That Fish Blog – Aquarium Advice and Information

I’m a sucker for animal stories in the news.  This morning I came across this short article in a news feed.  I found it pretty amazing and worthy of sharing here on the blog. Most of the stories we see in the news are about dogs, cats, and other furry creatures, and while I love them all the same, it is nice to read a story about one of our tiny ocean friends that is just as amazing and inspiring.

The story is about a tough little seahorse that (it is assumed) was picked up by a seagull on the British coast and dropped three miles inland.  The incredible thing is the amazing little lady survived the ordeal!  The species, Hippocampus guttulatus, is native to the southern and western coastlines of the isles in eel grass beds.  These rare Seahorses are currently being tagged and researched in hopes of preserving their dwindling populations.  The destruction of their natural habitat by anchors and boats is currently the biggest threat they face.  This one is super lucky to be alive!

You can read the full story here:   http://www.dailymail.co.uk/news/article-1181596/The-incredible-journey-Seahorse-miles-inland-scooped-seagulls-beak.html

And for more on the current research and conservation of seahorse species:  http://www.theseahorsetrust.org/
Enjoy!

Seahorses have long been one of the icons of the aquarium hobby, with graceful movements and a delicate, unusual appearance. Seahorses are members of a family of fish known as Sygnathids, meaning “spiny-finned fish”. Other members of the family include Sea Dragons and Pipefish. They each have a small tubular snout that enables them to suck in prey items like brine shrimp, copepods, and other similar crustaceans. Seahorses and their relatives are timid and slow-moving. They are most often found in beds or sea grass where they can use their tails to anchor themselves to the grass or corals and not be carried off by the current. Seahorses bear live young that are carried in a pouch, similar to a Kangaroo, until they are mature enough to be released.

A couple of years ago, seahorses were a rather common offering in Aquarium Stores nationwide. Seahorses have long been one of the icons of the aquarium hobby, with graceful movements and a delicate, unusual appearance. In recent years, the with the technical advancements in aquarium keeping, environments can be created to more easily and better suited to keeping these amazing fish. The possibility of keeping sea horses is more within reach than ever. But where have they gone?

In 2004, the Convention on International Trade in Endangered Species (CITES) upgraded the status of Seahorse species to “vulnerable” meaning that the seahorse populations are in danger of a 30% decrease due to targeted catch, accidental capture, and habitat loss. One of the biggest threats to these species is the high demand for their dried bodies in Asian and Southeast Asian medicine trades. Climate changes and habitat destruction are also taking huge tolls on these interesting and amazing little creatures.

With growing awareness and increased conservation efforts, captive breeding programs for these animals are growing in number and are becoming increasingly successful. If you’re lucky enough to venture into keeping them in a home aquarium, strive to purchase captive raised individuals. By doing so, stress on wild populations can be reduced, and these animals tend to adapt to aquarium conditions and diets with more ease than wild-caught specimens. Be sure to check out the related articles in the blog for more fascinating facts and tips on keeping these guys at home.

Thanks, Eileen

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

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:
http://www.georgiaaquarium.org/exploreTheAquarium/webcam-seadragon.aspx.

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.