes should be avoided, as they will out-compete the seahorses for food.  However, Atlantic seahorses will get along well with northern pipefish (these may be seined from eel grass beds where legal), hermit crabs, sea stars, small spider and horseshoe crabs and fifteen-spined sticklebacks, Spinachia spinachia (these last feed fairly slowly, but watch the seahorses’ intake carefully).

A quite interesting community tank can be built around the Atlantic seahorse and some of the creatures that share its habitat.  As these are generally over-looked by aquarists, the potential to learn something new is very great.  I would be most pleased if you shared your observations with me.

Other Considerations
Hailing as they do from temperate waters, Atlantic seahorses from northern populations should be kept in unheated aquariums.  Breeding (which I’ll cover in depth in the future) will be more likely if they are provided with natural fluctuations in day length and temperature.  This can be accomplished by situating their aquarium near a window (beware of over-heating during the summer) or by installing a light timer to regulate day length.  Atlantic seahorses may give birth to over 300 young.

Seahorses in Peril
Untold millions of seahorses are collected annually for use in Chinese and South Asian traditional medical practices, and for the curio and pet trade.  Many more perish due to habitat loss and as “by-catch” in commercial fishing operations.  Please be sure to purchase only captive-bred seahorses.

I became so enamored of these unique fishes that I wrote a book on their care and natural history – if you have a chance to read it, please forward your thoughts and suggestions to me.  I’ll write more about seahorses and their relatives in future articles.  Until then, please write in with your questions and comments.  Thanks, until next time, Frank.

Information about a reintroduction program for the Atlantic seahorse on Long Island, NY is posted at:
http://counties.cce.cornell.edu/suffolk/habitat_restoration/seagrassli/ecology/fauna_flora/seahorses.html

Seahorse (Hippocampus erectus). Taken at the New England Aquarium (Boston, MA, December 2006. Copyright © 2006 Steven G. Johnson and donated to Wikipedia under GFDL and CC-by-SA