I have decided to keep a tank specific journal on my newest tank I have set up. First, a bit about me, then a bit about the tank and its reasons for existing, then finally the journal entry itself. My hopes are in doing so to illustrate the vast differences between species an more importantly why you should be VERY careful in considering either of these animals as "pets**". Also, if I answer a few questions along the way then great. 
Disclaimer: I should note if anyone thinks to shoot off about how these animals should not be in captivity, what am I going to do when the crocodile hits 18-20 feet etc etc your in the wrong place. I know full well what I'm doing and this is not my first or even my 100th rodeo with these species. In fact in a given week a dozen will pass through my hands of various sizes from hatch-lings to fully set adults, and everything I deal with ends up in the wild, deep in the rainforests of Panama, usually tagged. I don't need, require or have any interest in your liberal crap. I'm not in the USA or any first world country so even if you wanted to do something about it you cannot.
I'm Grim! I have been keeping reptiles for the last 13 years or so of my life. I am not a fish man, nor do I own any birds or even want any. (Though I did seriously consider going for my apprentice falconry license at one time). My preference is stuff you cannot find in a pet shop or even usually a reptile specialty shop. I buy breed and broker as a way to support my hobby. Currently my collection is exclusively venomous with the exception of my caimans and crocodiles however this journal is not about the snakes/lizards.
The tank this journal is about is a 55 gallon "breeder" tank (48 1/4" long x 12 3/4" deep x 21" high). Its sole purpose is to provide a habitat for 1 Spectacled Caiman and 1 American Crocodile for the first year of their life. After that they will be moved. The tank was started with a hatchling Caiman, approximately 72 hours old. A month later a similar American Crocodile was added. Now, a month later I have some things to report. Also in the tank at inception were 9 Tiger Barbs, 12 Glass Shrimp, and 1 native algae eating snail that was about the size of a golf ball. Internally it has a 200GPH 3 stage filter, black Zoo Med Repti-sand (Yes, I use it under water. It works great and looks even better if you rinse it first), a few fake vine style plants, 1 large reptile branch, and finally a air stone mounted near the exit pipe for the filter to ensure proper circulation.
There, now, onto the progress. Here we are about 4 months in. In the first 48 hours the Crocodile ate every single living thing in the tank including the snail, despite being only 4 inches snout to vent. The Caiman I should note is currently 6 inches snout to vent. This kind of pissed me off for a few reasons. Firstly, I had taken great pains to ensure the water quality and setup could support a "prey" school of fish to encourage proper hunting behavior, that I assumed would get slowly eaten and I would slowly replace. Secondly all the creatures in the tank had survived just fine minus the occasional glass shrimp or tiger barb for an entire month with the Caiman in there alone. When I put the fish, shrimp etc in the tank I did so with the full expectation that they could be eaten and thus I chose according to what I was OK with replacing. What I was not ok with was hand feeding this Crocodile a huge quantity of diced salmon, shrimp, some beef heart, and ground chicken bone/cartilage just minute prior to it going into the tank, to the point it was nice and firmly fat, only to have it additionally eat every single thing in the tank in 2 days. So I simply did not replace anything after that with the exception of maintaining the school of native minnow style fish for them to hunt. These cost me $.01 each from the native kids along the river and I keep a small 10 gallon with a large school in there to supply me.
Now, shortly after going in the Crocodile and the Caiman began fighting. This lasted about 3 days even though the Caiman was nearly twice the total length of the Crocodile. I finally intervened and spent all day bonking em on the head with a 36 inch hemostat when they would start it. After that things settled down. Now, they only take nips at each other when its feeding time as they jockey for position as to who will eat first. Overall the caiman is far more laid back then the crocodile. An example of this is if you pick them both up the caiman will stop struggling within seconds. The Crocodile will not stop until its worked itself into total exhaustion. The Caiman will often come to the glass to see what I'm doing and just sit there even if I approach the tank. The Crocodile will only sneak up the the front when I'm sitting next to the tank and not looking so it can attempt to bite me through the glass. These experiences totally coincide with what I know about the behavior of these species overall, along with my own experiences with others of these species. In general the Crocodiles always seem more...pissy... then the Caimans I have dealt with. Each has their own personality to be sure but overall I feel that's an accurate statement. I have attached a picture but sadly being new, I'm not sure how to blow it up. I will continue to add to the journal every few days or as things develop but I feel this is a good starting place. Feel free to ask any questions you may have and I will do my best to answer them.
Disclaimer: I should note if anyone thinks to shoot off about how these animals should not be in captivity, what am I going to do when the crocodile hits 18-20 feet etc etc your in the wrong place. I know full well what I'm doing and this is not my first or even my 100th rodeo with these species. In fact in a given week a dozen will pass through my hands of various sizes from hatch-lings to fully set adults, and everything I deal with ends up in the wild, deep in the rainforests of Panama, usually tagged. I don't need, require or have any interest in your liberal crap. I'm not in the USA or any first world country so even if you wanted to do something about it you cannot.I'm Grim! I have been keeping reptiles for the last 13 years or so of my life. I am not a fish man, nor do I own any birds or even want any. (Though I did seriously consider going for my apprentice falconry license at one time). My preference is stuff you cannot find in a pet shop or even usually a reptile specialty shop. I buy breed and broker as a way to support my hobby. Currently my collection is exclusively venomous with the exception of my caimans and crocodiles however this journal is not about the snakes/lizards.
The tank this journal is about is a 55 gallon "breeder" tank (48 1/4" long x 12 3/4" deep x 21" high). Its sole purpose is to provide a habitat for 1 Spectacled Caiman and 1 American Crocodile for the first year of their life. After that they will be moved. The tank was started with a hatchling Caiman, approximately 72 hours old. A month later a similar American Crocodile was added. Now, a month later I have some things to report. Also in the tank at inception were 9 Tiger Barbs, 12 Glass Shrimp, and 1 native algae eating snail that was about the size of a golf ball. Internally it has a 200GPH 3 stage filter, black Zoo Med Repti-sand (Yes, I use it under water. It works great and looks even better if you rinse it first), a few fake vine style plants, 1 large reptile branch, and finally a air stone mounted near the exit pipe for the filter to ensure proper circulation.
There, now, onto the progress. Here we are about 4 months in. In the first 48 hours the Crocodile ate every single living thing in the tank including the snail, despite being only 4 inches snout to vent. The Caiman I should note is currently 6 inches snout to vent. This kind of pissed me off for a few reasons. Firstly, I had taken great pains to ensure the water quality and setup could support a "prey" school of fish to encourage proper hunting behavior, that I assumed would get slowly eaten and I would slowly replace. Secondly all the creatures in the tank had survived just fine minus the occasional glass shrimp or tiger barb for an entire month with the Caiman in there alone. When I put the fish, shrimp etc in the tank I did so with the full expectation that they could be eaten and thus I chose according to what I was OK with replacing. What I was not ok with was hand feeding this Crocodile a huge quantity of diced salmon, shrimp, some beef heart, and ground chicken bone/cartilage just minute prior to it going into the tank, to the point it was nice and firmly fat, only to have it additionally eat every single thing in the tank in 2 days. So I simply did not replace anything after that with the exception of maintaining the school of native minnow style fish for them to hunt. These cost me $.01 each from the native kids along the river and I keep a small 10 gallon with a large school in there to supply me.
Now, shortly after going in the Crocodile and the Caiman began fighting. This lasted about 3 days even though the Caiman was nearly twice the total length of the Crocodile. I finally intervened and spent all day bonking em on the head with a 36 inch hemostat when they would start it. After that things settled down. Now, they only take nips at each other when its feeding time as they jockey for position as to who will eat first. Overall the caiman is far more laid back then the crocodile. An example of this is if you pick them both up the caiman will stop struggling within seconds. The Crocodile will not stop until its worked itself into total exhaustion. The Caiman will often come to the glass to see what I'm doing and just sit there even if I approach the tank. The Crocodile will only sneak up the the front when I'm sitting next to the tank and not looking so it can attempt to bite me through the glass. These experiences totally coincide with what I know about the behavior of these species overall, along with my own experiences with others of these species. In general the Crocodiles always seem more...pissy... then the Caimans I have dealt with. Each has their own personality to be sure but overall I feel that's an accurate statement. I have attached a picture but sadly being new, I'm not sure how to blow it up. I will continue to add to the journal every few days or as things develop but I feel this is a good starting place. Feel free to ask any questions you may have and I will do my best to answer them.
