h. redei not eating

Dear Loveless:

That’s a problem that crops up all too often with wild-caught seahorses, particularly the beautiful Brazilian seahorses (Hippocampus reidi), which can be picky eaters under the best of circumstances. Captive-bred Brazilians are much better adapted for life in the aquarium than their wild conspecifics. This is perhaps best reflected in their eating habits. Wild-caught (WC) H. reidi are notoriously finicky eaters. Very often, they disdain frozen foods and outright refuse adult brine shrimp (Artemia) and guppy fry, which are the only live foods most hobbyists can readily provide. Consequently, many proud owners of wild-caught Brazilians go to a great deal of trouble and expense to provide them with live ghost shrimp, grass shrimp and Gammarus on a daily basis (Giwojna, Jun. 2002). Captive-bred H. reidi, of course, usually accept frozen Mysis as their staple diet quite readily, a tremendous boon for long-suffering supporters of this much-sought after species (Giwojna, Jun. 2002).

Unfortunately, the dietary requirements of wild-caught seahorses are very difficult to meet. Consequently, maintaining them in captivity–let alone breeding and rearing them–is a daunting challenge for the home hobbyist.

Proper nutrition is the primary problem. In their natural habitat, seahorses feed more or less continuously throughout the daylight hours, consuming great numbers of small crustaceans and other larval organisms that are collectively termed zooplankton. Thus, in the wild, they are free to select prey items from a lipid-rich planktonic soup consisting of countless copepods, mysids, amphipods, ostracods, isopods, shrimps and the larval stages of myriad larger crustaceans. Attempting to duplicate the quality and quantity of the seahorse’s natural diet is a tremendous challenge for the aquarist.

Furnishing wild-caught seahorses with a healthy, balanced diet is thus a painstaking, time-consuming process. It requires collecting live foods in the field, maintaining live food cultures at home, patiently training them to eat nonliving prey and frozen foods, and even conditioning them to accept handfeeding at times. For those fortunate enough to have access to the seashore, field collecting means enduring endless hours of slogging through saltmarshes in search of mosquito larvae and wading knee-deep across tidal flats at low tide to reach tidal pools that might contain amphipods or small shrimps. It means hand-seining seagrass beds for grass shrimps, towing plankton nets, and diving after shoals of live mysids. And it involves long afternoons at the beach toiling tirelessly under the hot sun, shaking malodorous mats of Sargassum and countless clumps of clammy seaweed over your collecting bucket in search of scuds and beach-hoppers. For the inland hobbyist, it means spending your spare time straining stagnant pools for freshwater Gammarus and Daphnia. After a live-food collecting expedition, insect bites, sunburn, and stinging cuts and abrasions on hands and knees are badges of courage proudly displayed by dedicated seahorse keepers everywhere.

Once back home from a collecting trip, it’s time to look after your catch and tend to your live food cultures. For starters, there is the obligatory large grow out tank for brine shrimp as well as separate tanks for raising amphipods and various types of live shrimp (ghost shrimp, grass shrimp, mysids, caprellids). Serious seahorse fanciers have even been known to employ wading pools and outdoor goldfish ponds (minus the goldfish) as their Artemia grow-out tanks. At least one good-sized aquarium is normally devoted to a harem of live-bearing tropicals, usually guppies or–even better–mollies adapted to full-strength saltwater, so the newborn fry they produce so prolifically can be fed to your hungry seahorses. Breeding a single pair of wild-caught seahorses might easily require a half dozen live-food culture tanks plus several refugia, a whole battery of Artemia hatcheries, rows of "greenwater" infusoria bottles, and banks of rotifer cultures in addition to all the live food that can be collected. In short, with its forest of gleaming glassware and glittering apparatus filled with hissing valves, bubbling flasks, and stewing vats filled with mysterious organisms, the fish room of a dedicated seahorse keeper used to resemble nothing so much as an overworked mad scientist’s diabolical laboratory.

So I can sympathize with your plight completely — I’ve been there and done that myself many times in the past. Nowadays, I always opt for domesticated seahorses that are pre-conditioned for the captive environment and pre-trained to eat frozen foods as their staple, everyday diet — it makes things so much easier for us seahorse keepers!

I think you’re right — your H. reidi must be grazing on the copepods and amphipods in your system. But it’s a good idea to keep supplementing her diet with ghost shrimp and homegrown Mysis and volcano shrimp on a regular basis lest the pod population in the tank becomes too depleted.

Best of luck with all your seahorses, loveless!

Happy Trails!
Pete Giwojna

Dear loveless:

There are several different kinds of ghost shrimp but they are all very difficult for the home hobbyist to culture, although they are often quite easy to collect if you have access to suitable bodies of water, as discussed below:

GHOST SHRIMP or GLASS SHRIMP

Pros (Giwojna, Oct. 1996):
· A highly nutritious, natural food for large seahorses.
· Available from pet shops or aquarium stores as well as through the mail.
· Very easy to gut-load and enrich with various supplements
· Good tolerance for saltwater: brackish ghosts last surprisingly long, and even freshwater ghost shrimp survive long enough to be a very useful food.

Cons (Giwojna, Oct. 1996):
· Suitable only for the largest specimens.
· Often too expensive to use more than occasionally.

Collecting Tips:
Ghost Shrimp are seasonally abundant along the Gulf Coast of the US in salt marshes, rivers that empty into the sea, tidal creeks and brackish bays (Ricketts, Robert T. 2003). Brackish Ghosts can be collected easily at low tide by vigorously shaking clumps of floating seaweed into a bucket of seawater, or by dragging a small seine or large aquarium net through tidal creeks or the grass flats just offshore (Giwojna, Oct. 1996). Similar techniques will often produce freshwater Ghost Shrimp from fresh streams or waterways, including grassy canals and ditches (Giwojna, Oct. 1996). Harvest only specimens that are small enough for your seahorses to swallow whole.

Aquarium specimens are available year round. Fish stores carry Ghost Shrimp both as feeders and as oddball pets for freshwater hobbyists (Giwojna, Oct. 1996).

Culture Instructions:
Ghosts do not thrive in soft water, so for best results keep them in slightly hard to alkaline water (Ricketts, Robert T. 2003). Like all crustaceans, these see-through shrimp shed their exoskeletons in order to grow. They may have difficulty molting and become stuck halfway through the process of extricating themselves from their old exoskeletons, particularly in soft water that is deficient in calcium (Ricketts, Robert T. 2003). For this reason, I recommend gradually converting your holding tank for Ghost shrimp to brackish conditions, using a high-quality marine salt mix to slowly raise the salinity (Ricketts, Robert T. 2003).

There are at least two distinct types of Ghost Shrimp (very likely more), which are very difficult to distinguish by casual examination (Ricketts, Robert T. 2003). One category of Ghost appears to be a true freshwater species. The freshwater Ghosts do not tolerate full-strength saltwater for any length of time but withstand brackish conditions without difficulty (Ricketts, Robert T. 2003). The other category of Ghost Shrimp is a brackish species that can be converted to full-strength saltwater, but which also tolerates freshwater for extended periods (Ricketts, Robert T. 2003).

One possible way to determine which type of Ghost Shrimp you have is to examine females that are "in berry" (carrying eggs attached to their swimmerets). The saltwater or brackish Ghosts carry huge numbers of extremely tiny eggs (Ricketts, Robert T. 2003). So small are these that individual eggs cannot be seen with the naked eye. The eggs of freshwater Ghosts are said to be much bigger so that separate eggs are visible (Ricketts, Robert T. 2003).

The freshwater Ghosts breed more readily in the aquarium, and the larval shrimp are somewhat easier to raise (Ricketts, Robert T. 2003), but home culture of Ghost Shrimp is not really practical regardless of which variety you obtain.

Feed Ghosts small amounts of dry food once daily. The fine, leftover particles that accumulate on the bottoms of nearly empty flake food containers are great for feeding Ghosts, or crumble fresh flakes between your fingers to create particles of that same consistency (Ricketts, Robert T. 2003). Soak these fine flakes in a good enrichment formula and then feed them to the shrimp about 30 minutes before feeding the Ghosts to your seahorses (Ricketts, Robert T. 2003). This will gut-load the shrimp and fortify them for maximum nutritional value. (You will actually be able to see the enriched flakes accumulate in the hindgut through the shrimp’s transparent body.)

A 10-15 tank will hold quantities of ghost shrimp, and smaller numbers will do fine in a 5-gallon bucket equipped with an airstone or air-driven foam filter (Ricketts, Robert T. 2003). Sponge filters will suffice; change water once a week to maintain water quality (Ricketts, Robert T. 2003).

Comments:
These shrimp are all but transparent, which explains why they are universally called ghost shrimp or glass shrimp. Their exoskeletons are perfectly clear, the underlying muscles nearly transparent, thus clearly revealing their internal organs and GI tract (Ricketts, Robert T. 2003). A loss of transparency is a sign of severe stress and poor health; upon death, Ghosts typically turn an opaque white like their namesakes (Ricketts, Robert T. 2003). Ghost shrimp are acrobatic swimmers, which propel themselves backward with amazing speed by flexing their tails beneath them.

Fully-grown Ghosts can reach two inches in length, but the best feeder shrimp for the greater seahorses are 1/10 to 1/4 that size, so select your specimens accordingly (Ricketts, Robert T. 2003). Hobbyists estimate that 100 eating-size Ghost shrimp is roughly a one-week supply for two large seahorses. With the high unit cost per shrimp, it’s easy to see than keeping your herd on a staple diet of store-bought ghosts is a very expensive proposition!

Ricketts, Robert T. 2003. Ghost Shrimp/Glass Shrimp: See-Through Inverts for Your Tank. Accessed 17 Nov. 2003. <http://www.tomgriffin.com/aquasource/ghostshrimp.shtml&gt;

You might have better luck keeping post larval shrimp for your H. reidi, as described below, loveless. They are very hardy and easy to maintain in the aquarium and are an available by the thousands:

POST LARVAE SHRIMP (PLS): Ecuadorian White Shrimp (Penaeus vannamei, a.k.a. Litopenaeus vannamei)

Pros:
· Feed-and-forget — thrive until eaten in full-strength saltwater.
· High Health — guaranteed disease-free feeder shrimp for our ponies!
· Natural, highly nutritious food seahorses are accustomed to eating in the wild.
· Easy to feed and maintain.
· Long lasting — remain in the bite-sized larval stage for months.

Cons:
· Only available if purchased in huge quantities.
· PLS are notorious cannibals– will fatten up on each other if not well fed.

Collection Tips:
None.

Culture Instructions:
Post Larvae Shrimp are not suitable for batch cultures and self-sustaining cultures are not possible, but home hobbyists can easily maintain them. A 10 to 15-gallon tank is sufficient for up to 1,000 larval shrimp (Cheryl Colburn, pers. com.). The culture tank can be either an aquarium or any other inert container of sufficient volume. For example, rubbermaid containers work well as long as they are equipped with adequate filtration.

Feeding PLS is a breeze. They will eat just about anything. They’ll take flake food and frozen foods and are especially fond of frozen Mysis relicta, which makes a superb staple diet for them (Cheryl Colburn, pers. com.). Whatever you feed them as their everyday diet, however, be sure to fortify the PLS with a good enrichment product. Enriching PLS with formulas that are rich in HUFA and long-chain fatty acids will assure that the larvae have maximum nutritional value when they are fed to your seahorses (Cheryl Colburn, pers. com.).

PLS will be 4-7 mm in length when you receive them, and at standard aquarium temps of 24 C (74-75 F) they will remain small enough to be eaten by large seahorses for at least 1-2 months (Cheryl Colburn, pers. com.). PLS are thus useful as fry food when they first arrive and are suitable for feeding small ponies for the next 3-4 weeks at 74 F.

Their growth rate is dependent on water temperature. If you can chill their tank, and maintain 60-70 F, they will grow at an extremely slow rate and remain in the larval stage for several months.

Cheryl Colburn is one hobbyist who has worked extensively with PLS and she reports they are almost indestructible in the aquarium. If fact, she has never lost one of her larvae for any other reason than predation by another PLS.

Comments:
If you can obtain them, PLS are the ideal live food for seahorses. They are the larvae of Ecuadorian White Shrimp (Penaeus vannamei), which are cultured in enormous numbers on shrimp farms for human consumption (Cheryl Colburn, pers. com.). Since they are destined to become people food, White Shrimp are raised at High-Health aquaculture facilities and are certified to free of specific pathogens and parasites. You couldn’t ask for a healthier, more nutritious food for your seahorses and all Hippocampines devour them greedily. They can be raised in hobby tanks to provide perfect fodder for any seahorses from fry to young ponies to mature adults, so they are suitable for every aquarist’s needs. Any of the larval shrimp that are able to hide out and evade capture long enough to mature, will eventually breed and provide nutritious nauplii for all your reef inhabitants (Cheryl Colburn, pers. com.).

Seawater Express (http://www.seawaterexpress.com/) is an excellent source for PLS shrimp and offers them in several different sizes. I know several hobbyists that order 1000 of the 1/4" to 1/2" PLS from seawaterexpress as live food for their finicky wild caught Brazilian seahorses (Hippocampus reidi) with excellent results.

Best of luck raising enough feeder shrimp to keep up with your H. reidi’s appetite, loveless!

Happy Trails!
Pete Giwojna