seahorse hitching post

Dear hobbyist:

Congratulations on your new Hippocampus kuda! Starting out with captive-bred-and-raised seahorses was absolutely the best choice you could have made.

H. kuda is not quite a start in the aquarium as Mustangs and Sunbursts (Hippocampus erectus) which have been raised in captivity for dozens of generations and have now reached a high level of domestication that makes them better adapted to aquarium conditions than other cultured seahorses. But like all captive-bred-and-raised seahorses, your domesticated H. kuda will be a great deal hardier than their wild conspecifics, and they should readily accept frozen Mysis as their staple, everyday diet. This makes the captive-bred-and-raised kuda like yours relatively easy to keep compared to the wild specimens.

Once you’re new H. kuda have matured and begun to pair off, and have had a chance to adjust to their strange new surroundings, they usually breed quite readily. They tend to be rather promiscuous in the aquarium and will breed year-round in captivity if conditions are to their liking once they begin to feel at home.

True kuda fry are difficult to rear. Large broods of small 6-8mm fry that undergo an extended pelagic phase make this a challenging species to culture. They have been raised commercially for Traditional Chinese Medicine at large seahorse farms in South East Asia, but success rates appear to be very low at public aquaria (Bull and Mitchell, 2002, p47) and home hobbyists typically struggle when attempting to raise true kuda.

The gestation period of H. kuda is strongly influenced by temperature. Gestation for true kuda is a mere 9-10 days at water temperatures of 82°F-86°F (28°C-30°C) (Truong and Doan 1994), but increases to 20-28 days (Mi 1993) at cooler temperatures. A gestation period of around 15-18 days is pretty typical at standard aquarium temperatures of 75°F-77°F. With three pairs of H. kuda, they are very prolific once they begin breeding and you will have new broods to work with at least every month, so you have plenty of time to practice your rearing techniques and get to the point where you can eventually raise some of the fry.

Broods are normally around 250-1000 (Mi 1993), but exceptionally large broods of over 1400 fry have been recorded (Truong and Doan 1994). As with other tropical seahorses that produce such enormous broods, the fry of true kuda are quite small at birth. Newborn H. kuda are about 5 – 8 mm in height and weigh roughly 2.5 mg (Mi 1993; Mi, Kornienko and Drozdov 1998). The fry of true kuda are pelagic and remain at the surface of the water for the first few weeks of life, only descending to the bottom after 19-22 days (Bull and Mitchell, 2002, p48). During the first week of their lives, only 20% of fry are capable of attachment to holdfasts (Mi, Kornienko, and Drozdov 1998).

The newborns are surface huggers that gradual begin to settle out and take up a bottom dwelling existence over a period of weeks. Only about 1 in 5 fry begin to seek out hitching posts and orient to the substrate within the first week (Mi, Kornienko, and Drozdov 1998). Most of the true kuda fry are not ready to descend to the bottom until they are around 3 weeks old (19-22 days) (Bull and Mitchell, 2002, p48).

True kuda fry grow rapidly, quadrupling in size within the first 2 weeks (Bull and Mitchell, 2002, p48). They reach sexual maturity between 6-12 months (Mi, Kornienko, and Drozdov 1998; Jiaxin 1990), and typically reproduce successfully for the first time when they reach a length of 3-4 inches (8-10 cm) (Truong and Doan 1994). The average height of the adults is about 5 inches (11-13 cm) (Bull and Mitchell, 2002, p47).

As for holdfasts or hitching posts for your H. kuda, I would play it safe and avoid using bamboo or any other types of wood as hitching posts. I think you’ll be much better off choosing an assortment of natural or lifelike artificial hitching posts instead, as discussed below:

Hitching Posts

Hitching posts can be either live or artificial marine sea grasses, algae and corals. If you decide to try an assortment of colorful artificial corals, seahorses often prefer red or orange pieces. Many hobbyists report good results using artificial finger sponges, staghorn coral, octopus coral and pillar coral in the appropriate colors to keep their seahorses looking their brightest (SigNature Coral Corporation). They look entirely natural and lifelike, with lots of branching projections that make great hitching posts for seahorses. Oh, and their cup coral makes a great ready-made feeding station! Let me know if you think you want to try some realistic artificial decorations and I will be happy to recommend several good types and manufacturers you can look up.

Macroalgae — Living Hitching Posts

For live hitching posts, I prefer decorative marine plants or macroalgae in a variety of shapes and colors and color–reds, golds, and yellows in addition to green varieties, some tall and feather, some short and bushy–to provide them with natural hitching posts and shelter. I like to start with a mixture of red and gold Gracilaria (Ogo) and artfully arrange them around a lush bed of assorted bright green Caulerpa. Any of the plumed (feathery) or long-bladed Caulerpa would be ideal for this, such as Caulerpa sertularioides, C. mexicana, C. ashmedii, C. serrulata or C. prolifera. The result is a colorful macroalgae garden with a very nice contrast of colors (reds, yellows, greens, and brown) and interesting shapes. A tank heavily planted with macros such as these is a lovely sight and mimics the seahorses’ natural seagrass habitat well. As an added benefit, the macroalgae act as an excellent form of natural filtration, reducing the available levels of phosphates and nitrites/nitrates.

Be sure to prune and trim back the fast-growing Caulerpa regularly; when you remove the clippings, you’re exporting phosphates, nitrates and other nutrients from the tank, thereby helping to maintain good water quality, and pruning the runners helps keep it from going sexual.

When pruning or trimming back macroalgae, take care not to actually cut it. Remember, you’re not pruning hedges or trimming trees — the idea is to carefully pull up and remove continuous, unbroken fronds. Simply thin out the colony of excess strands, gently plucking up convenient fronds that can be readily removed intact. A little breakage is fine, but cutting or breaking too many strands will result in leaching undesirable substances into the aquarium water as the Caulerpa’s lifeblood drains away. Too much cutting or breaking can thus sap the colony’s strength and cause die offs or trigger the dreaded vegetative events that judicious pruning otherwise prevents.

If you’re concerned about your ability to maintain and control of Caulerpa properly, just use a different forms of macroalgae that grows less rapidly instead and you can get the same sort of benefits at relatively little risk. In that case, some of the other macroalge you may wish to consider are Gracilaria, Ulva, Chaetomorpha, and Chlorodesmis. Hawaiian Ogo (Gracilaria sp.) are bushy red-to-brown macros that do well under low light levels. Sea Lettuce (Ulva sp.) are deep green sheets of algae that do best under a little stronger lighting. Maiden’s Hair (Chlorodesmis sp.) are bright green tufts or clumps of very fine-bladed algal mats to grow attached to small rocks. All of these types of macroalgae are much less prolific and slower growing than Caulerpa. However, like all macroalgae, they should still be harvested periodically in order to export the excess nutrients they have consumed.

Aside from red and brown Gracilaria and the bright green Ulva and Maiden’s Hair, some seahorse keepers also like the Chaetomorpha turf algae. It can best be described as looking like the clumps of the colorful plastic grass we use to fill Easter baskets. It is popular because it is slow growing and doesn’t require the kind of pruning that Caulerpa needs, and because it it comes loaded with microfauna: miniature feather dusters, copepods and amphipods, tiny snails and micro stars. In short, Chaetomorpha is another interesting marine plant that can add some extra variety to a lush bed of macroalgae.

Finally, in case you haven’t seen them already, there have been a few other threads on the Ocean Rider Club discussion board at seahorse.com from hobbyists who were just starting out with seahorses that you should also find to be of interest. They discuss setting up an ideal system for seahorses, filtration, feeding, lighting, circulation and so on. I’ve provided links to those discussions for you below, so please check them out. I think they will answer many of your questions about keeping seahorses:

Re:Hello, newbie here! – O http://www.seahorse.com/option,com_simpleboard/Itemid,144/func,view/id,1004/catid,2/

Click here: Seahorse.com – Seahorse, Sea Life, Marine Life, Aquafarm Sales, Feeds and Accessories – Re:Setting up a 100gal for
http://www.seahorse.com/option,com_simpleboard/Itemid,144/func,view/id,1382/catid,2/

Re: Guidance on Keeping Seahorses:
http://www.seahorse.com/option,com_simpleboard/Itemid,144/func,view/id,639/catid,2/

Re: New to seahorses and I have lots of questions!
http://www.seahorse.com/option,com_simpleboard/Itemid,144/func,view/id,152/catid,2/

Re: Tank set-up advice
http://www.seahorse.com/option,com_simpleboard/Itemid,144/func,view/id,715/catid,2

Re:New with lots of questions 🙂
http://www.seahorse.com/option,com_simpleboard/Itemid,144/func,view/catid,2/id,1050/#1050

Please let us know if you have any other questions about your H. kuda or keeping seahorses in general that were not answered in those previous discussions. If you contact me off list at the following email address, I will be happy to send you additional information about Hippocampus kuda and the best methods for rearing them: [email protected]

Best of luck with your new H. kuda!

Happy Trails!
Pete Giwojna