Aquatic Insects - PowerPoint PPT Presentation

Loading...

PPT – Aquatic Insects PowerPoint presentation | free to download - id: 3d56b2-MjViM



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Aquatic Insects

Description:

Aquatic Insects 8 April 2009 Aquatic Insects Insecta (even Hexapoda) are plesiomorphically terrestrial. But there have been numerous colonizations of the freshwater ... – PowerPoint PPT presentation

Number of Views:510
Avg rating:3.0/5.0
Slides: 31
Provided by: homeSand4
Learn more at: http://home.sandiego.edu
Category:
Tags: aquatic | insects

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Aquatic Insects


1
Aquatic Insects
  • 8 April 2009

2
Aquatic Insects
  • Insecta (even Hexapoda) are plesiomorphically
    terrestrial.
  • But there have been numerous colonizations of the
    freshwater aquatic environment.
  • Far fewer colonizations of marine aquatic
    environment.

3
Hemimetabolous Aquatic Insects
  • Some lineages have almost exclusively aquatic
    naiads.
  • Ephemeroptera
  • Odonata
  • Plecoptera (the only aquatic Polyneoptera)
  • All of these have terrestrial adults.

4
Hemimetabolous Aquatic Insects
  • There are multiple colonizations of aquatic
    environments by Heteroptera.
  • Most of these are also aquatic as adults.

5
Holometabolous Aquatic Insects
  • Colonized aquatic environments much more
    recently.
  • Numerous colonizations within numerous orders
  • Only two have exclusively aquatic larvae.
  • Only some Coleoptera remain aquatic as adults.

6
Holometabolous Aquatic Insects
  • Neuroptera One lineage (Sisyridae,
    spongillaflies).
  • Coleoptera Numerous colonizations throughout.
  • Diptera Numerous colonizations, especially in
    Nematocera.
  • Lepidoptera Numerous origins, but NOT common

7
Habitats for aquatic insects
  • Lotic flowing water
  • Influenced strongly by velocity of flow
  • Particle size
  • Substrate type
  • Inputs from outside and local nutrient supplies
  • Lentic standing water
  • Often strong zonation
  • Limnetic zone- penetrated by light
  • Profundal zone- deeper zone w/o much light

8
Unusual Habitats
  • Marine environments
  • Intertidal habitats
  • Between high and low tide
  • biting flies, plant feeding insects, detritivores
  • Littoral habitats
  • Coastal regions with shallow water
  • Some midges and beetles
  • Open ocean water striders feeding on food of
    terrestrial origin
  • RARE! WHY???

9
Unusual Habitats
  • Temporal water bodies (e.g. vernal pools)
  • Common in areas with seasonal rainfalls
  • Numerous adaptations
  • Ability to find ephemeral pools (meteorological
    cues?)
  • Desiccation resistant diapause
  • Very common as eggs
  • Some with ability to undergo numerous
    dehydrate/rehydrate cycles anhydrobiosis
  • Plant container habitats Phytotelmata

10
Oxygen Supplies
  • Air 200,000 ppm (20)
  • Lotic environments (15 ppm)
  • Depends on O2 production/consumption by plants
  • Affected by turbulence and water quality
  • Lentic environments
  • Oxygen levels vary with temperature, salinity,
    and depth
  • Turbulence affects nutrient and oxygen
    distribution
  • Anoxic
  • No oxygen present

11
How do aquatic insects obtain oxygen?
  • Atmospheric oxygen
  • Keep part of body out of water
  • Carry oxygen into water
  • Aqueous oxygen
  • Use of open tracheal system
  • Adult insects
  • Immature forms
  • Use of closed tracheal system
  • Specialized structures for gas exchange in water
  • Often adults have open tracheal system

12
Tracheal System
13
Closed Tracheal System
  • Gills- lamellar extensions of tracheal system
  • Found in many insect orders
  • Gills may be in many places
  • Base of legs
  • Abdomen
  • End of abdomen
  • How is this analogous to insect ears?

14
Open tracheal system in flies
  • Respiratory siphons near abdomen or thorax
  • Different location in mosquito pupa than larva

15
Open tracheal system in diving beetles
  • Bubble stored beneath elytra
  • Gas exchange can occur in water

Does the bubble increase linearly with oxygen
consumption? What happens to the exhalation
product?
16
Other air bubble gills
  • Water kept away from body through hairs or
    mesh
  • Oxygen diffuses from water to air against body
  • Usually slow moving insects with low oxygen demand

17
Lotic Adaptations
  • Flattened bodies
  • Attachment through suckers

Water pennies (Coleoptera Psephenidae)
Net-winged midges (Diptera Blephariceridae
18
More Lotic Adaptations
  • Nets Cases

Trichoptera net
Trichoptera cases
19
Lentic Adaptations
  • Taking advantage of surface tension of still water

Water Strider (Gerridae)
Whirligig Beetle (Gyrinidae)
20
Adaptations to nearly anoxic environments
  • Hemoglobins
  • Many larval chironomid midges (Diptera)
    bloodworms
  • Some notonectid bugs (Heteroptera) backswimmers
  • Very, very high affinity for oxygen (unlike us)
  • Only downloads when oxygen concentrations in
    tissues decrease, not when tissues become acidic

21
Using insects to monitor aquatic environments
  • Usefulness
  • Diverse taxa to choose from, many common
  • Functionally important to ecological community
  • Ease of sampling many individuals without major
    ethical constraints
  • Ability to identify species
  • Responses
  • Increases of certain taxa in waters with
    sediment, low
  • Oxygen, increases in temperature
  • Loss of diversity with pollution and or
    eutrophication

22
Ephemeroptera
  • Naiads often with abdominal gills
  • Also maxillary and labial gills!
  • Generally 3 styli on naiads and adults.
  • As many as 45 instars
  • Anything else?

23
Odonata
  • Dragonflies Damselflies
  • Rectal/anal internal gills.
  • Caudal lamellae also serve as gills.
  • Up to 20 instars.
  • Predators as naiads and adults.

24
Plecoptera
  • Mostly temperate regions
  • 10-33 instars
  • Closed tracheal system with anal gills.
  • Need high oxygen, good environmental indicators.

25
Hemiptera True Bugs
Notonectidae Backswimmers
  • Diving or at surface
  • Adults and naiads both aquatic.
  • Highly modified legs.
  • Generally wings still functional as adults, can
    disperse between waterways.

Corixidae Water Boatmen
Naucoridae Creeping water bugs
Gerridae Water striders
26
Hemiptera
  • Left Nepidae (water scorpions) tails are
    breathing tubes
  • Right Belostomatidae (toe-biters) egg tending by
    males

27
Trichoptera
  • Case net makers.
  • Abdominal tracheal gills.

28
Coleoptera
  • Aquatic larvae, aquatic adults
  • Aquatic larvae, terrestrial adults
  • Terrestrial larvae, aquatic adults
  • Pretty much all pupate on land

29
Diptera
  • Often with anal spiracles breathing at surface
  • Very diverse
  • Almost all disease vectoring Diptera have aquatic
    larvae (?)

30
Megaloptera Neuroptera
About PowerShow.com