- Shrimps:
Hymenocera picta - hard to breed and need live starfish to eat.
Thor amboinensis - hard to keep alive and hard to breed
Lysmata debelius - not hard to breed but hard to rear young.
Lysmata wurdemanni - easy to breed and can be reared in captivity.
Lysmata amboinensis - easy to breed, easy to rear but hard to get to metamorphose and settle.
Stenopus hispidus - easy to breed, hard to rear.
- Crabs:
Mithraculus sculptus -
Stenorhynchus seticornis
Lybia tessellata
Neopetrolisthes maculatus - porcelain crab
-Snails:
Nassarius vibex
Turbo fluctuosus
Engina mendicaria
Crabs aren't normally kept in marine tanks because they are nocturnal predators and kill and eat things that can catch. They also knock rocks and corals over during the night. Subsequently there aren't many people that even think about keeping or breeding small species of crab. Larger commercial species are sometimes being farmed in captivity.
Assuming you can get males and females (males have a longer tail and females have a shorter wider tail), and you can get them to maturity without them killing each other, then they breed quite readily. However, the problem is rearing the larvae and they need small species of single celled algae and other types of zoo plankton for the first few months of life. This also applies to shrimp and snail larvae. Once the larvae settle to the bottom, they will eat normal foods that the adult crab, shrimp, snail eat.
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Most shrimp are easy to breed and shed their newly hatched larvae at night. The larvae can be put into small shallow rearing tanks and fed single celled algae and other types of zoo plankton and they grow. But most don't settle. The most common reason they don't settle is incorrect diet.
In aquariums the larvae are usually fed newly hatched brineshrimp, which will let the larval shrimp grow but it does not have enough nutrition. I was working with Lysmata amboinensis for several years and got their larvae to 2 months and they never settled. I was starting to add fish eggs to their diet in addition to the newly hatched brineshrimp and that should have done the job. But things went bad then and I haven't had fish since.
I was going to add rainbowfish eggs to the larvae rearing containers. Rainbowfish are easy to breed and you can pick the eggs off spawning mops and handle them. So I figured they would be easier to use than other fish that scatter eggs in plants or on the bottom.
Green water (single celled algae) and small species of rotifer might also help them metamorphose and settle.
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My adult shrimp were kept in tanks that were 18 inches long x 14 inches wide x 12 inches high. They had coverglass and an air operated sponge filter and heater in the tanks. There was a 1/4 inch layer of crushed shells or beach sand on the bottom of the tanks, and some rocks for the shrimp to hang out under.
The shrimp were fed 2-3 times a day and given as much food as they could eat. Uneaten food was removed after the adults had stopped eating. They were fed marine mix, which consisted of prawn, fish and squid, blended up and frozen into cubes. The cubes were defrosted and broken up and the shrimp were hand fed. They tame down quickly and would crawl over my hands to get the food.
There were no fish, crabs, or any other creatures in the tanks. They were kept in single species tanks that contained 2 shrimp. I had 6 tanks with 2 shrimp in each tank. Most of the Lysmata shrimp are hermaphrodites (both male and female) and will breed after shedding their skin. So having 2 shrimp per tank is fine. Some of them do live in groups and L. amboinensis and L. wurdemanni after often found in huge colonies living together.
I used air operated sponge filters to keep the water free of ammonia and nitrite, and did a 90% water change each month. I used natural sea water from the ocean for the water changes.
If you use power filters, you suck up the larvae and won't have any babies to try and rear up. So you have to use air operated sponge filters.
The adult shrimp don't eat the larvae unless they are hungry. By having the shrimp in single species tanks with an air operated filter, I could collect the larvae during the day and didn't have to worry about fish eating them or filters sucking them up.
The larvae swim around near the surface and I used a small plastic container to scoop them out of the tanks and put them into semi-transparent Chinese food containers that were about 5 inches long x 4 inches wide x 2 inches high. I had about 1 inch of water in the containers and changed the water each day. I simply poured it into the adult's tank and refilled the container from the adult's tank.
I added newly hatched brineshrimp to the containers each day and had the containers sitting on top of the parent's tanks under the light. The larvae would eat the newly hatched brineshrimp and grew to about 6mm long (1/4 inch). I never got them to settle and I am fairly certain they need omega fish oils to do that. That is where fish eggs would come in.