WETLAND, FOREST & OTHER BIOMES

BIOMES: "A major community of living or-
ganisms; a complex of climax communities
of plants and animals in a major region."
"A major life zone, biotic formation."
"A major ecological community type."

AQUATIC INSECTS AND PLANKTON
Freshwaters harbor a variety of insects and other arthropods. Along with microscopic plants, their larvae are an important part of the plankton. 3 pgms. 60 slides, guides.
EP #452X SLIDES
$99.95

*****************************************************************************************************************
SAVE OVER $27.00 ON 3 SLIDE SET BUNDLE ORDER EP #452X.......$99.95
*****************************************************************************************************************

REPRESENTATIVE AQUATIC INSECTS Order #452........$42.50

Revised 1999

A survey of common insects which occur in freshwater environments and details
of their life history and significance. Includes close-ups of mayfly and stonefly nymphs,
giant water bug, backswimmer, water boatman, water strider, water tiger, predaceous
diving beetle, water scavenger beetle, whirligig beetle, dragonfly and damselfly nymphs,
caddisfly, black fly and mosquito larvae and hellgrammite. 2O slides and detailed guide
with images for easy reference.

CONTENT SAMPLE: 21025 This predaceous diving beetle is the adult form of the water
tiger and it too is an aquatic predator. While its mandibles are not nearly as sharp as those of the
water tiger, they are nonetheless capable of crushing the hard exoskeleton (outer shell) of other
insects.

Most predaceous diving beetles vary in size from 7 to 50 mm (0.25 to 2 in.) in length,
depending on the particular species. Many are brown or black and some have bright yellow
markings. Like scuba divers, predaceous diving beetles carry their air supply with them. An air
bubble is stored under the forewings, enabling them to stay submerged for long periods of time.
In this picture, part of the air bubble can be seen protruding from the rear of the abdomen.

REVIEWS: "An excellent slide program..." Previews.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

FRESHWATER PLANKTON Order #SS-0095S........$34.95

Photomicrographs of microscopic plants and animals that show great seasonal
fluctuations in our freshwater lakes, streams and ponds. 15 frames and guide. (Filmstrip
#SS-0095F.......$15.00.)

CONTENT SAMPLE: 6. The next largest group of plankton are the Dinoflagellata, undul-
ipodiated organisms which, though less numerous, are a greater source of nutrition for the zoo-
plankton (the consumers). Several species such as the one depicted also occur in marine envi-
ronments.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

FRESHWATER BIOLOGY Order #SS-0090S.......$49.95

Introduces a fresh water environment with examples of food chains. Emphasizes
microscopic and insect life. Concludes with a brief consideration of the adaptation of
organisms to this habitat. 25 frames and guide. (Filmstrip #SS-0090F.......$15.00.)

CONTENT SAMPLE: 6. Of the few algae that can live in running water, these filamen-
tous algal forms (left) are the best suited, since they can bend with the currents. Algal mats
(right) often form on the surface of water which has excessive nutrients (such as phosphorus from
detergents).

*****************************************************************************************************************
RELATED PROGRAMS WORTH NOTING
*****************************************************************************************************************

PLANKTON COMMUNITIES Slides order #SS-0825S.......$42.50

Beginning with a discussion of plankton, this program compares phytoplankton
and zooplankton. It offers a detailed view of the relationship between the two, and
discusses the dependence on various levels of the food chain by developing fish. 15
frames, cassette and guide. (Filmstrip order SS-0825F.......$15.00.)

CONTENT SAMPLE: 4. Diatoms generally reproduce by asexual fission. Under favor-
able conditions diatoms may reproduce two or three times a day. If all of the progeny survived a
single diatom could potentially give rise to some 100 million descendants within a month.
Conditions that foster such exponential growth are generally short-lived in marine waters
however, being confined to a relatively brief period in the spring in polar waters and in the spring
and fall in temperate waters. During these seasonal blooms the surface waters are replenished
with nitrates and phosphates by vertical water movements that accompany seasonal turnovers of
the thermocline. The onset of blooms also coincides with conditions of ample illumination and
sufficient thermocline stability to maintain diatom populations above the compensation level.
Under such favorable conditions the surface waters become colored yellow-brown due to the
tremendous populations of diatoms, sometimes billions in every gallon of surface seawater.

Polar waters experience only a single diatom bloom each year. This occurs during the
local summer months in high-latitude arctic and Antarctic waters when the sun's illumination is
sufficient to foster a bloom. Temperate waters are generally characterized by two diatom blooms
per year, one in the spring and another in the autumn. Onset of the spring bloom is correlated
with increasing illumination that penetrates surface waters already primed with nutrients by the
winter thermocline turnover. Phytoplankton blooms are generally short-lived because the
available nutrient salts are soon incorporated into organic compounds and removed from the
surface waters. The autumn bloom in temperate waters occurs when nutrient salts are recycled
into the surface waters as the stable summer thermocline breaks down. The autumn bloom is
limited by the diminishing incidence of solar radiation.

Diatom blooms are soon followed by population explosions of herbivorous zooplankton
and their predators. Not only are diatoms the principal producers of chemical energy in polar and
temperate waters, they are the ultimate source of many vitamins as well. The vitamins A and D
in cod liver oil, for example, have been traced back through the food chain from cod to small
capelin fish to synthesis in diatoms.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

PHYTOPLANKTON Slides order #SS-1025S........$42.50

Examines the microscopic algae that inhabit sunlit surface waters and their role
as the productive base of most marine food chains. Diatoms, the dominant phytoplankton
in cool, polar water, and dinoflagellates, which abound in warm tropical waters, are
considered. Other forms of phytoplankton, along with their various characteristics, are
also viewed. 15 frames, cassette and guide. (Filmstrip order SS-1025F........$15.00.)

CONTENT SAMPLE: 3. The two most important types of phytoplankton are the dia-
toms and the dinoflagellates. Diatoms are the dominant phytoplankton of cool polar waters, while
dinoflagellates abound in warm tropical waters.

Diatoms belong to the class Bacillariophyceae of the golden-brown algae, phylum
Chrysophyta. Diatom size ranges from just visible, 1 or 2 mm long, to extremely tiny forms, as
small as 2 microns, and remember 1 micron = 1/1000 mm. Diatoms are distinguished by
elaborate shells or frustules of glass-like silica. Each frustule is composed of two overlapping
valves or thecae. A larger epitheca overlaps a smaller hypotheca, much as the lid of a pillbox fits
over a smaller bottom. Both valves are often highly ornamented with intricate patterns of pits and
perforations intermixed with spikes and thorn-like extensions. The valves have various shapes,
with radially symmetrical forms (Centricae) predominating in marine waters and bilateral types
(Pennatae) in fresh waters. Diatoms are the predominant phytoplankton in cool temperate and
polar waters. Diatoms are also found in freshwater plankton and in moist soils. Benthic forms
glide about bottom substrata in marine and freshwater shallows. Diatoms may exist as solitary
individuals or several may be joined together to form ladder-like chains.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

ZOOPLANKTON Slides order #SS-1035S.........$42.50

A plankton community features representatives from almost every group of
marine animals. This study considers the types of permanent plankton, or holoplankton,
along with several categories of meroplankton. The permanent plankton spend entire
lives drifting in sunlit surface waters, while other organisms exist in the planktonic state
for only a portion of their life cycles. 15 frames, cassette and guide. (Filmstrip order
SS-1035F.....$15.00.)

CONTENT SAMPLE: 10. After the copepods, the most abundant types of crustaceans
in the permanent plankton are the euphausiacea. Euphausids are somewhat larger than
copepods, varying in length from one to two inches, with shrimp-like bodies. Well- developed
abdominal appendages are used for swimming. Filter-feeding forms have long setae on their
thoracic appendages that form a funnel-shaped net. Diatoms and/or zooplankton are trapped in
this filter basket as the euphausid swims forward. Other euphausids are raptorial feeders that
actively pursue arrow worms and other large prey. The thoracic setae of these forms are poorly
developed but their elongated third thoracic appendages are armed with pincers.

Euphausids are found at all depths of the water column. Many populations are compo-
nents of deep scattering layers that undergo diurnal vertical migrations, rising to forage in the
productive surface waters after sunset and then sinking by sunrise to the aphotic zone. Others
reside entirely among the surface plankton. Shown here is Euphausia superba, a two-inch polar
form that is the chief food of many baleen whales. These euphausids are known as "krill" to
mariners. They feed on diatoms, and in Antarctic waters during the December to March bloom
euphausids transform some 3,500 square miles of surface waters into a milky, reddish-tinted
"soup."
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


~0193-73~ Predaceous diving beetle. photo by Ron West.

Copyright (c) MCMXCVII Educational Images Ltd., Elmira, NY, USA. All rights reserved.

EDUCATIONAL IMAGES LTD.

P.O.Box 3456 Westside Station

Elmira, N.Y., USA, 14905-0456

Telephone: 800-527-4264; 607-732-1090

Fax: 607-732-1183

E-Mail: edimages@edimages.com