Urodacus manicatus - Black Rock Scorpion,Rock Scorpion,Southern Rock Scorpion
Gravid female bought approx 6 months ago,no signs of being gravid when purchased.
Gestation Period typical for the species up to 18 months.
* Brood status: A successful brood of 7,all now second instars and separated from the mother.
* Environmental conditions for the gravid female: A small false bottom system in a "self cleaning" betta tank. Substrate - 30% sand, 70% coir peat. Ventilation - minimal. Decor - Bluestone and driftwood. No mould or fungus present. No heating used. Ambient Temperature outside of enclosure between 22 and 28C,extremes up to 36C for two separate periods lasting 4 or 5 days.
* Number of young born: 7
* Number of young eaten by mum: 0
* Number of young surviving to 2.instar: 7
* Number of days taken for the young to moult into 2.instar from birth: Most around 21,most sources report 12 to 16 days. One was still 1st instar at 35 days.
* Number of days taken for the 2.instar scorplings to dismount from mom's back: For most 35/40 days before not returning to mothers back,2 left the mothers back permanently around 25 days but took up residence in the mothers scrape.
*Environmental conditions for the female with young: higher humidity than previously(by reducing ventilation further),enclosure screened with black card.
* Mom's feeding schedule before and after giving birth: Before giving birth 1 live medium or two small crickets approx once a week,mother fed 1 freshly dead medium sized cricket approx every three days after birth,always eaten.
Note - My experience here is different from most reports regarding this species. The young stayed as 1st instar over twice as long as usual,and returned to their mothers back as second instars for far longer than usual. Most advise not to feed the mother while young are present to minimise disturbance,however I offered freshly dead crickets pretty much whenever she appeared at the mouth of her scape in a "waiting for prey" stance,which was every few days,she always ate them,up until she only had 1 baby on her back. While she had all the young on her back she was eating twice as much as is usual for her.
It's proven that 1st instars derive nourishment from their mother while on her back,and that this genus can absorb water from the substrate via osmosis.
My tentative theories:
- I think they develop into second instars,developing mouth parts,when they no longer get enough nourishment from their mother.
- Being that the mother was so well fed they stayed longer and grew larger as 1st intars rather than becoming 2nd instars and finding their own food. Perhaps they stayed on the mother longer than usual as 2nd instars because they still derived nourishment or at least moisture from her.
I have more gravid females of this species so hopefully I will be able to experiment a little.