Download The biodiversity of Running Waters

The Biodiversity of Running
Waters
BY
L. Seward,T. Stockley, M. Avery,
J. Tilley, N. Jackson, E. Axmann
Talk outline
Introduction
 Natural Biota
 Insects
 Invertebrates (not including insects)
 Plants
 Mammals and other vertebrates
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The Natural Biota
Insects
Plecoptera
Odonata (see opposite)
Hemiptera
Hymenoptera
Tricoptera
Lepidoptera
Coleoptera
Diptera
Ephemaoptera
Megaloptera
Plecoptera (Stoneflies) and Odonata
(Dragonflies and Damselflies)
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Around 3000 known
species (only 34 in Britain)
Nymphs important in
fish diet
Prefer running water
with stony/gravely
bottoms
intolerant of pollution
adults live for only a
few weeks
e.g. leuctra fusca, Nemoura cinerea
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113 European species (40 in
Britain)
Two suborders Zygoptera
(Damselflies) and Isoptera
(Dragonflies)
Favour slow moving water
Isopteran Larvae carnivorous
e.g. Coenagrion puella (Zygoptera)
and Anax imperator (Emperor
Dragonfly)
Hemiptera (true bugs) and Hymenoptera
(Bees, wasps, ants etc)
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Can include surface living bugs
(e.g. pondskaters, gerris lacustris) or
true water bugs (e.g. water
boatmen corixa punctata)
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Amphibicorisae (surface living bugs)
all have fine waterproof hairs on
underside, and hunt by
detecting vibrations on surface
film
Cryptocerata (true water bugs) are
a diverse group all with
concealed antennae. Most are
predatory and can bite, If
caught.
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This order lives at water
edge with few ‘water
species’.
split into two main groups
-symphyta (sawflies,no waist)
-Apocrita (bees, ant and
wasps, narrow waist)
Pondskater
Tricoptera (caddis flies) and
Lepidoptera (butterflies and moths)
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Only holometabolic group
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where young stages are aquatic
over 6000 species (190 British)
Most adults don’t feed, with a 
long larval stage.
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Larvae built characteristic
cases, or silk nets
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Adult Caddis fly
Can be split into butterflies
(posses clubbed antennae)
and moths
lepidoptera means ‘scaly
wings’
Flower pollinators
both larvae and adult feed on
rich vegetation at river banks.
Coleoptera (beetles) and
Diptera (true flies)
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6 main aquatic families
range from free swimming
whirligigs (gyrinus nator), to
bottom dwelling algal
feeding haliplidae (haliplus
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over 140 British water beetle
species
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fulvus)
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Dipteran larvae important as
predators, collectors,
shredders, scrapers and
even some parasites
adults often breed near
freshwater
often seen in mating swarms
around over river
Great Diving
Beetle
Ephemaoptera (mayflies)
and Megaloptera (alderflies)
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Distinguishable by short
antannae, delicate wings and
2-3 long tails
usually found in vicinity of
water
important in fish diet
adults don’t feed, and in
many species live less than a
day
3 types of nymphs Ephemera, Ecdyonurus and
Ephemerella, all adapted
brilliantly to ecological niches
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From order neuroptera
in aquatic larvae appendages
are reduced and form
feathery gills
larvae and adults are
carnivorous with biting
mouthparts
Invertebrate diversity
(excluding insects)
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Major freshwater
groups
–
–
–
–
–
–
zooplankton
Rotifera
Hydra (Cnidaria)
Annelida
Crustacea
Mollusca
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Minor groups
– Planariidae
(Platyhelminthes)
– Porifera (sponges)
– Nematoda
From Z to M
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Zooplankton includes
– Rotifera
– Cladocera
– Copepoda
– ostracod and mysid crustaceans
– water mites (Hydracarina/Arachnida)
– larval molluscs
– Tardigrada
Phyla Rotifera and Cnidaria
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1,800 known species
94% restricted to
freshwater
mostly benthic and
littoral
algal, filter or detritus
feeders
some are carnivorous,
herbivorous or even
obligate parasites
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Class Hydrozoa
Hydra is the one of
the few freshwater
genera
Green Hydra
Phylum Annelida
15,000 sp. of segmented worms
– Hirudinea (500 sp.)
leeches are freshwater ectoparasites
– Oligochaeta (3,500 sp.)
aquatic worms are bottom dwellers
3 or 4 families in littoral areas
– Polychaeta (typical annelid)
a curiosity in freshwater but 8,000 marine
species
Subphylum Crustacea
(most of the 40,000 sp.
are marine)
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Class Copepoda
(>10,000 sp.)
5 freshwater orders
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Class Ostracoda
tiny bivalved bottom
dwellers
Order Podocopa is the
only freshwater one
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Class Branchiura
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Class Malacostraca:
– Subclass Syncarida
– Subclass Eucarida
Order Decapoda
(crayfishes and crabs)
– Subclass Peracarida:
4 Orders (shrimps and
crayfishes)
 Mysidacea
 Thermosbaenacea
 Isopoda
 Amphipoda
Phylum Mollusca
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Class Bivalvia
clams and mussels are
typical of the river fauna
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Family Unionidae
Family Sphaeriidae
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Class Gastropoda
(mostly marine)
>40,000 snail and slug
species
– subclass
Prosobranchia:
3 freshwater families
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Ancylidae
Potamopyrgidae
Pleuroceridae
– subclass Pulmonata:
limpets
Factors controlling benthic
invertebrates
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Ecological factors
– interspecific
competition
– substratum:
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type of surface
vegetation
– dissolved
substances:
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oxygen
salinity
acidity
hardness
– food availability
– oviposition habits
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Physical factors
– current speed
– temperature:
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altitude
season
– liability to drought
and floods
– shade
– proximity of suitable
habitats
Aquatic plants
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Microphytes
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Algae
Diatoms
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Macrophytes
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Bryophtes
Angiosperms
Large algae(charales)
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Diatoms
Microphytes
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No one family is
entirely aquatic, so
rather than classing
them in families they
are split into 3 Types
of groups based on
where they’re found
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Epiphytes
Epilithic
Epilic plants
Macrophytes
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Attached plants
– Mosses and liver
words
– Flattened Lichens
– Two angiosperm
species
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Rooted plants
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–
–
–
Reeds
rushes
sedges
Other aquatic
angiosperms
– Charlaes
Macrophytes cont..
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Floating plants
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–
–
–
Duckweed
Papyrus (tropical)
water Hyacinth
Floating grass
Freshwater fishes of the
British Isles
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Lamprey Family
Sturgeon Family
(rare)
Salmon Family
Pike Family
Carp Family
Loach Family
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Pike
Catfish Family
Eel Family
Perch Family
Bullhead Family
Stickleback Family
Important qualities of
freshwater habitats
Water velocity
 Level of dissolved oxygen
 Summer temperatures
 level of chemical and biological richness
 Degree of pollution
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Running water in mountainous
regions
Hard insoluble rocks
 Poor soils
 Acid waters, so they are poor in
minerals
 Invertebrate life is poor in species
 Salmonid fishes, Atlantic Salmon
 Brown Trout and Arctic Charr
 Only some coarse fish
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Lowland rivers and streams
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Soluble mineral rich
strata
Run-off from rich
agricultural soils
High pH ‘alkaline’
Biologically rich
Eutrophic
Aquatic vegetation
and invertebrate
fauna
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High summer water
temperatures
Coarse fish species
e.g most carp
Many other
stenohaline fishes
Aquatic Mammals
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Mainly live in holes in riverbank.
Tend to be nocturnal.
Carnivores - e.g. Otters and Mink
Insectivores - e.g. Water Shrews
Herbivores - e.g. Water Voles
Swimming Adaptations
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Webbed feet.
Bristles on tail and hind feet. (e.g. water
shrew).
Water-proof fur. (e.g water voles). Insulated
fur layer underneath guard hair.
Streamline body and long tail.
Sensitive whiskers for finding food
underwater.
Feeding
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Otters: Mainly fish also crayfish, amphibians,
insects and worms. Versatile and varied diet.
Mink: Fish and waterfowl. Land mammals
such as rabbits during food shortages.
Water Shrew: Aquatic crustaceans and insect
larvae. Terrestrial beetles and worms. Must
eat 50% of own body weight each day.
Water Vole: Mainly vegetarian, feeds on
bank-side vegetation.
Anything else!
There are a large
number of
lizards and
amphibians that
also play a role
in aquatic
habitats. So I
suppose this
speaks for
itself!!!!!!!!!!!!!