This Wet Beast Wednesday I'm going to talk about gars. This needs some clarification because there are a lot of different fish called gar, garfish, or garpike. I'm referring to fish of the family Lepisostidae, the only surviving members of the ancient clade Ginglimodi, which I mostly brought up because Ginglimodi is a funny name.
(image: a longnose gar)
Gars are predatory fish found exclusively in North and Central America, though they have been introduced outside of their native range. Their ancestors evolved in Triassic period and once occupied most of North America and large portions of Europe back when the continents were still connected. They are freshwater fish, though a few species will go into brackish or even marine waters temporarily. The name "gar" is though to come from the old english word for "spear", which is appropriate as gar are very elongated fish and often have pointy snouts. Many other groups of elongated fish are also given the common name of gar or garfish for this reason. Their long snouts are filled with sharp teeth which are used to crush through shells and flesh. Gars are opportunistic predators who feed largely on crustaceans, frogs, and fish and will eat carrion if they find it. The long snouts are also used to dig through sediment in search of prey They move slowly through the water, but are capable of short bursts of speed to catch prey. Most species are apex predators with no natural predators as adults.
(image: a longnose gar with mouth open, displaying the teeth)
The body of a gar is covered with thick, diamond-shaped scales. Their scales are an ancient variety known as ganoid scales which are notable for their shape and composition. Where most bony fish scales have layers of a spongy, bony substance called cosmene, ganoid scales instead have an enamel-like substance called dentine, which is also a component in teeth. The scales are also covered in a rigid, glassy substance called ganoine where other scales use enameloid. Ganoid scales also don't overlap, instead laying next to each other in a manner that provided protection while still allowing flexibility. The result is a suit of armor that makes gar very durable. Because of how durable the scales are, they habe been used by humans for many purposes. Multiple Native American groups would use scales as arrowheads, there are reports of native Caribbean peoples wearing breastplates made of gar skin, and Europeans colonists would layer their plow heads with the scales to protect the,. There is currently a market for jewelry made of the scales.
(image: a close-up of ganoid scales)
(image: an arrowhead made of a gar scale)
Gar typically lay their eggs in early spring, with the female coating vegetation with thousands of sticky eggs. The eggs are toxic to humans, capable of causing sickness when ingested. Because of this, they are unsuitable for caviar. Scientists initially thought that the toxin was an adaptation to prevent predation, but natural predators of the eggs like channel catfish and bluegill are immune. Crayfish are affected by the eggs, though it's not clear if the poison is an adaptation targeting them or not.
(image: a shortnose gar)
The swim bladder of gar is highly vascularized, allowing them to act as lungs. Most gar will surface occasionally to take a gulp of air. While they are capable of surviving on their gills alone in good-quality water, air gulping allows gar to thrive in low-oxygen water where their prey will be sluggish from oxygen deprivation. Most species live around 20 years, but the alligator gar can live upwards of 70 years.
(image: a spotted gar)
There are seven living species of Gar: the Cuban gar, tropical gar, spotted gar, longnose gar, shortnose gar, Florida gar, and alligator gar. The shortenose gar is the smalles species, reaching an average length of 62.5 cm (24.6 in) while the alligator gar is the largest species and one of the largest of all American freshwater fish at an average length of 1.8 m (6 ft) in length. The largest alligator gar on record measured in 2.57 m (8 ft 5 in) and 148 kg (327 lbs). Alligator gar were long considered a nuisance species by fishermen as they preyed on sportfish and as a result, they were frequently killed. This resulted in population losses and the fish being extirpated from many states it was once native to. Now multiple states have laws and regulations protecting them and the population is starting to see a resurgence. Alligator gar and now a popular sportfish and have been introduced to places outside of their native range, becoming an invasive species in many areas including China.
(image: two fishermen with an alligator gar)
Gar meat is edible and is described as having a very unique taste compared to other fish meat. They are not commonly eaten in modern times, but some people consider them a delicacy. Gar meat is known to carry environmental toxins like pollutants and heavy metals, which can make eating them risky. Gar are mostly fished for their scales or for sport. Only the Cuban car is endangered (and critically so) while other species may be locally endangered, but as a whole are not threatened. Gar are used as aquarium fish due to their unique appearance, though they need large tanks due to their size.
(image: a close-up of an alligator gar's head)
