The Mega-Fish of Armand Bayou

Written By Mark Kramer

Many a paddler has returned to the shores of Armand Bayou convinced that they have had a close encounter with an alligator or even worse, a monster from the deep. A huge splash rocks the boat and soaks the person from head to toe. The culprit is most certainly one of the three species of gar occurring in Armand Bayou. Gar are harmless to humans. Yet, a surprise encounter creates a moment that will be remembered. I have certainly had my share of these heart-stopping paddling adventures and they never seem to be less exciting.

Gar are ancient fishes which are specially adapted for life in shallow sluggish moving bayou waters. They are among a group of fishes which pre-date bony fish and whose skeleton is composed largely of cartilage. Gar scales function as an interlocking armor plating. These type of ganoid scales are more protective than other fish scales which typically overlap (cycloid scales). It was once believed that gar were a fish which impacted sport fish populations. Today, it is known that gar are primarily scavengers and have little impact on “desirable” sport fish species populations. 

Gar surfaces to gulp air and also takes in some Armand Bayou bird watching-Photo by Gary Seloff

The key to gar success in bayou waters lies in their unusual adaption to breath air. Gar are able to absorb oxygen from the water through the use of gills as are most fish. However, they also have a specially adapted swim bladder which functions as a primitive lung. The swim bladder in most fish is a “balloon” type organ which helps to float or position the fish in the water column. Inflated, the fish rises nearer the water surface; deflated, the fish sinks. The gar’s swim bladder, when inflated, also functions like a primitive lung. The swim bladder lining is rich with blood vessels and can absorb oxygen to supplement the gills’ uptake of dissolved oxygen from the water. The gar’s swim bladder is also attached to the esophagus. This allows the fish to surface and “gulp” air to inflate the bladder and “breathe”. I occasionally witness a large gar surface near my kayak and there is a sound resembling a person taking a sudden gasp for air when the swim bladder is inflated.

The long hot days of summer can cause fish kills around Galveston Bay – Photo by Mark Kramer

During the hot summer months, bayou water temperatures hover around 90 degrees. An important physical property of water to understand is that the warmer the water temperature, the less dissolved oxygen the water is capable of holding. Water quality may be further compromised by excessive populations of plankton and algae in bayou water. Long day length, bright sun, and warm temperatures create perfect conditions for a “plankton bloom”. Often, bayou water resembles split pea soup during these peak algae bloom periods. These conditions further rob dissolved gases, including oxygen, from the water. Virtually all aquatic life as we know it depends on adequate dissolved oxygen levels to survive. When water temperatures reach such extreme highs and are coupled with plankton blooms, fish may be killed due to low dissolved oxygen levels (hypoxia) in the water. These fish kill events are typically associated with more sensitive species as is shown with the Gulf menhaden in the above picture. Gar have evolved the unusual ability to supplement oxygen intake through the swim bladder, allowing their species to thrive during these difficult periods.

Spotted Gar (Lepisosteus oculatus) are commonly seen at the water’s surface during eco-tours on the Bayou Ranger - Photo by Mark Kramer

Four species of gar occur in Texas. I have documented three species in Armand Bayou. Shortnose gar (Lepisosteus platostomus) are the only species not yet identified in Armand Bayou. The most common is the spotted gar. Spotted gar are the smallest gar species found in the bayou and average 2-3 feet long. Spotted gar prefer low salinity levels in the water and are typically found in upper Armand Bayou. 

Longnose gar (Lepisosteus osseus)-Photo by Mark Kramer

Most people consider gar to be an ugly or frightful fish. Maybe this contributes to the general lack of respect the fish receives. I suggest that there is beauty in the enduring design of the fish which has lived unchanged for millions of years. I would further disagree when discussing the longnose gar. Seldom seen, the long-nose gar is sleek with an extended slender snout which has beautiful black markings.

Alligator gar are the second largest freshwater fish in North America with a world record of 327lbs.-Photo by Mark Kramer

Alligator gar are the largest freshwater fish in Texas. Adults average six feet in length but some have been known to grow ten feet long and live for over sixty years! While they are classified as a freshwater fish, I have encountered them while paddling in waters ranging from Lake Livingston to San Luis Pass. The animal has a stout head that resembles the head of an alligator. Its large size and gruesome appearance have given it an ill-fated reputation. In fact, in 1933 the Texas Fish and Game Commission undertook a statewide effort to eradicate gar from many Texas water bodies. This philosophy endured for years around the country and today the alligator gar has been extirpated in Indiana, Illinois, and Ohio due largely to lack of adequate harvest regulations. The species has been considered a “rough” or “trash” fish, and only in recent years received the appropriate protection to promote its long-term survival.

Bow fishermen on Armand Bayou

While this large, long-lived, specially adapted fish may seem invulnerable after surviving on earth for many millions of years, there are several chinks in its defenses. The fish are slow to reach maturity, taking about ten years to reach reproductive age. This long maturation period makes for a lengthy recovery if the adult breeding population is removed. Alligator gar also have a very specific set of requirements needed to trigger spawning. Flood events motivate reproductive behavior, stimulating fish movement to adjacent flooded shallow fields where spawning occurs in the spring and summer. In the Bayou City, most all of those bayous have now been channelized. This man-made alteration of bayou hydrology is designed to help minimize flooding, but has also largely eliminated those adjacent fields needed for reproductive habitat. The unusual air-breathing characteristic puts the fish at the water’s surface frequently. This surfacing makes gar an easy target for bow hunters who shoot the fish with barbed arrows when they surface. 

Few fishermen find gar to be desirable table fair and choose to release these mega-fish of the Bayou City. Photo by Mark Kramer

I worked as eco-tour guide Captain of the pontoon tour boats operated by Harris County Parks Department during the 1980’s. The free boat tours ran out of Bay Area Park five days per week. Those electric boats had seats which were positioned to the very front edge of the boat. Each trip began with a word of caution – “please be aware that we are likely to bump a huge fish which will rock the boat, create a gigantic splash, and cover you folks in front with water”. Those gar interactions occurred regularly for years, but have now become very rare. A lack of harvest regulations, loss of reproductive habitat, and a bad reputation have all contributed to gar population decline throughout their range. Today, fishermen with concern for the future are increasingly embracing catch and release practices.