donna13350
01-29-2009, 10:56 PM
i got one..!! i am happy..she is interesting...:thm:but i am so diselusioned about the info out there about them...:help:i googled them..read everything i could..thought they were peaceful and wouldn't harm my fish...well...i was wrong...they are CARNIVORES....they have hunted and gotten my angels...they look like hedge clippers got them....then when i fed the angels krill, the marmokrebs came out, like they could smell it, and ran around frantically till a piece sunk, then grabbed it and took HUGE bites out of it..............
just be warned...these are no different than regular crayfish, (other than their breeding habits)..but they are carnivores and will, and do...eat your fish...donna
black_sun
01-30-2009, 11:59 AM
Are you sure you have a Mamorkreb and not maybe P. fallax or P. enoplosternum (very similar looking species)? Mamorkrebs are a species that prefers vegetable matter to meat matter (They are not carnivores, like all crayfish species they are omnivores.) and is "normally" a very passive species unless it's been harassed by a tankmate or starved for food. I've never had a Mamorkreb actively hunt (and they'd only eat meat matter if it was prepared - pellets, food scraps, etc) nor known any other keepers that had them do such (not to say that they can't, they are crayfish after all, and as such are "opportunistic scavengers" and if they're hungry they're going to want to eat whatever is available).
Additionally, they CAN smell the food. The smaller set of antennas, the antennules, are for the smell of food. And the smaller worm-like appendages, the maxillipeds, near their mouth serve a similar function. Additionally, they can do the same with their pinchers and walking legs, the pereiopods. (Info from "Freshwater Crayfish: Biology, Management and exploitation" by Holdich)
Personally, if you do have a true Mamorkreb it sounds like you've introduced them to a bad scenario and unintentionally caused issues with tankmates and feeding times. The behavior described seems normal for the aggressive species of crayfish, but abnormal for the more passive species (Mamorkrebs included in this category). And as such, sounds like the crayfish you obtained was ill-cared for and not properly fed before you got it. And that frantic behavior was caused by them smelling the introduction of food to the tank and having to fight with a semi-aggressive type of fish in competition for food.
I'd suggest setting up different feeding times and areas for your fish and crayfish. And "fattening" your crayfish up with a little more frequent than normal feedings for a few weeks. And at an extreme, which you are free to disregard at your discretion, I'd suggest setting up a different tank for your crayfish. Mamorkrebs are normal a passive species, but if they are bothered they will actively defend themselves... and fish with long fins are easy to grab and tear up when defending themselves. Additionally, that behavior can easily turn into a feeding opportunity, the whole "opportunistic" thing again. While, it isn't an active behavior in Mamorkrebs, no animal is going to give up an opportunity to feed itself.