Ghost Shrimp

[Ghazanfar Ghori]

<strong>Ghost Shrimp/Glass Shrimp</strong>

See-Through Inverts for Your Tank


Commonly sold as feeders for predatory fish (puffers love them by the way), these US Gulf Coast natives are worth a closer look for peaceful tanks with small fish or those with non-predatory habits. They have been suggested on the boards as algae eaters. In my experience this is a bit of an exaggeration. They are omnivorous, and will eat some soft algaes if there is no flake or small pellets available, but prefer to compete with their finny tankmates for normal aquarium fare. Between meals they will scavenge the tank, making a group of these inverts one of the more efficient selections for tank cleaners, at least where uneaten food is concerned. They are not at all limited to the bottom of the tank. They will forage all over the rocks, driftwood, plants, and even the glasses of the tank sides.



These creatures are caught along the Gulf Coast in marshes, rivers, and less-than-marine bays. Originally seasonal (they are really common and easy to harvest seasonally), they are now captured at peak and kept in holding ponds and vats for off-season stock. For me they do best in at least slightly hard to hard somewhat alkaline water. They do withstand long-term exposure to softer water; so don’t fret about whatever your tank conditions may be, possibly unless you are breeding them. In tanks with non-threatening tankmates, these shrimp seem to be active almost 24/7. In a multi-shrimp tank I seem to see activity whenever I look. With threatening tankmates, they will be largely nocturnal in my experience. I have poor results with these shrimp with my larger Synodontis cats which are nocturnal. They jump or climb out of the tanks – whether being chased, or just being spooked by being brushed by catfish whiskers in the night I do not know. I can imagine this happening with other nocturnal fish, even if they are not shrimp-eaters.



There seem to be at least two and probably several species of Ghost Shrimp carried by local fish stores as feeders. The two main divisions I find hard to tell apart. One is true freshwater (FW), but will withstand brackish without problems. The other is brackish to marine, but will withstand FW for extended to indefinite periods. The real FW Ghost Shrimp breeds readily in tanks, the female attaching fertilized eggs to her swimmerets after a fresh molt. The eggs may have been stored in her body following mating until time for molt, but these events tend to follow one another closely. The female carries these with her until they hatch, fanning her swimmerets periodically to clean and oxygenate the eggs, which individually are fairly large. Development of the eggs/larvae can be seen as darkening of the eggs as the enclosed embryos mature. When the female releases the larvae, they are individually tiny, but visible. They are miniatures of the adults. They can take fine fry food such as Liquifry or the finest powders or even newly hatched baby brine shrimp immediately. However, for they do better with live foods available in their tank and live baby brine supplements. The adults (along with any fish in the tank) will consider the babies as sushi, so survival is likely only in the most heavily planted tanks, or in isolation tanks. If you set a tank for hatching with a near-term female carrying eggs as the only inhabitant, watch her and remove her as soon as possible after the fry are released. She will have no objection to cannibalizing her own offspring. Heavy planting here as well gives more refuge, and a richer source of infusoria for the fry to graze. The length of time for the eggs to develop to hatching is variable with temperature. Three weeks from the last molt seems about normal at temperatures in the mid to upper 70s F. For me these shrimp seem to need at least moderately hard (7-9 GH, calcium and magnesium hardness) and pH 7.5-7.8. These are the parameters of my current water supply. Years ago attempts to breed these in softer water were not very successful, but this could well have been contributed to by other uncontrolled or un-noticed factors. All filters should be sponge-protected if you don’t want to risk the fry. The sponges make excellent grazing sites for the shrimp as well, with captured food particles and infusoria feeding on these. These fry are the invert equivalent of small Tetra or Rainbow fry. Masses of Java Moss are a wonderful nursery – these harbor loads of infusorians and provide plenty of refuges at the same time.



The other common Ghost Shrimp, the brackish/marine type, also breeds in captivity, but the “fry” are quite different from the adults, true larvae, tiny even in relation to their FW kin, and live free-floating in brackish to marine water, drifting with the plankton eating the tiniest plankton. They go through multiple molts and life cycle stages during this period, so are extremely difficult to raise in captivity. They live this free-floating existence for many days to weeks before they come to resemble the parents and settle out of the water column to an adult life style. If you have seen both types of females carrying eggs on their swimmerets, the difference is obvious. The brackish/marine forms have tiny, tiny eggs and many, many of them. The eggs of the FW form(s?) are much larger and even to aging eyes can be seen as individual eggs (well, on occasion with the help of a magnifying lens).



Both these shrimp are all but transparent. Their shells are clear, their muscles very nearly so. The hindgut contents are clearly visible. If they have been grazing algae, then get a colored-flake food meal, before too long a dividing line in the color of the hindgut is noticeable. Once they die, or if they are ill or severely stressed to near-death, they become translucent white. Sometimes they even turn pinkish, as do boiled edible shrimp and lobsters after death. When they grow, as with other crustaceans, they shed their external skeleton and develop a new larger one. In very soft near calcium-free water they sometimes have trouble shedding the old exoskeleton, occasionally becoming trapped in the partially shed shell. They or their con-specifics frequently but not always consume the cast-off shell (recycling). They are agile swimmers, and in common with many relatives, can snap backward at great speed from a startle reflex snap forward of their tail.



Due to their seasonal low prices and ready availability, these are fascinating creatures for early forays into invert keeping. They can inhabit any size tank, but for watching a dozen or so of them on their own, a 15-gallon tank is near ideal, a ten will do for a smaller group. The fine particles at the bottom of your used-up flake food containers are ideal staple food. If your area is iodine-deficient, adding a few drops of marine/reef iodine supplement every month would not be bad, especially if you have experienced molt problems with your shrimp. An alternative would be a teaspoon or so if marine mix per month in the tank to serve the same need. If you want to try your hand at planted tanks, these are perfect inhabitants for the novice invert or plant keeper. It you have will power, hold off on tankmates other than possibly MTS snails or Otocinclus cats. The Ghost Shrimp are not nearly as good at algae clearing as are Amano shrimp, but they cost a tiny fraction of the price of an Amano, and are just as hardy or more so. They are not long-lived, about a year and a half seems to be average. They can reach two inches, but are usually smaller. Keep a species tank of them for a while, then set up a second, smaller tank, and try your hand at breeding and rearing inverts. Not worthwhile trade goods at the LFS due to their low unit cost, but lots of fun and personal satisfaction from something quite different from a guppy tank.

<strong>Written by Robert T. Ricketts rtricketts@erols.com</strong>    

[tomterp80]

Ghazanfar, I was going back and reading this old article you posted, and just wanted to chip in with a comment. There are plenty of grass shrimp available locally to collectors as well. I have seined up large quantities in the Potomac down in the area of Purse State Park, while looking for killies or bluespotted sunfish. The water in that area is mostly fresh, just a very low salinity, so I would think those shrimp might be adaptible to pure freshwater aquaria.

Next time I go down there I might have to keep a few.