Download 3rd. practical lesson in zoology Arthropoda

3rd. practical lesson in zoology
Arthropoda
Arthropoda Segmented body, exoskeleton (needs to be shed =„ecdysis“ as the body grows), open vascular system, various respiratory systems,
most diverse group of organisms in number of species
3 important subphyla:
Chelicerata • No antenae
• chelicerae, pedipalps, • adults have 4 pairs of legs
Crustacea • 2 pairs of antennae
• mandibulae • 2 pairs of maxillae
Insecta (Hexapoda) • 3 pairs of legs
antennae, mandibulae, maxillae, labium, labrum, palpi labiales, palpi maxillares, Subphylum: Chelicerata Class: Arachnida
1. chelicers, 2. pedipalps, no antennae, venom glands Orders of class Arachnida:
• Spiders (Aranae)
• Scorpions (Scorpionida)
• False scorpions (Pseudoscorpionida)
• Mites and tics (Acari)
• Harvestmen (Opilionida)
• Solifugae (Soliphugida)
• Acid scorpions (Uropygida)
and more…
order: Aranae ­ spiders
• Orthognatha (=Mygalomorphae)
Primitive: chelicers pointing straight down, no typical webs, • Bird spider (tarantula) ­ living specimen (Lasiodora parahybana)
• exuvium (shed cuticle) ­ Psalmopoeus cambridgei
• Labidognatha (=Araneomorphae)
Modern, chelicers pointing agains each other
• Ability to make typical spider­
webs
Orders:
Pseudoscorpionida vs. Scorpionida
• Chelifer sp. (order Pseudoscorpionida), predator of mites and small insects
• pincer­like pedipalps with venom gland
• Scorpions: • pincerlike pedipalps, preabdomen, postabdomen, • Stinger with venom gland
Order Acari – ticks and mites
• Tyrophagus sp. ­ mite, storage pest (destruction of food ­ flour etc.) allergies
• Itch mite (Sarcoptes scabiei) parasite, cause of scabies or sarcoptic mange (skin disease of mammals including humans)
• small enough to breathe through skin
order: Acari
Varroa destructor • most dangerous parasite of bees,
• sex. dimorphism, has spread from South Asia
Dermanyssus gallinae (poultry/red mite)
ectoparasite of birds
At night sucks blood, during day hidden.
Argasidae – soft ticks tick (Ixodes ricinus)
• Female tick (Ixodes ricinus) vector of TBE (tick­borne encephalitis), Lyme disease ­ diseases with natural foci. hypostome, • for removal never use oil (it accelerates the transfer of viruses or bacteria to blood). • sexual dimorphism – male greater shield and smaller mouthparts
• Tick (Ixodes ricinus) larva – 3 pairs of legs (x nymph, imago ­ 4 pairs)!!!
• blood sucking in all stages, several hosts
Subphylum: Crustacea
very complex group with many old and species rich lineages… difficult system…
Originaly biramous apendages some with direct, some indirect developement
shown Classes:
Branchiopoda Maxillopoda
Malacostraca
Branchiopoda
Order: Cladocera
• Daphnia sp. ("water flea") motion by using antennae, • part of plankton, fed to aquarium fish, • heterogony (alternation of sexual reproduction and parthenogenesis), • egg case (ephippia) order: Notostraca tadpole shrimp – Lepidurus sp.
Freshwater, in ephemeral waters
• Eggs survive for years dried waiting for rain
order: Anostraca
salt brime shrimp – Artemia salina
Class: Maxillopoda
Subclass: Copepoda
• Larval stage (nauplius)
• Copepod (Cyclops) legs – branched in 2 egg sacs (female), long antennules, furca Part of freshwater zooplankton
Intermediate host of procercoids of some tapeworms (e. g. Diphyllobothrium latum), and larvas of Dracunculus medinensis (Spirurida, Nematoda). • parasites in Copepoda
Ergasilus sp. • anchor worm – Lernea sp.
Subcalss: Branchiura
• Fish louse (Argulus) order Branchiura, fish ectoparasite, adaptations ­ stylet, suckers
• Infraclass: Cirripedia (Barnacles ) • Sessile (attached to substrate)
• filterfeeders in seas
• Gonochorists
• http://vimeo.com/7461478
• Free swimming larva
• Live on rocks, ships, whales, turtles…
• One group adapted to internal parasitism of crabs:
Sacculina sp.
Class:Malacostraca
Order: Amphipoda • Gammarus sp. • legs differ in form and function,
• important segment of fish nutrition,
• intermediate host of acanthocephalans
• Indication of water quality – oligotrophic, clean waters
Class: Malacostraca Order: Isopoda
• Freshwater sow bug (Asellus aquaticus) • legs do not differ, important segment of fish nutrition, • intermediate host of acanthocephalans
• bottom of slow or not flowing freshwaters
terrestric species
Class: Malacostraca
• Subclass: Hoplocarida
• mantis shrimp – Squilla mantis
• Catching and clubbing appendages
• Can injure • Nocturnal, predatory
• Locally used as seafood – adriatic sea, Asia
Class:Malacostraca order: Decapoda • hermit carab – Pagurus sp. • Needs gastropod shells for protection
• Mutualistic symbiosis with anemones – defense / feeding
• Has to change shells as the body grows
Class:Malacostraca order: Decapoda • Norway lobster – Nephrops norvegicus • scavenger and predator
• tail is muscular and is frequently eaten under the name “scampi"
• shrimp – Palaemon sp. Class:Malacostraca order: Decapoda crabs – Maja sp., Ilia sp., Pachygrapsus sp.
Abdomen hidden under cephalothorax
Sexual dimorphism – males narrow abdomen, females wide abdomen (they keep eggs there)
Myriapoda •
•
•
•
•
class centipedes – Chilopoda • Class millipedes – Diplopoda
Carnivores
• vegetarians
1 pair of venom legs on head • Doubled body segments(2pairs of legs, 1 pair legs per segment
spiracles, ganglia)
Flat body
• Body round on section
Hexapoda
Class: Entognatha
Subclass: Apterygota
Subclass: Pterygota
Class: Insecta, Ectognatha
Hexapoda
• 3 pairs of legs, terrestric, trachea,
• „primitive types“ class: Collembola springtails (and other) small, soil, part of the edaphon ­ decomposers
Insecta • „progresive“ – class: – diversity
• Metamorphosis incomplete/complete, mouthparts, • 2 pairs wings (but wingless forms!)
• Head, thorax, abdomen
• Trachea (openings called spiracles, the same thing as stigmata in mites)
The insect mouthparts. The primitive chewing mouthparts of a grasshopper in the centre (A) (you will observe chewing mouthparts of a beetle).
From the chewing mouthparts various specialisation arose in the evolution of insects, this is variability of potential food is one of the expalanation for the vast number of species within class Insecta.
lapping type (B) of a bee the siphoning type (C) of a butterfly sucking type (D) of a female mosquito. Legend: a, antennae; c, compound eye; lb, labium; lr, labrum; md, mandibles; mx, maxillae hp hypopharynx.
Insect anatomy
tracheal system of insects
• similar system found in some Chelicerates( e.g. Acari, modern spiders) and Myriapoda
• direct transport of gases to/from tissues and enviroment – no need for circulatory system for O2 transport • mechanical support by a spiral taenidium (like vacum cleaner tube)
metamorphosis
•
• Complete ­ holometabolic
• Egg, larva, pupa, imago(adult)
•
•
•
• many insects use pheromones so males can track females – receptors are on enlarged anntenae
Incomplete ­ hemimetabolic
Egg, nymph
(several instars),
imago
Presented orders of hemimetabolan insects: Ephemeroptera – mayfly; nymph (tracheal gills)
Odonata – dragonflies; predatory chewing mouth, 2 pairs of wings, water nymphs, Hemiptera – important suborder Heteroptera:
normaly 2 types of wings(hemielytrae and membraceous), piercing sucking, Cimex sp. bedbug (lost wings)
Presented orders of hemimetabolan insects: Phthiraptera (Anoplura, Amblycera, Ischnocera) ectoparasites, piercing­
sucking or chewing mouthparts, adaptations to ectoparasitism, visibility of antenae
Blattodea – cocroaches; chewing, ootheca, 2 pairs wings, pests
Orthoptera – crickets, katydids and grasshoppers, chewing, stridulation 2 pairs wings(first for stridulation) Dermaptera – earwigs, parental care, 1st pair of wings very small, 2nd pair membraceous for flight, cerci – defense, wing folding, copulation, sex. dimorphic
Presented orders of holometabolan insects:
Siphonaptera: fleas, chewing, wingless
Diptera: flies, sponging mouth or stylet, 1 pair of wings + 1 pair of halteres
Coleoptera: beetles, chewing, 1 strong pair of wings elytra, 1 for flying
Lepidoptera – butterflies and moths, 2 pairs of scaly wings, proboscis
Hymenoptera – wasps, bees, ants, membraceous wings, ovipositor – sting, eusociality, haplodiploid sex­determination system