GarLab I [The Tank] - Cuban Gar study
- Thread starter E_americanus
- Start date
just a quick update as i measured the CBGs today - managed to get bitten only 3x, haha.
some stats:
- largest fish was just over 9.5", mean length is right around 8.7"
- over 42 days, fish have increased in weight by ~272%
- consumption rough estimate is ~60 feeder minnows/CBG per week over 6 weeks
more to come as i get the time--
--solomon
some stats:
- largest fish was just over 9.5", mean length is right around 8.7"
- over 42 days, fish have increased in weight by ~272%
- consumption rough estimate is ~60 feeder minnows/CBG per week over 6 weeks
more to come as i get the time--
--solomon
xander;5029253; said:
haha you have to put it into perspective xander, your gar is probably showing similar growth. you had yours at around 9" last (estimated) measure right? in aquaculture and fish ecology we often evaluate weight, as it tends to depart quickly from length in terms of increase with development and growth (scientifically called ontogeny).
at first measure the mean weight was around 11.2g for an individual fish, now the mean is 41.5g...so you can calculate increase in weight. for just about any gar it's pretty insane (compared to more "typical fishes"). i will have to look up the numbers, but for SPG it wasn't quite as fast, but it was still really fast compared to most other fishes. gator gars have the fastest (which we kind of would expect even with just hobby data), and at some points in development their feed conversion ratio (FCR) is actually lower than 1 (means they are super-efficient).
also keep in mind i am trying to maintain all the fish the exact same way, so i am not toying around with feed type at all...other than making sure minnows are generally always available. as you guys change things up with pellets and frozen fish, it can change up the gar itself (not necessarily a bad thing, but i need to control for as many variables as possible).
now get this...most studies have shown that at very early life stages, gators/Cubans/tropicals all actually did better on pelleted food than on live food. a major factor here is that we usually deal with our pet fish long after the hatchery/farm converts the youngsters to pellet food...LFS will usually give them live food, and since we are usually dealing with just 1-2 individual fish, we don't want to run the risk of starving them/killing them while trying to convert them back to pellets. it should be noted that the hatcheries often experience 40% mortality...and that's not something we can afford as hobbyists buying just one fish.
anyway, more info to ponder. we'll be expanding on this stuff in the future (hopefully) as well. oh, and the literature and those who have experience raising them in large numbers indicate that Lepisosteus genus gars are notoriously hard to convert to pellets at the very early life stages, and mortality is really high.--
--solomon
xander;5029253; said:
Have to gree with Alex thats some very nice growth on those guys.
What was the mean length of the gars at the beginning of the study?
pharmaecopia;5029492; said:
mean length at initial measure was 15.2 cm. mean % increase in length is ~46%, so although that's a good increase in length, they are obviously putting on more weight. this is what we would call well beyond allometric growth (that being relatively equal growth in the dimensions of length and weight).
will try to get some new video tonight; will definitely be shooting pics of the fish on the final measurement day, which will either be next week or the week after.
the study won't be running any longer than 2 more weeks (which is about as long as planned, but i may cut it off a bit earlier as we have good data so far and the cost of feeding these fish live is absolutely ridiculous).--
--solomon
E_americanus;5030444; said:
Interesting growth on those guys, seems to me that mine might be growing faster than yours. I know what your taking about as far as feeders, I just bought 500 myself on tuesday and the cubans have already gone through about 100 between the 4 and this is while being fed other items.
pharmaecopia;5030518; said:
yeah, there is a high possibility that the lower density fish may be growing slightly faster, but at the same time it is really hard to compare - different setups, different age, different husbandry, low sample size for yours (mine is already a pretty small sample stat-speaking).
your fish came in smaller than mine, so that initial growth is actually somewhat faster in all gars. i really wish we had the exact age, but at this point that can only be determined via otoliths, branchios, or fin ray clip...none of which i am willing to do at this time (first two are lethal).
again, hard to comment, i would say xanders and mine are probably going to have the closest growth rates (and the other guy who got one at the same time), yours may show slightly faster growth at first, but it should even out once they reach the point where ours started. hard to explain, but this is why we shoot for the largest sample possible - that and previous lit shows that YOY gar growth is highly variable within populations and year classes.
keep track of the days you have had them and if you can get a regular measure there may be something to discuss there, but again, we are all dealing with low sample size.
i just ran out of feeders today (i have 200 kept separately for the SPGs and 2 dozen large feeders for TPGs...so unfortunately i will have to buy another large batch tomorrow). PELLETS are so much cheaper in the long run!!!--
--solomon
E_americanus;5030585; said:
I've been tracking a couple things so far. Measurements, water parameters, and water changes, as well as anything else I feel is noteworthy.
pharmaecopia;5030623; said:
that's good! how often are you taking (length) measurements and are you taking them out of the tanks to do so? we can all measure through the glass, but it's seldom very accurate other than a rough estimate.
i was going to comment on the water changes...that definitely helps things along. i'm trying to stay somewhat consistent with our previous work, so water changes are 1x a week unless absolutely needed (powerfilters are covering that now). we're eventually looking at results that will use the least amount of water turnover as possible too...so that does sacrifice some growth for less water use (but that gets into all kinds of other stuff).
we have a large recirc system at one of our labs (where the SPGs are currently), but the temp fluctuates like crazy and there have been a lot of crazy issues there lately...so it seemed like the LAST place to keep a group of CBGs, haha--
--solomon
