By William Berg of Sweden, for http://www.aquaticcommunity.com

If you take a quick look at this species they don't seem like aquarium fishes. They are large and highly predatory. But then again, these are qualities that attract some, like me! If you've been keeping aquariums for a while and have room to keep large predatory fishes I recommend you try these fish, but not until you've done your homework and know gars' requirements and what you are getting yourself into.

Species of gar:

Florida spotted gar, Lepisosteus platyrhinchus A highly varied species of gar. Has more spots on its body and a shorter snout than many other gars. Easily mistaken for spotted gar.

Spotted gar, Lepisosteus oculatus Long snout and spots. Spots to a higher degree towards posterior of its body. Easily mistaken for Florida spotted gar.

Shortnosed gar, Lepisosteus platostomus The shortnosed gar can be identified by its short snout, and by lack of teeth rows in upper jaw like alligator gar, and lack of spots on its body.

Long-nosed gar, Lepisosteus osseus The long-nosed gar is, as name suggests, identified by its long slender snout, and also by its slender body.

Alligator gar, Atractosteus spatula The alligator gar has a short broad snout and two big rows of teeth in upper jaw. This species is spotted on posterior part of body and to a lesser extent on other parts of body.

Tropical gar, Atractosteus tropicus A very rare species.

Manfari or Cuban gar, Atractosteus tristoechus Looks very similar to alligator gar and since it is very rare in trade you can usually assume that your gar is an alligator gar and not a Cuban gar unless otherwise stated. The Cuban gar has a broader snout and lacks pattern on its body.

Beside these species there are a number of hybrids such as crocodile gar.

By William Berg of Sweden, for http://www.aquaticcommunity.com

In text below I shall try to give a short overview of some of basics when breeding crayfish. Particular species may have other behaviours and demands. It should be said that my main experience as an aquarist is with relation to fish, but I shall try to convey what little knowledge I have.

Sexing Crayfish Sexing crayfish isn't always easy. The genital openings are located in different places on body depending on whether it's a male or a female. Males have their genital openings behind/under their posterior pair of legs. Females have their genital openings under third pair of legs counted from posterior. However, many individuals have a male as well as a female genital opening, making sexing much more complicated. But these are always either male or female; usually male but you can't be sure.

Mating and egg carrying In aquariums, spawning is possible any time of year. The male makes a little sperm packet and places it on female's stomach. The female then spawns her eggs, passing them through sperm packet so that eggs get fertilized. It is not uncommon for female to lose a claw during this process. She then places eggs under her tail where they will be kept until they are ready to be released. How long this will be depends on water temperature and species, but it will be at least 4 weeks. A lot of other factors can also affect length of egg carrying period, such as water quality, and food supply and quality. The mother will watch over young for a short time after birth.