Date:August 25th, 8:00PM
Happy Monday, everybody! Today's fish of the day is the shortnose gar!
The shortnose gar, also known as the billy gar, and scientific name Lepisosteus platostomus, is a common ancient fish. This name comes from the relatively short snout, when compared to the other fish in the Lepisosteus family, with Lepososteus coming from the Greek words for "bony scale" and platostomus coming from the Greek words for "broad mouth". Found in and around the Mississippi river, ranging from Montana to Ohio, and then South down the river and its tributaries to Louisiana, Texas, and Alabama. These fish live in and around quiet pools and backwaters, as well as oxbow lakes. These fish prefer areas of calm warm water, although these fish are tolerant of higher turbidity than other gars. The shortnose gar can also be found in areas of very low oxygen, as these fish have a special and highly vascularized swim bladder, which allows them to take in oxygen through the mouth. This leads to a behaviour called "breaking", where these fish will come to the surface before opening and closing the mouth loudly. This gives them not only the ability to live in areas of low oxygen, rife with edible invertebrates, but also gives them the ability to survive outside of water for up to 24 hours. The shortnose gar fish are visually distinct from the other three Lepisosteus fish, as they have only one set of teeth (as opposed to the two sets found on alligator gar), a shorter snout than the longnose gar, and have little or indistinct spotted as compared to the spotted gar.
The diet of the shortnose gar is primarily made of fish, however as opportunistic feeders they are often found consuming crayfish and insects as well. Young gar primarily eat insect larvae, although once they reach a size of 3cm they will begin feeding on minnows. When flooding occurs, they are also often found feeding terrestrial insects and amphibians they previously could not reach, and can occasionally be territorial over favorable pools during the periodical cicada bloom. As the smallest of the gar family, coming in at a whopping 28inches on average for a full grown adult, with the largest found being 32in, they're prone to eating the most invertebrates. Like all gars, these fish are stalking predators, rather than ambushes. They vibrate their fins in small movements, propelling them forward with little movement, before lunging out at prey. The teeth are not made for ripping or breaking up fish, but rather to make escape impossible until the fish goes limp, and the gar can swallow prey whole, headfirst. These fish are not easily predated on, as the hard diamond shaped scales and bony-esc armor make them a hard snack for larger fish.
Shortnose gar spawn around May-July, depending on water temperature and conditions. Once the water reaches 60 degrees F, gar will begin to seek another out, although actual laying of eggs will only occur once waters reach 70 degrees or higher. Female gar can be found either in a pairing with a male gar, or one female surrounded by multiple males. These eggs will be scattered onto vegetation or other submerged structures, where the bright yellow eggs are likely to not be eaten, as they are incredibly toxic to warm blooded animals. The eggs will hatch after 8 days, and young will become active a week after this, once the fry have finished absorbing the yolk sac. These young will spend a majority of their time first consuming small crustaceans and insect larvae at the surface of the water, where they are said to look like floating black matchsticks. Once these fish have reached an age of 3, and about 15 inches, they can begin breeding, with most surviving only 9 years, although one aquarium specimen survived for 20 before succumbing to old age.
That's the shortnose gar, everybody! Have a wonderful Monday!
Sources:
“Shortnose Gar.” Missouri Department of Conservation,mdc.mo.gov/discover-nature/field-guide/shortnose-gar.
“Shortnose Gar (Lepisosteus Platostomus).”RSS,tpwd.texas.gov/huntwild/wild/species/sng/.
Montana Natural Heritage Program and Montana Fish. “MTNHP." Shortnose Gar, 2025, fieldguide.mt.gov/speciesDetail.aspx?elcode=AFCBA01030.
“Lepisosteus Platostomus Summary Page.” FishBase,www.fishbase.se/summary/2597