Re:Swollen belly in female

Pete Giwojna

Dear Pat:

I’m very sorry to hear that you lost your breeding female. All my condolences on your loss!

It sounds like you’re doing everything right to prevent potential problems with egg binding, Pat. You have pairs of seahorses that were actively breeding and have produced healthy broods of young for you in the past, so the female Sunburst certainly had opportunities to mate and your aquarium is obviously tall enough for the seahorses to mate comfortably.

It’s very difficult to say why a problem with egg binding may have developed under the circumstances, but the tangle of white threads that has been periodically protruding from her vent over the last few days could be a clue. That suggests that she may have had a number of worms in her gut (possibly the larvae of livebearing nematodes, or maybe cestodes, or even Camallanus worms). Fishes can pick up these types of worms from live foods or occasionally by eating frozen Mysis off the bottom of the tank that has been contaminated by fecal pellets or a dirty substrate, and a heavy infestation can sometimes lead to intestinal blockages or problems with egg binding.

The former can be avoided by obtaining live foods from high health aquaculture facilities (I would be happy to provide a list of good live foods sources for you, if you like), and the latter can be prevented by handfeeding your seahorses or setting up a feeding station for them, if you haven’t already done so. As you know, Pat, a feeding station is very simple concept. In essence, it is a simple feeding tray that will safely contain the frozen Mysis while your seahorses dine on it. The feeding trough thus prevents the food from being wafted away by currents or stolen by bottom feeders before the seahorses can slurp it up, and it makes cleaning up after meals a snap.

Seahorses respond very well when they are fed at the same time and place each day. They quickly learn the routine and will come to recognize their keeper as the one who feeds them — the giver of gourmet delights! Once that happens, they will often beat you to the spot, gathering around their feeding station as soon as they see you approach.

For best results, I recommend elevating the feeding station, which provides several benefits for our galloping gourmets:

(1) First and foremost, it isolates the feeding trough from the bacteria-laden substrate and provides the seahorses with a sanitary lunch counter from which to feed.

(2) Secondly, it keeps the feeding station beyond the reach of bottom scavengers such as bristleworms, Nassarius snails and hermit crabs, which are attracted to the frozen Mysis.

(3) Finally, it provides a sterile feeding surface for the ponies that is easy to remove and keep clean, thereby making it a breeze to dispose of leftovers, which safeguards your water quality. Keeping the feeding tray elevated makes it convenient to clean and sterilize between feedings.

Once your seahorses have adjusted to their new home and are eating well, you will find that it’s fun and easy to train them to take frozen Mysis from your fingers or to use a feeding station. I wrote an article in Conscientious Aquarist that explains everything there is to know about setting up a feeding station and teaching your seahorses to use it. It’s available online at the following URL:

Click here: Seahorse Feeders

All kinds of different objects will make a suitable feeding post or feeding trough. The following link will take you to a site with photographs of different types of feeding stations that seahorse keepers have devised to give you a better idea of the possibilities:


You can also buy ready-made feeding stations if you feel that would be easier than improvising one of your own. For example, the Aquarium Fish Dish sold here works well in some seahorse tanks:


Or you could try the following feeder that was designed specifically for seahorses:


Regarding replacing your female Sunburst, yes, I do feel that seahorses of both sexes are happier when they are allowed to mate. The seahorses certainly enjoy a richer, more natural life when they have the opportunity to interact, court one another, pair up and reproduce.

I think your female Mustang is definitely capable of breeding. As I mentioned in my earlier post, female seahorses are fractional spawners that keep their ovarian assembly line running at all times. Your Mustang mare has eggs in all stages of development ready and waiting, but for some reason she has not yet been receptive to breeding. Females only hydrate or ripen their mature eggs in the final stages of courtship when breeding is imminent. She has simply never gotten to that point as of yet, for reasons unknown. That may change now that the receptive female Sunburst, which both studs seemed to fancy, is no longer available for mating. Perhaps the female Mustang will respond favorably to the advances of the stallions now that she is the only gal in town and the sole object of their attention. Or maybe not. There’s no way of telling for sure…

I would wait a few weeks before you do anything and see if a budding romance doesn’t develop between the female Mustang and one of your stallions now that the seductive Sunburst filly is out of the picture. If not, then you can certainly consider adding another female or two to spice things up again. Getting them two new females instead of one won’t guarantee that both males find a receptive partner, but it will certainly increase your chances of winding up with two pairs of actively breeding seahorses. Since Mustangs and Sunbursts are the same species and interbreed freely, it doesn’t really matter whether the new female(s) are ‘stangs or ‘bursts.

Whether the old Mustang female becomes receptive or a new female pairs up, let me know when you have more fry on the way and I will be happy to provide you with some suggestions that will increase your success at rearing the young.

Best wishes with all your fishes, Pat! Here’s hoping that your remaining trio of seahorses become a happy threesome and begin mating regularly.

Pete Giwojna

America's Only Seahorse Aqua-Farm and One of Hawaii's Most Popular Attractions

Ocean Rider seahorse farm is a consistent Trip Advisor Certificate of Excellence Award Winner and "Top 10 Things To Do" Kona, Hawaii attraction. Our "Magical Seahorse Tours" are educational and fun for the whole family.

Tour tickets are available for Purchase On-Line. Space is limited and subject to availability.

small seahorse Ocean Rider, Inc. is an Organic Hawaiian-Based Seahorse Aqua-Farm & Aquarium that Follows Strict Good Farming Practices in Raising Seahorses and Other Aquatic Life.

Seahorse Hawaii Foundation

Inspiring ocean awareness by saving the endangered seahorse and sea dragons around the world from extinction through conservation, research, propagation, and education.

Help us save the seahorse and the coral reefs they live in with a tax deductible contribution to the Seahorse Hawaii Foundation. You will be helping to protect and propagate over 25 species of endangered seahorses, sea dragons and friends.

Make A Tax-Deductible Donation Today!

A Different Kind of Farm (Video) »

Ocean Rider Kona Hawaii

Ocean Rider Kona Hawaii
Seahorse Aqua-Farm & Tours

73-4388 Ilikai Place

Kailua Kona, Hawaii 96740

Map & Directions


Contact Ocean Rider

Copyright ©1999-2023
All Rights Reserved | Ocean Rider Inc.

My Online Order Details

Purchase Policy

Site Terms and Conditions