Observations by laurenhalbert

This diatom, genus Gyrosigma, was found towards the middle of the Colorado River, on top of a shoal. The water was no more than 6 inches deep, and was moving at a moderate rate.

Gyrosigma species are symmetrical braphids that are sigmoid in shape, or shaped like an S-curve. Their striae are punctate, meaning they have tiny pores. The central area is circular or elliptical in shape ("Gyrosigma." Diatoms of the United States. University of Colorado, 2009. Web. 17 Nov. 2016.).

Photo - "Gyrosigma." Protist Images. Protist Information Server, n.d. Web. 17 Nov. 2016.

This diatom, genus Punctastriata, was found in water 4-6 inches deep in the edge of the Colorado River. The water was moving at a very slow rate and there was a moderate amount of aquatic vegetation.

This genus of diatoms is a cosmopolitan type of brown algae. Punctastriata species are araphids, and thus do not possess a raphe. Striae are triangular and composed of net-like areolae. Spines are present, and are often used to link multiple diatoms together to form chains (Spaulding, S. "Punctastriata." Diatoms of the United States. University of Colorado, 2013. Web. 17 Nov. 2016.).

This water strider (family Gerridae) was found in the littoral zone of a wetlands pond off of Proctor Lake. The water was 2-4 inches deep and contained an abundance of aquatic plants and grasses, both below and above the surface.

Water striders have elongated or oval shaped bodies that are covered with fine hairs. They possess three pairs of legs, two longer pairs protruding from the body and one short front pair near the head. Water striders can be winged or wingless, and an intermediate form is also possible. Species of this family range in size, with the larger species being anywhere from 12-16 millimeters. Tiny hairs on the end of the two long pairs of legs allows water striders to skim on top of the water. These hairs are hard to wet, and thus allow flotation. The length of their legs is also a key factor in skimming, as it spreads out the mass of the insect over a larger area; this keeps the insect from breaking the surface tension of the water.

Water striders are predatory insects; they feed on insects that fall and become trapped on the surface of the water or on aquatic insects that breach the surface to get air. The two pair of long legs they possess allow for quick skimming and swimming, and the front pair of legs is used for grasping prey. Water striders use their piercing-sucking mouthparts to inject paralytic saliva that disables their prey and begins to digest its tissues
("Water Striders." Colorado Insects of Interest. Colorado State University, 2013. Web. 12 Nov. 2016.).

Many birds feed on water striders, which returns the nutrients gained by striders from terrestrial insects back to land ecosystems. Fish do not seem to prefer water striders and rarely eat them ("Water Striders." MDC Discover Nature. Missouri Department of Conservation, n.d. Web. 12 Nov. 2016.).

This minnow mayfly nymph (Baetidae) was found in the littoral zone of a pond in the wetlands of Proctor Lake. This organism was in water approximately six inches deep and abundant with aquatic plants, algae, and terrestrial plant debris.

Minnow mayflies, during the nymph stage, are small, streamlined larvae that possess long antennae, usually 2-3 times the length of the head's width. The head is vertically oriented. Hind wing pads are usually very small, if present at all. Oval shaped gills protrude laterally from the abdominal segments. Either two or three tails are present on minnow mayfly nymphs. When mature, they range in size from 3-12 millimeters ("Order Ephemeroptera - The Small Minnow Mayflies" Digital Key to the Aquatic Insects of North Dakota. Valley City State University, n.d. Web. 12 Nov. 2016.).

Minnow mayflies are found throughout North America and worldwide in lentic and lotic aquatic habitats. These mayflies are very sensitive to pollution, so they require clean, well-oxygenated water. Nymphs feed on dead organic matter and adult mayflies do not possess mouthparts. Minnow mayfly nymphs and adults serve as a primary food source for fish and other aquatic organisms ("Order Ephemeroptera - Mayflies." Bug Guide. Iowa State University, n.d. Web. 12 Nov. 2016.).

This yellow nutsedge (Cyperus esculentus) was found on the immediate banks of Proctor Lake, approximately 3 feet from the edge of the water. This plant was very abundant along the fine-grained shores of the lake.

Yellow nutsedge is a grass-like member of the sedge family that grows all across the United States and up into Canada. This large range is due to the plant's durability; it has a high tolerance to heat, drought, and flooding, and is usually able to regrow after disturbance. Yellow nutsedges possess linear, narrow, folded leaves that tend to be 4-12 inches long and are less than half an inch wide. Flowers are very small and are contained in a cluster of spikes, that is in turn surrounded by a whorl of leaf-like bracts.Foliage is bright green and inflorescence is yellow or golden-brown ("Weed Profile: Yellow Nutsedge (Cyperus Esculentus) and Purple Nutsedge (C. Rotundus)" EXtension. EXtension, 2013. Web. 13 Nov. 2016.).

Raccoons, skunks, and crows will dig up the tubers of yellow nutsedge, and deer and squirrels will feed on any tubers left exposed ("Yellow Nutsedge." Coquillo Facts. The Ojos Negros Research Group, n.d. Web. 12 Nov. 2016.).