Getting a female to breed is usually not difficult if you have a male of the same size and species. Some species such as P. ciliata, G. smithii and O. scyllarus will mate at any time in the females reproductive cycle, so you just have to put them together for a few minutes and remove the male after they mate. Many gonodactylids mate guard and typically females will not mate until the ovaries are developed. You can tell this by looking at the cement glands on the ventral thorax. If they appear packed and very white, the female will probably mate. In these species you can put the male and female together. If they move into a cavity together, they will stay together for a few days until the female lays her eggs. At this time the male leaves. It is a good idea to remove him at this time.
If females mate, they can store sperm for up to several months - as long as they do not molt. The sperm are stored in a special structure that is shed when the female molts. She will then have to re-mate to lay fertile eggs.
Once the eggs are laid and the female molds the mass into a disk or ball, she will carry them in her maxillipeds until hatching. The mass can be put down, but generally the mass must be cleaned and aerated by the female if they are going to hatch. The length of time that it takes to hatching varies by species and seems to be a function of size and temperature. The fact is that we don't know how long the eggs of most species take to hatch, but it can be as short as 11-12 days for Pullosquilla and as long as 6 several months for some temperate water species. Most gonodactylids take about 3 weeks.
At this point, the larvae my leave the burrow and enter the plankton or remain with the mother for a bit longer. Gonodactylids typical remain with the mother for a week, burrowing lysiosquillids and squillids leave immediately on hatching. In all cases that I'm aware of, the larvae become photopositive when they are ready to enter the plankton and swim up into the water column. To our knowledge, all species of stomatopods have planktonic larvae. The problems associated with raising them are many.
1. They are planktonic. This means that either you need a Kriesel tank or you have to change the water at least every other day.
2. They are cannibalistic. That means one per container or a large , effective Kriesel.
3. They only take live food. Initially that means rotifers, nutrient soaked brine nauplii, etc. As they get larger, you can use larger, adult brine (again with supplements). The larvae will not feed on demersal prey, so amphipods are out.
4. The larvae are subject to various algal and fungal infections as well as unknown bacterial and/or viral disease. Some people who have successfully reared larvae included antibiotics (I did not.)
5. Long larval period and large size. Gonodactylids and some species such as Pullosquilla settle out at 7-11 mm, but some species such as P. ciliata (22 mm), Lysiosquillina (20+ mm and Odontodactulus (25 mm) remain in the plankton for months. This means a lot of work.
6. The cues for settling are not well understood. During some attempts to rear larvae, they remained planktonic and would not settle even though they appeared large enough. We see the same thing sometimes in the field. I've seen N. oerstedii settle at 6 mm and at other times not recruit until they were 11mm.
7 Once you have postlarvae, for most species it will be 1-2 years until they breed and for something like Lysiosquillina it could be 5 years or more.
It isn't easy and I doubt that it will ever be cost effective. That said, Manning reared N. oerstedii, Morgan and Goy reared N. wennerae and I have reared N. bredini and N. chiragra.
Roy
