Monday, September 29, 2008

"Life in Ponds at Selah" by Amanda & Steven Fulton

I want to thank Steven and Amanda for the work they did on this post.

When I found out about the two weeks of treatments I would be getting in Houston at MD Anderson Cancer Center, I asked Amanda and Steven Fulton if they would take pictures and write about them for the September 29th post. Both of them are good biologists, and they decided to feature some of the aquatic plants and animals that are common here at Selah. Animals and plants were collected by Steven Fulton and photographed by Amanda Fulton. Amanda took some of the photographs in the field.

Steven and Amanda worked as a team. Steven went out and captured fish, insects, larval critters and some aquatic plants. He brought them home and put them into an aquarium. Amanda took pictures which you'll see in this post. Gathering information and writing captions was done by both of them.

Those of us who work at Selah find the living things in creeks and ponds very interesting. Right now the creeks at Selah are mostly dry due to the drought. There are plants, animals, & microscopic creatures and plants. Like any habitat, there are food chains and communities in which the inhabitants interact and are dependent upon the health of the whole ecosystem.

I hope you enjoy this interesting look into the watery world.

Aquatic Plants:
There are plants that live entirely submerged in water, others that have their roots at the bottom of the pond, but a good part of them is above water (think of cattails). Some plants float on the top of water, like duckweed and water lillies, and others that need to be along the edge of water where their roots are always wet.

Coontail (Ceratophyllum spp.) This submerged plant inhabits ponds with still water such as Madrone Lake. It is usually one of the most abundant fresh water plants.

Pondweed (Potamogeton nodosus). A plant with floating leaves approximately 3 inches long and 1/2 inch broad. The seeds are on cylindrical spikes floating on or extending above the water. These plants have roots in the the bottom of the lake, and tend to extend upward into the swimming zone near the shore of Madrone Lake, which makes them the most visible plant.

This little aquatic plant is common but we don't know the name of it, and couldn't find it in the field guides we have. If you know what it is, please let us know by leaving a comment, or going on our website and sending an e-mail to the ranch.

Some aquatic insects live in water but breathe air, some that spend their larval period under water and get oxygen from the water with their gills. Many of the aquatic larvae go through metamorphosis to become flying insects that are seen around water, such as dragonflies.

Water Scorpion (Ranatra fusca). Some people may mistake the water scorpion for a walking stick because of their similarities to their terrestrial insect relatives. They move about very slowly and often sit motionless for long periods of time. The stinger-like tail is actually breathing tube used to attach them to the waters surface. Note the dimple on the water's surface, where their breathing-tube reaches the surface. Their front legs are modified for catching prey. They are predatory insects that feed on other insects by injecting digestive enzymes into their prey and sucking the liquid from them and leave the exoskeleton behind.

Dragonflies are ferocious predators in both the larval and adult stages, they feed on other insects.

Dragonfly larvae are also known as nymphs. They are found in a range of permanent and temporary aquatic habitats. The larvae harpoon other aquatic insects by extending their lower lip at lightning speed. They are green and brown in color helping them to be camouflaged in their environment. If this nymph looks dead to you it is because it is dead. The water scorpion killed it.

Roseate Skimmer (Orthemis ferruginea). The Roseate Skimmer has a pale-bluish thorax and a bright pink or purple abdomen. The wings are transparent with orange veins and black tips. They are very active foragers and prefer tall vegetation. My observation of the skimmer was that if perched, any movement by other dragonflies or myself, the skimmer would take off in flight. The Roseate skimmer is an aggressive predator, feeding on insect only slightly smaller. At this particular feeding sight they were outnumbered by the Twelve-spotted Skimmer.

Twelve-spotted Skimmer (Libellula pulchella). The Twelve-spotted Skimmer has a very distinct wing pattern of dark brown or black wing spots. The male is characterized by having two white spots on each forewing and three on each hindwing. I thought that the white spots of the male looked more pale blue than white. They prefer open pond and lake shores well exposed to sunlight. While watching them I noticed that they are very territorial. I often saw them chasing other dragonflies away.

Burrowing Mayfly (Family Ephemeridae, Hexagenia limbata). These aquatic larval insects were given their name because they burrow into sediment at the bottom of lakes and streams. The feather-like gills you see extending out of their abdomen allow them to breathe in oxygen depleted environments.

Fish are born in water, live and breathe in water. A variety of different kinds of fresh water fish live at Selah. Some of them are featured in this post. All of these fish were in an aquarium and were small. In looking at the pictures in Freshwater Fishes of Texas (Which is #2 on the list of sources at the end of this post), I believe that they all (except for the Longear Sunfish) have juvenile markings, and certainly were in the size range for juveniles (1.5 to 3 inches).

Juvenile Channel Catfish (Ictalurus punctatus). One of my favorite fish to catch and eat, the channel catfish can be found in most lakes and rivers in Texas and is a popular fish to release into stock ponds. It is mostly a bottom feeder; we know this because of observation and the telling characteristic of its mouth located underneath its head. Catfish are scale-less fish with their skin covered in a slimy mucus. Although many people are repulsed by their covering of mucus, the catfish needs it because the mucus is an important defense against harmful bacteria. Finally, the characteristic whiskers that give this fish its name are not whiskers at all and are scientifically known as barbels which are sensory structures that aid this fish in finding food in dark environments.

Juvenile Large-mouthed Bass (Micropterus salmoides). The large-mouthed bass is the most sought after fish by sport fisherman. Its aggressive behavior and large mouth, make it fairly easy to catch with almost any type of bait. Its large mouth also distinguishes it from other bass species in this area. Before introducing this species to a newly developed aquatic habitat, be sure to have established populations of smaller baitfish, otherwise the large-mouth bass will eat itself into oblivion.

Juvenile Bluegill (Lepomis macrochirus). The bluegill is a common sunfish that is found statewide in most aquatic environments. It is a favored game fish for many anglers, especially fly fisherman. Reaching lengths of up to 16 inches, it is one of our largest sunfish; however, I have caught very few of large size here at Selah. This is possibly due to our cyclic droughts that reduce the size of pools in the creek, which makes the larger individuals more susceptible to predation.

Juvenile Green Sunfish (Lepomis cyanellus). The green sunfish is common in many aquatic environments, especially in backwaters and ponds. I find them to be very aggressive and their large mouths enable them to capture and swallow larger prey items than the other sunfish featured here. They are very competitive and when introduced to stock ponds they will quickly become the dominant baitfish species. This sunfish will also reach large sizes (up to 10 inches) and will react to many types of bait—live or artificial.

Longear Sunfish (Lepomis megalotis). Of the three sunfish featured here the Longear is moderately aggressive and smallest in size; however what they lack in size they makeup for in fight, making them enjoyable to catch with a pole-line. Their blue, green, and red coloration also makes them an attractive aquarium pet.

1. Kaufman Field Guide to Insects of North America by Eric R. Eaton & Kenn Kaufman
2. Freshwater Fishes of Texas by Chad Thomas, Timothy H. Bonner, & Bobby G. Whiteside
3. Dragonflies and Damselflies of Texas and the South-Central United States by John C. Abbott
4. A Guide to Freshwater Ecology by Texas Natural Resource Conservation Commission

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