Electric Blue Crayfish Behavior- is this normal?

[DirtyPaws949]

Hi folks. I have 10 juvie Florida blue crayfish, and have noticed their favorite place to hang out is at the surface, sometimes partially above water, on the hyacinths. They are fairly new, and have noticed them doing it more gradually.
i am curious whether this is a normal (feeding/ socializing/ happy) behavior, or indicative of some issue (oxygen? Stress?). They typically do this the most at night, but some will do it in the daytime. They don’t seem in distress, and there was two successful molts between last night and tonight (I actually got to watch one!)

I was warned to provide lots of places for them to hide since they can be aggressive towards one another. At least at the surface, mine seem content sharing space and hang out in groups.




IN CASE ITS INDICATIVE OF AN ISSUE
Here are the tank specifics in advanced

6ft x 2ft x 2ft galvanized steel tank, sealed with pond armor epoxy.
Sand substrate 2-3”, sponge filter.
there are calcium blocks in the tank for the snails and crays

water parameters
pH: 7.2-7.4
Ammonia: 0 ppm
Nitrites: 0 ppm
Nitrates: 0 ppm
Temp: 74F (had to turn the heater off during a heatwave, outside tank)

tankmates: bettas, platys, guppies, corydoras, Buenos Aires tetras, bloodfin tetras, Golden clams, mystery snails, Malaysian trumpet snails, ramshorn snails, pond snails, small organisms (can list it necessary).

plants: water hyacinth, water lettuce, salvinia minima, duckweed, azolla caroliana, frogbit, Anacharis, Najas grass, hornwort, 1 small lily

Diet: consists of crab-cuisine, shrimp pellets, tropical flakes and crisps, Algae waters, bloodworms, brine shrimp, blanched veggies, I’m guessing an endless plant/snail/critter/fry buffet.
They are fed a variety 2-3x per day.
I have not noticed any significant loss in adult fish.

 

[DirtyPaws949]

When I first got them they were fighting in the bags, when I initially put them in the tank they did go after a couple fish, but they’ve become pretty peaceful... I’d read nightmare posts where people say they’re blood thirsty and evil ?
I just watched one grab a snail, hold it for a min, then let it go, and when they do bump into each other they both jump back like, whoa sorry.
If they’re usually as mean as I’ve read, the placid behavior may also be a indication of something “off” in either the tank or the crayfish themselves.

 

[Deadeye]

I’m not an expert, but from what I’ve read, they tend to be peaceful with each other while they’re young and adult females tend to get along.
They may be trying to get more oxygen or see what’s out of the water. In the past mine have gone high to try to catch fish, so it could be that.
If they are still acting normal, then they should be fine.
That tank is beautiful by the way.

 

[Kelly_Aquatics]

could you post a full tank shot? just curious

 

[DirtyPaws949]

could you post a full tank shot? just curious

ya, here it is top-view.
it’s outside, so the glare/reflection makes it really difficult to photograph the inside right now.

 

[DirtyPaws949]

could you post a full tank shot? just curious

here’s a video I took earlier today of a feeding, so you can get an idea on what the inside looks like ??

Edit: forgot to link the video ??‍

 

[Kelly_Aquatics]

wow thats a beautiful tank i think its just them maybe trying to catch fish as they go bye or maybe looking for bugs that fall in the water

 

[DirtyPaws949]

wow thats a beautiful tank i think its just them maybe trying to catch fish as they go bye or maybe looking for bugs that fall in the water

thank you! I’m trying to make sure everyone is happy and mentally stimulated. I’ve been adding more plants/rocks/wood... so the bottom is now a variable labyrinth of fun stuff for critters to explore. I was worried it’s too busy, but they still have a ton (almost literally ?) of swimming space. I’m not really used to community fish, I have had big cichlids the past 9 years. The corydoras really love hanging out ontop of rocks, especially the albinos. Since I’ve been adding more to the bottom of the tank, I’ve been trimming the roots of the floaters.

As for the surface behavior, the plants soaking up the oxygen at night was my biggest suspect. I got an air pump and hooked the sponge filter up to an airline, and left the circulation pump running near the surface on its own with a bubble-tube-thing that it came with. The pump was too strong and would suck the sponge filter in as far as it would go, add debris clogging the intake, Flow and surface agitation was very low.
Since this change, the behavior has greatly decreased. Some still do it some of the time, but not en masse or as frequently/prolonged.
though it could also have been the addition of more decor/nooks on the bottom.

I had my first bad molt today ?
Last night I saw one that was acting odd, this morning I found one dead at the bottom, someone drilled through it’s exoskeleton (pretty impressive hole). I checked for any issues with the gills (someone had given me a crawfish but it died shortly after I got it, took it apart and it had black spots EVERYWHERE. I’m not really sure what that’s indicative of, but it was about 6-7” long and living in a 5.5gal tank half filled with water and fed twice a week, the tanks were absolutely filthy). While checking the gills, I noticed the exoskeleton came off easily (in sections) so I’m chalking the death up to a bad molt. The inside was clean.

The crays seem pretty content staying in the 180gal, but a couple days ago I filled it too high (I usually leave about 2-3” from the rim for mystery snails eggs) and one had crawled out. I found it on the patio and plopped it back in. It was in poor shape, but alive.

 

[EntoStentor]

Eh, I wouldn't worry. The climbing behavior is a little weird but as long as they not actually trying to climb out on masse it's probably not oxygen deprivation.

 

[Kelly_Aquatics]

how warm is it? might be a silly idea but maybe they are trying to bask in the sun like reptiles