YuccaPatrol wrote:I only read that abstract, but it was missing some critical data to show mortality rates beyond 18 hours of storage in the cold sawdust.
According to the report:
The 100% survival durations for non-ovigerous adult
M. rosenbergii stored at around 15 C in chilled sawdust following cold-induced anesthetization at the same temperature were, for three different rates of chilling from 25 C (-1.26 C/hour, -2.52 C/hour, and -5.04 C/hour), as follows: 7.39, 6.98, and 4.54 hours. 95% survival spans were obtained for spans of 16.47, 12.14, and 8.35 hours, respectively.
On the other hand, identical procedures secured 100% survival rates for berried females up to 7.87, 8.17, and 6.43 hours; 95% survival continued up to 18.49, 19.02, and 11.11 hours.
YuccaPatrol wrote:I can imagine such techniques being acceptable for large scale for-profit aquaculture in which the mortality rate is offset by a significant decrease in shipping cost. However, without any data to show survival rates beyond 18 hours, this just doesn't seem very applicable to our purposes in the hobby.
For the most part, I agree, but current U.S. and U.K. restrictions on liquids in airline carry-on have led me to contemplate some non-standard transport options. Though I know it's not unheard of for bait-purpose freshwater ghost shrimp in the southern U.S. to be packed between layers of moistened newspaper positioned over ice, I have somewhat of a visceral opposition to the idea of keeping shrimp out of water for long.
On the other hand, some researchers I've spoken with have brought up the possibility of draping shrimp in clean, wet rags -- sans chilling -- for much briefer lengths (say, six hours).
Moreover, both
this French-language web page on the fauna of the Antilles and the newsletter of the Department of Ecology & Biodiversity at the University of Hong Kong (
Porcupine) report certain species of shrimp to at least occasionally venture beyond water in the wild. Of course, the time spans involved are probably rather brief.
From the former (on
M. acanthurus):
La nuit, elle peut se déplacer hors de l'eau vers d'autres milieux aquatiques grâce aux chambres branchiales de son céphalothorax qui conservent l'humidité.
That is:
At night, it can exit the water to seek other aquatic environments, thanks to the humidity-conserving branchial (gill) chamber of its cephalothorax.
From the latter:
Returning from an evening of fieldwork on a warm September night, I stopped short; there in front of me was a Macrobrachium shrimp walking over a footbridge that crosses a tributary of Tai Shing Stream in Shing Mun Country Park! It had apparently climbed a 50 cm precipice to get there. The ground was completely dry and the shrimp was facing upstream as I came across it. Startled by my close scrutiny of it with my headlamp, it turned around and scuttled into a "safer" position on a lower ledge of the footbridge. It waved its chelae around a bit and then after about two minutes it suddenly walked across the ledge, jumped headlong into the water and disappeared downstream. I wondered if these were the ramblings of a deranged individual or a phenomenon so rare that I had not come across it in my year and a half of night observations?
After talking to my co-workers, I learned that two other ecologists (Sze-man Cheung and Rita Yam) have observed similar behavior for two species of freshwater shrimps, Macrobrachium hainanense and Caridina cantonensis, in other streams. Strangely enough, Rita has witnessed a Macrobrachium in a tree!